JP3146912U - External terminals for electrolytic capacitors and electrolytic capacitors - Google Patents

Abstract

An electrolytic capacitor external terminal capable of preventing leakage of an electrolytic solution and an electrolytic capacitor incorporating the electrolytic capacitor external terminal are provided.
The contact portion 4 of the electrolytic capacitor external terminal 1 with the sealing body 20 is immersed in an alkaline solution at a pH of 10 or more and 80 ° C. to 90 ° C. for 5 minutes to roughen the surface of the electrolytic capacitor external terminal 1. . And the external terminal 1 for electrolytic capacitors immersed in this alkaline liquid is dried at 100 degreeC for 30 minutes. The electrolytic capacitor external terminal 1 is fixed to the sealing body 20 by insert molding. And using this sealing body 20, the opening part of the electrolytic capacitor which has a low and low cylindrical case is sealed, and an electrolytic capacitor is comprised.
[Selection] Figure 1

Description

  The present invention relates to an external terminal provided in a sealing body portion of an electrolytic capacitor and an electrolytic capacitor having the external terminal.

  In the electrolytic capacitor, the opening of the case is sealed with a sealing body made of synthetic resin. The sealing body is provided with a metal external terminal having a role as an electrode. This external terminal is fixed to the sealing body by insert molding.

  There exists a thing of patent document 1 as an external terminal fixed to a sealing body by the above insert molding. FIG. 5 shows the configuration of the external terminal described in Patent Document 1. In FIG.

The external terminal 10 is made of a cylindrical metal member such as aluminum. The upper portion thereof has a connection portion 11 between the capacitor and another device, and the lower portion has a connection portion 12 with a capacitor element enclosed in the case. Is provided. Further, a plurality of grooves 13 for fitting with the sealing body 20 are formed on the outer periphery of the external terminal 10, and the external terminals 10 are firmly coupled to the sealing body 20 by the engagement between the grooves 13 and the sealing body 20. ing.
JP 2004-235340 A

  By the way, in the prior art, the external terminal 10 is manufactured by pressing or cutting a metal member such as aluminum. However, the surface of the external terminal 10 is as it is at the time of manufacture, that is, a smooth surface. Therefore, even when the sealing body 20 is formed by insert molding using the conventional external terminal 10, the adhesion between the surface of the external terminal 10 and the surface of the resin sealing body 20 is low, and the electrolytic capacitor is Electrolyte may leak out when placed under high temperature.

  This is because when the electrolyte in the case expands at a high temperature, the external terminal and the sealing body are displaced due to an increase in the pressure in the case, and a gap is generated between the external terminal and the sealing body.

  As shown in FIG. 5, the conventional external terminal 10 is provided with a groove 13, but when the pressure applied during the injection is applied to the groove 13 from the outer peripheral side of the external terminal 10, the bottom of the groove 13. The pressure was concentrated on the external terminals, and the external terminals could be deformed.

  The present invention has been proposed in order to solve the above-described problems of the prior art, and the purpose of the present invention is to provide an electrolytic capacitor external device that can prevent leakage of electrolyte due to an increase in pressure inside the electrolytic capacitor case. An object of the present invention is to provide an electrolytic capacitor having a terminal and an external terminal.

  Another object of the present invention is to provide an electrolytic capacitor external terminal capable of preventing deformation due to the applied pressure during injection and an electrolytic capacitor having this external terminal.

  In order to solve the above problems, the present invention is a cylindrical external terminal fixed to a synthetic resin sealing body of an electrolytic capacitor by insert molding so as to penetrate the front and back of the sealing body, The external terminal is provided with a connection portion between the capacitor and another device in the upper portion, a connection portion between the capacitor element sealed in the case at the lower portion, and a close contact portion with the sealing body on the surface of the external terminal. The contact portion with the sealing body on the surface of the external terminal is etched.

  Further, the etching process is performed by immersing the external terminal in an alkaline solution, and a groove is provided along the circumference on the outer periphery of the close contact portion with the sealing body on the surface of the external terminal, The cross-sectional shape of the groove is V-shaped, and an electrolytic capacitor having the above configuration is also one aspect of the present invention.

  As described above, according to the present invention, the surface portion of the external terminal to which the sealing body is in close contact is roughened by etching, thereby preventing leakage of the electrolyte due to an increase in pressure in the case of the electrolytic capacitor. Can do. In addition, it is possible to prevent the external terminal from being deformed by the applied pressure during the injection.

The best mode for carrying out the present invention will be described below with reference to FIGS.
(1-1) 1st Embodiment As shown in FIG. 1, the external terminal 1 in 1st Embodiment of this invention is the connection part 2 with a capacitor | condenser element, the connection part 3 with another apparatus, It is comprised from the close_contact | adherence part 4 with the sealing body 20, and the contact part 4 with the sealing body 20 is etched. The close contact portion 4 of the external terminal 1 with the sealing body 20 is provided with three grooves 5 along the circumferential direction of the external terminal 1, and the cross-sectional shape of the grooves is a U-shape.

  This external terminal 1 is made of metal, and it is preferable to use aluminum as the metal material in the present embodiment in relation to the etching process described in detail below, but the surface is roughened by the etching process. If possible, other metals may be used.

  Next, the etching process of the adhesion part 4 with the sealing body 20 of this external terminal 1 is demonstrated. First, the adhesion part 4 with the sealing body 20 is immersed in an alkaline solution at 80 ° C. to 90 ° C. for 5 minutes at a pH of 10 or more. Then, it is dried at 100 ° C. for 30 minutes. Thus, the etching treatment is preferably not an acid but an alkaline solution. This is because if the acid is used, the surface of the contact portion 4 of the external terminal 1 with the sealing body 20 becomes too rough in a short time, and a gap is formed between the resin constituting the sealing body 20 and the external terminal 1. This is because of a decrease. The etching process may be performed not only on the contact portion with the sealing body but also on the entire surface of the external terminal.

  As a modified example, an acid can naturally be used if the time of the etching process is appropriately managed. Moreover, in this embodiment, although the detergent liquid Chemicoat (trademark) of Chemicoat Co., Ltd. was used for the alkaline liquid, the kind of alkaline liquid can be changed suitably.

(1-2) Usage Mode The electrolytic capacitor shown in FIG. 2 will be described as a usage example using the external terminal shown in the first embodiment. This electrolytic capacitor 21 is configured by housing a capacitor element 22 impregnated with an electrolytic solution in a bottomed cylindrical aluminum case 23 and sealing it with a sealing body 20 having an external terminal of the first embodiment. .

  The sealing body 20 is formed by injecting polypropylene mixed with glass fibers into a disk-shaped mold having a concave portion, and solidifying this, but when molding the sealing body by injecting the sealing body into the mold The external terminal 1 of the first embodiment is inserted in advance.

  According to the external terminal of the present embodiment as described above and the electrolytic capacitor having the external terminal, the surface of the external terminal, specifically, the contact portion with the sealing body on the surface of the external terminal is subjected to an etching process, and the external By roughening the surface of the terminal, the adhesion between the surface of the external terminal and the resin constituting the sealing body is improved, and even if the electrolyte expands at high temperatures and the pressure in the case rises, A gap can be prevented from being formed.

(2) Second Embodiment An external terminal 1 according to a second embodiment of the present invention is obtained by improving the cross-sectional shape of the groove 5 of the external terminal 1 shown in the first embodiment. As shown in FIG. 3, the external terminal 1 of the present embodiment has a groove 5 between two flange-shaped protrusions provided on the external terminal. In addition, the method of the etching process performed to the contact | adherence part 4 with the sealing body 20 of the external terminal 1 is the same as that of 1st Embodiment.

  According to the external terminal of the present embodiment as described above, in addition to the effect of improving the adhesion between the external terminal surface and the resin constituting the sealing body produced by the device of the first embodiment, as described below, It is possible to prevent the external terminal from being deformed by dispersing the pressure applied to the external terminal at the time of injection.

  This will be specifically described with reference to FIG. FIG. 4 shows the direction of pressure applied to the external terminal and the magnitude of the pressure during injection. Reference numeral 30 denotes an arrow indicating the direction of pressure and the magnitude of pressure. The thicker the arrow 30, the higher the pressure, and the thinner the arrow 30, the lower the pressure. FIG. 4A shows an enlarged view of the cross-sectional shape of the groove provided in the external terminal described in Patent Document 1. FIG. 4B shows an enlarged view of the cross-sectional shape of the groove provided in the external terminal of the device of the present embodiment.

  As shown in FIG. 4A, in the technique described in Patent Document 1, there is a possibility that the external terminal 1 is deformed by the pressure from the outer peripheral direction applied to the external terminal 1 during the injection concentrated on one point on the bottom surface of the groove. .

  On the other hand, in the structure of the present invention in which the cross-sectional shape of the groove of the external terminal 1 is V-shaped, there is no surface formed perpendicular to the pressure direction as shown in FIG. The pressure from is distributed up and down without concentrating on one point. Specifically, as shown in FIG. 4B, the pressure is dispersed up and down as indicated by the traveling direction A of arrows 30 and B and C.

  Thus, the external terminal 1 in this embodiment forms the cross-sectional shape of the groove 5 in a V shape, thereby dispersing the pressure applied to the external terminal during injection and preventing the external terminal from being deformed. be able to.

  In order to disperse the pressure during injection, the cross-sectional shape of the groove of the external terminal is formed in a V shape in this embodiment, but the angle of the groove can be changed as appropriate, the size of the external terminal, The number can be changed as appropriate. Moreover, as an example of use of the external terminal of the present embodiment, there is an electrolytic capacitor having the external terminal of the present embodiment as in the first embodiment.

The side view of the external terminal for electrolytic capacitors which concerns on this invention. Sectional drawing of the electrolytic capacitor which has the external terminal for electrolytic capacitors which concerns on this invention. The side view of the external terminal for electrolytic capacitors which concerns on this invention. The figure of the pressure added to the external terminal for electrolytic capacitors at the time of injection. The side view of the external terminal for capacitors concerning the conventional device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,10 ... External terminal 2,12 ... Connection part 3,11 with capacitor element ... Connection part 4 with external device ... Close contact part 5,13 ... Slot 20 ... Sealing body 21 ... Electrolytic capacitor 22 ... Capacitor Element 23... Case 30... Arrows A, B, C... Representing pressure direction and pressure magnitude. Arrows representing pressure direction and pressure magnitude.

Claims (4)

A cylindrical external terminal fixed to the synthetic resin sealing body of the electrolytic capacitor by insert molding so as to penetrate the front and back of the sealing body,
In the external terminal,
A connection between the capacitor and another device at the top;
The connection part with the capacitor element enclosed in the case at the bottom,
A close contact portion with the sealing body on the external terminal surface,
An external terminal for an electrolytic capacitor, wherein a close contact portion with a sealing body on the surface of the external terminal is etched.   The electrolytic capacitor external terminal according to claim 1, wherein the etching process is performed by immersing the external terminal in an alkaline solution. A groove is provided along the circumference of the outer periphery of the contact portion with the sealing body on the external terminal surface,
The external terminal for an electrolytic capacitor according to claim 1 or 2, wherein a cross-sectional shape of the groove is V-shaped.   The electrolytic capacitor provided with the external terminal for electrolytic capacitors of any one of Claims 1-3.

Images