JPH0539621Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention relates to the improvement of electrolytic capacitor elements, and in particular, a protective paper other than electrolytic paper is interposed near the winding shaft to improve the winding condition. Regarding capacitor elements.

[Conventional technology]

As shown in FIG. 2, a typical capacitor element has a structure in which an anode foil 2 and a cathode foil 3 are stacked one on top of the other, and electrolytic paper 4 is interposed between the anode foil 2 and the cathode foil 3 and wound. Consisting of

The anode foil 2 is composed of a dielectric oxide film layer formed on the surface of an etched metal foil such as aluminum, and determines the capacitance of the electrolytic capacitor.

Further, since the anode foil 2 has an etched surface and is mechanically fragile, in the winding process, the cathode foil 3 and the electrolytic paper 4 are wound several times and then sandwiched between them.

In order to improve the volumetric efficiency and increase the capacitance of such a capacitor element 1, it is conceivable to subject the anode foil 2 to extreme etching treatment to excessively expand the surface area of the anode foil 2. in this case,
The mechanical strength of the anode foil 2 becomes extremely weak.

Further, the capacitance may be increased by using a capacitor element 1 having a so-called double anode structure, in which two or more anode foils 2a and 2b are wound in an overlapping manner.

[Problem to be solved]

However, when increasing the capacitance with the conventional capacitor element 1, the anode foil 2 with a high magnification that has been subjected to excessive etching treatment has extremely weak mechanical strength. There was a risk that it might break. This cracking of the anode foil 2 often occurs near the beginning of winding of the capacitor element 1 because the anode foil is rolled up forming a steep angle as shown by circle A in FIG.

Furthermore, when the capacitor element 1 is formed into a double anode structure, as shown in FIG. 2, since a plurality of anode foils 2a and 2b are wound at the same time, distortion occurs in the winding state of the capacitor element 1. It ends up. This distortion in the winding state gives mechanical stress to the anode foils 2a, 2b themselves, which may cause foil cracking or the like.

Further, the winding start end of the anode foil 2 forms a corner 6. This corner 6 may damage the electrolytic paper 4 located outside the anode foil 2, and may also cause an electrical short circuit accident.

The purpose of this invention is to provide a capacitor element that prevents foil cracking of a high-magnification anode foil and achieves a good winding state.

[Means to solve problems]

This invention is based on a capacitor element formed by winding an anode foil and a cathode foil together with electrolytic paper, in which a protective paper is interposed at least outside the winding start end of the anode foil to cover the winding start end. It is characterized by

〔Example〕

Examples of this invention will be described below with reference to the drawings.

1 and 3 are partial cross-sectional views of a double anode structure capacitor element according to an embodiment of the invention.

The anode foils 2a and 2b are made of metal foils such as aluminum, as in the past, and have etched surfaces and a dielectric oxide film layer formed thereon.

Further, the cathode foil 3 is made of metal foil such as aluminum, like the anode foils 2a and 2b, and has an etched surface.

The electrolytic paper 4 is made of manila paper or the like, and the anode foil 2
a, 2b and the cathode foil 3 are separated, and the electrolyte is held.

As shown in FIG. 3, the cathode foil 3 and the electrolytic paper 4 are wound around the winding shaft 7 in a stacked state. That is, the cathode foil 3 is sandwiched between a plurality of electrolytic papers 4 and wound around the winding shaft 7 several times. Furthermore, a protective paper 5 is sandwiched between the electrolytic paper 4 and the cathode foil 3 located inside the capacitor element 1 . This protective paper 5 is made of manila paper or the like like the electrolytic paper 4, and is formed thicker than the electrolytic paper 4.
It is wound several times together with the cathode foil 3 and the electrolytic paper 4.

After the cathode foil 3, electrolytic paper 4, and protective paper 5 are wound several times, the anode foils 2a and 2b are wound further inside the electrolytic paper 4 located inside. A plurality of high-magnification anode foils 2a, 2b having etched holes formed on their surfaces are stacked one on top of the other.

[Effect]

The anode foils 2a and 2b are a capacitor element 1 formed by winding a cathode foil 3, an electrolytic paper 4, and a protective paper 5.
As shown in Figure 1, near the center,
A protective paper 5 thicker than the electrolytic paper 4 is interposed outside the plurality of anode foils 2a, 2b.

This protective paper 5 corrects the distortion in the winding state caused by the anode foils 2a, 2b, and also uses the corners formed at the winding start ends of the anode foils 2a, 2b to and prevents the electrolytic paper 4 from being damaged.

In addition, in the embodiment of this invention, the protective paper 5
Although the protective paper 5 is located outside the anode foils 2a, 2b and the inner electrolytic paper 4, it is sufficient that the protective paper 5 is located at least outside the anode foils 2a, 2b. 2a and 2b may be directly faced.

Further, in the embodiment, the protective paper 5 is the cathode foil 3
Although the electrolytic paper 4 and the electrolytic paper 4 are sandwiched and wound around the winding shaft 7, they may be interposed only near the winding start ends of the anode foils 2a and 2b.

Furthermore, this invention is not limited to a capacitor element with a double anode structure as in the embodiment, but even when a single sheet of anode foil is wound, it is possible to prevent distortion of the capacitor element by interposing a protective paper. Needless to say, it is possible to calibrate the

[Effect of idea]

As described above, this invention provides a capacitor element formed by winding an anode foil and a cathode foil together with electrolytic paper, at least providing protection to the outside of the winding start end of the anode foil to cover the winding start end. Since the paper is interposed, distortion of the capacitor element due to the winding start end of the anode foil can be easily corrected. Therefore, even if the anode foil of high magnification is extremely weak in mechanical strength due to the distortion of the capacitor element, there is no risk of it being damaged as in the prior art, and the yield in the production process can be improved.

Further, since the corner formed at the winding start end of the anode foil is covered with the protective paper, the electrolytic paper or the anode foil itself will not be damaged by the corner. Therefore, in addition to improving the reliability of the completed capacitor element, it is also possible to improve the mechanical strength, earthquake resistance, etc. of the capacitor element itself.

Further, even in the process of winding the anode foil with high magnification, it becomes possible to wind the anode foil tightly, making it easy to increase the capacitance per unit volume.

As described above, this invention is a useful invention in which the distortion of the capacitor element is easily calibrated by interposing a protective paper outside the winding start end of the anode foil.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view showing the wound state of a capacitor element obtained by this invention, FIG. 2 is a partial cross-sectional view of a conventional capacitor element, and FIG. 3 is an explanatory diagram showing the winding process according to an embodiment of this invention. 1...capacitor element, 2...anode foil, 3...
Cathode foil, 4...electrolytic paper, 5...protective paper, 7...winding shaft.

Claims (1)

[Scope of utility model registration request] In a capacitor element formed by winding an anode foil and a cathode foil together with electrolytic paper, a protective paper thicker than the electrolytic paper is placed at least outwardly of the winding start end of the anode foil and at a position covering this winding start end. A capacitor element characterized by having a.