JPS6133638Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to improvements in electrolytic capacitors used in audio equipment and the like.

In recent years, electronic components such as capacitors used in audio systems have been designed with emphasis on electrical characteristics. Furthermore, with the development of audio technology, it is known that not only electrical characteristics but also evaluation of sound quality in audio systems has become more important. Electrolytic capacitors, in particular, are electronic components that are often subject to improvement, as differences in components and structure greatly affect the sound quality of audio equipment.

As shown in FIG. 1, a conventional electrolytic capacitor is manufactured by connecting an external lead terminal 1 to an anode foil and a cathode foil by caulking or the like, and then winding the terminals with electrolytic paper interposed therebetween to form a capacitor element 2.
Next, the element 2 was impregnated with an electrolytic solution, a sealing member 3 made of rubber or the like was attached, and the element 2 was inserted into a case 4 made of aluminum or the like, and the opening of the case 4 was sealed.

When a high frequency current is passed through such an electrolytic capacitor, generally in the case of a metal case such as aluminum, the loop current is extremely small due to the magnetic flux caused by winding the aluminum electrode of the capacitor element, although it is not as strong as with magnetic metal. It was found that this occurs at the bottom of shaped metal cases. However, it is known that loop current is a major cause of distortion in sound quality in audio technology.In order to eliminate this loop current, a cylindrical metal pipe without the bottom of the cylindrical metal case is used, and the bottom is made of rubber-baked resin. Structures made of materials such as metal and resin cases have been used instead of metal cases, but these have not yet been fully satisfactory.

The present invention eliminates the above-mentioned drawbacks and seeks to provide an electrolytic capacitor whose loop current can be easily reduced or eliminated without significantly changing the working method.

In other words, the present invention is based on the knowledge that when graphite is ground, carbon-carbon bonds are broken, causing a large change in magnetic susceptibility and inducing paramagnetism.
In particular, various types of ground carbon are heated to 400 to 700℃.
Taking advantage of the property that heat treatment produces a large difference in magnetic receptivity, we have developed a new technology that utilizes the characteristics of carbon and its high conductivity among non-metals, as well as conventional non-metallic cases such as resin. After impregnating the capacitor element of an electrolytic capacitor housed in the paste with the paste, applying the rated voltage to the electrodes of the element and measuring the potential difference between the top lead extraction side and the bottom side of the element, it was found that the lower circumference , the potential on the bottom side is high,
In addition, phenomena such as the generation of a potential difference of several mV to several tens of mV are observed. This invention focuses on the fact that it can be molded even if carbon black is added to case materials mainly made of pulp fiber, glass fiber, and carbon fiber, and as a result of various experiments, we found that pulp fiber, glass fiber, and carbon black can be used for case molding. It was found that the strain rate characteristics were significantly improved by adding an increased amount of ground carbon.

That is, the present invention involves molding pulp fibers or a mixture of pulp fibers and glass fibers by adding fine powder of ground carbon such as polycrystalline graphite, acetylene black, carbon black, activated carbon, etc. The capacitor element is housed and hermetically sealed by forming a case, and then forming a thin film layer of polypropylene or the like with high chemical resistance on the inner circumferential surface, outer circumferential surface, or both surfaces thereof.

Hereinafter, the electrolytic capacitor of the present invention will be described in detail based on an embodiment shown in FIG. 2. 5 is an external lead terminal, 6 is a capacitor element, 7 is a case, 8 is an elastic sealing body, 9 is a filled resin, Reference numeral 10 indicates an explosion-proof valve, and a capacitor element 6 is formed by attaching an external lead terminal 5 to an anode foil and a cathode foil by caulking or the like, and winding the capacitor element 6 through a separator such as electrolytic paper. A base is made of a mixture of black and glass fiber, and a cylindrical container with a bottom is formed by containing ground carbon such as polycrystalline graphite, acetylene black, carbon black, activated carbon, etc. in fine powder. The capacitor element 6 is housed in a case 7 made of a chemical-resistant thin film layer of polypropylene or the like formed on the inner circumferential surface, outer circumferential surface, or both surfaces of the container, and an elastic sealing member 8 is fitted into the opening of the case 7. , and is further filled with resin 9 and sealed.

In addition, 10 is an explosion-proof valve, which is an explosion-proof mechanism part provided with a cut groove or a thin wall part at the bottom of the case 7. The thin wall part or cut groove is not limited to the bottom part, but may be on the side surface.

Since the present invention is constructed as described above, the electrolytic capacitor of the present invention prevents the magnetic flux generated from the capacitor element perpendicular to the bottom surface of the case by the paramagnetism of the ground carbon at the bottom surface of the case. Therefore, the magnetic flux does not permeate perpendicularly, but its path is bent, thereby reducing and eliminating the influence on other parts due to the mounting of the board and the loop current generated in the board, etc., which were conventionally caused by the magnetic flux. This is presumed to be due to the carbon acting as an electrostatic shield, and the potential difference on the surface of the capacitor element decreases or disappears due to the conductivity of the carbon.

As mentioned above, the electrolytic capacitor of the present invention (rated at 50WV, 1000V) contains carbon black in the case.
μF) and conventional electrolytic capacitors (rated 50WV,
1000μF) is shown in Figure 3. Figure 3 A shows the case of the invented product, where the case is made of pulp fibers.
50% glass fiber, 40% glass fiber, and 10% carbon black, and a thin layer of polypropylene is provided on the inner circumferential surface of the case. Figure 3 B is the first
As shown in the figure, the case of a conventional product using an aluminum case as the case 4 is shown. As is clear from the figure, the electrolytic capacitor of the present invention has a significantly improved distortion rate at 30KHz, and is found to have a remarkable effect. In addition, when the electrolytic capacitor of the present invention was installed in the listening circuit of an audio system shown in Figure 4 and listened to, it was found that the three-dimensional effect was improved and the sound quality was superior compared to conventional electrolytic capacitors. I understand. 11 in Figure 4 is an electrolytic capacitor sample, 1
2 is a rectifying element, 13 is an amplifier, and 14 is a speaker.

As mentioned above, the present invention is characterized by being housed in a case made of pulp fibers containing ground carbon such as polycrystalline graphite, acetylene black, carbon black, activated carbon, or a mixture of pulp fibers and glass fibers. With electrolytic capacitors, the sense of distortion in the sound range is eliminated, the bass sounds are produced more clearly, the distortion rate characteristics in the high frequency range are greatly improved, and the third harmonic is significantly reduced, making it suitable for audio systems and various types of audio. When used in transmission systems, etc., it provides a remarkable effect of high fidelity.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a conventional electrolytic capacitor, Figure 2 is a cross-sectional view of a conventional electrolytic capacitor.
The figure is a cross-sectional view of one embodiment of the electrolytic capacitor of the present invention, and Figure 3 is a distortion factor characteristic diagram of the electrolytic capacitor. It is an explanatory diagram. 5: External lead terminal, 6: Capacitor element, 7: Case, 8: Elastic sealing body, 9: Resin, 1
0: Explosion-proof valve.

Claims (1)

[Scope of utility model registration request] The base material is pulp fiber or a mixture of pulp fiber and glass fiber, and is further mixed with ground carbon such as polycrystalline graphite, acetylene black, carbon black, activated carbon, etc. to form a cylinder, a cylinder with a bottom, or a polygonal cylinder. , a case formed in the shape of a polygonal cylinder with a bottom, and provided with a thin film layer having high chemical resistance such as polypropylene on at least one of the inner peripheral surface or the outer peripheral surface, a capacitor element housed in the case, and a capacitor element housed in the case; An electrolytic capacitor characterized by being composed of an elastic sealant and resin that seals the opening.