JPS6225882Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a new flat electrolytic capacitor, in particular, a novel and excellent property that has a small tan δ, generates little heat, and has no fear that the electrodes will vibrate due to the Coulomb force acting between them. The purpose of this invention is to provide a flat electrolytic capacitor.

Conventional electrolytic capacitors are generally made by winding an aluminum film for the anode and an aluminum film for the cathode with an electrolytic paper film interposed between them as an insulating material to create a ring-shaped element, which is then electrolyzed. It is impregnated with liquid, attached with electrodes, subjected to aging treatment, etc., and then mounted inside a case. However, electrolytic capacitors made by such winding have the following problems that cannot be ignored. First, in order to obtain sufficient capacitance and withstand voltage, the diameter and height of the capacitor must be considerably increased, which makes it difficult to respond to the miniaturization of electronic devices such as audio devices. or,
An electrolytic capacitor made by winding generates a magnetic flux that surrounds the annular element, which adversely affects electronic circuits using the capacitor and generates, for example, hum. Furthermore, if the chassis or the like is made of a magnetic material such as iron, there is a problem in that the lines of magnetic force are disturbed by the chassis or the like, and as a reaction to this, the current flowing through the capacitor is distorted.

For this reason, attention has been paid to flat electrolytic capacitors whose element is a laminate in which a plurality of pairs of anode foils and cathode foils are stacked facing each other with electrolytic paper interposed therebetween. This is because this type of electrolytic capacitor can be made extremely thin, making it suitable for miniaturization of electronic equipment, and since the element is flat, it is much easier to use than a ring-shaped element. This is because, in contrast, almost no magnetic flux is generated, and therefore there is little room for hum or current distortion caused by the generation of magnetic flux. However, as electronic devices become more sophisticated, the characteristics required of electrolytic capacitors have become extremely high, and it is said that simply making electrolytic capacitors flat can easily meet these high demands. Do not mean. This point will be explained more specifically using a power amplifier using an electrolytic capacitor as an example. Figure 1 shows a power supply circuit and an output circuit in an example of a power amplifier. Both terminals of the secondary coil of a transformer T are connected to the anodes of diodes D1 and D2, and the cathodes of the diodes D1 and D2 are connected to each other. They are connected together to form an anode, and the middle tap of the secondary coil forms a cathode. A smoothing electrolytic capacitor CC is connected between the anode and cathode.
Further, a push-pull output circuit consisting of an NPN transistor Q1 and a PNP transistor Q2 is connected between the anode and the cathode. SP is a speaker serving as a load of the push-pull output circuit, and C is a capacitor connected in series with the speaker SP. Electrolytic capacitor CC used in the amplifier
CC absorbs ripples as a smoothing capacitor in the power supply circuit, but it also serves as a path for AC signals, so the characteristics of the electrolytic capacitor CC have a non-negligible effect on the characteristics of the amplifier. Therefore, tan
δ is also required to be very small. However,
The electrolytic capacitor CC has an electrolytic solution interposed between opposing electrodes, and the internal resistance of the electrolytic solution is a factor that increases (deteriorates) tan δ and is also a cause of Joule heat generation. Therefore, simply making an electrolytic capacitor flat does not necessarily provide characteristics suitable for sophisticated electronic devices. Further, when an alternating current signal flows through the electrolytic capacitor CC, a Coulomb force is generated by the charges charged on the anode and the cathode, and the anode and cathode attract or repel each other and vibrate. This vibration was a factor in deteriorating the characteristics.

Therefore, in the present invention, a laminate consisting of an anode foil, a cathode foil, and an electrolytic paper is pressed between the main body of the case and the lid with an appropriate force, so that the tan δ is small and the amount of heat generation is small. Furthermore, the present invention aims to provide a flat electrolytic capacitor in which there is no fear that the anode foil and the cathode foil will vibrate due to the Coulomb force acting between them. A flat electrolytic capacitor in which a laminate formed by stacking a plurality of pairs of laminates is housed in a case, characterized in that the case is provided with appropriate holding means for pressing the laminate.

The present invention will be described in detail below with reference to embodiments shown in the drawings.

FIG. 2 shows a first embodiment of the flat electrolytic capacitor of the present invention. In the figure, numeral 1 denotes a laminate forming an element of an electrolytic capacitor, which is made up of anode foils 2 and cathode foils 3 alternately stacked with electrolytic paper 4 interposed therebetween. The anode foils 2, 2, . . . are partially protruded from the electrolytic paper 4, 4, . . . to the left side in FIG. are stacked on top of the electrolytic papers 4, 4, . and,
This laminate 1 has a laminate storage recess 5 and a case body 6.
It is housed in a metal case 7 having a Specifically, first, the laminate 1 is attached to the lid 8 in the following manner. Thin electrode plates 9 and 10 made of metal are welded to the portions of the anode foils 2, 2, . . . and the cathode foils 3, 3, . . . that protrude from the electrolytic paper 4, 4, . Connect in advance with
A part of the electrode plate 9 connected to the anode foils 2, 2, . . . is fixed to the back surface of the cover plate 8 while being electrically insulated therefrom. Describing this fixing method in detail, a rod-shaped terminal 11 is passed through the electrode plate 9, and one end of the terminal 11 is welded to the electrode plate 9.
A pair of annular insulating spacers 13 and 14 are attached to the terminal attachment holes 12 formed in the cover plate 8.
The insulating spacers 13 and 14 each have an engaging flange 15 at one end that engages with the peripheral edge of the terminal mounting hole 12,
16, the outer diameter of one insulating spacer 13 is made slightly smaller than the diameter of the terminal attachment hole 12, and the outer diameter of the other insulating spacer 14 is made slightly smaller than the inner diameter of the insulating spacer 13. Then, for example, an insulating spacer 13 is inserted into the terminal attachment hole 12 from the back side of the lid 8, and an insulating spacer 14 is inserted into the insulating spacer 13 from the front side of the lid plate 8. Next, the terminal 11, whose one end is connected to the electrode plate 9, is inserted into the insulating spacer 14 in this state from the back side of the lid 8. Then, a metal disk 17 is externally fixed to the base of the portion of the terminal 11 protruding from the insulating spacer 14 by means such as welding.

Furthermore, a spacer 18 made of rubber, plastic, mylar, etc. is interposed between the laminate 1 and the back surface of the lid 8, and the electrode plate 10 is connected to the cathode foils 3, 3, . . . in this state. A part of the cover body 8 is directly fixed to the back surface of the lid body 8 by welding or the like. The thickness of the spacer 18 is set so that the sum of the spacer 18 and the thickness of the laminate 1 is appropriately larger than the depth of the laminate storage recess 5. And the lid body 8
A rod-shaped terminal 19 is erected on the surface by welding or the like. 20 is the laminate storage recess 5 of the case body 6
An annular waterproof ring storage groove provided on the outside of the
An annular waterproof ring 21 made of rubber or the like is housed in the waterproof ring storage groove 20 .

The laminate 1 is housed in the case 7 by joining the main body 6 and the lid 8 of the case 7 at their peripheral edges by welding or other means. Then, the laminate 1 is stored in the laminate storage recess 5 while being compressed by the main body 6 of the case 7 and the lid 8 with an appropriate force. That is, the spacer 18 is interposed between the back side of the lid 8 of the case 7 and the laminate 1, so that the sum of the thickness of the laminate 1 and the thickness of the spacer 18 is appropriately larger than the depth of the laminate storage section 5. It's like that. Therefore, by joining the lid 8 with the laminate 1 attached to the case body 6 at their peripheries as described above, the laminate 1 is connected to the lid 8 and the case body through the spacer 18. It is compressed by the main body 6 and sealed in the case 7 in that state.

Therefore, the flat electrolytic capacitor shown in FIG. 2 has a small tan δ. That is, the electrolytic solution interposed between the anode foil 2 and the cathode foil 3 has an internal resistance, and this internal resistance becomes the resistance component of the capacitor and causes an increase in tanδ. In the electrolytic capacitor, the laminated body 1 is sandwiched between the cover plate 8 and the case body 6 via the spacer 18, so that the distance between the anode foil 2 and the cathode foil 3 becomes smaller. Therefore, the resistance that exists between the electrodes also becomes smaller, and tan δ becomes smaller. Since the resistance component becomes smaller, the amount of Joule heat generated naturally becomes smaller, making it possible to further reduce the temperature rise of the capacitor.

In addition, in a general capacitor, when an AC signal flows, a Coulomb force is generated by the electric charge on the anode foil 2 and the electric charge on the cathode foil 3, and the anode and cathode attract or repel each other. However, in the flat electrolytic capacitor shown in Fig. 2, the laminate 1 is compressed, so
Vibrations are prevented. Therefore, it is possible to eliminate the fear that the characteristics will vary due to vibration and the signal will be modulated thereby.

In addition, in order to obtain the above-mentioned effects more effectively, it is preferable that the narrow pressure applied to the laminate 1 be applied to at least the central portion of the laminate 1.

3 and 4 show a second embodiment of the flat electrolytic capacitor of the present invention. In this embodiment, a portion of the lid 8 of the case 7 that corresponds to the approximate center of the laminate 1 is recessed toward the back side of the lid 8 to form a holding portion 22, and the laminate 1 is held between the holding portion 22 and the case. The pressure is narrowed by the main body 6. still,
A rib may be provided on the back surface of the lid 8 and this may be used as a pressing means.

FIG. 5 shows a third embodiment of the flat electrolytic capacitor of the present invention. In this embodiment, the lid 8 of the case 7 is deflected as a whole so that its substantially central portion becomes a convex curved surface toward the back side, and the laminate 1 has its central portion bent over the convex curved surface of the lid 8. The center portion and the case body 6 are appropriately compressed. Note that instead of having the center portion protrude toward the back side, the entire portion may be bent in an arched manner so that the center portion protrudes toward the back side.

FIG. 6 shows a fourth embodiment of the flat electrolytic capacitor of the present invention. In this embodiment, unlike the above-mentioned embodiments, a holding portion 23 is provided on the case body 6. That is, the central part of the laminate storage recess 5 of the case body 6 is raised toward the front side of the case to form a presser part 23, and the laminate 1 is pressed against the case lid 8 by the presser part 23. The pressing means can also be provided in the main body 6 of the case 7 in this way.

As described above, various types of pressing means for pressing the laminate 1 can be considered, and therefore, the present invention can have various embodiments.

As described above, the flat electrolytic capacitor of the present invention is a flat electrolytic capacitor in which a laminate formed by laminating a plurality of pairs of anode foils and cathode foils facing each other with electrolytic paper interposed therebetween is housed in a case. The present invention is characterized in that the case is provided with appropriate pressing means for pressing the laminate. Therefore, since the laminate of the flat electrolytic capacitor is always pressed with an appropriate force, the distance between the anode foil and the cathode foil becomes small, and the resistance component interposed therebetween becomes small. Therefore, tan δ becomes small. Furthermore, since the resistance component is reduced, the amount of Joule heat generated is also reduced, making it possible to reduce the temperature rise of the capacitor.

Furthermore, since the laminate is compressed with an appropriate force, it is possible to prevent the anode foil and the cathode foil from vibrating due to the Coulomb force acting therebetween.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing the main parts of an amplifier using electrolytic capacitors to explain the importance of the characteristics of electrolytic capacitors, and Figure 2 is a vertical cross-sectional view showing the first embodiment of the flat electrolytic capacitor of the present invention. , Figures 3 and 4 show a second embodiment of the flat electrolytic capacitor of the present invention, where Figure 3 is a longitudinal sectional view, Figure 4 is a reduced perspective view, and Figure 5 is a flat electrolytic capacitor of the present invention. FIG. 6 is a schematic cross-sectional view showing a fourth embodiment of the flat electrolytic capacitor of the present invention. Explanation of symbols, 1... Laminate, 2... Anode foil, 3
... Cathode foil, 4 ... Electrolytic paper, 5 ... Storage space, 6
... Case body, 7 ... Case, 8 ... Lid body, 1
8, 22, 23...pressing means.

Claims (1)

[Scope of utility model registration request] In a flat electrolytic capacitor in which a laminate formed by laminating a plurality of pairs of anode foils and cathode foils facing each other with electrolytic paper interposed therebetween is housed in a case, an appropriate pressing means for pressing the laminate against the case is provided. A flat electrolytic capacitor characterized by: