JP2559923Y2 - Electrolytic capacitor - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention relates to an electrolytic capacitor.
In particular, it relates to a safety device for an electrolytic capacitor.

[0002]

2. Description of the Related Art Aluminum electrolytic capacitors, for example,
The capacitor element is housed in a cylindrical outer case with a bottom made of aluminum.The capacitor element is made by winding an anode foil and a cathode foil made of aluminum foil with a separator between them, and impregnating with electrolyte. The opening of the outer case is hermetically closed by a sealing body. When a reverse voltage, an overcurrent or an excessive temperature is applied to the electrolytic capacitor, gas is generated by decomposition of the electrolytic solution, and the internal pressure increases, which may cause an explosion. For this reason, an explosion-proof valve is provided in the outer case or the sealing body so that the generated gas is released when the internal pressure rises more than a specified value. However, when the explosion-proof valve is activated, the emitted gas is mistaken for a fire in the equipment, giving the user of the equipment unnecessary anxiety, and in some cases, the electrolyte scatters along with the internal gas and shorts the circuit. There is also a risk.

Therefore, for example, as shown in FIG. 3, a method is employed in which the inner case 20 containing the capacitor element is placed in a larger outer case 30 as shown in FIG. A capacitor element 21 is housed in the inner case 20, and the capacitor element 21 is fixed by a fixing agent 22. 23 is a sealing body, 24 is an internal terminal, and 25 is an explosion-proof valve. On the other hand, the opening of the outer case 30 is also hermetically sealed by the sealing body 31, and the outer terminal 32 and the rivet 26 of the inner case 20 are connected by a lead wire 33 made of a material that can be easily cut. A deformable spacer 34 made of paper, resin, or the like is disposed in the outer case 30 so as to support the inner case 20 from below, and a space between the outer portion of the inner case 20 and the inner portion of the outer case 30 is provided. −
A ring 35 is provided to seal the space inside the outer case 30 so as to be airtightly divided into an upper space A and a lower space B. When the internal pressure in the inner case 20 rises for some reason and the explosion-proof valve 25 is activated and the generated gas or electrolyte is ejected from the explosion-proof valve 25, the pressure in the upper space A increases and the lead wire 33 is cut off. Inner case 2 like
0 is pushed down, and the spacer 34 is compressed and deformed. By expanding the upper space A in this way,
The pressure is absorbed to prevent the generated gas and the electrolytic solution from being ejected to the outside of the outer case 30.

[0004]

[Problem to be solved by the invention]
Operates, the pressure in the upper space A increases, and the inner case 20
Is to be pushed down, the lead wire 33 made of a material that is easily cut is not cut for some reason,
Therefore, the inner case 20 cannot move downward, and the generated gas may squirt out of the outer case.

According to the present invention, when an explosion-proof valve is operated in an electrolytic capacitor in which an inner case housing a capacitor element is housed in an outer case and the outer case is hermetically partitioned, each of the cases is provided. An object of the present invention is to provide an electrolytic capacitor in which a lead wire is reliably cut so that an inner case can move downward.

[0006]

In order to achieve this object, according to the present invention, a sealing member having an explosion-proof valve is provided in a cylindrical outer case whose upper opening is hermetically closed by a sealing member. An upper opening is hermetically closed and a bottomed cylindrical inner case in which a capacitor element is housed is housed, and an upper space in which the explosion-proof valve of the inner case is located in the outer case is airtightly divided, In this upper space, an electrolytic capacitor in which a lead wire is connected between an internal terminal that is drawn out of the capacitor element and is guided to the sealing member of the inner case and an external terminal provided in the sealing member of the outer case. In the above, one or a plurality of easy-to-cut portions are provided so as to be easily cut by at least one lead wire.

[0007]

[Action] When the internal pressure in the inner case rises for some reason and the explosion-proof valve operates and the generated gas or electrolyte gushes from the explosion-proof valve, the pressure in the upper space where the explosion-proof valve is located rises, Begins to move to the other space, the lead wire is easily cut at a place where it is easy to cut, the inner case further moves and the upper space spreads, the pressure is absorbed, and the generated gas and electrolyte solution go out of the outer case. Ejection is prevented.

[0008]

1, an electrolytic capacitor 1 according to the present invention has an inner case 2 and an outer case 3 in which the inner case 2 is housed. The inner case 2 is made of aluminum and has a cylindrical shape with a bottom. The upper opening is hermetically closed by a sealing body 4 made of a rubber-clad laminate, and an explosion-proof valve 5 is provided in the sealing body 4. A capacitor element 6 is housed in the inner case 2, and the capacitor element 6 is formed by winding an anode foil and a cathode foil made of aluminum foil with a separator interposed therebetween and impregnating with an electrolytic solution. It is fixed in the case 2. 8 is an internal terminal, 9 is a rivet. On the other hand, the outer case 3 is also made of aluminum and has a bottomed cylindrical shape, and the upper opening is a sealing body 1 made of a rubber-clad laminate.
0 and hermetically closed by a lead wire 12 between the external terminal 11 and the rivet 9 of the inner case 2. As the lead wire, a combination of tin or solder-plated steel core copper wire, brass wire, phosphor bronze wire, beryllium copper wire or nickel-white wire is suitable. Each of the lead wires 12 is provided with a cut 12a and a thin portion. Inner case 2
A recess 13 is provided around the upper part of the outer case 3, and a sealing member 14 made of a rubber O-ring is arranged between the recess 13 and the inner wall of the outer case 3. The space to be removed is airtightly divided into an upper space A and a lower space B. Below the inner case 3 is the inner case 3
Is disposed. Spacer 15
Is made of a deformable material such as paper or resin.

When the internal pressure in the inner case 2 rises for some reason and the explosion-proof valve 5 is operated and the generated gas or electrolyte is ejected from the explosion-proof valve 5, the pressure in the upper space A increases and both the lead wires 12 Is cut at the cut 12a where cutting is easy, and the inner case 2 is pushed down. Therefore, the upper space A is expanded, and the pressure is absorbed to prevent the generated gas and the electrolytic solution from being ejected to the outside of the outer case 3.

The cuts, which are places where the lead wires 12 can be easily cut, may be provided at a plurality of places. Also, instead of notching, a thin portion 12b is formed on the lead wire 12 as shown in FIG.
May be provided to facilitate cutting. In addition, an easy-to-cut portion may be provided only on one of the two lead wires 12. As the sealing member, besides rubber, plastic having elasticity can be used, and the shape is not limited to the O-ring. In addition, one of the lead wires 12 may be lengthened without providing an easy-to-cut portion, or may be difficult to cut, and may be suspended so that the inner case that has moved downward does not wobble and rattle. Is also good. Note that a spacer that supports the inner case may not be provided below the inner case 2, and the lower space B may be open to the atmosphere.

[0011]

[Effect of the Invention] In the electrolytic capacitor of the present invention, when the internal pressure in the inner case rises for some reason, the explosion-proof valve is activated, and the generated gas or electrolyte is ejected from the explosion-proof valve, the space where the explosion-proof valve is located. The pressure inside increases. When the inner case starts to move to the other space, the lead wire is easily cut at the place where it is easy to cut, the inner case moves securely, and the space where the explosion-proof valve is located expands, and pressure is absorbed. Prevents generated gas and electrolyte from spouting out of the outer case.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the electrolytic capacitor of the present invention.

FIG. 2 is a sectional view showing another embodiment of a lead wire.

FIG. 3 is a sectional view of a conventional electrolytic capacitor.

FIG. 4 is a view showing a state in which the explosion-proof valve is operated and the inner case is pushed down in the conventional electrolytic capacitor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrolytic capacitor 2 Inner case 3 Outer case 4 Sealing body 5 Explosion-proof valve 6 Capacitor element 7 Fixing agent 8 Internal terminal 9 Rivet 10 Sealing body 11 External terminal 12 Lead wire 12a Easy cut (cut) 12b Easy cut (Thin portion) 13 Recess 14 Sealing member 15 Spacer

Claims (1)

(57) [Scope of request for utility model registration] An upper opening is hermetically closed by a sealing body having an explosion-proof valve, and a capacitor element is housed inside a cylindrical outer case with a bottom having an upper opening hermetically closed by a sealing body. The inner case in which the explosion-proof valve of the inner case is located in the outer case is hermetically partitioned, and in this upper space, the sealing member of the inner case is drawn out of the capacitor element and is closed. In an electrolytic capacitor in which a lead wire is connected between an internal terminal guided to the point and an external terminal provided in a sealing body of an outer case, each of the electrolytic capacitors is easily cut to at least one lead wire. An electrolytic capacitor having a plurality of easily cut portions.