JPH04218907A - Electrolytic capacitor - Google Patents

Abstract

PURPOSE:To prevent generated gas and electrolytic solution from sputtering even if explosion-proof valve operates. CONSTITUTION:An electrolytic capacitor C itself is contained inside a bottomed tubular safety case 18 with an O-ring 17 mounted around to form a bottom part space B of a specified capacity. A second sealing plate 19 with a pair of external terminals 20a, 20b is provided on an opening part side of the safety case 18. A pair of inside lead lines 16a, 16b, at least one thereof functions as a fuse line, are connected between an anode terminal 14a and a cathode terminal 14b of a sealing plate 15 of the electrolytic capacitor C and the external terminals 20a, 20b. An interior of the safety case 18 is divided into the bottom space B and an air-tight upper space A by the O-ring 17.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an electrolytic capacitor,
More specifically, the present invention relates to a safety device for aluminum electrolytic capacitors.

0002

2. Description of the Related Art An aluminum electrolytic capacitor is formed by winding an anode foil and a cathode foil made of aluminum foil with a separator in between, and includes a capacitor element impregnated with a predetermined electrolyte. The capacitor element is housed in a bottomed cylindrical outer case made of aluminum, for example, and the opening thereof is hermetically closed with a sealing member.

By the way, this electrolytic capacitor has a reverse voltage,
If overvoltage or excessive temperature is applied, internal gas will be generated due to decomposition of the electrolyte, increasing internal pressure and potentially causing an explosion. In addition, the internal pressure may rise abnormally due to other causes.

[0004] Conventionally, therefore, an explosion-proof valve is provided in the outer case to release the internally generated gas to the outside when a specified internal pressure is reached.

[0005]

[Problem to be solved by the invention] Although explosions are prevented by operating the explosion-proof valve, the emitted gas may be mistaken for a fire in the set (equipment), causing unnecessary anxiety to the user. be. Furthermore, in some cases, the electrolyte may be scattered around together with the generated gas, potentially causing a short circuit.

[0006]

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned conventional drawbacks, and its structural features are that a capacitor element is housed in a cylindrical outer case with a bottom,
The opening is sealed with a sealing plate having an explosion-proof valve, and the anode lead and cathode lead drawn out from the capacitor element are connected to the anode terminal and cathode terminal provided on the sealing plate, respectively. In this electrolytic capacitor, the electrolytic capacitor itself is stored in a bottomed cylindrical safety case with an O-ring attached around it so that a predetermined volume of bottom space is created, and the opening of the safety case is A second sealing plate having a pair of external terminals on the side thereof is provided, and a pair of internal lead wires, at least one of which acts as a fuse wire, is wired between the anode terminal and the cathode terminal and each of the external terminals, and The inside of the safety case is divided into the bottom space and the airtight top space by an O-ring.

[0007] In this case, the O-ring is attached to the throttle groove of the outer case. Further, it is preferable that the other internal lead wire has a longer dimension than the one internal lead wire that acts as a fuse wire, and is made of a wire material that is relatively difficult to cut with respect to the fuse wire. Furthermore, a spacer that can be deformed by a predetermined pressure may be provided between the outer bottom surface of the outer case and the inner bottom surface of the safety case.

As both internal lead wires, a combination of copper-under-tin plated steel wire (CP wire), brass wire, phosphor bronze wire, beryllium copper wire or nickel silver wire is suitable.

[0009]

[Operation] When the internal pressure rises for some reason and the explosion-proof valve is activated, the generated gas blows out into the airtight upper space of the safety case through the explosion-proof valve. This increases the pressure in its head space and moves the electrolytic capacitor to the bottom side of the safety case.

[0010] Due to this movement, the internal lead wires are pulled and eventually cut. At this time, the generated gas is confined within the airtight upper space and does not leak out of the case.

[0011]

Embodiment Embodiment 1 FIG. 1 shows a schematic side sectional view of an electrolytic capacitor according to a first embodiment of the present invention. According to the figure, this electrolytic capacitor C includes a capacitor element 10 formed by winding an anode foil and a cathode foil, such as aluminum foil, with a separator in between.

A ribbon-shaped anode lead 11a and a cathode lead 11b are drawn out from the capacitor element 10. After the capacitor element 10 is impregnated with a predetermined electrolyte, it is housed in an exterior case 12 made of aluminum and having a cylindrical shape with a bottom, for example.

The capacitor element 10 is fixed in a case 12 with a suitable fixing agent 13, and the opening of the outer case 12 is covered with a sealing plate 1 having an anode terminal 14a and a cathode terminal 14b.
It is sealed by 5. In this case, the anode terminal 14a and the cathode terminal 14b are made of aluminum rivets, and the anode lead 11a is provided inside the case of each terminal 14a, 14b.
and the cathode lead 11b are connected. In addition, each terminal 14
Fuse wires 16a and 16b made of, for example, hard steel wire are welded to the outside of the cases a and 14b, respectively.

According to this embodiment, one fuse wire 1
The fuse wire 6a has a diameter of 0.3 mm, but the other fuse wire 16b is thicker and longer than that. The sealing plate 15 is made of a rubber-clad laminate, and an explosion-proof valve 15a is provided approximately in the center thereof.

This electrolytic capacitor C has a bottom space B with a predetermined volume on the bottom side in a safety case 18 having a bottomed cylindrical shape with an O-ring 17 attached to the throttle groove 12a of the outer case 12, for example. It is stored so that it is left behind. In this example, the safety case 18 is made of aluminum, and its inner diameter is determined so that the outer peripheral surface of the O-ring 17 comes into close contact with the inner surface of the safety case 18.

Further, the upper end opening of this safety case 18 is closed by a second sealing plate 19. As a result, the inside of the safety case 18 is airtightly divided into an upper space A and a bottom space B by the O-ring 17.

The second sealing plate 19 is provided with a pair of external terminals, in this embodiment lug type terminals 20a and 20b. In this case, the lug terminals 20a, 20b are preferably made of a solderable metal, such as a copper rivet, each having an insertion hole for passing the fuse wire 16a, 16b therethrough.

That is, each of the fuse wires 16a and 16b is inserted into its insertion hole and soldered, but in this example, since the other fuse wire 16b is long, it is bent as shown in the figure. be made into a state of The second sealing plate 19 is made of a rubber-clad laminate similar to the sealing plate 15 described above, and is caulked to secure the safety case 18.
is airtightly fixed to the upper end of the

On the other hand, a spacer 21a is provided between the outer surface of the bottom of the outer case 12 and the inner surface of the bottom of the safety case 18.
, 21b are provided. These spacers 21a, 21
b may be, for example, resin, sponge, paper, metal, etc., but in any case, a material that deforms under a predetermined pressure is used.

Example 2 In Example 1, a brass wire with a diameter of 0.5 mm was used as the fuse wire 16a, and a CP wire with a diameter of 1.0 mm was used as the fuse wire 16b. The rest is the same as in Example 1.

Example 3 In Example 1, a phosphor bronze wire with a diameter of 0.3 mm was used as the fuse wire 16a,
A CP wire with a diameter of 0.7 mm was used as the fuse wire 16b. The rest is the same as in Example 1.

Example 4 In Example 1, a beryllium copper wire with a diameter of 0.2 mm was used as the fuse wire 16a, and a CP wire with a diameter of 0.6 mm was used as the fuse wire 16b. The rest is the same as in Example 1.

Example 5 In Example 1, a nickel silver wire with a diameter of 0.2 mm was used as the fuse wire 16a, and a CP wire with a diameter of 0.5 mm was used as the fuse wire 16b. The rest is the same as in Example 1.

Example 6 In Example 1, a beryllium copper wire with a diameter of 0.4 mm was used as the fuse wire 16a, and a phosphor bronze wire with a diameter of 0.8 mm was used as the fuse wire 16b. The rest is the same as in Example 1.

Example 7 In Example 1, a nickel silver wire with a diameter of 0.5 mm was used as the fuse wire 16a, and a phosphor bronze wire with a diameter of 1.0 mm was used as the fuse wire 16b. The rest is the same as in Example 1.

For reference, Table 1 shows the combinations of the fuse wires 16a and 16b of Examples 1 to 7.

[0027]

[Table 1] Next, the operation of these electrolytic capacitors C will be explained with reference to FIG. First, when the internal pressure inside the outer case 12 increases for some reason and the explosion-proof valve 15a is activated, the generated gas is ejected into the upper space A of the safety case 18.

At this time, since the upper space A and the bottom space B are separated by the O-ring 17, the pressure in the upper space A of the safety case 18 is reliably increased by the generated gas. This moves the electrolytic capacitor C to the bottom side of the safety case 17. Along with this, the spacers 21a and 21b are deformed so as to be crushed, and
One fuse wire 16a is cut.

Furthermore, the generated gas is confined within the upper space A and does not leak to the outside. In this embodiment, the other fuse wire 16b is long and thick, so even if one fuse wire 16a is cut, this fuse wire 16b will remain. Therefore, this electrolytic capacitor C can be used even after an explosion in the safety case 18.
It is suspended within the fuse wire 16b without wobbling.

In the above embodiment, both the upper space A and the bottom space B are airtight, but the bottom space B may be open to the atmosphere. Further, the spacer may be omitted depending on the case.

[0031]

[Effects of the Invention] As explained above, according to the present invention,
The electrolytic capacitor itself is stored in a safety case with an O-ring attached around it, and an airtight space is formed on the explosion-proof valve side to prevent the gas and electrolyte generated when the explosion-proof valve is operated into the same space. The electrolytic capacitor is moved toward the bottom of the safety case due to the resulting pressure increase, and the fuse wire is cut, so the generated gas and electrolyte are not scattered around. Furthermore, it is possible to provide an electrolytic capacitor equipped with a safety device that ensures reliable operation of cutting the fuse wire.

[Brief explanation of the drawing]

FIG. 1 is a schematic side sectional view of an electrolytic capacitor according to an embodiment of the present invention.

FIG. 2 is a schematic side sectional view for explaining the action of the electrolytic capacitor.

[Explanation of symbols]

10 Capacitor element 11a Anode lead 11b Cathode lead 12 Exterior case 12a Aperture groove 14a Anode terminal 14b Cathode terminal 15 Sealing plate 15a Explosion-proof valve 16a, 16b fuse wire 17 O-ring 18 Safety case 19 Second sealing plate 20a, 20b lug type terminal 21a, 21b spacer

Claims (4)

[Claims] Claim 1: A capacitor element is housed in a cylindrical outer case with a bottom, the opening of the capacitor element is sealed with a sealing plate having an explosion-proof valve, and an anode lead and a cathode lead drawn out from the capacitor element are connected to each other. In an electrolytic capacitor which is connected to an anode terminal and a cathode terminal respectively provided on the sealing plate, the electrolytic capacitor itself is placed in a bottomed cylindrical safety case with an O-ring attached around it. A second sealing plate having a pair of external terminals is provided on the opening side of the safety case, and a second sealing plate having a pair of external terminals is provided between the anode terminal and the cathode terminal and each of the external terminals. A pair of internal lead wires, at least one of which acts as a fuse wire, are wired, and the inside of the safety case is divided into two by the O-ring into the bottom space and the airtight top space. Electrolytic capacitor. 2. The electrolytic capacitor according to claim 1, wherein the O-ring is fitted into a throttle groove of the outer case. 3. The electrolytic capacitor according to claim 1, wherein the other internal lead wire has a longer dimension than the one internal lead wire that acts as a fuse wire, and is made of a wire material that is difficult to cut. 4. The electrolytic capacitor according to claim 1, further comprising a spacer that can be deformed by a predetermined pressure between the outer bottom surface of the outer case and the inner bottom surface of the safety case.