JPH0572127U - Electrolytic capacitor - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an electrolytic capacitor in which the internal lead wire is surely cut and the energization to the capacitor element is blocked when the explosion-proof valve operates. [Structure] An electrolytic capacitor body A is arranged below a safety case 7, an explosion-proof valve 4 is provided below an outer case 3 of the electrolytic capacitor body A, and internal lead wires 10a,
At least one of 10b includes a cutting member 11b arranged upward from the sealing plate 5 of the electrolytic capacitor main body A and a cutting member 11a arranged downward inside the second sealing plate 8 of the safety case. It is arranged so as to cross the vicinity of the tip.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an electrolytic capacitor, and more particularly to a safety device for an aluminum electrolytic capacitor.

[0002]

[Prior Art]

 The aluminum electrolytic capacitor is provided with a capacitor element in which an anode foil and a cathode foil made of aluminum foil are wound with a separator interposed therebetween and impregnated with a predetermined electrolytic solution. The capacitor element is housed in an outer case made of, for example, aluminum and having a cylindrical shape with a bottom, and its opening is hermetically closed by a sealing plate.

By the way, when a reverse voltage, an overvoltage, or an excessive temperature is applied to this electrolytic capacitor, the internal gas is generated due to the decomposition of the electrolytic solution, and the internal pressure may be increased to explode. In addition, because the internal pressure may rise abnormally due to other causes, conventionally, an explosion-proof valve that releases the internally generated gas to the outside when the specified internal pressure is reached is provided on the sealing plate. ..

Although the explosion of the electrolytic capacitor is prevented by the operation of the explosion-proof valve, the generated gas may be mistaken for a fire of the set (equipment), which may give the user an uncomfortable feeling. Also, in some cases, the electrolytic solution may scatter with the generated gas to the surroundings, causing a short circuit.

Therefore, there is a double structure in which the entire electrolytic capacitor is housed in a safety case as shown in FIG. In FIG. 6, the electrolytic capacitor main body D has an outer case 20 made of aluminum and having a cylindrical shape with a bottom, and a capacitor element 21 housed in the outer case. The case 20 is fixed inside the case 20, and the opening of the outer case 20 is sealed by a sealing plate 24 having an anode terminal 23a and a cathode terminal 23b. An explosion-proof valve 25 consisting of a hole is provided at a substantially central portion of the sealing plate 24.

Inside the casings of the anode terminal 23a and the cathode terminal 23b, the anode lead 26a and the cathode lead 26b drawn out from the capacitor element 21 are connected, and the casings of the terminals 23a and 23b are connected. Internal lead wires 27a and 27b, which are fuse wires, which are easily broken when pulled, are welded to the outside of the case.

The whole electrolytic capacitor main body D is housed in a bottomed cylindrical safety case 28 made of aluminum, and the upper opening of the safety case 28 is hermetically sealed by a second sealing plate 29. Has been closed. The second sealing plate 29 is provided with a pair of lug-type terminals 30a and 30b as external terminals, and the lug-type terminals 30a and 30b are connected to the internal lead wires 27a and 27b, respectively. A sealing member 31, such as an O-ring, is disposed between the outer side wall of the electrolytic capacitor body D and the inner side wall of the safety case 28, and the space inside the safety case 28 is located above the electrolytic capacitor body D. The space E and the bottom space F below are airtightly separated.

If the internal pressure in the outer case 20 rises and the explosion-proof valve 25 operates for some reason, the gas generated in the electrolytic capacitor body D is jetted into the upper space E of the safety case 28. As a result, the pressure in the upper space E rises, the electrolytic capacitor body D moves vigorously toward the bottom space F of the safety case 28, and the inner lead wires 27a and 27b are pulled and stretched accordingly. Be disconnected. The generated gas is confined in the upper space E and does not leak to the outside of the safety case 28.

[0009]

[Problems to be solved by the device]

 In the electrolytic capacitor of FIG. 6, since the electrolytic capacitor D moves to the lower side of the bottom space to cut the internal lead wires 27a and 27b, a sufficient movement distance for cutting the internal lead wires 27a and 27b is provided. Will be needed. This enlarges the size of the electrolytic capacitor as a whole and is not preferable because the space utilization rate is poor. Further, since the electrolytic capacitor D is located in the middle of the safety case 28, it was weak and unstable against external vibration.

An object of the present invention is to provide an electrolytic capacitor that is small in size, resistant to external vibration, and capable of reliably cutting off the internal lead wires to prevent energization of the capacitor element when the explosion-proof valve operates. There is.

[0011]

[Means for Solving the Problems]

 In order to achieve this object, in the present invention, an electrolytic capacitor main body, in which a capacitor element is housed in a cylindrical outer case having a bottom and the opening is sealed by a sealing plate, is a safety case having a cylindrical bottom. -The inside of the safety case is enclosed by a second sealing plate having a pair of external terminals, and the inside of the safety case is located inside the safety case. The sealing member arranged between the side part and the side wall airtightly divides the space into an upper space and a lower space, and in the upper space, the inner lead drawn from the capacitor element to the sealing plate and the second sealing plate. In the electrolytic capacitor, which is connected to the external terminal by an internal lead wire, the electrolytic capacitor body is placed below the safety case, and the explosion-proof valve is provided below the outer case of the electrolytic capacitor body. Within At least one of the lead wires is near the tip of the cutting member placed upward from the sealing plate of the electrolytic capacitor body and the cutting member placed downward inside the second sealing plate of the safety case. It was configured so that it was crossed across.

When at least one of the cutting members is made of an insulating material and the explosion-proof valve operates to move the upward cutting member upward, the cutting members facing downward are moved in contact with each other to cut the internal lead wires. Ensure that they are placed close together, the cutting members are spaced apart from each other, or that there are holes near the tips of both cutting members so that the inner leads are placed through both holes. May be.

[0013]

[Action]

 When the internal pressure of the electrolytic capacitor rises for some reason and the explosion-proof valve operates, the generated gas is ejected into the airtight lower space of the safety case through the explosion-proof valve. As a result, the pressure in the lower space is increased, and the electrolytic capacitor moves above the safety case. By this movement, the upward cutting member moves upward to cut the internal lead wire and deactivate the electrolytic capacitor. At that time, the generated gas is confined in the airtight lower space and does not leak out of the safety case.

[0014]

【Example】

 FIG. 1 shows a schematic side sectional view of an embodiment of an electrolytic capacitor according to an embodiment of the present invention. The electrolytic capacitor body A includes a capacitor element 1 formed by winding, for example, an aluminum foil anode foil and a cathode foil with a separator interposed therebetween. From the capacitor element 1, a ribbon-shaped anode lead and cathode lead 2 are provided. Are drawn out respectively. The capacitor element 1 is impregnated with a predetermined electrolytic solution and is housed in an outer case 3 made of, for example, aluminum and having a bottomed cylindrical shape. An explosion-proof valve 4 made of a thin portion is provided at the bottom of the outer case 3, and an opening of the outer case 3 is hermetically sealed by a sealing plate 5 made of an insulating material. The sealing plate 5 is provided with a terminal 6 penetrating the sealing plate, and the anode lead and the cathode lead 2 are connected to the terminal 6, respectively.

The electrolytic capacitor main body A is housed below the safety case 7 such that the bottom thereof is in contact with the inner wall of the bottom of the safety case 7 or is in close proximity without contact. The safety case 7 is made of, for example, aluminum, and the upper opening of the safety case 7 is hermetically sealed by a second sealing plate 8 made of an insulating material. The second sealing plate 8 is provided with a pair of external terminals 9 penetrating through the sealing plate 8, and an internal lead wire 10a made of hard steel wire is provided between the external terminal 9 and the anode lead and the cathode lead 2. They are connected by 10b.

Along the one inner lead wire 10a, cutting members 11a and 11b made of an insulating material for cutting the inner lead wire 10a extend from the second sealing plate 8 and the sealing plate 5. That is, the cutting member 11a extends downward from the second sealing plate 8 and the cutting member 11b extends upward from the sealing plate 5. The internal lead wire 10a is arranged so as to cross between the tip ends of the cutting members 11a and 11b. Each of the cutting members 11a and 11b is a rod-shaped member having a quadrangular cross section, and its tip portion is obliquely cut. The tip ends of the cutting members 11a and 11b may be partially overlapped in the vertical direction in advance. A blade may be attached to the tip ends of the cutting members 11a and 11b so as to easily cut the inner lead wire 10a. Further, one of the cutting members 11a and 11b may be made of a conductive material.

A sealing member 12 composed of an O-ring is arranged between the outer peripheral side of the outer case 3 of the electrolytic capacitor main body A and the inner peripheral side of the safety case 7, and the inside of the safety case 7 is surrounded by the electrolytic capacitor. An upper space B above the main body A and a lower space C other than the main body A are airtightly separated from each other.

Explaining the operation of the electrolytic capacitor, first, when the internal pressure in the outer case 3 rises for some reason and the explosion-proof valve 4 operates, the generated gas is ejected into the lower space C of the safety case 8. To do. At this time, since the upper space B and the lower space C are separated by the sealing member 12, the generated gas surely increases the pressure in the lower space C of the safety case 8. As a result, the electrolytic capacitor body A is vigorously moved above the safety case 8 as shown in FIG. 2, and along with this, the upward cutting member 11b moves upward while being in contact with the cutting member 11a. As a result, the internal lead wire 10a is cut and the electrolytic capacitor body A is deactivated. The generated gas is confined in the lower space C and does not leak to the outside of the safety case 8.

3 and 4 are views showing another embodiment of the cutting member of the electrolytic capacitor of the present invention. In this embodiment, the cutting members 15a and 15b are both made of a conductive material and are arranged apart from each other. The internal lead wire 10a is arranged so as to cross between the two. When the explosion-proof valve 4 is activated, the cutting members 15a and 15b are moved away from each other as shown in FIG. 4, and the cutting member 15b moves upward to cut the internal lead wire 10a. Both or one of the cutting members 15a and 15b may be made of an insulating material.

FIG. 5 is a view showing still another embodiment of the cutting member of the electrolytic capacitor of the present invention, wherein the cutting members 17a and 17b are made of an insulating or conductive material, and the tip end portions of the cutting members 17a and 17b. A hole 18 is provided in the hole 18 and the internal lead wire 10 a is arranged through the hole 18. When the explosion-proof valve 4 operates, the cutting member 17b moves upward to cut the internal lead wire 10a.

[0021]

[Effect of the device]

 As described above, according to the present invention, when the internal pressure of the electrolytic capacitor rises for some reason and the explosion-proof valve is activated, the generated gas passes through the explosion-proof valve and enters the airtight lower space of the safety case. When the electrolytic capacitor moves above the safety case, the upward cutting member moves upward and cuts the internal lead wire. , Make sure to deactivate the electrolytic capacitor. At that time, the generated gas is confined in the airtight lower space and does not leak out of the safety case.

Further, in the electrolytic capacitor of the present invention, the explosion-proof valve of the electrolytic capacitor body is not a sealing plate but is provided below the electrolytic capacitor body, and when the explosion-proof valve operates, the electrolytic capacitor body moves upward. As described above, it is not necessary to provide a bottom space for the electrolytic capacitor body that moves downward when the explosion-proof valve operates, and the safety case can be downsized.

Further, the electrolytic capacitor body is not arranged in the middle of the upper space and the bottom space as in the conventional case, but the bottom of the electrolytic capacitor body contacts the inner wall of the bottom of the safety case, or does not contact. However, since it is housed in the lower part of the safety case so as to come very close to it, the electrolytic capacitor body will not rattle due to vibration.

[Brief description of drawings]

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

FIG. 2 is a view showing a state in which an explosion-proof valve of the electrolytic capacitor body of FIG. 1 is activated and an internal lead wire is cut by a cutting member.

FIG. 3 is a view showing another cutting member according to the present invention.

FIG. 4 is a view showing a state of the cutting member when the explosion-proof valve operates in FIG.

FIG. 5 is a view showing still another cutting member according to the present invention.

FIG. 6 is a schematic sectional view of a conventional electrolytic capacitor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Capacitor element 2 Anode lead, cathode lead 3 Exterior case 4 Explosion proof valve 5 Sealing plate 6 Anode terminal, cathode terminal 7 Safety case 8 Second sealing plate 9 External terminal 10a Internal lead wire 10b Internal lead Line 11a Cutting member 11b Cutting member 12 Enclosing member (O-ring) 15a Cutting member 15b Cutting member 17a Cutting member 17b Cutting member

Claims (4)

[Scope of utility model registration request] 1. An electrolytic capacitor body in which a capacitor element is housed in a cylindrical outer case having a bottom and an opening thereof is sealed by a sealing plate is housed in a safety case having a cylindrical bottom. The upper opening of the safety case is sealed by a second sealing plate having a pair of external terminals, and the inside of the safety case is between the outer peripheral side of the electrolytic capacitor and the inner peripheral side of the safety case. Is sealed airtightly into an upper space and a lower space by means of a sealing member disposed in the space between the internal lead drawn from the capacitor element to the sealing plate and the external terminal of the second sealing plate. In the electrolytic capacitor connected by the internal lead wire, the electrolytic capacitor body is arranged below the safety case, and the explosion-proof valve is provided below the outer case of the electrolytic capacitor body, and at least one of the internal lead wires is provided. A cutting member that is upwardly disposed from the sealing plate of the electrolytic capacitor body, safety Yoke - of the scan second
The electrolytic capacitor is characterized in that the electrolytic capacitor is arranged so as to cross the vicinity of the tip of the cutting member arranged downward inside the sealing plate. 2. When at least one of the cutting members is made of an insulating material and the explosion-proof valve is activated to move the upward cutting member upward, the downward cutting member moves in contact with each other to cut the internal lead wire. The electrolytic capacitors according to claim 1, wherein the electrolytic capacitors are arranged close to each other. 3. The electrolytic capacitor according to claim 1, wherein the cutting members are arranged apart from each other. 4. The electrolytic capacitor according to claim 1, wherein holes are provided in the vicinity of the tips of both the cutting members, and the internal lead wires are arranged through the both holes.