JP2000286141A - Capacitor having safety means - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safe and reliable capacitor, having a safety means which can prevent liquid leakage after safety operation and can easily actuate safe operation at a prescribed pressure. SOLUTION: In a capacitor 51 having a safety means, a lid has a metallic plate 14 provided with an external terminal 21, an insulating plate 6 stacked on the plate 14 and provided with an inner terminal 2 which is led out from a capacitor element 1, and a lead-out terminal 12 connected between the terminals 21 and 2, the case is mounted to a case 3. Increase in the inner pressure of the case causes the capacitor 51 to cut off the terminal 12. The plate 14 is fitted with the plate 6 at peripheral edges 9 and 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a capacitor with a security device.

[0002]

2. Description of the Related Art Capacitors such as aluminum electrolytic capacitors, metallized paper capacitors, and impregnated metallized film capacitors have a structure in which, for example, a capacitor element is stored in a case together with an impregnating liquid, and a lid is attached to the case to seal the case. Has become. By the way, these capacitors, when the pressure inside the case rises due to gas generated during use,
Fumes and destroys.

Conventionally, to prevent such destruction,
For example, a capacitor 60 with a security device having a structure as shown in FIG. In the capacitor 60 with a security device, a capacitor element 61 is housed in a case 62,
A lid 63 having a security device is attached to the case 62. The lid 63 is formed by laminating a metal plate 64 and an insulating plate 65, and has a protruding portion projecting from the metal plate 64 to the outside of the case 62 and from the insulating plate 65 to the inside provided near the opening 66 of the case 62. 67 and placed inside the case. The metal plate 64 has an insulating seat 68 made of an insulating material such as epoxy resin and an external terminal 69 such as a Faston terminal.
Are attached through the upper rivet 70. Also,
A rubber ring 72 is placed on the peripheral edge 71 of the metal plate 64, and the peripheral edge 71 is wound around the ring 72. Then, the mouth 66 of the case 62 is bent so that its tip is bitten by the ring 72, the lid 63 is attached to the case 62, and the case 62 is sealed. The insulating plate 65 has an internal terminal 73 drawn from the capacitor element 61.
Are attached by a lower rivet 74 penetrating therethrough. A foil-like drawing terminal 75 is connected between the internal terminal 73 and the external terminal 69 via an upper rivet 70. And this kind of condenser 60 with security device
Is the case 6 because of the gas generated by the reaction of the impregnating liquid.
When the pressure in the cover 2 rises, the portion of the insulating plate 65 of the cover 63 hardly moves, and the metal plate 64 of the cover 63 normally moves.
Move toward the outside of the case 62. For this reason, a force is applied to the extension terminal 75 in the extending direction,
When the predetermined value is reached, the lead-out terminal 75 is cut off. When the lead-out terminal 75 is cut, the capacitor 60 with a security device is electrically released from the circuit to which it is connected, the rise in the pressure in the case 62 stops, and breakage and the like are avoided.

[0004]

By the way, in the capacitor 60 with a security device, the security operation is mechanical such that the metal plate 64 moves. For this reason, even if the pressure of the case 62 reaches a predetermined value, the security operation does not move immediately but is delayed. For example, when the pressure in the case 62 is set to 10 kg / cm ² when the pressure in the case 62 is slowly increased and the lead-out terminal 75 is cut to perform a security operation, the capacitor element 61 explodes due to an explosion or the like. When the pressure in the case 62 rises rapidly, the security operation does not work even if the pressure in the case 62 becomes 10 kg / cm ² . And, depending on the rate of rise of the pressure in the case 62, for example, the pressure in the case 62 is 20 kg /
cm ² and the security operation works. For this reason, as shown in FIG. 5B, since the pressure in the case 62 is extremely high, the peripheral portion 71 wound around the ring 72 of the metal plate 64 may be stretched and come off the case 62. is there. When the metal plate 64 is detached from the case 62, the impregnating liquid in the case 62 leaks out of the case 62, and there is a disadvantage that surrounding electronic components and a mounted substrate are damaged.

In order to prevent this kind of defect, it is conceivable to increase the thickness of the metal plate or use a hard material as the material. There is.

The present invention improves the above-mentioned drawbacks, prevents a liquid leak when the security operation is performed, and easily operates the security operation at a predetermined pressure. The task is to provide.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a metal plate provided with external terminals, and an insulating plate having an internal terminal attached to the metal plate and drawn out of a capacitor element. In a capacitor with a security device, a cover having a plate and a lead-out terminal connected between the external terminal and the internal terminal is attached to a case, and the lead-out terminal is cut off by an increase in internal pressure of the case. The metal plate and the insulating plate are fitted to each other at a peripheral portion.

That is, in the present invention, since the metal plate and the insulating plate are fitted to each other at the peripheral edge thereof, the peripheral edge of the metal plate is not easily stretched even if the pressure in the case rises sharply. , It is hard to come off the case. For this reason, the sealing performance when the security operation is performed is improved, and the failure that the impregnating liquid leaks can be prevented. Also, thickening the metal plate,
Since it is not necessary to use a hard material, a security operation can be performed at a predetermined internal pressure, and safety and reliability are improved.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a capacitor element. The capacitor element 1 has a structure in which, for example, an anode foil and a cathode foil are laminated via electrolytic paper, wound, and internal terminals 2 such as tab terminals and lead terminals are drawn out. The anode foil is formed by forming an oxide film on a valve action metal foil such as an etched high-purity aluminum foil, and the cathode foil is a valve action metal foil such as an etched aluminum foil as it is or is formed by low pressure forming to be thin. An oxide film was formed. The internal terminals 2 are connected to the anode foil and the cathode foil by a cold welding method, a caulking method, or the like. Manila paper or kraft paper is used as the electrolytic paper. In addition, as the capacitor element 1, a metallized paper or a metallized film in which a metal layer is formed by vacuum-depositing a metal such as zinc on a capacitor paper or a plastic film is wound, and a metallikon is provided on both end surfaces. A structure in which a lead wire is connected to the connector may be used.

[0010] The capacitor element 1 is housed in the case 3 with its bottom surface in contact. The case 3 is made of a metal such as aluminum and is formed in a cylindrical shape. In the vicinity of the mouth 4 of the case 1, an R-shaped or trapezoidal protrusion 5 protruding inward is provided.

An insulating plate 6 made of an insulating material such as PPS or phenol resin is placed on the projecting portion 5. As shown in FIG. 2, the insulating plate 6 has a thin central portion, a square through hole 7, and circular through holes 8 on both sides of the through hole 7. The peripheral portion 9 has a thin brim-like shape, and the concave portions 10 are provided at predetermined intervals. Then, the lower terminal rivet 13 made of aluminum is passed through the washer 11, the internal terminal 2 pulled out from the capacitor element 1, the lead terminal 12, and the through hole 8, and the internal terminal 2, the lead terminal 12, and the like are separated from the insulating plate 6. Attached to.

A metal plate 14 is laminated on the insulating plate 6. The metal plate 14 is provided with a through hole 15 having a large diameter at a position facing the through hole 8 of the insulating plate 6, and a projection 17 is formed at a peripheral portion 16 at a position facing the recess 10 of the insulating plate 6. The convex portion 17 is provided and fitted into the concave portion 10. And the peripheral part 16 of the metal plate 14
A rubber ring 18 is mounted and wrapped around it, and its tip bites into the ring 18. In addition, the tip of the mouth 4 of the case 3 is bent on the ring 18,
The metal plate 14 is bitten in the middle of the peripheral portion 16 so as to be laminated on the metal plate 14. Thereby, the insulating plate 6 and the metal plate 14 are attached and fixed to the case 3. The lead terminal 12, the pipe 19 made of silicon rubber or the like, the through hole 15, the insulating seat 20 made of PBT or the like, and the upper terminal rivet 22 made of aluminum are passed through the external terminal 21, and the lead terminal 12, the external terminal 21, etc. Is attached to the metal plate 14.

As shown in FIG. 2, the lead-out terminal 12 is made of metal foil, has a through hole 23 through which the upper rivet 22 penetrates at one end, and a small-diameter through-hole at the bent portion on the metal plate 14 side. Is provided, and when a force for elongation is applied, the weak point 24 is formed.
It is designed to be cut at. The other end 12 </ b> A is formed in a U-shape, bent, and connected to the lower rivet 13.

The insulating seat 20 has a shape in which U-shaped parts 25 are juxtaposed on the left and right sides and connected at the center.
Is taller than the outer one. A groove 27 is formed inside the center wall 26, and a + or-polarity display 28 is provided at the top. A through hole 29 through which the upper rivet 22 penetrates is provided at the center of the U-shaped portion 25.

The external terminal 21 is made of a metal plate bent in a U-shape. A through hole 30 is provided on a side to be connected to other electronic parts and the like, and a press nut 31 is attached to the through hole 30. Have been. External terminal 2
1 has a projection 32 on the inner side surface, which is fitted in a groove 27 provided in the insulating seat 20. Thereby, the position of the through hole 30 can be made constant. Note that the external terminals are not limited to U-shaped ones, but may be S-shaped ones or the like with a partially bent shape.

The upper rivet 22 and the lower rivet 1
3 may be in contact with each other or apart from each other.

A lid as shown in FIG. 3 may be used in addition to the lid made of the insulating plate 6, the metal plate 14, and the like. That is, in FIG. 3A, a convex portion 35 is provided on a peripheral portion 34 of the insulating plate 33, a concave portion 38 is provided on a peripheral portion 37 of the metal plate 36, and the convex portion 35 is fitted into the concave portion 38 and fitted. I have.

In FIG. 3B, a convex portion 41 is provided on a peripheral portion 40 of the insulating plate 39, and a peripheral portion 4 of the metal plate 42 is provided.
3 is provided with a through hole 44, and the convex portion 41 is inserted into the through hole 44 and fitted.

In FIG. 3C, a groove 47 is provided circumferentially on the peripheral portion 46 of the insulating plate 45, and the tip 50 of the peripheral portion 49 of the metal plate 48 is bent, and the tip 50 is inserted into the groove 47. And fitted.

Next, a method of manufacturing the capacitor 51 with a security device shown in FIG. 1 will be described. The manufacturing method of the capacitor element 1 and the case 3 is the same as the conventional method, and thus the description is omitted. First, the pull-out terminal 12 is attached to the brim portion 22A of the upper rivet 22.
Is connected by ultrasonic welding or the like. Metal plate 1
4, the insulating seat 20 and the external terminal 21 before bending are overlapped. Then, the ring 18 is fitted into the upper rivet 22, and the through hole 15 of the metal plate 14 and the through hole 2
9. Penetrate through hole 30 of external terminal 21 and crush the tip.
Next, the external terminal 21 is bent, and the protrusion 32 is fitted into the groove 27 of the insulating seat 20. Thus, the external terminals 21 and the like are attached to the metal plate 14 and integrated. In addition, the lower rivet 13 is inserted into the through hole 8 of the insulating plate 6 and inserted. Then, the metal plate 14 is placed on the insulating plate 6, and the lead-out terminal 12 is passed through the through hole 8 of the insulating plate 6. Then, the drawer terminal 12 is connected to the lower rivet 1.
3 is connected to the flange portion 13A by ultrasonic welding or the like. After that, the internal terminal 2 drawn out of the capacitor element 1
Through the lower rivet 13 and crush the tip. Thereafter, the capacitor element 1 impregnated with an impregnating liquid such as an electrolyte is
To be stored. Then, the insulating plate 6 is placed on the protruding portion 5 of the case 3. Next, the ring 18 is placed on the peripheral portion 16 of the metal plate 14. The mouth 4 of the case 3 and the peripheral portion 16 of the metal plate 14
Are bent at the same time, bite into the ring 18, the lid is attached to the case 3, and the case 3 is sealed.

According to the above-mentioned capacitor 51 with a security device, even when the pressure in the case 3 rises sharply, the metal plate 14 is provided with the convex portion 17 provided on the peripheral portion 16 of the insulating plate 6. The insulating plate 6 fits into the recess 10 provided in the
As shown in FIG. 4, the metal plate 14 does not come off the peripheral portion 16 of the case 3 as shown in FIG.
Are moved in a state where they are kept substantially parallel to, and the lead-out terminal 12 is cut off.

When connecting the capacitor 51 with a security device to other electronic parts or the like in the electric equipment in which it is incorporated, it is connected to a plate-like metal bar fixed in the equipment.
It may be connected to other electronic components or the like via this metal plate. In this case, if the external terminal is on a straight line such as a Faston terminal, the pressure inside the case 3 increases and the Faston terminal or the like hits the metal bar, so that the metal plate of the lid is difficult to move, and the security operation is performed. Is difficult to work. On the other hand, according to the capacitor 51 with a security device, since the external terminal 21 is bent in a U-shape, when the internal pressure of the case 3 increases, the external terminal 21 is further bent even if it hits the metal bar. Thus, the metal plate 14 can be easily moved. Therefore, security operation works without mistake.

[0023]

EXAMPLE Next, with respect to an example of an aluminum electrolytic capacitor having a rating of 400 WV, 470 μF, an outer diameter of 64 mm and a length of 156 mm, the hermeticity of the aluminum electrolytic capacitor in the case where a safety operation was performed was measured together with the conventional example. The conditions of the embodiment are as follows. Example: Overall shape-as shown in FIG. Metal plate-an aluminum disk having a thickness of about 0.5 to 2 mm External terminals-an aluminum plate having a thickness of about 1 mm, which is bent in a U-shape with a radius of about 6 mm. However, at the time of assembly, it is in a bent state of 1/4 turn. Leader terminal-aluminum foil Pipe-silicon rubber Upper rivet, lower rivet-aluminum material Further, the conventional example has a shape as shown in FIG. 5A, and other conditions are the same as those of the embodiment.

Then, a capacitor having a capacity of 10,000 μF is connected in parallel with the sample, and a rating of 1 KVD
C, a voltage is applied using a power supply of 10 ADC. The applied voltage is 450 VDC to 700 VDC. A copper bar having a fixed position is connected to the external terminal of the embodiment, and a flexible electric wire is connected to the external terminal of the conventional example, and a voltage is applied to each. The number of samples is 10 for each applied voltage. Table 1 shows the measurement results.

[0025]

[Table 1]

As is clear from Table 1, according to the embodiment, 7
Within the range of the applied voltage up to 00 VDC, no sealing failure occurs after the security operation has been performed. On the other hand, in the conventional example, in the range of the applied voltage of 600 to 700 VDC, 6 to 10 sealing failures occur, and the electrolyte leaks out of the case.

[0027]

As described above, according to the present invention, according to the present invention, a metal plate provided with an external terminal, an insulating plate laminated on the metal plate and having an internal terminal drawn out from a capacitor element, an external terminal and an internal terminal are provided. In a capacitor with a protective device that attaches a lid having a lead-out terminal connected between the terminal and the case to the case and cuts the lead-out terminal by increasing the internal pressure of the case, the metal plate and the insulating plate are separated from each other at the periphery. Since the fitting is performed, poor sealing after the security operation can be prevented, the security operation operates according to a predetermined value, and a capacitor with a security device having high safety and reliability can be obtained.

[Brief description of the drawings]

FIG. 1 shows a cross-sectional view and a perspective view of an embodiment of the present invention.

FIG. 2 is an exploded view before assembling a lid used in the embodiment of the present invention.

FIG. 3 shows a sectional view of another embodiment of the present invention.

FIG. 4 is a cross-sectional view after a security operation according to the embodiment of the present invention.

FIG. 5 is a cross-sectional view of a conventional example before and after a security operation.

[Explanation of symbols]

1: Capacitor element, 2: Internal terminal, 3: Case,
6, 33, 39, 45 ... insulating plate, 9, 16, 34, 3
7, 40, 43, 46, 49 ... peripheral part, 10, 38 ... concave part, 12 ... lead-out terminal, 14, 36, 42, 48 ... metal plate, 17, 35, 41 ... convex part, 21 ... external terminal, 4
7 ... groove, 50 ... tip of peripheral part, 51 ... capacitor with security device. Reference number P2502

Claims (1)

[Claims] 1. A metal plate provided with an external terminal, an insulating plate laminated to the metal plate and having an internal terminal drawn out of a capacitor element, and connected between the external terminal and the internal terminal. A lid having a lead terminal is attached to a case, and in the capacitor with a security device that cuts the lead terminal by an increase in internal pressure of the case, the metal plate and the insulating plate are fitted to each other at a peripheral portion. Characteristic capacitor with security device.