JP2580072Y2 - Aluminum electrolytic capacitor - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum electrolytic capacitor having an improved terminal plate structure.

[0002]

2. Description of the Related Art Conventionally, a relatively large aluminum electrolytic capacitor using a screw terminal as an external terminal has a large surface area by electrochemically roughening a high-purity aluminum foil as shown in FIG. Next, the internal lead-out terminal 12 of the capacitor element 11 which is wound through a capacitor paper between the anode foil and the cathode foil each having a dielectric oxide film formed by anodic oxidation and impregnated with a driving electrolyte is shown in FIG. As shown in FIG. 9, the screw terminal 13 is stored in a bottomed cylindrical metal case 16 while being connected to the rivet portion 15 of the resin molded terminal plate 14 formed by insert molding. The metal case 16 is abutted, and the distal end of the opening of the metal case 16 is tightly wound so as to bite into a rubber ring 17 arranged on the outer periphery of the resin molded terminal plate 14 to be sealed.

Here, the resin molded terminal plate 14 will be described in more detail.
A step 18 is provided for disposing the step 7, and a sharp-angled projection 19 for making a rubber ring 17 bite is provided in a substantially central portion of the step 18 in a ring shape. Therefore, there is a difference between the thickness of the portion 20 into which the screw terminal 13 is inserted and the thickness of the step portion 18 in the outer peripheral portion, and the thickness of the step portion 18 is generally thin.

An explosion-proof valve 24 is provided at an arbitrary position of the resin molded terminal plate 14 by fixing a thin rubber packing 22 to an explosion-proof valve 21 with a metal washer 23 as shown in FIG.

[0005] An aluminum electrolytic capacitor having the above configuration generally has a danger of explosion due to a sudden rise in the internal pressure of the capacitor when an overvoltage, reverse voltage or overcurrent is applied due to a circuit abnormality during use. Therefore, as described above, the explosion-proof valve is provided on the resin molded terminal plate 14, and the explosion-proof valve 24 opens when the internal pressure of the capacitor rises, releasing the internal gas to prevent explosion.

However, as the size of the capacitor increases, the internal pressure instantaneously increases when an overvoltage is applied.
Before the explosion-proof valve was operated, the resin molded terminal plate 14 was destroyed and exploded, and the surrounding electronic parts were destroyed, or there was a very fatal defect that a short circuit occurred inside the capacitor and fired.

However, such a resin molded terminal plate 14
Is caused by the fact that the thickness of the stepped portion 18 of the outer peripheral portion constituting the resin molded terminal plate 14 is thin and the strength is weak.

[0008]

[Problems to be Solved by the Invention] An aluminum electrolytic capacitor sealed by a resin molded terminal plate as described above is
Before the explosion-proof valve was operated under an instantaneous increase in internal pressure due to overvoltage application as the size was increased, there was a problem that an explosion was generated due to the destruction of the resin molded terminal plate having a weak strength.

The present invention has been made in view of the above points, and is intended to operate the explosion-proof valve reliably without breaking the resin molded terminal plate even if there is a sudden increase in internal pressure due to an abnormal assembly circuit or the like. It is an object of the present invention to provide an improved aluminum electrolytic capacitor.

[0010]

SUMMARY OF THE INVENTION An aluminum electrolytic capacitor according to the present invention is formed by winding a capacitor element, which is wound between an anode foil and a cathode foil through a capacitor paper and impregnated with a driving electrolyte, into a bottomed cylindrical metal. In an aluminum electrolytic capacitor which is housed in a case and the opening of the metal case is sealed with a resin molded terminal plate provided with an explosion-proof valve, a round flat washer is formed inside the outer peripheral step portion of the resin molded terminal plate. Metal reinforcement
It is characterized by being buried concentrically .

[0011]

According to the aluminum electrolytic capacitor having the above-described structure, a metallic reinforcing material made of a round flat washer is concentrically provided inside the outer peripheral step portion of the resin molded terminal plate having the weakest strength. Because it is buried, it has a structure that does not easily warp, and even if there is a sudden increase in internal pressure due to a circuit abnormality or the like, a metal case
The resistance against internal pressure is increased.
Thus, the explosion-proof valve operates reliably without breaking the resin molded terminal plate, and fatal defects such as explosion, short circuit, and ignition are eliminated.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. That is, as shown in FIG. 1, the internal lead-out terminal 2 of the capacitor element 1, which is wound between the anode foil and the cathode foil via a capacitor paper and impregnated with the driving electrolyte, is connected to the rivet portion 4 of the resin molded terminal plate 3. Connect to The resin molded terminal plate 3 concentric reinforcement 6 metallic consisting round flat washer shape as shown in FIG. 3 in the interior of the stepped portion 5 of the outer circumference as shown in FIG. 2
And the screw terminal 7 is insert molded.
As shown in FIG. 10, a thin rubber packing 22 is fixed to an explosion-proof valve 21 with a metal washer 23 at an arbitrary place as described in the conventional example, and an explosion-proof valve 24 is provided.

The capacitor element 1 is housed in a cylindrical metal case 8 having a bottom and the resin molded terminal plate 3 is brought into contact with the opening of the metal case 8. Is wound into a rubber ring 9 disposed on the step portion 5 on the outer periphery of the resin molded terminal plate 3 and sealed.

According to the aluminum electrolytic capacitor configured as described above, even if the internal pressure is rapidly increased due to a circuit abnormality or the like during use in a required circuit, the resin molded terminal plate 3 can be used.
Since the reinforcing member 6 of metal consisting of round flat washer-shaped inside of the stepped portion 5 of the outer periphery of which is embedded in 3 concentrically resin molded terminal plate, a resin molded terminal plate 3 in the warp by the reinforcing member 6 Ku
As the force against internal pressure is increased , the explosion-proof valve 24 operates reliably without breaking the resin molded terminal plate 3, and it is possible to prevent an explosion and further a fatal defect such as short circuit or ignition. it can.

Next, comparison of characteristics between the present invention and the conventional example will be described based on experimental results. That is, the present invention (A) configured as shown in FIG. 1 and the conventional example (B) configured as shown in FIG.
As a result of examining the operation of the explosion-proof valve and the state of destruction and ignition of the resin molded terminal plate when an overvoltage of 0 A was applied, the results are as shown in the table below. Samples are rated at 400 for both (A) and (B)
V-5600 μF was used for each of the 20 samples.

[0016] The resin molded terminal board present invention (A), sub
In both cases (B) and (B), the reinforcing material 6 in (A) was made of stainless steel.

[0017]

【table】 As apparent from the above table, the conventional example (B) will stop the explosion-proof valve operation <br/> work very poorly half of explosion-proof valve 24, breakdown of the resin molded terminal plate 14 of fairly even fire than the original In contrast to the occurrence at a high frequency, in the case of the present invention (A), the explosion-proof valve was operated, and the resin molded terminal plate 3 was destroyed.

In the above embodiment, a simple circular structure is used as the structure of the reinforcing member 6 embedded inside the outer peripheral step portion of the resin molded terminal plate.
Although an example of using a flat washer-shaped one has been described,
As shown in FIG. 4, a reinforcing member 6 made of a round flat washer having a partially omitted circle, or a round flat plate provided with an appropriate bridge portion 10 between inner circumferences as shown in FIGS. Washer-like structure
To obtain the same function and effect even when the reinforcing material 6 made of
Can be.

[0019]

According to the invention present invention, even if there is sudden increase in internal pressure by a circuit abnormality, among outer peripheral step portion of the resin molded terminal plate
By the action of the round flat washer-like reinforcing material 6 embedded in the part
The resin-molded terminal plate has a structure that does not warp easily, and resists internal pressure
Therefore, the explosion-proof valve operates reliably without breaking the resin-molded terminal plate, and it is possible to obtain an extremely safe aluminum electrolytic capacitor that does not short-circuit and ignite inside the capacitor.

[Brief description of the drawings]

FIG. 1 is a front view showing an aluminum electrolytic capacitor according to an embodiment of the present invention.

FIG. 2 is a front sectional view showing a resin molded terminal plate constituting FIG. 1;

FIG. 3 is a plan view showing a reinforcing member constituting FIG. 2;

FIG. 4 is a plan view showing a reinforcing member according to another embodiment.

FIG. 5 is a plan view showing a reinforcing member according to another embodiment.

FIG. 6 is a plan view showing a reinforcing member according to another embodiment.

FIG. 7 is a plan view showing a reinforcing member according to another embodiment.

FIG. 8 is a front sectional view showing an aluminum electrolytic capacitor according to a conventional example.

FIG. 9 is a front sectional view showing the resin molded terminal plate constituting FIG. 8;

FIG. 10 is a cross-sectional view showing an explosion-proof valve portion constituting the resin molded terminal plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Capacitor element 3 Resin molding terminal board 5 Outer peripheral step part 6 Reinforcement material 8 Metal case

Claims (1)

(57) [Scope of request for utility model registration] 1. A capacitor element which is wound between an anode foil and a cathode foil via a capacitor paper and impregnated with a driving electrolyte is accommodated in a bottomed cylindrical metal case, and the opening of the metal case is explosion-proof. In an aluminum electrolytic capacitor sealed with a resin molded terminal plate provided with a valve, a metallic reinforcing material made of a round flat washer is concentrically provided inside an outer peripheral step portion of the resin molded terminal plate.
Aluminum electrolytic capacitor, characterized in that embedded in.