JPS6028133Y2 - Electrolytic capacitor - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to the structure of an electrolytic capacitor in which an explosion-proof valve is formed at the bottom of a metal case.

Conventionally, electrolytic capacitors with explosion-proof structure are shown in Figure 4a,
The bottom part 2 of the metal case 1 was formed with a straight line passing through the center as shown in b, or a curved groove 4 or a thin wall part as shown in c of the same figure. Since the valve operating pressure is lower, it is easier to create an explosion-proof part, but if the explosion-proof valve is located near the center of the bottom of the case, the opening becomes too large when the valve is activated, and when the valve is opened, a higher pressure than the inside can be generated. When the gas is vigorously discharged, the internal elements often fly out.

For this reason, as shown in Figures 5d and 5e, there are some cases in which grooves 4 and thin walls for the explosion-proof valve are provided around the case bottom 2, but as mentioned above, due to the operating pressure of the explosion-proof valve, this is not necessary. It was difficult to create an explosion-proof valve because it was necessary to form deeper grooves and thin wall pressure parts in order to operate under the operating pressure.

In addition, metal cases are stamped from plate-shaped materials by press forming, but the properties of the bottom of the finished case vary depending on the rolling direction of the raw plate material, so such cases may have grooves or thin-walled parts. When an explosion-proof valve is installed, in order to maintain the uniformity of the explosion-proof valve, it is necessary to process the grooves and thin-walled parts that will become the explosion-proof valve during the molding of the case. It was necessary to establish a department.

The present invention eliminates the above-mentioned drawbacks of the conventional type.
The present invention will be explained with reference to an embodiment shown in FIGS. 3 to 3. Reference numeral 1 is a case made of metal such as aluminum, and the bottom plate 2 of the case 1 has a bottom plate 2 facing each other at the center with an interval A larger than the plate thickness t. , the tips of the opposing parts are circular arcs 3, and three U-shaped grooves 4 are formed at an angle θ of 120° as shown in FIG. 2, or two U-shaped grooves 4 are formed at an angle θ of 180° as shown in FIG. The cross-sectional shape of these grooves may be U-shaped, U-shaped, rectangular, or the like.

With the above configuration, the groove 4 as an explosion-proof valve formed in the bottom plate 2 of the case 1 is formed near the center of the bottom plate 2, and a plurality of grooves 4 are arranged in a U-shape, and each groove 4 is arranged in a U-shape.
By making the shortest distance equal to or greater than the wall thickness of the bottom plate 2, the explosion-proof valve can be operated easily, and the center of the bottom of the case does not open wide during operation, and internal elements do not pop out.

Moreover, by bringing each groove 4 closer to the center, the operating function as an explosion-proof valve can be enhanced without increasing the depth of the groove 4.

That is, in forming the case 1, the ingot material is squeezed with a press and the material is stretched, but the direction is radial with the case bottom plate 2 as the center, and the above-mentioned strip 4 is formed into a U-shape so as to be drawn closer to the center. As a result, the grooves 4 are formed along the radial direction, which improves press workability and improves the uniformity of the explosion-proof valve operating pressure.

In particular, even when processing a plate material by punching while pressing it, by forming the tip of the V-shaped groove 4 as an arc 3 on the side near the center of the case bottom, the operating pressure as an explosion-proof valve is reduced due to the directionality of rolling of the plate material. It is possible to easily eliminate variations in

[Brief explanation of the drawing]

Fig. 1 is a cutaway side view of a main part of an electrolytic capacitor case showing one embodiment of the present invention, Fig. 2 is a bottom view of the case, and Fig. 3
This figure is a bottom view of a case showing another embodiment, and FIGS. 4 and 5 are bottom views of a case of a conventional electrolytic capacitor, respectively. In the same figure, 1... Case, 2... Bottom plate, 3
...Circular arc, 4 ... Groove.

Claims (1)

[Scope of utility model registration request] An electrolytic capacitor with an explosion-proof structure in which a plurality of U-shaped grooves are formed radially on the bottom plate of a metal case, facing each other in the center with an interval greater than the thickness of the metal case, and the tips of the opposing parts are circular arcs.