JPH0414922Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an electric double layer capacitor in which a predetermined number of coin-shaped capacitor cells are housed in an exterior case.

[Conventional example]

Coin-shaped capacitor cells are mainly used as memory backup power supplies, etc., and can be said to be convenient in that the desired voltage can be easily obtained by stacking multiple coin-shaped capacitor cells, but they themselves do not have external terminals. When mounting on a circuit board, etc., the cell stack is housed in a bottomed cylindrical metal outer case via an insulating tube, etc., and an electrode plate with an external terminal is placed in the opening of the case. After that, the opening is caulked so that it looks like an electrolytic capacitor, and its external terminals are used to mount it on a circuit board, etc.

[Problem that the invention attempts to solve]

However, after storing the capacitor cells, electrode plates, etc. in the exterior case as described above, the opening of the case is caulked as a final step, but if the pressure at the time of caulking is too strong, the liquid from the capacitor cell will leak out. Leakage occurs, and on the other hand, if the crimping pressure is weak, the electrode plate may rotate inadvertently within the case opening, and the defect rate is generally high during this crimping process.It takes considerable skill to adjust the crimping pressure. is required.

Regarding this point, for example, in Japanese Patent Application No. 58-122840 (Japanese Patent Application Laid-Open No. 60-15911), a metal cushioning material is arranged between the electrode plate or the outer case and the cell laminate. According to this, the equivalent series resistance increases as the number of contact points increases, so
This is unfavorable due to the characteristics of the capacitor.

This idea was developed in view of the above-mentioned drawbacks of the conventional technology, and its purpose was to create an electric double layer capacitor with a structure that can absorb the mechanical stress applied to the capacitor cell when the case is crimped without increasing the number of contact points. It is about providing.

[Means for solving problems]

In order to achieve the above object, in this invention, a plurality of tongue pieces having spring elasticity are provided at the bottom of the outer case by cutting out the bottom of the outer case and integrally formed with the bottom. .

[Effect]

The mechanical stress generated when the case opening is caulked is absorbed by the tongue piece, so there is no risk of excessive pressure being applied to the cell stack, and the number of points of contact between the capacitor cell, the outer case, and the electrode plate increases. Not at all.

〔Example〕

Hereinafter, embodiments of this invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, this electric double layer capacitor includes a bottomed cylindrical outer case 1 made of a metal material. According to this embodiment, there are three coin-shaped capacitor cells 2 inside the outer case 1.
A cell laminate 2 is housed in which the cell laminate 2 is formed by stacking cells 2 and 3 and covering the periphery with an electrically insulating heat-shrinkable sleeve 3. A sealing member 4 is arranged above the cell stack 2 .

That is, this sealing member 4 consists of a first electrode plate 5 having an external terminal 5a and a second electrode plate 6 also having an external terminal 6a, which are arranged oppositely with an electrically insulating plate 7 in between. The electrode plate 5 is placed in contact with one electrode surface of the cell stack 2 . Then, the opening of the outer case 1 is caulked so as to come into contact with the periphery of the second electrode plate 6, and according to this invention, a spring is installed at the bottom of the outer case 1 to absorb the mechanical stress at that time. A plurality of elastic tongue pieces 8 are formed. Note that this tongue piece 8 can be integrally formed at the bottom of the outer case 1 by providing a notch 10 of a predetermined shape in the bottom of the case. In this embodiment, as shown in FIG. 2, four tongue pieces 8 are provided, each of which has a predetermined initial angle that points from the bottom periphery of the outer case 1 toward the inside of the case. It's attached. Therefore, according to this,
Since the caulking pressure at the opening of the case 1 is moderately buffered by each of the tongues 8, there is no risk of electrolyte leaking out from the capacitor cell 2a. In addition, the pressure contact force between the first electrode plate 5 and the cell stack 2 and between the second electrode plate 6 and the caulked part of the case opening is increased due to the repulsive force when the tongue piece 8 is compressed. Therefore, the sealing member 4 will not be inadvertently rotated within the case opening.

Note that the number of tongue pieces 8 can be selected arbitrarily.
FIG. 4 shows a pair of tongue pieces 8 at the bottom of the outer case 1.
An example in which 8 is provided is shown. Furthermore, although the disk-shaped electrically insulating plate 7 is used in the above embodiment, an electrically insulating tube 9 whose upper end is closed may be used instead, as shown in FIG. According to this, the upper wall 9a provides insulation between the electrode plates 5 and 6, and the side wall 9b provides insulation between the capacitor cell 2a and the exterior case 1, so the sleeve 3 is unnecessary. Become.

[Effect of idea]

As is clear from the above description of the embodiment, according to this invention, by providing a plurality of tongue pieces 8 having spring elasticity at the bottom of the outer case 1, the capacitor cell 2a can be effectively clamped against excessive caulking pressure. In addition, it is possible to prevent the sealing member 4 from rotating within the case opening. Also,
Cell laminate 2, exterior case 1, and electrode plates 6, 7
Since there is no need to particularly increase the number of contacts between the

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of an electric double layer capacitor according to this invention, Fig. 2 is a plan view of an exterior case used in the capacitor, and Fig. 3 is a sectional view taken along the - line in Fig. 2. FIG. 4 is a plan view of an exterior case according to another embodiment, and FIG. 5 is a sectional view showing a modification of the electrical insulation means used in the same capacitor. In the figure, 1 is an exterior case, 2 is a cell stack, and 2a
3 is a capacitor cell, 3 is a sleeve, 4 is a sealing member, 5 and 6 are electrode plates, 7 is an insulating plate, and 8 is a tongue piece.

Claims (1)

[Claims for Utility Model Registration] (1) At least one coin-shaped capacitor cell is housed in a bottomed cylindrical metal exterior case, and a first electrode plate is arranged on one electrode surface of the capacitor cell. In addition, in an electric double layer capacitor, a second electrode plate is placed on the electrode plate via electrical insulation means, and the opening of the outer case is caulked to the peripheral edge of the second electrode plate,
A plurality of tongue pieces having spring elasticity are provided at the bottom of the exterior case facing the other electrode surface of the capacitor cell, which are cut out from the bottom of the exterior case and integrally formed with the bottom. An electric double layer capacitor characterized by: (2) The electric double layer capacitor according to claim (1), wherein each of the tongues extends inward from the bottom periphery of the outer case at a predetermined angle.