JPS629711Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a winding core for winding up a capacitor element.

Figure 1 shows the winding core that has been commonly used in capacitor winding machines that alternately stack multiple sheets of electrode foil, that is, aluminum foil, and separators and wind them in a predetermined amount to form a capacitor element. A slit b is formed in the round bar a to penetrate in the diametrical direction, and the tips of an electrode foil (hereinafter referred to as aluminum foil) F, a separator S, etc. are inserted into the slit, or two There was one in which elongated pins were arranged symmetrically about the center of rotation, and the tips of aluminum foil or the like were inserted between the pins.

By the way, the outer diameter (diameter) of the capacitor elements used in small capacitors called _φ4 and _φ5 must be 3.5 mm or less and 4.3 mm or less, respectively, due to the inner diameter dimensions of the aluminum case. Therefore, it is required to reduce the diameter of the winding core. On the other hand, in order to improve the characteristics of a capacitor, it is necessary to keep the distance between the cathode and anode aluminum foils small and uniform, and for this purpose, when winding up the capacitor element, tension is applied to the aluminum foil, separator, etc. Requires winding. For this reason, the winding core must have mechanical strength that can withstand the tension in order to wind up the aluminum foil, etc., and there is a limit to the diameter of the winding core that can be made smaller.

Additionally, tabs for lead wires are attached to the aluminum foil, and two tabs are arranged symmetrically with respect to the axis of the capacitor element for each capacitor element. It is thicker and harder than aluminum foil, and the width of the tab cannot be made too small due to the connection process between the tab and the aluminum foil.

For this reason, when winding aluminum foil, etc. with a conventional round rod-shaped winding core, the tabs do not fit into the circular shape of the winding core, resulting in a winding shape as shown in Figure 2, which creates a large gap G between the elements. Not only that, but the external shape is oval, which has the disadvantage of creating a large amount of wasted space when housed in a perfectly circular aluminum case. There was also the problem that the soft aluminum foil would be cut by the edge of the tab T when it was wound into the shape shown in FIG. Furthermore, in the case of a round bar-shaped winding core, the aluminum foil contacts the winding core due to the biting at the beginning of the winding.
There was also the problem that separators and the like adhered tightly to the core, and the attached portions were cut off when the core was pulled out.

The present invention was developed in view of the drawbacks and problems faced by conventional winding cores, and its purpose is to reduce the internal voids as much as possible and to make the cross-sectional shape as true as possible. It is an object of the present invention to provide a winding core which can be wound into a nearly circular shape and which is less likely to break aluminum foil or the like.

The winding core for winding a capacitor element according to the present invention is
Parallel planes are formed at diametrically symmetrical positions on the outer periphery of the winding core, and slits are formed obliquely to the planes, and an electrode foil or the like can be inserted into the slits.

An embodiment of the present invention will be described below with reference to the drawings.

3 and 4, one embodiment of a winding core for winding up a capacitor element according to the present invention is shown. The winding core 1 of this embodiment has a diametrically symmetrical position with respect to the axis of a thin metal round bar partially removed to form a pair of planes 2 that are parallel to each other, and that are oblique to the planes. It is made by forming a slit 3 extending along the axial direction of the winding core.

When making a capacitor element using the winding core according to the present invention, the tips of the aluminum foil F and the separator S are wound up by passing them through the slit 3 as shown in FIG. so that they are placed symmetrically about the axis. In this case, the aluminum foil and separator are
It is bent at the obtuse edge 4 formed by the slit, and is prevented from being bent at the acute edge 5.

As is clear from the winding shape shown in FIG. 5, the winding core of the present invention can provide the following effects.

(a) The winding shape of the capacitor element is closer to a perfect circle than the conventional one (Figure 2), so it can be easily inserted into the aluminum case and does not increase unnecessary space inside the case. .

(b) Since the gap G′ within the capacitor element can be made small and the aluminum foil and separator can be tightly wound, a capacitor element with excellent electrical characteristics can be produced.

(c) Since the aluminum foil, etc. can be bent at the obtuse edge, the edge at the beginning of the winding is less likely to get wedged, and there is less risk of damage to the aluminum foil, etc. when removing the element.

(d) Since the bending angle θ' of the aluminum foil at the edge of the tab is more obtuse than the angle θ formed by the conventional winding core, there is less risk of the aluminum foil being cut at that portion, reducing shot defects.

(e) Even if the cross-sectional area of the winding core is approximately twice that of a conventional round bar-shaped core, it is possible to wind a small capacitor element with the same outer diameter, and the mechanical strength of the winding core is increased. is possible.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing how a capacitor element is wound up using a conventional round bar-shaped winding core, Fig. 2 is an enlarged end view of a capacitor element wound up using a conventional round bar-shaped winding core, and Fig. 3 is a capacitor element according to the present invention. FIG. 4 is a perspective view of the winding core, FIG. 4 is a sectional view taken along line A--A in FIG. 3, and FIG. 5 is an enlarged end view of a capacitor element wound with the winding core of the present invention. 1: core, 2: plane, 3: slit, F: aluminum foil (electrode foil), S: separator, T: tab.

Claims (1)

[Scope of utility model registration request] A feature is that planes parallel to each other are formed at symmetrical positions in the diametrical direction of the outer periphery of the winding core, and slits are formed obliquely to the planes, and an electrode foil for a capacitor element can be inserted into the slits. Winding core for winding capacitor elements.