JP2021022628A - Capacitor, manufacturing installation of capacitor and manufacturing method of capacitor - Google Patents

Abstract

To provide a capacitor element having a profile close to a perfect circle, and to provide a manufacturing installation and a manufacturing method of the capacitor element.SOLUTION: A capacitor includes a capacitor element 10 formed by interposing an anode terminal 5 and a cathode terminal 6 in a cylindrical wound body formed by winding an anode foil 2 and a cathode foil 3 via a separator, and a bottomed cylindrical outer case for receiving the capacitor element 10. The anode terminal 5 has a tabular tab part 5c to be fixed to the anode foil 2, the cathode terminal 6 has a tabular tab part 6c to be fixed to the cathode foil 3, the tab parts 5c, 6c are placed in parallel with each other across the medial axis of a wound body, and the opposite part 9a of a wound body 9 facing the tab part 5c and placed on farther inside than the tab part 5c is inclining to separate from the tab part 5c from the starting end toward the terminal side of the anode foil 2 in the tab part 5c.SELECTED DRAWING: Figure 8

Description

The present invention relates to a capacitor, a capacitor manufacturing apparatus, and a capacitor manufacturing method.

As an element of a wound capacitor, one having a structure in which a separator is interposed between an anode foil and a cathode foil and wound is known (Patent Document 1).
FIG. 11 is an explanatory diagram showing a part of a conventional capacitor element manufacturing apparatus and manufacturing process. The manufacturing apparatus 100 includes a winding core 101, a rotation driving device 102 that rotates the winding core 101, and a drive control device 103 that controls driving, stopping, and the like of the rotation driving device 102.

In the manufacture of the capacitor element, first, the anode terminal 5 is crimped and connected at a predetermined position of the anode foil 2 and the cathode terminal 6 is crimped and connected at a predetermined position of the cathode foil 3. Next, as an example, the laminate 8 in which the separator 4a, the cathode foil 3, the separator 4b, and the anode foil 2 are stacked in this order is attached to the winding core 101 of the manufacturing apparatus. Next, the winding body 9 is formed by rotating the winding core 101 and winding the laminated body 8 around the winding core 101. At this time, the anode terminal 5 is interposed between the anode foil 2 and the separator 4b, the cathode terminal 6 is interposed between the cathode foil 3 and the separator 4a, and the anode terminal 5 and the anode terminal 6 and the anode terminal 6 are interposed from one end face of the winding body 9. The lead rod of the cathode terminal 6 extends. Then, after winding an element stop tape (not shown) around the outer circumference of the winding body 9, the winding body 9 is pulled out from the winding core 101. As a result, the capacitor element is manufactured.

After impregnating the capacitor element manufactured in this way with an electrolyte, the capacitor element is inserted into the outer case, and the opening of the outer case is completely airtightly sealed by a sealing body to manufacture a wound capacitor. ..

12A and 12B are explanatory views showing a schematic configuration of a conventional winding core 101, FIG. 12A is an enlarged view of the front surface (cross section) of the winding core 101, and FIG. 12B is FIG. 12A. ) Is viewed in the X direction, and FIG. 12 (c) is a side view of FIG. 12 (a) viewed in the Y direction.

The winding core 101 includes a base portion 51 and a winding portion 52.
The base portion 51 is formed in a columnar shape, and the winding portion 52 extends from one end of the base portion 51 in the central axial direction along the central axial direction.

The winding portion 52 has a substantially oval cross section formed by forming missing portions 52a and 52b on a part of side surface portions facing each other in the radial direction with respect to a cylindrical body coaxial with the base portion 51. There is. In the winding portion 52, the side surfaces of the missing portions 52a and 52b are flat and parallel to each other. Further, a virtual plane (hereinafter referred to as a reference plane A) parallel to the side surfaces of the missing portions 52a and 52b, which passes through the central axis of the base portion 51 and extends in the major axis direction of the winding portion 52, has two winding portions 52. Divide into equal parts. Further, in the winding portion 52, the side surface of the portion that is not missing is the circumferential surface flush with the circumferential surface of the base portion 51. The winding portion 52 is rotationally symmetric with respect to the central axis of the base portion 51 and is symmetrical with respect to the reference plane A.

Further, as shown in FIGS. 12A and 12B, a slit 53 extending from the end surface of the winding portion 52 toward the base portion 51 is provided. The slit 53 extends along the central axis direction of the base portion 51. Further, as shown in FIGS. 12A and 12B, a taper 54 is formed on the end surface of the winding portion 52 so as to be inclined downward from the outer edge toward the slit 53.

When manufacturing a capacitor element, as shown in FIG. 12A, the anode terminal 5 is opposed to the side surfaces of the missing portions 52a and 52b of the winding portion 52 with an electrode foil and a separator (not shown) sandwiched between them. The tab portion 5c and the tab portion 6c of the cathode terminal 6 are positioned. As a result, even if the outer peripheral side of the tab portion of the anode terminal 5 and the cathode terminal 6 swells each time the laminate 8 is wound around the winding core 101, it is possible to prevent the missing portions 52a and 52b from protruding more than necessary.

Japanese Unexamined Patent Publication No. 2017-188541

However, as shown in FIG. 12A, when the element is wound using the winding core 101 having a symmetrical shape with respect to the reference surface A, depending on the state of the electrode foil, the tab portion 5c of the anode terminal 5 There is a problem that the rear side in the winding direction bulges with respect to the element diameter, and the element becomes a shape away from a perfect circle.

The cause of this phenomenon will be described with reference to FIGS. 13 and 14. FIG. 13 is an explanatory diagram showing the states of the cathode terminal 6 and the anode terminal 5 when the laminate 8 is wound around the winding core 101. 14A and 14B are explanatory views showing a state in which the laminated body 8 is wound around the winding core 101, FIG. 14A is a schematic view, and FIG. 14B is an X-ray photograph showing a cross section of a conventional capacitor element. is there.

First, a laminate in which the separator 4a, the cathode foil 3, the separator 4b, and the anode foil 2 are stacked in this order is attached to the winding core 101 of the manufacturing apparatus, and the winding core 101 is rotated as shown in FIG. 13A. The laminate 8 is wound around the winding core 101. As the winding of the laminate 8 around the winding core 101 is advanced, as shown in FIG. 13B, a tab of the cathode terminal 6 is interposed between the separator 4b and the cathode foil 3, and further, the tab of the cathode terminal 6 is interposed. As the winding of the laminated body 8 around the winding core 101 is advanced, as shown in FIGS. 13 (c) and 13 (d), the anode terminal 5 interposed a tab at a predetermined portion between the separator 4a and the anode foil 2. To do.

Here, the thickness of the anode foil 2 is, for example, about 70 [μm] to 120 [μm], and the thickness of the cathode foil 3 is, for example, about 20 [μm] to 50 [μm]. That is, the anode foil 2 is thicker than the cathode foil 3. In particular, when the anodic oxide film formed by the chemical conversion treatment becomes thick, the anodic foil 2 becomes hard and loses its flexibility.

Further, when the tab portion 5c of the anode terminal 5 crimp-connected to the anode foil 2 is wound around the winding core 101 together with the laminate 8, one end side (front side in the winding direction) of the tab portion 5c is first. After being in close contact with the surrounding members, the other end side (rear side in the winding direction) of the tab portion 5c is in close contact with the surrounding members. At this time, the tab portion 5c of the anode terminal 5 continues to be pressed by the surrounding separators 4a and 4b and the cathode foil 3, and the flexibility of the anode foil 2 is shown as shown by the arrow P in FIG. 13 (d). The side where the tab portion 5c last contacted the winding body 9 (the tab portion 5c) rather than the side where the tab portion 5c first contacted the winding body 9 (the front side in the winding direction of the tab portion 5c). The rear side in the winding direction) tends to rise. That is, the gap with respect to the surrounding members is larger on the other end side (rear side in the winding direction) than on one end side (front side in the winding direction) of the tab portion 5c. As a result, as shown in FIG. 14A, the surface of the tab portion 5c of the anode terminal 5 is wound so as not to be parallel to the side surfaces of the missing portions 52a and 52b (inclined state). .. As a result, the cross-sectional shape of the capacitor element may be distorted as shown by the dotted line in FIG. 14B.

If the cross-sectional shape of the capacitor element is distorted, the internal space of the outer case made of a cylindrical body is wasted, and the anode foil, cathode foil, and separator cannot be stored, which leads to a decrease in the capacity of the capacitor. .. For this reason, it is desired that a capacitor element having a cross-sectional shape close to a perfect circle, a manufacturing apparatus for manufacturing the capacitor element, and a manufacturing method appear.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a capacitor having a cross-sectional shape close to a perfect circle, a manufacturing apparatus for manufacturing the capacitor, and a manufacturing method.

In order to achieve the above object, the present invention includes the configurations described below.

(1) An anode terminal connected to the anode foil and a cathode terminal connected to the cathode foil are interposed in a columnar winding body formed by winding an anode foil and a cathode foil via a separator. With a capacitor element
A bottomed cylindrical outer case for accommodating the capacitor element and
With
The anode terminal has an anode tab portion fixed to the anode foil.
The cathode terminal has a cathode tab portion fixed to the cathode foil.
The anode tab portion and the cathode tab portion are arranged so as to be parallel to each other with the central axis of the winding body interposed therebetween.
The facing portion of the winding body facing the anode tab portion and arranged inside the anode tab portion is separated from the anode tab portion from the start end side to the end side of the anode foil in the anode tab portion. A capacitor characterized by being tilted like this.

According to (1), the facing portion of the winding body facing the anode tab portion and arranged inside the anode tab portion is from the anode tab portion from the start end side to the end side of the anode foil in the anode tab portion. Since it is inclined so as to be separated, the rear side of the anode tab portion in the winding direction (the end side of the anode foil) does not bulge outward in the manufacturing process of the anode tab, and the anode tab portion and the cathode tab portion are wound. They are arranged so as to be parallel to each other with the central axis of the anode in between. Therefore, the distortion of the cross-sectional shape of the capacitor element is reduced in the vicinity of the anode tab portion of the capacitor element, and the cross-sectional shape of the capacitor element can be made close to a perfect circle. This makes it possible to increase the storage efficiency of the capacitor element in the outer case and improve the capacity of the capacitor.

(2) A manufacturing apparatus for manufacturing the capacitor of (1).
A winding core having a winding portion around which the anode foil, the cathode foil, and the separator are wound around,
It is equipped with a rotary drive unit that rotates the winding core.
The winding portion is formed of a cylindrical body having a substantially oval cross section with both sides partially missing, and is a virtual reference surface that passes through the central axis of the winding portion and extends in the major axis direction of the winding portion. Formed asymmetrically with respect to
The inclination of one part of the winding body wound around one missing portion with respect to the reference plane is greater than the inclination of the other part of the winding body wound around the other missing portion with respect to the reference surface. Capacitor manufacturing equipment characterized by its large size.

According to (2), the winding portion around which the anode foil, the cathode foil and the separator are wound is partially missing on both sides of the central axis, and the winding body wound around one of the missing portions. The inclination of one portion with respect to the reference plane is greater than the inclination of the other portion of the winding body wound around the other missing portion. Therefore, in the manufacturing process of the capacitor element, the inclination of the anode tab portion is corrected according to the difference in the inclination angle between one portion and the other portion of the winding body, and the anode tab portion and the cathode tab portion are formed. They are arranged so as to be parallel to each other with the central axis of the winding body in between. As a result, the cross-sectional shape of the capacitor element 10 can be made close to a perfect circle, the storage efficiency of the capacitor element in the outer case can be improved, and the capacity of the capacitor can be improved.

(3) The above-mentioned action and effect are simplified by forming the thickness between both side portions of the winding portion of the manufacturing apparatus of (2) so that the end side is smaller than the start end side of the wound anode foil. It can be played with various configurations.
(4) A method for manufacturing a capacitor using the manufacturing apparatus of (2) or (3).
The rotation driving unit winds the winding core in a direction in which the anode foil, the cathode foil, and the separator are wound in a direction approaching the reference surface from a side far from the reference surface in one missing portion of the winding portion. Rotate to
A fixing portion of the anode tab portion in the anode foil is set so that the anode tab portion faces the anode foil, the cathode foil, and the separator wound around the one missing portion.
It is characterized in that the fixing portion of the cathode tab portion in the cathode foil is set so that the cathode tab portion faces the anode foil, the cathode foil and the separator wound around the other missing portion. How to make a capacitor.

According to (4), in the manufacturing process of the capacitor element, the anode tab portion and the cathode tab portion can be arranged so as to be parallel to each other with the central axis of the winding body interposed therebetween. As a result, the cross-sectional shape of the capacitor element can be made close to a perfect circle, the storage efficiency of the capacitor element in the outer case can be improved, and the capacity of the capacitor can be improved.

According to the present invention, the cross-sectional shape of the capacitor element can be made close to a perfect circle, the storage efficiency of the capacitor element in the outer case can be improved, and the capacity of the capacitor can be improved.

It is a front view which shows the appearance of the wound capacitor 1 in one Embodiment of this invention. It is an exploded view which shows the component part of the wound capacitor 1 in one Embodiment of this invention. It is explanatory drawing which shows the component part of the capacitor element 10 which concerns on one Embodiment of this invention. It is an external view of the anode terminal 5 and the cathode terminal 6. It is a figure which shows the structure of the winding core 50 which concerns on embodiment of the manufacturing apparatus of the capacitor element of this invention. It is an enlarged view of FIG. 5A. It is explanatory drawing which shows a part of the process of manufacturing a capacitor element 10. It is explanatory drawing which shows the arrangement of the anode terminal 5 and the cathode terminal 6 in a capacitor element 10. It is explanatory drawing about the method of obtaining the optimum inclination angle of the side surface 58. It is explanatory drawing which shows the modification of the winding core 50. It is explanatory drawing which shows a part of the manufacturing apparatus and manufacturing process of the conventional capacitor element. It is explanatory drawing which shows the schematic structure of the conventional winding core 101. It is explanatory drawing which shows the state of the part of the cathode terminal 6 and the anode terminal 5 when the laminated body 8 is wound around a winding core 101. It is explanatory drawing which shows the state which the laminated body 8 is wound around a winding core 101.

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

[Construction of wound capacitor]
FIG. 1 is a front view showing the appearance of the wound capacitor 1 according to the embodiment of the present invention, and FIG. 2 is an exploded view showing the components of the wound capacitor 1 according to the embodiment of the present invention.

As shown in FIG. 2, the wound capacitor 1 of the present embodiment includes a capacitor element 10, an outer case 21, and a sealing body 22.

The capacitor element 10 (see FIG. 2) is an element that stores and discharges electric charges by a storage action, and is housed inside the outer case 21.
The outer case 21 is a bottomed cylindrical body made of an aluminum material, and one end side in the axial direction is open and the other end side is closed.

The sealing body 22 is a columnar member having an insulating property that seals the opening of the outer case 21, and is made of, for example, rubber or synthetic resin.

Then, after impregnating the capacitor element 10 with the electrolyte, the capacitor element 10 is inserted into the outer case 21 and the opening of the outer case 21 is sealed by the sealing body 22. After that, the side surface of the opening of the outer case 21 is drawn and the inside of the outer case 21 is completely airtightly sealed by the sealing body 22, so that the wound capacitor 1 is configured as shown in FIG. ..

[Capacitor element configuration]
Next, the capacitor element 10 will be described using an electrolytic capacitor as an example. The present invention is particularly suitable for electrolytic capacitors using thick anode foils, for example, aluminum electrolytic capacitors in which the flexibility of the anode foil is reduced by forming an anodic oxide film by chemical conversion treatment.

FIG. 3 is an explanatory diagram showing components of the capacitor element 10. The same components as the components of the conventional capacitor element shown in FIG. 11 are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 3, the capacitor element 10 has an anode foil 2, a cathode foil 3, two separators 4, an anode terminal 5, a cathode terminal 6, and an element stop tape 7. ..

The anode foil 2 is a long strip-shaped electrode foil formed of a valve acting metal such as aluminum, and an oxide film serving as a dielectric is indispensably formed on the surface of the anode foil 2 as described later. Like the anode foil 2, the cathode foil 3 is a long strip-shaped electrode foil made of a valve acting metal such as aluminum. The anode foil 2 and the cathode foil 3 are rectangular, and for convenience of the following description, the width extending in the elongated direction is referred to as the horizontal width, and the width extending in the longitudinal direction is referred to as the vertical width in the rectangle. To do. The vertical widths of the anode foil 2 and the cathode foil 3 are the same, but the horizontal width of the cathode foil 3 is set to be slightly larger than that of the anode foil 2.

The surface of the anode foil 2 is roughened (etching pits are formed) by an etching process and an anodized film is formed by anodizing (chemical formation). Further, the cathode foil 3 is also made of aluminum or the like like the anode foil 2, and its surface is roughened (etching pits are formed) and a natural oxide film is formed.

The separator 4 has a rectangular strip shape, and a driving electrolyte and / or a solid electrolyte is held on both sides thereof. According to this embodiment, two separators 4a and 4b are used. The thickness of the separator 4 is, for example, about 30 [μm] to 90 [μm]. The vertical width of the separators 4a and 4b is set to be slightly longer than the vertical width of the anode foil 2 and the cathode foil 3, and the horizontal width of the separators 4a and 4b is set to be longer than the horizontal width of the cathode foil 3.

FIG. 4 is an external view of the anode terminal 5 and the cathode terminal 6. The anode terminal 5 is a conductive metal member that comes into contact with the anode foil 2. The anode terminal 5 includes a cylindrical portion 5a, a cylindrical anode lead rod 5b thinner than the cylindrical portion 5a extending coaxially with the cylindrical portion 5a from one end surface of the cylindrical portion 5a, and a cylindrical portion from the other end surface of the cylindrical portion 5a. It is composed of 5a and a flat plate-shaped tab portion 5c extending in the coaxial direction.

The cathode terminal 6 is composed of a cylindrical portion 6a, a cathode lead rod 6b, and a tab portion 6c. The cathode terminal 6 has the same shape as the anode terminal 5 except that the length of the cathode lead rod 6b is shorter than that of the anode lead rod 5b.

The element stop tape 7 has a rectangular strip shape and is made of a long film such as polypropylene or polyphenylene sulfide as a base material, and at least both ends in the long direction of one surface are adhesive surfaces. The other surface is a non-adhesive surface. The vertical width of the element stop tape 7 is equal to or less than the vertical width of the separator 4, and the horizontal width is set longer than the outer circumference of the winding body 9 (see FIG. 3).

[Capacitor element manufacturing equipment]
Next, an apparatus for manufacturing a capacitor element will be described.
5A and 5B are views showing the configuration of a winding core 50 according to an embodiment of the capacitor element manufacturing apparatus of the present invention. FIG. 5A is a front view (cross-sectional view), and FIG. 5B is a view. 5 (a) is a side view in the X direction, and FIG. 5 (c) is a side view in which FIG. 5 (a) is viewed in the Y direction. FIG. 6 is an enlarged view of FIG. 5 (a). The parts having the same configuration as the conventional winding core 101 shown in FIG. 12 or the parts having the same functions are designated by the same reference numerals, and detailed description thereof will be omitted.

The capacitor element manufacturing apparatus of the present invention uses the winding core 50 described below instead of the winding core 101 in the manufacturing apparatus 100 shown in FIG.

As shown in FIGS. 5A to 5C, the winding core 50 includes a base portion 51 and a winding portion 52, similarly to the winding core 101 shown in FIG.

The base portion 51 is formed in a columnar shape, and the winding portion 52 extends from one end of the base portion 51 in the central axial direction along the central axial direction.

As shown in FIG. 5 (a), the winding portion 52 is formed in a columnar shape having a substantially oval cross section, and as shown in FIGS. 5 (b) and 5 (c), from the end face of the winding portion 52. A slit 53 extending toward the base portion 51 is provided. As shown in FIG. 5B, the slit 53 extends from the tip end side of the winding portion 52 to the base portion 51 along the central axis of the base portion 51. Further, as shown in FIG. 5B, a taper 54 is formed on the end surface of the winding portion 52 so as to be inclined downward from the outer edge toward the slit 53 on the center side.

The winding core 101 according to the conventional manufacturing apparatus shown in FIG. 12A is symmetrical with respect to the reference plane A, whereas the winding core 50 according to the manufacturing apparatus of the present embodiment is shown in FIG. As described above, the plane is asymmetrical with respect to the reference plane A (a plane that passes through the central axis O and extends in a direction orthogonal to the forming direction of the slit 53). Specifically, in the winding core 50 according to the manufacturing apparatus of the present embodiment, the missing portion 52c is formed instead of the missing portion 52a, and the winding core according to the conventional manufacturing apparatus shown in FIG. 12A is shown. In 101, the missing portion 52a and the missing portion 52b are symmetrical, but in the winding core 50 according to the manufacturing apparatus of the present embodiment, the missing portion 52c and the missing portion 52b are left-right asymmetric.

As shown in FIG. 6, the side surface 56 of the winding portion 52 facing in the major axis direction is a circumferential surface extending from the side surface of the base portion 51, and the side surfaces 57 and 58 of the missing portions 52c and 52b are flat surfaces. Is. The side surface 57 is parallel to the reference surface A, and the side surface 58 is inclined by an angle θ with respect to the reference surface A (a plane parallel to the reference surface A) as shown in FIG. That is, as shown in FIG. 6, the winding portion 52 is asymmetric with respect to the reference plane A. The winding core 50 configured in this way is fixed to the rotation driving device 102 (see FIG. 11), and when the laminated body 8 (see FIG. 11) is wound, the arrow Q direction (winding direction) in FIG. 6 is used. ), That is, the end of the side surface 58 on the side closer to the reference surface A rotates in the direction toward the end on the side surface 58 on the side farther from the reference surface A. Therefore, the laminated body 8 (see FIG. 11) comes into contact with the end portion on the starting end side (the portion indicated by the arrow C1 in FIG. 6) far from the reference surface A on the side surface 58, and passes through the side surface 58 on the side surface 58. The end portion on the side closer to the reference plane A (the portion indicated by the arrow C2 in FIG. 6) comes into contact with each other.

[Assembly method of capacitor element]
Next, the method of assembling the capacitor element 10 is the same as that of the conventional technique described with reference to FIG. 11. First, the starting ends of the separator 4a, the cathode foil 3, the separator 4b, and the anode foil 2 are stacked in this order to form a laminated body. 8 is formed. The stacking order is not limited to this, and the cathode foil 3, the separator 4b, the anode foil 2, and the separator 4a may be used. As shown in FIG. 3, the separators 4a and 4b, the anode foil 2 and the cathode foil 3 constituting the laminated body 8 are set on the winding core 50 in order in a predetermined positional relationship, and the winding core 50 is rotated to laminate the layers. The body 8 is wound around the winding core 50 to form the winding body 9. The anode lead rod 5b and the cathode lead rod 6b project from one end surface of the winding body 9.

As shown in FIG. 2, the positions of the anode lead rod 5b and the cathode lead rod 6b are when the capacitor element 10 is inserted into the outer case 21 and the opening of the outer case 21 is sealed by the sealing body 22. , Is inserted into two through holes (not shown) formed in the sealing body 22.

Then, as shown in FIG. 7 (a), after the cathode foil 3 and the separator 4b are wound to the end, the element stop tape 7 is wound around the outer circumference of the winding body 9 as shown in FIG. 7 (b). The terminal portion of the element stop tape 7 is attached to a predetermined portion of the element stop tape 7 on the inner peripheral side. As described above, the capacitor element 10 is manufactured.

FIG. 8 is an explanatory diagram showing the arrangement of the anode terminal 5 and the cathode terminal 6 in the capacitor element 10. The tab portion 5c of the anode terminal 5 is crimp-connected to the anode foil 2, and the tab portion 6c of the cathode terminal 6 is crimp-connected to the cathode foil 3. The crimping connection position of the anode terminal 5 in the anode foil 2 is set so that the tab portion 5c is arranged on the side of the side surface 58 when the laminate 8 is wound around the winding core 50. The crimping connection position of the cathode terminal 6 in the cathode terminal 6 is set so that the tab portion 6c is arranged on the side of the side surface 57 when the laminate 8 is wound around the winding core 50.

When the laminated body 8 is wound around the winding core 50, the laminated body 8 is wound around the winding core 50, and in particular, the laminated body 8 is inclined to the side of the side surface 58 with respect to the reference surface A. 8 are stacked. Then, when the tab portion 5c of the anode terminal 5 reaches the side of the side surface 58, the rear side of the tab portion 5c in the winding direction tends to bulge outward, but the laminate 8 is inclined in accordance with the side surface 58. As a result, the inclination of one part of the winding body 9 wound around the one missing portion 52c (FIG. 6) with respect to the reference surface A is wound around the other missing portion 52b (FIG. 6). It is larger than the inclination of the other part of 9 with respect to the reference surface A. Therefore, the bulging tab portion 5c is corrected toward the gap portion pointed by the arrow P in FIG. 8 (the tab portion 5c is prevented from bulging outward on the rear side in the winding direction). That is, the thickness between both side portions of the winding core 50, that is, between the side surface 57 and the side surface 58 is smaller on the end side than the start end side of the wound anode foil 2, so that the thickness is inside the tab portion 5c. The anode foil 2 to be arranged can be inclined inward, and the tab portion 5c is arranged so as to be parallel to the tab portion 6c.

As described above, according to the capacitor element 10 manufactured by using the winding core 50, the tab portion 5c and the tab portion 6c are arranged so as to be parallel to each other with the central axis O of the cylindrical winding body 9 interposed therebetween. The facing portion 9a of the winding body 9 arranged inside the tab portion 5c, which faces the tab portion 5c, is separated from the tab portion 5c from the start end side to the end side of the anode foil 2 in the tab portion 5c. It is inclined to (Fig. 8).

[How to find the optimum angle]
FIG. 9 is an explanatory view of how to obtain the optimum inclination angle of the side surface 58.

9 (a) is an explanatory view showing the angle of each part when the laminated body is wound around the conventional winding core 101, and FIGS. 9 (b) and 9 (c) are photographs showing the cross-sectional shape of the capacitor element. Is.

In FIG. 9A, a is the angle of the tab portion 6c with respect to the reference plane A, and b is the inner circumference of the tab portion 6c side (cathode side) with respect to the horizontal plane B (the plane passing through the central axis O and orthogonal to the reference plane A). The angle of the foil surface, c is the angle of the inner peripheral foil surface on the tab portion 5c side (orthogonal side) with respect to the horizontal plane B, and d is the angle of the tab portion 5c with respect to the reference surface A. The optimum angle θ of the inclination angle of the side surface 58 of the winding core 50 can be obtained by the following equation using these angles.
θ = -a + bc + d

FIG. 9B shows a cross-sectional shape of a capacitor element manufactured by using an anode terminal 5 and a cathode terminal 6 having a tab thickness of 0.33 mm on a conventional winding core 101 having a major axis of 3.0 mm and a minor axis of 1.8 mm. It is a photograph to show. When the angles a to d were measured based on this photograph,
a = 0 °, b = 0 °, c = -4 °, d = 1 °
I was able to find the value. When the optimum angle θ was obtained based on these values,
θ = 5 °
I was able to find the value.

Therefore, when the winding core 50 having the optimum angle θ = 5 ° was created to create the capacitor element 10, the tab portion 5c and the tab portion 6c became substantially parallel, and the capacitor element 10 having a cross-sectional shape close to a perfect circle. Was able to be manufactured.

FIG. 9C shows a cross-sectional shape of a capacitor element manufactured by using an anode terminal 5 and a cathode terminal 6 having a tab thickness of 0.25 mm on a conventional winding core 101 having a major axis of 3.0 mm and a minor axis of 1.8 mm. It is a photograph to show. When the angles a to d were measured based on this photograph,
a = 0 °, b = 0 °, c = -1 °, d = 4 °
I was able to find the value. When the angle θ was calculated based on these values,
θ = 5 °
I was able to find the value.

Therefore, when the winding core 50 having an angle θ = 5 ° was created to create the capacitor element 10, the tab portion 5c and the tab portion 6c became substantially parallel, and the capacitor element 10 having a cross-sectional shape close to a perfect circle was formed. I was able to manufacture it. In this case, although the tab thickness is thinner than that shown in FIG. 9B, the tab strength for supporting the capacitor element 10 could still be secured.

According to the present embodiment configured in this way, the tab portion 5c can be set to an appropriate position and direction, distortion of the cross-sectional shape of the capacitor element 10 is reduced, and the cross-sectional shape of the capacitor element 10 is a perfect circle. It becomes possible to approach. As a result, the internal space of the outer case made of a cylindrical body can be efficiently used, so that the capacity of the capacitor can be improved.

[Modification example]
Although the embodiments of the present invention have been described above, the embodiments of the present invention are not limited to those described above. For example, in the above-described embodiment, the side surface of the anode terminal 5 on the winding core 50 on the tab portion 5c side is provided with an angle (angle θ1 in FIG. 10A) with respect to the reference surface A, but the present invention is limited to this. Instead, as shown in FIG. 10A, the side surface of the cathode terminal 6 on the winding core 50 on the tab portion 6c side may also have an angle θ2 with respect to the reference surface A. In this case, since the cathode foil 3 is thinner than the anode foil 2, the angle θ2 is set smaller than the angle θ1.

Further, in the above-described embodiment, the side surface 58 on the tab portion 5c side of the anode terminal 5 in the winding core 50 is an inclined surface inclined with respect to the reference surface A, but the surface is not limited to this and is shown in FIG. 10B. As described above, the shape may be a combination of a plane 581 substantially parallel to the reference plane A and a substantially plane 582 orthogonal to the plane 581. Even with this configuration, it can be replaced with an inclined surface that connects points C3 and C4 in a straight line. Further, the configuration instead of the inclined surface connecting the C3 point and the C4 point is not limited to the combination of the plane 581 and the plane 582, and may be composed of a curved surface connecting the C3 point and the C4 point, or a plurality of planes. That is, it is applicable as long as the laminated body 8 wound between the winding core 50 and the tab portion 5c of the anode terminal 5 is configured to have an angle with respect to the reference surface A.

Although the aluminum electrolytic capacitor has been described in the above-described embodiment, it can also be applied to a wound capacitor such as an electric double layer capacitor and a lithium ion capacitor as long as the inclination of the anode tab portion becomes a problem.

1 Winding capacitor 2 Anode foil 3 Cathode foil 4, 4a, 4b Separator 5 Anode terminal 5b Anode lead rod 5c Anode tab part 6 Cathode terminal 6b Cathode lead rod 6c Cathode tab part 7 Element stop tape 9 Winder 9a Winding Opposing part of the body 10 Condenser element 21 Exterior case 22 Sealing body

Claims (4)

A capacitor element formed by interposing an anode terminal connected to the anode foil and a cathode terminal connected to the cathode foil in a columnar winding body formed by winding the anode foil and the cathode foil via a separator. ,
A bottomed cylindrical outer case for accommodating the capacitor element and
With
The anode terminal has an anode tab portion fixed to the anode foil.
The cathode terminal has a cathode tab portion fixed to the cathode foil.
The anode tab portion and the cathode tab portion are arranged so as to be parallel to each other with the central axis of the winding body interposed therebetween.
The facing portion of the winding body facing the anode tab portion and arranged inside the anode tab portion is separated from the anode tab portion from the start end side to the end side of the anode foil in the anode tab portion. A capacitor characterized by being tilted like this. A manufacturing apparatus for manufacturing the capacitor according to claim 1.
A winding core having a winding portion around which the anode foil, the cathode foil, and the separator are wound around,
It is equipped with a rotary drive unit that rotates the winding core.
The winding portion is composed of a columnar body having a substantially oval cross section with both sides partially missing, and is a virtual reference surface that passes through the central axis of the winding portion and extends in the major axis direction of the winding portion. Formed asymmetrically with respect to
The inclination of one part of the winding body wound around one missing portion with respect to the reference plane is greater than the inclination of the other part of the winding body wound around the other missing portion with respect to the reference surface. Capacitor manufacturing equipment characterized by its large size. The capacitor manufacturing apparatus according to claim 2, wherein the thickness between both side portions of the wound portion is smaller on the end side than on the start end side of the wound anode foil. A method for manufacturing a capacitor using the manufacturing apparatus according to claim 2 or 3.
The rotation driving unit winds the winding core in a direction in which the anode foil, the cathode foil, and the separator are wound in a direction approaching the reference surface from a side far from the reference surface in one missing portion of the winding portion. Rotate to
A fixing portion of the anode tab portion in the anode foil is set so that the anode tab portion faces the anode foil, the cathode foil, and the separator wound around the one missing portion.
It is characterized in that the fixing portion of the cathode tab portion in the cathode foil is set so that the cathode tab portion faces the anode foil, the cathode foil and the separator wound around the other missing portion. How to make a capacitor.