JP7208871B2 - CAPACITOR, CAPACITOR MANUFACTURING APPARATUS, AND CAPACITOR MANUFACTURING METHOD - Google Patents

Description

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

As an element of a wound capacitor, 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, etc. of the rotation driving device 102 .

In manufacturing the capacitor element, first, the anode terminal 5 and the cathode terminal 6 are crimped to a predetermined position on the anode foil 2 and to a predetermined position on the cathode foil 3, respectively. 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 wound 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, and the cathode terminal 6 is interposed between the cathode foil 3 and the separator 4a. A lead rod of the cathode terminal 6 extends. Then, after winding an element fixing tape (not shown) around the outer circumference of the wound body 9 , the wound body 9 is pulled out from the winding core 101 . Thereby, a capacitor element is manufactured.

After impregnating the capacitor element manufactured in this manner with an electrolyte, the capacitor element is inserted into an exterior case, and the opening of the exterior case is completely airtightly sealed with a sealing member 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 front view (cross section) of the winding core 101, and FIG. ) is viewed in the X direction, and FIG. 12C is a side view of FIG. 12A 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 cylindrical shape, and the winding portion 52 extends from one end portion of the base portion 51 in the central axis direction along the central axis direction.

The winding portion 52 has a substantially oval cross-section by forming missing portions 52a and 52b in portions of the side surfaces of the cylindrical body coaxial with the base portion 51, which face each other in the radial direction. there is In the winding portion 52, the side surfaces of the missing portions 52a and 52b are flat and parallel to each other. An imaginary plane (hereinafter referred to as a reference plane A) passing through the central axis of the base portion 51 and extending in the longitudinal direction of the winding portion 52 and parallel to the side surfaces of the missing portions 52a and 52b divides the winding portion 52 into two. Divide equally. Moreover, in the winding portion 52 , the side surface of the portion that is not missing is a circumferential surface that is flush with the circumferential surface of the base portion 51 . The winding portion 52 is rotationally symmetrical about the central axis of the base portion 51 and bilaterally symmetrical about the reference plane A. As shown in FIG.

Moreover, 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. This slit 53 extends along the central axis direction of the base portion 51 . Further, as shown in FIGS. 12A and 12B, the end surface of the wound portion 52 is formed with a taper 54 that slopes downward from the outer edge toward the slit 53 .

When manufacturing the capacitor element, as shown in FIG. 12A, the anode terminal 5 is arranged so as to face the side surfaces of the missing portions 52a and 52b of the winding portion 52 with an electrode foil and a separator (not shown) interposed therebetween. The tab portion 5c and the tab portion 6c of the cathode terminal 6 are positioned. As a result, even if the outer peripheral sides of the tabs of the anode terminal 5 and the cathode terminal 6 swell each time the laminated body 8 is wound around the winding core 101, the missing portions 52a and 52b are prevented from protruding more than necessary.

JP 2017-188541 A

However, as shown in FIG. 12(a), when the element is wound using a winding core 101 having a bilaterally symmetrical shape with respect to the reference plane A, depending on the state of the electrode foil, the tab portion 5c of the anode terminal 5 may be bent. A problem arises in that the rear side in the winding direction swells with respect to the element diameter, and the element becomes out of a perfect circle.

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

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 core 101 of the manufacturing apparatus, and the core 101 is rotated as shown in FIG. 13(a). The laminate 8 is wound around the winding core 101 by using the As the laminate 8 is wound around the winding core 101, as shown in FIG. As the laminate 8 is wound around the winding core 101, the tab of the anode terminal 5 intervenes at a predetermined position between the separator 4a and the anode foil 2, as shown in FIGS. 13(c) and 13(d). 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 anodized film formed by the chemical conversion treatment becomes thick, the anode foil 2 becomes hard and loses its flexibility.

Further, when the tab portion 5c of the anode terminal 5 crimped-connected to the anode foil 2 is wound around the winding core 101 together with the laminate 8, one end side (the front side in the winding direction) of the tab portion 5c is the first. After the tab portion 5c is brought into close proximity and contact with the surrounding members, the other end side (rear side in the winding direction) of the tab portion 5c comes into close proximity and 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 increased as indicated by the arrow P in FIG. 13(d). As a result, the side where the tab portion 5c contacts the wound body 9 last (the front side of the tab portion 5c in the winding direction) is closer to the side where the tab portion 5c first contacts the wound body 9 (the front side of the winding direction of the tab portion 5c). winding direction rear side) becomes easy to float. 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 the one end side (front side in the winding direction) of the tab portion 5c. As a result, as shown in FIG. 14(a), the surface of the tab portion 5c of the anode terminal 5 is wound in a state not 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 indicated by the dotted line in FIG. 14(b).

If the cross-sectional shape of the capacitor element is distorted, the internal space of the external case made of a cylindrical body is wasted, and the anode foil, cathode foil, and separator cannot be accommodated, leading to a decrease in the capacity of the capacitor. . Therefore, it is desired to develop a capacitor element having a cross-sectional shape close to a perfect circle, and a manufacturing apparatus and manufacturing method for manufacturing the capacitor element.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a capacitor having a nearly circular cross section, and a manufacturing apparatus and method for manufacturing the capacitor.

In order to achieve the above object, the present invention has 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 cylindrical wound body formed by winding an anode foil and a cathode foil with a separator interposed therebetween. a capacitor element;
a bottomed cylindrical exterior case that houses the capacitor element;
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 across the central axis of the wound body,
The facing portion of the wound body, which faces the anode tab portion and is arranged inside the anode tab portion, separates from the anode tab portion toward the terminal end side from the starting end side of the anode foil in the anode tab portion. A capacitor characterized in that it is slanted as

According to (1), the facing portion of the wound body, which faces the anode tab portion and is arranged inside the anode tab portion, extends from the anode tab portion toward the terminal end side of the anode foil in the anode tab portion. Since it is slanted away, the rear side of the anode tab portion in the winding direction (end side of the anode foil) does not bulge outward during the manufacturing process of the capacitor element. They are arranged so as to be parallel to each other across the central axis of the rotating body. 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 approximated to a perfect circle. As a result, it is possible to increase the storage efficiency of the capacitor element in the exterior 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;
and a rotation drive unit that rotates the winding core,
The winding portion is formed of a cylindrical body having a substantially oval cross section with both side portions missing, and a virtual reference plane passing through the central axis of the winding portion and extending in the major axis direction of the winding portion. formed asymmetrically with respect to
The inclination of one portion of the wound body wound around one of the missing portions with respect to the reference plane is greater than the inclination of the other portion of the wound body wound around the other missing portion with respect to the reference plane. A capacitor manufacturing apparatus characterized by being large.

According to (2), the winding part 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 is wound around one of the missing parts. The inclination of one portion with respect to the reference plane is greater than the inclination of the other portion of the wound 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 inclination angle between one portion and the other portion of the wound body, and the anode tab portion and the cathode tab portion are They are arranged so as to be parallel to each other across the central axis of the wound body. As a result, the cross-sectional shape of the capacitor element 10 can be approximated to a perfect circle, and the storage efficiency of the capacitor element in the exterior case can be increased, thereby improving the capacity of the capacitor.

(3) By forming the thickness between both sides of the winding portion of the manufacturing apparatus of (2) so that the end side is smaller than the starting end side of the anode foil to be wound, the above effects can be easily achieved. It can be played in a simple configuration.
(4) A method of manufacturing a capacitor using the manufacturing apparatus of (2) or (3),
The rotation drive unit rotates the core in a direction in which the anode foil, the cathode foil, and the separator are wound in a direction closer to the reference plane from a side farther from the reference plane at one missing portion of the winding section. and rotate to
setting the fixing portion of the anode tab portion of the anode foil so that the anode tab portion faces the anode foil, the cathode foil, and the separator wound around the one missing portion;
The fixing portion of the cathode tab portion of 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. A method of manufacturing 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 across the central axis of the wound body. As a result, the cross-sectional shape of the capacitor element can be approximated to a perfect circle, and the storage efficiency of the capacitor element in the exterior case can be increased, thereby improving the capacitance of the capacitor.

According to the present invention, it is possible to make the cross-sectional shape of the capacitor element closer to a perfect circle, improve the efficiency of accommodating the capacitor element in the exterior case, and improve the capacity of the capacitor.

1 is a front view showing the appearance of a wound capacitor 1 according to an embodiment of the present invention; FIG. 1 is an exploded view showing components of a wound capacitor 1 according to an embodiment of the present invention; FIG. FIG. 2 is an explanatory diagram showing constituent parts of a capacitor element 10 according to one embodiment of the present invention; 4 is an external view of an anode terminal 5 and a cathode terminal 6. FIG. 1 is a diagram showing the configuration of a winding core 50 according to an embodiment of a capacitor element manufacturing apparatus of the present invention; FIG. It is an enlarged view of Fig.5 (a). FIG. 4 is an explanatory diagram showing a part of the process of manufacturing the capacitor element 10; 4 is an explanatory diagram showing the arrangement of anode terminals 5 and cathode terminals 6 in capacitor element 10. FIG. FIG. 5 is an explanatory diagram of how to obtain an optimum tilt angle of a side surface 58; FIG. 5 is an explanatory diagram showing a modification of the winding core 50; It is explanatory drawing which shows the manufacturing apparatus of the conventional capacitor element, and a part of manufacturing process. FIG. 3 is an explanatory diagram showing a schematic configuration of a conventional winding core 101; 4 is an explanatory view showing the state of the cathode terminal 6 and the anode terminal 5 when winding the laminated body 8 around the core 101. FIG. FIG. 3 is an explanatory diagram showing a state in which a laminate 8 is wound around a winding core 101;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

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

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

Capacitor element 10 (see FIG. 2) is an element that stores and releases electric charge by means of power storage, and is housed inside exterior case 21 .
The exterior case 21 is a bottomed cylindrical body made of an aluminum material, and is open at one end in the axial direction and closed at the other end.

The sealing member 22 is a cylindrical member having insulating properties that seals the opening of the exterior case 21, and is made of, for example, rubber or synthetic resin.

After the capacitor element 10 is impregnated with the electrolyte, the capacitor element 10 is inserted into the exterior case 21 and the opening of the exterior case 21 is sealed with the sealing member 22 . After that, the side surface of the opening of the exterior case 21 is subjected to a drawing process, and the interior of the exterior case 21 is completely airtightly sealed with a sealing member 22, thereby forming the wound capacitor 1 as shown in FIG. .

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

FIG. 3 is an explanatory diagram showing components of the capacitor element 10. As shown in FIG. Parts that are the same as those of the conventional capacitor element shown in FIG.

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 fixing tape 7. .

The anode foil 2 is a long belt-like electrode foil made of a valve metal such as aluminum, and as will be described later, an oxide film that serves as a dielectric is essentially formed on the surface. The cathode foil 3 is a long belt-like electrode foil made of a valve metal such as aluminum, like the anode foil 2 . The anode foil 2 and the cathode foil 3 are rectangular, and for the convenience of the following description, the width extending in the longitudinal direction of the rectangle will be referred to as the lateral width, and the width extending in the direction perpendicular to the longitudinal direction will be referred to as the longitudinal width. do. The vertical width of the anode foil 2 and the cathode foil 3 are the same, but the width of the cathode foil 3 is set slightly larger than that of the anode foil 2 .

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

The separator 4 is in the form of a rectangular band, and both sides of the separator 4 hold driving electrolyte and/or solid electrolyte. According to this embodiment, two separators 4a, 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 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 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. FIG. Anode terminal 5 is a conductive metal member that contacts anode foil 2 . The anode terminal 5 includes a cylindrical portion 5a, a cylindrical anode lead rod 5b that is thinner than the cylindrical portion 5a and extends coaxially with the cylindrical portion 5a from one end surface of the cylindrical portion 5a, and a cylindrical portion extending from the other end surface of the cylindrical portion 5a. 5a and a flat 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-fixing tape 7 is in the form of a rectangular belt, and is made of a long film such as polypropylene or polyphenylene sulfide as a base material, and at least both longitudinal ends of one surface thereof are adhesive surfaces. The other surface is a non-adhesive surface. The vertical width of the element fixing 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 periphery of the wound body 9 (see FIG. 3).

[Capacitor element manufacturing equipment]
Next, an apparatus for manufacturing a capacitor element will be described.
5A and 5B are diagrams showing the configuration of a winding core 50 according to an embodiment of the apparatus for manufacturing a capacitor element of the present invention, FIG. 5A is a side view of FIG. 5A viewed in the X direction, and FIG. 5C is a side view of FIG. 5A viewed in the Y direction. FIG. 6 is an enlarged view of FIG. 5(a). It should be noted that the same reference numerals are given to the same parts or parts having the same functions as those of the conventional winding core 101 shown in FIG. 12, and detailed description thereof will be omitted.

The capacitor element manufacturing apparatus of the present invention uses a 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 core 50 includes a base portion 51 and a winding portion 52, like the core 101 shown in FIG.

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

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

The core 101 according to the conventional manufacturing apparatus shown in FIG. 12A is bilaterally symmetrical with respect to the reference plane A. , it is asymmetrical with respect to the reference plane A (a plane passing through the central axis O and extending in a direction perpendicular to the direction in which the slits 53 are formed). Specifically, in the winding core 50 according to the manufacturing apparatus of the present embodiment, a missing portion 52c is formed instead of the missing portion 52a. 101, the missing portion 52a and the missing portion 52b are bilaterally symmetrical, but in the core 50 according to the manufacturing apparatus of the present embodiment, the missing portion 52c and the missing portion 52b are bilaterally asymmetrical.

As shown in FIG. 6, a side surface 56 of the winding portion 52 facing in the major axis direction of the substantially oval shape is a circumferential surface extending from the side surface of the base portion 51, and 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 plane A, and the side surface 58 is inclined at an angle θ with respect to (a plane parallel to) the reference plane A, as shown in FIG. That is, the winding portion 52 is asymmetrical with respect to the reference plane A as shown in FIG. The winding core 50 configured in this way is fixed to the rotary drive device 102 (see FIG. 11), and when winding the laminated body 8 (see FIG. 11), the direction of the arrow Q in FIG. ), that is, the end of the side surface 58 closer to the reference plane A rotates in the direction toward the end of the side surface 58 farther from the reference plane A. For this reason, the stack 8 (see FIG. 11) first contacts the end of the side surface 58 on the starting end side far from the reference surface A (the portion indicated by the arrow C1 in FIG. 6), and passes through the side surface 58 to The end nearer to the reference plane A (the portion indicated by the arrow C2 in FIG. 6) comes into contact.

[Method for assembling capacitor element]
Next, the method of assembling the capacitor element 10 is the same as that of the prior art described with reference to FIG. 8 is formed. Note that the stacking order is not limited to this, and may be cathode foil 3, separator 4b, anode foil 2, and separator 4a. The separators 4a and 4b, the anode foil 2 and the cathode foil 3, which constitute the laminate 8, are sequentially set on the winding core 50 in a predetermined positional relationship, and the winding core 50 is rotated to form the laminate as shown in FIG. The body 8 is wound around the winding core 50 to form the wound body 9 . An anode lead rod 5b and a cathode lead rod 6b protrude from one end surface of the wound body 9. As shown in FIG.

The positions of the anode lead rod 5b and the cathode lead rod 6b are determined when the capacitor element 10 is inserted into the exterior case 21 and the opening of the exterior case 21 is sealed with the sealing member 22, as shown in FIG. , are inserted into two through holes (not shown) formed in the sealing member 22 .

Then, as shown in FIG. 7(a), after the cathode foil 3 and the separator 4b are wound to the end, the element fixing tape 7 is wound around the outer periphery of the wound body 9, as shown in FIG. 7(b). Then, the end portion of the element fixing tape 7 is adhered to a predetermined portion of the element fixing tape 7 on the inner peripheral side. Capacitor element 10 is manufactured in the manner described above.

FIG. 8 is an explanatory diagram showing the arrangement of the anode terminal 5 and the cathode terminal 6 in the capacitor element 10. As shown in FIG. The tab portion 5c of the anode terminal 5 is connected to the anode foil 2 by caulking, and the tab portion 6c of the cathode terminal 6 is connected to the cathode foil 3 by caulking. The caulking connection position of the anode terminal 5 on the anode foil 2 is set so that the tab portion 5c is arranged on the side of the side surface 58 when the laminated body 8 is wound around the winding core 50 . The caulking 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 laminated body 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 with respect to the reference plane A on the side of the side surface 58. 8 are superimposed. Then, when the tab portion 5 c of the anode terminal 5 reaches the side of the side surface 58 , the rear side of the tab portion 5 c in the winding direction tries to bulge outward, but the laminated body 8 is inclined to match the side surface 58 . As a result, the inclination of one portion of the wound body 9 wound around one missing portion 52c (FIG. 6) with respect to the reference plane A becomes 9 is larger than the inclination with respect to the reference plane A of other portions. Therefore, the bulging tab portion 5c is corrected toward the gap indicated by the arrow P in FIG. 8 (the bulging of the tab portion 5c rearward in the winding direction is prevented). That is, the thickness between both sides of the winding core 50, that is, between the side surfaces 57 and 58, is smaller on the terminal side than on the starting side of the wound anode foil 2. The arranged anode foil 2 is allowed to incline inward, and the tab portion 5c and the tab portion 6c are arranged so as to be parallel to each other.

Thus, according to the capacitor element 10 manufactured using the winding core 50, the tab portions 5c and 6c are arranged so as to be parallel to each other with the central axis O of the cylindrical wound body 9 interposed therebetween. A facing portion 9a of the wound body 9 arranged inside the tab portion 5c, which faces the tab portion 5c, is arranged so as to separate from the tab portion 5c toward the terminal end side from the starting end side of the anode foil 2 in the tab portion 5c. (Fig. 8).

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

FIG. 9(a) is an explanatory view showing the angles of each part when the laminate 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 (a plane passing through the central axis O and perpendicular 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 (anode side) with respect to the horizontal plane B, and d is the angle of the tab portion 5c with respect to the reference plane A, respectively. The optimum angle θ of the inclination angle of the side surface 58 of the winding core 50 can be obtained by the following formula using these angles.
θ=-a+b-c+d

FIG. 9(b) shows the cross-sectional shape of a capacitor element manufactured by using a conventional winding core 101 with a major diameter of 3.0 mm and a minor diameter of 1.8 mm and an anode terminal 5 and a cathode terminal 6 with a tab thickness of 0.33 mm. It is a photograph to show. Based on this photograph, when the angles a to d were measured,
a=0°, b=0°, c=-4°, d=1°
value could be obtained. Based on these values, the optimum angle θ was found,
θ=5°
value could be obtained.

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

FIG. 9(c) shows the cross-sectional shape of a capacitor element manufactured by using a conventional winding core 101 with a major diameter of 3.0 mm and a minor diameter of 1.8 mm and an anode terminal 5 and a cathode terminal 6 with a tab thickness of 0.25 mm. It is a photograph to show. Based on this photograph, when the angles a to d were measured,
a=0°, b=0°, c=-1°, d=4°
value could be obtained. Based on these values, the angle θ was calculated as
θ=5°
value could be obtained.

Therefore, when the winding core 50 having an angle θ of 5° was produced and the capacitor element 10 was produced, the tab portions 5c and 6c became substantially parallel, and the cross-sectional shape of the capacitor element 10 was close to a perfect circle. could be manufactured. In this case, although the thickness of the tab was thinner than the case shown in FIG.

According to this embodiment configured as described above, it is possible to set the tab portion 5c in an appropriate position and direction, reduce the distortion of the cross-sectional shape of the capacitor element 10, and make the cross-sectional shape of the capacitor element 10 a perfect circle. can be brought closer to As a result, it is possible to efficiently use the internal space of the exterior case made of a cylindrical body, so that it is possible to improve the capacitance of the capacitor.

[Modification]
As mentioned above, although embodiment of this invention was described, embodiment of this invention is not restricted to what was mentioned above. For example, in the above-described embodiment, the side surface of the anode terminal 5 on the tab portion 5c side of the winding core 50 is angled with respect to the reference plane A (angle θ1 in FIG. 10A), but this is not the only option. First, as shown in FIG. 10A, the side surface of the winding core 50 on the side of the tab portion 6c of the cathode terminal 6 may also be formed at an angle θ2 with respect to the reference plane A. As shown in FIG. 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.

Furthermore, in the above-described embodiment, the side surface 58 of the core 50 on the side of the tab portion 5c of the anode terminal 5 is an inclined surface that is inclined with respect to the reference plane A. , 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 is possible to substitute an inclined surface that linearly connects points C3 and C4. Further, the structure that replaces the inclined surface connecting the points C3 and C4 is not limited to the combination of the plane 581 and the plane 582, and may be composed of a curved surface connecting the points C3 and C4, or a plurality of planes. That is, any configuration in which the laminated body 8 wound between the core 50 and the tab portion 5c of the anode terminal 5 is angled with respect to the reference plane A is applicable.

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

1 Wound Capacitor 2 Anode Foil 3 Cathode Foil 4, 4a, 4b Separator 5 Anode Terminal 5b Anode Lead Rod 5c Anode Tab Portion 6 Cathode Terminal 6b Cathode Lead Rod 6c Cathode Tab Portion 7 Element Fixing Tape 9 Winding Body 9a Winding Body facing part 10 Capacitor element 21 Exterior case 22 Sealing body

Claims (4)

a capacitor element having an anode terminal connected to the anode foil and a cathode terminal connected to the cathode foil interposed in a cylindrical wound body formed by winding an anode foil and a cathode foil with a separator interposed therebetween; ,
a bottomed cylindrical exterior case that houses the capacitor element;
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 across the central axis of the wound body,
The facing portion of the wound body, which faces the anode tab portion and is arranged inside the anode tab portion, separates from the anode tab portion toward the terminal end side from the starting end side of the anode foil in the anode tab portion. A capacitor characterized in that it is slanted as 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;
and a rotation drive unit that rotates the winding core,
The winding portion is composed of a columnar body having a substantially oval cross section with both side portions missing, and a virtual reference plane passing through the central axis of the winding portion and extending in the major axis direction of the winding portion. formed asymmetrically with respect to
The inclination of one portion of the wound body wound around one of the missing portions with respect to the reference plane is greater than the inclination of the other portion of the wound body wound around the other missing portion with respect to the reference plane. A capacitor manufacturing apparatus characterized by being large. 3. The apparatus for manufacturing a capacitor according to claim 2, wherein the thickness between both sides of the wound portion is smaller on the terminal side than on the starting side of the anode foil to be wound. A capacitor manufacturing method using the manufacturing apparatus according to claim 2 or 3,
The rotation drive unit rotates the core in a direction in which the anode foil, the cathode foil, and the separator are wound in a direction closer to the reference plane from a side farther from the reference plane at one missing portion of the winding section. and rotate to
setting the fixed portion of the anode tab portion of the anode foil so that the anode tab portion faces the anode foil, the cathode foil, and the separator wound around the one missing portion;
The fixing portion of the cathode tab portion of 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. A method of manufacturing a capacitor.

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