JP4498010B2 - Method for manufacturing cylindrical wound electrode body - Google Patents

Description

  The present invention relates to a manufacturing method and a manufacturing apparatus for a cylindrical wound electrode body for a battery in which a strip-like positive electrode plate and a negative electrode plate are wound in a spiral shape with a separator interposed therebetween.

  Various proposals have been made as a method for manufacturing a cylindrical wound electrode body of a battery, and general ones among them are disclosed in Patent Documents 1 and 2 and the like. A manufacturing method of this type of conventional cylindrical wound electrode body will be described with reference to FIGS.

A pair of core members 51 and 52 having a semicircular cross-sectional shape is fixed to a pair of cores 50 with a separator 53 made of a strip insulator interposed therebetween, and tension is applied so that the separator 53 does not become loose. The winding core 50 is rotated in the applied state, and the separator 53 is wound around the outer periphery of the winding core 50. Then, the positive electrode plate 54 and the negative electrode plate 55 are laminated in a state of being insulated in a predetermined positional relationship via the separator 53. Then, by rotating the winding core 50, a spiral electrode body including the positive electrode plate 54, the separator 53, and the negative electrode plate 55 is formed. Then, the cylindrical and spiral electrode body (cylindrical saddle-shaped rotating electrode body) was manufactured by removing the core 50 from the electrode body.
Japanese Patent Publication No. 4-37549 JP-A-8-315830

  However, in the conventional method of manufacturing a cylindrical wound electrode body, a separator 53 is sandwiched between a set of cores 50 each including two core members 51 and 52 having a semicircular cross-sectional shape. When the core 50 is fixed and rotated, the separator 53 is preliminarily tensioned so as not to loosen the separator 53. Therefore, the semicircular core members 51 and 52 are respectively applied to the semicircular core members 51 and 52 at the beginning of winding. The forces in the opposite directions are applied and they are displaced in the opposite directions as indicated by the dotted arrows in FIG. Therefore, the cross-sectional shape inside the formed electrode body becomes a distorted elliptical shape as shown in FIG. 10B (in FIG. The deviation direction of the core 50 was the maximum diameter of the electrode body. As a result, when the electrode body is inserted into the cylindrical outer container, the outer peripheral portion showing the maximum diameter of the electrode body interferes with the edge of the outer container, and the outer peripheral portion of the electrode body is damaged. It was.

  Further, in order to reduce poor insertion into the cylindrical outer container, the total length of the positive electrode plate 54 and the negative electrode plate 55 is shortened, or the thickness of the positive electrode plate 54 and the negative electrode plate 55 is reduced. Although the outer diameter has been reduced, in this case, there has been a problem that it is difficult to increase the capacity of the battery.

  The present invention solves the above-described conventional problems, and eliminates the adverse effects caused by the deviation of the core that occurs at the beginning of winding, and provides a manufacturing method and manufacturing apparatus that can form an accurate cylindrical electrode body with high yield. The purpose is to provide.

In order to achieve the above object, a method of manufacturing a cylindrical wound electrode body according to the present invention includes a positive electrode plate and a negative electrode plate each having a strip shape and a separator separating them in a spiral state using a winding core. A cylindrical wound electrode body manufacturing method for manufacturing a cylindrical wound electrode body by winding it into a cylindrical shape, wherein the tip portion is provided with an inclined surface that is inclined closer to the outer peripheral surface, and has a convex shape A step of fixing the convex core member formed in the concave shape and the concave core member formed in a concave shape to the support portion, and a step of retracting the convex core member relative to the concave core member in the support portion A step of pressing the separator against the concave core member, and by advancing the convex core member and scooping up the separator on the inclined surface, the concave core member and the convex core member the concavely core portion across the front Symbol separator between the And a step of bringing fits the convex core member with each other, the winding core by a predetermined angle, a step of along each separator to the outer peripheral surface of the concave core member and the convex core member, said concave winding In a state where tension is applied to the separator so that the core member and the convex core member are fitted to each other, a positive electrode plate and a negative electrode plate are stacked on the separator, and the core is rotated to rotate around the core. And a step of drawing the core in an axial direction from an electrode body formed by winding into a cylindrical shape .

  In this manufacturing method and manufacturing apparatus, when a separator is wound around a core composed of a plurality of core members, the core members are fitted to each other with the separator interposed therebetween. In this way, since the core is configured so that the core members are fitted and integrated with each other, the core is simply formed by two core members having a semicircular cross-sectional shape as in the past. The rigidity of the core itself is increased as compared with the case of forming. And the uneven | corrugated shaped part of a some core member fits mutually, and the shift | offset | difference between several core members does not generate | occur | produce. Therefore, the positive electrode plate, the separator, and the negative electrode plate can be laminated well without deteriorating the deviation of the core that has occurred at the beginning of winding of the separator, that is, the roundness of the core as in the past. A good cylindrical wound electrode body can be manufactured.

  As described above, according to the manufacturing method and the manufacturing apparatus of the cylindrical wound electrode body of the present invention, it is possible to form an accurate cylindrical wound electrode body with high yield, and the cylindrical exterior Insertion failure into the container can be reduced. Further, if the accuracy of the outer shape of the wound electrode body is improved, the length and thickness of the positive electrode plate and the negative electrode plate can be increased, and the capacity of the battery can be increased.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1, FIG. 2 (a), (b) shows the structure of the core provided in the manufacturing apparatus while using it for the manufacturing method of the cylindrical winding type electrode body which concerns on embodiment of this invention. .

  The core 1 is composed of a concave core member 2 and a convex core member 3 which are divided into the following split pin types. The concave core member 2 is formed by deleting 90 degrees of the cross-sectional shape from the axial center O of the cylinder into a V-groove shape, and the cross-section is a cross-sectional shape with a large opening angle of about 270 degrees centering on the axial core O. The shape is extended to. On the other hand, the convex core member 3 has an opening angle of about 90 degrees remaining about the axis O as a center, and the convex portion 3b of the V-shaped groove portion 2a of the concave core member 2 is provided. Is a convex shape that fits with each other, and the outer surface has an arc shape and is extended in the axial direction. And it is comprised so that it may become a substantially cylindrical shape by the convex core member 3 fitting in the V-groove shape part 2a of the concave core member 2. FIG. As shown in FIG. 3 and the like, an inclined surface 3a is formed at the distal end portion of the convex core member 3 so as to be inclined closer to the outer peripheral surface from the axial core portion closer to the proximal end portion toward the distal end.

  The core 1 composed of the concave core member 2 and the convex core member 3 is detachably attached to a winding device (not shown) that performs a winding operation described later. The concave core member 2 is fixed to a support portion 4 provided in the winding device with a screw or the like, and is also provided in a retractable portion 5 that is movable along the direction of the axis O in the support portion 4. The proximal end portion of the convex core member 3 is fixed with a screw or the like, whereby the convex core member 3 is moved from the retracted posture shown in FIG. It is arranged to be relatively movable along the axial direction up to the protruding forward posture shown by 4 (b). Further, the concave core member 2 and the convex core member 3 are integrally supported by the winding device so as to be movable in the axial direction and rotatable about the axial core O.

Next, the process of winding the separator 10 around the core 1 will be described with reference to FIGS.
Here, the separator 10 is composed of a strip-shaped insulator that electrically separates the positive electrode plate 12 and the negative electrode plate 13 each having a strip shape.

  First, as shown in FIGS. 5 (a) and 5 (b), the convex core member 3 is retracted into the support portion 4 together with the retracting / retracting portion 5, and no tension is applied to the separator 10. Then, both end portions of the V-shaped groove portion 2 a in the concave core member 2 are pressed against the separator 10 so that the separator 10 covers the V-shaped groove portion 2 a of the concave core member 2.

  Next, as shown in FIGS. 5C to 5F, the protruding and retracting portion 5 is advanced and the convex core member 3 attached to the protruding and retracting portion 5 is gradually protruded from the support portion 4. As a result, one end in the width direction of the separator 10 is scooped up by the inclined surface 3 a formed at the tip of the convex core member 3. Then, as shown in FIGS. 6A to 6D, the convex core member 3 is moved in the axial direction until the separator 10 is completely transferred from the inclined surface 3 a of the convex core member 3 to the convex portion 3 b. Further, the separator 10 is finally sandwiched between the V-groove shaped portion 2 a of the concave core member 2 and the convex portion 3 b of the convex core member 3.

  Next, with the tension applied to such an extent that the separator 10 does not loosen, the core 1 (concave core member 2 and convex core member 3) is placed as shown in FIGS. 6 (e) and 6 (f). The separator 10 is rotated by a predetermined angle, for example, 180 degrees, and the separators 10 are placed along the outer peripheral surfaces of the concave core member 2 and the convex core member 3, respectively, and further along the tangential direction of the outer peripheral surface of the core 1. Apply tension to pull.

  Thereafter, as shown in FIG. 7, the separator 10 is laminated with the positive electrode plate 12 and the negative electrode plate 13 while continuously applying tension to the separator 10 along the tangential direction of the outer peripheral surface of the core 1. The core 1 is rotated and the separator 10, the positive electrode plate 12, and the negative electrode plate 13 are wound around the core 1. Although two separators 10 are used, after one separator 10 is wound around the core 1 to the state shown in FIGS. 6E and 6F, another separator 10 is used at this time (see FIG. 6). 7 and in the state shown in FIGS. 6 (e) and 6 (f)), or two separators 10 from the beginning (stage shown in FIGS. 5 (a) and 5 (b)) are wound around the core 1. You may be wound around.

  Here, in the state shown in FIG. 7, the convex core member 3 to which tension is applied via the separator 10 fits with the convex portion 3 b hooked on the V-groove shape portion 2 a of the concave core member 2. In this structure, no further deflection occurs. Further, the concave core member 2 to which the tension of the separator 10 is applied in the state shown in FIG. 7 has a cross-sectional area as compared with the conventional core member having a semicircular cross-sectional shape. Since it is large and the cross-sectional second moment of the shape is also large, the deflection is greatly reduced. In this way, the V-groove shaped portion 2a of the concave core member 2 and the convex portion 3b of the convex core member 3 are caught with each other, and the concave core member 2 and the convex core member 3 are in opposite directions. It is wound around the core 1 (concave core member 2 and convex core member 3) in a state where no further deviation occurs, and is disposed on the core 1 in a predetermined positional relationship and insulative state via a separator 10. The positive electrode plate 12 and the negative electrode plate 13 are laminated, wound sequentially and wound.

  According to the present invention, when tension is applied to the separator 10 wound around the core 1 divided into two (the concave core member 2 and the convex core member 3), the V-groove portion of the concave core member 2 is applied. 2a and the convex part 3b of the convex core member 3 are hooked and fitted to each other, and no further deviation occurs. Further, when the separator 10 wound around the concave core member 2 is tensioned, the deflection is significantly greater than that of the conventional semicircular cross-sectional shape due to the increase in the cross-sectional area and the increase in the secondary moment of the cross-section. Because of the decrease, there is little deviation. Therefore, the positive electrode plate 12, the separator 10, and the negative electrode plate 13 are not deteriorated as in the conventional case, without causing the deviation of the core 1, that is, the roundness of the core 1, which has occurred at the beginning of winding of the separator 10. Can be laminated well and wound.

  Finally, after the winding operation of the cylindrical wound electrode body manufactured in this manner is completed, the core 1 (concave core member 2 and convex core member 3) is pulled out from the electrode body, Insert into a cylindrical outer container having a diameter. In this case, since the cylindrical wound electrode body has no deviation of the winding core 1 and the circularity of the winding core 1 is good, the cylindrical wound electrode body has a predetermined diameter. It can be smoothly inserted into a cylindrical outer container.

  In addition, since an accurate cylindrical electrode body can be formed with a high yield, the total length and thickness of the positive electrode plate 12 and the negative electrode plate 13 can be increased, and the capacity of the battery can be increased.

  In the present embodiment, the case where the angle of the convex portion 3b of the convex core member 3 is about 90 degrees and the opening angle of the concave core member 2 is about 270 degrees has been described. However, the concave core member 2 is formed at an opening angle larger than 180 degrees, the convex core member 3 is formed at an opening angle smaller than 180 degrees, and within a range in which the concaves and convexes fit each other. Needless to say, the effect can be obtained even if the angle is changed.

The direction in which the separator 10, the positive electrode plate 12, and the negative electrode plate 13 are wound and the direction in which tension is applied may be reversed.
Further, the tip shape of the convex portion 3b of the convex core member 3 may be changed. For example, a convex or concave curved shape or a shape of a so-called chamfered structure in which a corner portion is deleted is possible. In this case, it is desirable to pay attention so that the functions of fitting each other do not deteriorate.

  The method and apparatus for manufacturing a cylindrical wound electrode body according to the present invention is particularly suitable for a cylindrical wound electrode body for a battery or the like, but is not limited to this, and various wound electrode bodies. Applicable to.

The perspective view of the core provided in the winding apparatus which is the manufacturing apparatus while being used for the manufacturing method of the cylindrical winding type electrode body which concerns on embodiment of this invention (A) And (b) is a sectional view and a side view of the same core Perspective view of convex core member of same core (A) is a longitudinal cross-sectional view of the same core in a state where the convex core member is in the retracted position, (b) is a cross-sectional view taken along line AA in FIG. 4 (a), and (c) is the same volume. A longitudinal cross-sectional view of the core in a state in which the convex core member is in the protruding forward posture, (d) is a cross-sectional view taken along line AA in FIG. (A) is a longitudinal cross-sectional view of the same core in the case where the convex core member is in the retracted position, (b) is a cross-sectional view taken along line AA in FIG. 5 (a), and (c) is the same volume. A longitudinal cross-sectional view of the core in a state where the convex core member is slightly advanced from the retracted posture, (d) is a cross-sectional view taken along the line AA in FIG. 5 (c), and (e) is the same core. FIG. 5C is a longitudinal sectional view in a state where the convex core member is slightly advanced from the posture shown in FIG. 5C, and FIG. 5F is a sectional view taken along line AA in FIG. (A) is the longitudinal cross-sectional view in the state which the convex core member of the same core advanced further from the attitude | position shown in FIG.5 (e), (b) is an AA line arrow view of Fig.6 (a). Sectional view, (c) is a longitudinal sectional view of the same core in a state where the convex core member is further advanced from the posture shown in FIG. 6 (a), and (d) is an AA in FIG. 6 (c). A sectional view taken along line A, (e) is a longitudinal sectional view of the same core in a state where the convex core member is in a projecting forward posture, and (f) is a sectional view taken along line AA in FIG. 6 (e). The longitudinal cross-sectional view in the attitude | position which wound the core further than the attitude | position shown to FIG.6 (e) of the same core The perspective view which shows the state which starts winding a positive electrode plate, a separator, and a negative electrode plate with the conventional winding core Side view showing a state in which the separator starts winding with the conventional winding core (A) And (b) is a side view which respectively shows the state which started winding the separator with the conventional core.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Core 2 Concave type core member 2a V groove shape part 3 Convex type core member 3a Inclined surface 3b Convex part 4 Support part 5 Retracting part 10 Separator 12 Positive electrode plate 13 Negative electrode plate

Claims (1)

Cylindrical wound electrode for producing a cylindrical wound electrode body by winding a positive electrode plate and a negative electrode plate each having a belt shape and a separator separating them into a spiral shape in a laminated state using a winding core. A method of manufacturing a body,
A step of fixing a convex core member formed in a convex shape and a concave core member formed in a concave shape to the support portion by providing an inclined surface that is inclined closer to the outer peripheral surface toward the distal end at the distal end portion; and
Retreating the convex core member with respect to the concave core member in the support portion;
Pressing the separator against the concave core member;
By scooping the separator with the inclined surface by advancing the convex core member, said concave core member and said sandwiching the previous SL separator between the convex core member and the concave core member A step of fitting the convex core members together,
Rotating the winding core by a predetermined angle, and placing the separator along the outer circumferential surface of each of the concave winding core member and the convex winding core member ;
In a state where tension is applied to the separator so that the concave core member and the convex core member fit each other, a positive electrode plate and a negative electrode plate are stacked on the separator and the core is rotated to rotate the core. A process of winding around,
And a step of drawing the core in the axial direction from an electrode body formed by winding into a cylindrical shape. A method for producing a cylindrical wound electrode body, comprising:

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