JP3475010B2 - Spiral electrode body manufacturing apparatus and spiral electrode body manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing a spiral electrode body used in a cylindrical battery and a method for producing the spiral electrode body.

[0002]

2. Description of the Related Art A spiral electrode body used for a cylindrical battery is generally wound on a strip-shaped separator so as to insulate a positive electrode plate and a negative electrode plate from each other, sandwiched by a winding core, and wound in a spiral shape. It is produced continuously by repeating the process of removing the core. In order to meet the demand for higher capacity of the battery, when the spirally wound electrode body is wound, it is tightly tightened so that the density of the electrode body is increased.

As the core used for manufacturing the spiral electrode body, a split pin-shaped core or a core composed of a pair of pins is known. The split pin-shaped winding core described in JP-A-63-318072 is a cylindrical winding core 200 having slits 201 as shown in FIG. 10. The winding core 200 is a separator. Positive electrode plate 30 on 300
A stack of 1 and the negative electrode plate 302 is sandwiched in the slit 201 and wound.

A winding core composed of a pair of pins described in Japanese Patent Laid-Open No. 63-318072 is composed of a cylindrical pin 210 and an auxiliary pin 211 shown in FIG. A stack of the negative electrode plate 302 and the negative electrode plate 302 is sandwiched between the cylindrical pin 210 and the auxiliary pin 211 and wound. In addition, Japanese Patent Application Laid-Open No. Hei 3 (1999) -3 is used for a winding core composed of a pair of pins.
As described in JP-A-141558, there is also described one which is formed into a cylindrical shape when both pins are engaged. In this publication, the cross-sectional shape of a pair of pins is a semicircular shape obtained by symmetrically dividing a circle as shown in FIG. 12 (a), or as shown in FIGS. 12 (b) and 12 (c). A shape in which a circle is asymmetrically divided is described.

By the way, in the center of the spirally wound electrode body manufactured by using such a winding core, a space left after the core is removed remains, but in order to increase the density of the spirally wound electrode body. It is desirable to use a thin winding core to reduce the space of the extracted trace.

[0006]

However, when a spirally wound electrode body is continuously produced using a thin winding core,
The core is easily broken. This core breakage causes the core to be removed in the process of removing the core from the spiral electrode body while the spiral electrode body is being tightened, so that tension is applied to the core, thereby It is thought that the main cause is fatigue.

When the core is broken, the production is interrupted and the core is replaced with a new core. However, much time is spent for adjustment such as alignment of the replaced core. Therefore, it is an important issue from the viewpoint of improving productivity to suppress the occurrence rate of core breakage to a low level. In view of such a problem, the present invention provides a high-capacity spiral electrode body by providing a spirally wound electrode body manufacturing apparatus and a manufacturing method in which the occurrence rate of core breakage is low even when a thin core is used. The purpose is to be able to manufacture with high productivity.

[0008]

As a result of further study on the cause of core breakage that occurs when continuously manufacturing spiral electrode bodies, the inventors of the present invention have found that the conventional core has a surface holding the separator. Since it is formed parallel to the winding axis of the winding core, when the winding core is removed from the spirally wound electrode body in the axial direction, a large tension is applied to the winding core for a long time, and the core is not fatigued. It was understood that it was the cause.

According to the present invention, the separator is sandwiched between the first and second pins provided to face each other, and the separator is wound around the first and second pins as a winding core to form a spiral electrode body. In a spirally wound electrode body manufacturing apparatus to be manufactured, a sandwiching surface formed by a first pin and a second pin is inclined with respect to a winding axis direction of a winding core, and each pin is formed to be narrower on a tip side than a root side thereof. did.

With this structure, when the core is removed from the spirally wound electrode body, the core is immediately released from the tightening pressure applied to the core, so that the core is less fatigued. Therefore, even with a thin core, the core is unlikely to break. Further, in such a winding core, the outer peripheral surfaces of the two pins may be formed into a single cylindrical body with the separator held therebetween, and in this case, particularly for increasing the capacity of the battery. Considered to be advantageous.

Further, when manufacturing the spirally wound electrode body using such a winding core, in the winding step, the separator surrounding the first pin and the second pin is placed at a position higher than that of the first pin.
In the process of winding and pulling it out so that it comes into contact with many pins, by pulling out the first pin before the second pin,
Fatigue affecting the winding core can be further reduced. This is because the first pin receives less tightening pressure than the second pin, so the tension received when the first pin is pulled out is relatively small, and if the first pin is pulled out first, the second pin Is also released from the tightening pressure and does not receive tension during extraction.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (Description of Structure of Core) FIG. 1 is a perspective view of a core of the spirally wound electrode body manufacturing apparatus according to the present embodiment. As shown in the figure, the winding core 1 is composed of a pair of symmetrical pins 10 and 20, and each of the pins 10 and 20 is supported by the main body of the apparatus by a support driving unit 41 and 42.

The pins 10 and 20 are cylindrical trunks 11 and 2, respectively.
1 and sandwiching portions 12 and 22 extending from the trunk portions 11 and 21 and having a semicircular cross section. The sandwiching portions 12 and 22 are
It has flat holding surfaces 13 and 23 and is formed in a tapered shape. Each of the pins 10 and 20 is manufactured by cutting a metal cylindrical rod. 2 (a), (b)
[FIG. 3] is a side view and a plan view showing the shape of the winding core 1, showing a state in which the pins 10 and 20 are united.

As shown in the drawing, the winding core 1 is formed into a cylindrical shape when the pin 10 and the pin 20 are united with the pinching surface 13 and the pinching surface 23 facing each other. The axis of this cylinder coincides with the rotation axis 30 of the winding core 1. Further, the sandwiching surfaces 13 and 23 are inclined with respect to the shaft 30 of the winding core 1 by a slight inclination angle α. As shown in FIG.
20, the trunk portions 11 and 21 are mounted on the support driving portions 41 and 42 and are coaxially supported. And the pins 10, 20
Can be rotationally driven about the shaft 30 and reciprocally driven in the axial direction along with the support driving portions 41 and 42.

3 (a) and 3 (b) are a side view and a top view showing how the winding core 1 holds the separator. As shown in the drawing, the pinching surface 13 of the pin 10 and the pin 2
The separator 2 is clamped by the clamping surface 23 of 0. As will be described later, in the present embodiment, the separator 2 is actually composed of a pair of separators 2a and 2b (see FIG. 4), and sandwiches where the respective tip ends are overlapped, but for convenience of explanation, The expression of sandwiching the separator 2 will be used.

The holding surfaces 13 and 23 have a width W of the separator 2.
It is set to be slightly longer than that, and the separator 2 is sandwiched by the sandwiching surfaces 13 and 23 over the entire width direction.
In the present embodiment, the separator 2 is sandwiched by the central portions of the sandwiching surfaces 13 and 23. The pin 10 and the pin 20 when sandwiching the separator 2 are separated from each other by the distance L in the axial direction as compared with the state where they are combined as shown in FIG. This distance L, inclination angle α, and separator thickness M
And, there is a relationship of L × sin α = M.

(Explanation on Method of Manufacturing Spiral Electrode Body)
FIG. 4 is a perspective view showing one step of manufacturing the spiral electrode body.
As shown in the figure, a pin 10 and a pin 20 are arranged so as to face each other, and rolls 3a and 3b formed by winding a separator material are arranged on both sides of the pin 10 with a distance therebetween. Then, the separator 2 fed from the rolls 3a and 3b
Pins 10 and 20 are attached to the tips 7a and 7b of a and 2b.
The spirally wound electrode body is manufactured by sandwiching between the positive electrode plate 4 and the negative electrode plate 5 and sandwiching the positive electrode plate 4 and the negative electrode plate 5.

FIG. 5 is a diagram for sequentially explaining the steps of manufacturing the spirally wound electrode body. The steps will be described in order with reference to this figure. Clamping process: As shown in FIG. 5 (a), pin 10 and pin 2
0 is made to stand apart and the separator 2a is paid out from the roll 3a, the separator 2b is paid out from the roll 3b, and the tip part 7a of the separator 2a and the tip part 7b of the separator 2b are placed between the pin 10 and the pin 20. Overlap with. In FIG. 5A, the tip portion 7a of the separator 2a is hidden behind the tip portion 7b of the separator 2b.

Subsequently, the pin 10 and the pin 20 are moved closer to each other in the axial direction indicated by the arrows a1 and a2 in the figure to clamp the overlapping tip portions 7a and 7b. Winding step: As shown in FIGS. 4 and 5 (b), the positive electrode plate 4 is inserted into one surface of the separator 2a in the direction of arrow b1 and the negative electrode plate 5 is inserted in the direction of b2 on the other side of the separator 2b. While inserting, the pins 10 and 20 are rotated in the direction of arrow d in FIG. 4 to wind the separators 2a and 2b. At this time, the positive electrode plate 4 is inserted between the tip portion 7b of the separator 2b and the separator 2a, and the negative electrode plate 5 is inserted between the tip portion 7a of the separator 2a and the separator 2b.

FIG. 5C shows a state where the separators 2a and 2b, the positive electrode plate 4 and the negative electrode plate 5 are being wound in a spiral shape. In order to increase the density of the electrode winding body, tension is applied to the separators 2a and 2b at the time of winding, and the separators are wound while being tightened. Extraction step: As shown in FIG. 5D, when the winding is completed, the separators 2a and 2b are cut at the winding end of the spiral electrode body 6 thus produced, and the pins 10 and 20 are simultaneously moved in the axial direction (in the figure). It moves to the arrow c1, c2) and is withdrawn from the spiral electrode body 6.

By repeating the above steps, the spiral electrode body 6 is continuously produced. (Explanation of Effect of Core 1) In the core 1, since the holding surfaces 12 and 22 are inclined with respect to the shaft 30, the pins 10 and 20 are provided.
Are separated from each other in the direction of the axis 30, the clamping surface 13 and the clamping surface 23
The interval between and changes.

Therefore, in the pinching step, the pin 10 and the pin 20 are brought closer to each other in the direction of the axis 30 so that the pinching surfaces 12 and 22 press the separator 2 for reliable pinching (see FIG. 3). . This reduces the chuck failure rate. Here, the outer diameter of the winding core 1 when the separator 2 is sandwiched is considered. As shown in FIG. 3 (a), the outer diameter of the winding core 1 is constant in the direction orthogonal to the surface of the separator 2 (that is, the vertical direction in FIG. 3 (a)). As shown, with respect to the direction of the surface of the separator 2 (that is, the vertical direction in FIG. 3B), the distance L in the axial direction is at the center of the winding core 1.
A small-diameter portion 31 having a slightly smaller outer diameter is formed over the entire length. In the small diameter portion 31, the pin 10 and the pin 20 are
It can be considered that it is caused by being separated by the distance L in the axial direction.

The wound separator 2 and electrode plates 3, 4
Receives a force in the direction from the larger diameter to the smaller diameter, that is, in the direction of being drawn into the small diameter portion 31. Therefore, winding deviation of the separator 2 is prevented. FIG. 6 shows the core 1 in the extraction process.
6A is a diagram showing the state of FIG. 6A, FIG. 6A is a state before extraction, and FIG. 6B is a diagram showing a state during extraction.

Before extraction, the peripheral surface 1 of the holding portion 12
Since 4 is in close contact with the inner surface of the spirally wound electrode body 6 and the sandwiching surface 13 is in close contact with the sandwiching portion 22 via the separator 2, the sandwiching portion 12 is subjected to tightening pressure as indicated by the white arrow. Although not shown, the holding portion 22 also receives the same tightening pressure. Therefore, in this state, the pins 10,
When trying to pull out 20, the pins 10 and 20 are axially tensioned.

In the state (b), the pins 10 and 20 are moved in the axial direction by the distance N compared with the state (a). At this time, the distance between the sandwiching surface 13 and the sandwiching surface 23 is expanded by 2N × sin α as compared with the state of (a).
From this, it can be seen that even if the pins 10 and 20 are separated from each other in the axial direction even slightly, the distance between the sandwiching surface 13 and the sandwiching surface 23 is expanded, and the tightening pressure received by the sandwiching portions 12 and 22 is rapidly reduced. That is, the pins 10 and 20 are
It can be seen that the tightening pressure is released immediately after the start of extraction.

Therefore, when the pins 10 and 20 are pulled out, tension is applied to the pins 10 and 20 only for a short time, and the fatigue applied to the pins 10 and 20 is small. This reduces the occurrence of pin breakage. Further, the shape of the sandwiching portion 12 and the sandwiching portion 22 is tapered and the root side is thicker, which also contributes to the reduction of pin breakage.

Although it is considered that these effects become greater as the inclination angle α is set larger, the range in which the inclination angle α can be set depends on the ratio between the length of the holding portions 12 and 22 and the diameter of the winding core 1. Limited. (Second Embodiment) A winding core 50 used in the present embodiment is similar to that of the first embodiment, and is composed of pins 60 and 70 as shown in FIG.

FIG. 7 is a view showing how the spirally wound electrode body is manufactured by the winding core 50. The method of manufacturing the spirally wound electrode body of the present embodiment is the same as that of the first embodiment, but in the sandwiching step, the separator 2 is sandwiched at the center of the sandwiching surface in the first embodiment, whereas In the embodiment, as shown in FIG. 7, the holding position of the separator 2 is different from the center of the holding surface in the root direction of the pin 60. Further, in the extraction process, in the first embodiment, the pins 10 and 20 are simultaneously extracted, whereas in the present embodiment, the pin 70 is first extracted and then the pin 60 is extracted. There is.

As can be seen from FIG. 7, the pin 70 is inserted shallower than the pin 60 with respect to the spirally wound electrode body 6 during the winding step, and the pin 70 has a spiraler electrode body 6 than the pin 60. The area of contact with is small. That's it, pin 7
No. 0 has a smaller tightening pressure received from the spirally wound electrode body 6 than the pin 60, and has a small tension received at the time of extraction.

In the extracting step, the pin 60 and the pin 70 are released from the tightening pressure by pulling out the pin 70 first. Fatigue applied to the pin 70 when the pin 70 is pulled out is relatively small, and almost no tension is applied when the pin 60 is pulled out. Therefore, in the present embodiment, the occurrence of pin breakage can be further reduced as compared with the case of the first embodiment.

(Example 1) In the core 1 of the first embodiment, the pins 10 and 20 are made of stainless steel and have a total length of 1
27 mm, inclination angle α = 0.62 °, diameter is 2.
It was made with two values of 5 mm and 3.0 mm. Using this core, the spiral electrode body 6 is manufactured based on the manufacturing method of the first embodiment.
Was produced. The separator 2 is made of nylon and has a width of 40 m.
m, thickness 0.18 mm, the positive electrode plate 4 was a sintered nickel electrode plate, and the negative electrode plate 5 was a sintered cadmium electrode plate.

Then, using the produced spiral electrode body 6,
A size cylindrical nickel-cadmium battery was prepared. (Example 2) Using the same winding core as in Example 1, a spirally wound electrode body 6 and a cylindrical nickel-cadmium battery were manufactured based on the manufacturing method of the second embodiment. The same separator 2, positive electrode plate 4, and negative electrode plate 5 as in Example 1 were used.

(Comparative Example) FIG. 8 is a view showing how a spirally wound electrode body is produced by the core of this comparative example. The core of this comparative example was the same as that of Example 1, except that the inclination angle α was set to 0, and the diameter was set to 3.0 mm and 4.0 mm.

Using this core, a spiral electrode body 106 and a cylindrical nickel-cadmium battery were manufactured by the same manufacturing method as in Example 1. The same separator 2, positive electrode plate 4, and negative electrode plate 5 as in Example 1 were used. As shown in the figure, in the core of this comparative example, since the pinching surfaces 113 and 114 of the pins 110 and 120 are parallel to the axis, even if the pins 110 and 120 are moved in the axial direction, the pinching surface 113 is formed. The distance between the clamping surfaces 114 does not change.

Therefore, even if the pins 110 and 120 are made to approach each other in the axial direction, the separator 2 cannot be firmly sandwiched as in the case of the first embodiment. Also,
Even in the extraction step, the distance between the sandwiching surface 113 and the sandwiching surface 123 does not expand as in the case of the first embodiment, so that the sandwiching portions 112 and 122 can be released from the tightening pressure.
The pins 110, 120 need to be spaced far apart.

Therefore, when the pins 110 and 120 are pulled out, tension is applied to them for a long time.
Fatigue added to 20 is great. (Experiment) With respect to the manufacturing method using each core of Examples 1 and 2, and the comparative example, the pin breakage occurrence rate was measured, and the battery capacity of the manufactured cylindrical nickel-cadmium battery was measured.

Table 1 is a table showing the results of this experiment. Regarding the battery capacity, the case where the diameter of the core of the comparative example is 3.0 mm is taken as a standard (100%), and the ratio is displayed.

[0038]

[Table 1] Further, the winding misalignment occurrence rate and the chuck failure rate were measured for the case where the core diameter was 3.0 mm in Example 1 and the case where the core diameter was 4.0 mm in the comparative example. Table 2 is a chart showing the results of this experiment.

[0039]

[Table 2] In the experiment, 10,000 spirally wound electrode bodies were manufactured, and the number of pin breaks, winding misalignments, and chuck failures that occurred at that time were measured. In Table 1, the diameter of the core is 3.0m
Comparing the case of m, the pin breakage occurrence rate of the comparative example is 0.03%, while the pin breakage occurrence rate of the comparative examples is 0.
%. Moreover, in Examples 1 and 2, the diameter of the winding core is 2.5.
Even in mm, pin breakage occurrence rate is 0% and 0.01%
That is a small value.

When the diameter of the winding core is 3.0 mm, the battery capacity is reduced by 10% when the diameter is 4.0 mm.
When the diameter is 2.5 mm, the battery capacity is improved by 5%.
From these results, it was confirmed that by using the winding core of the present invention, the winding core can be made thinner than the conventional one to achieve a high capacity, and the pin breakage occurrence rate can be reduced. Table 2
Therefore, compared with the case where the diameter of the winding core is 4.0 mm in the comparative example,
It can be seen that in Example 1, when the winding core diameter is 3.0 mm, both the winding deviation occurrence rate and the chuck failure rate are lower.

(Other Matters) In the first and second embodiments, the separator 2 is a pair of separators 2a, 2
Although the example in which the end portions of the separators b are overlapped with each other is sandwiched and wound up is shown, the same effect can be obtained even when the center portion of one separator is sandwiched and wound up.

Further, in the above-described first and second embodiments, the winding core has a columnar shape and is composed of a pair of symmetrically shaped pins each having a planar holding surface. The present invention is not limited to the core having such a shape, and can be implemented in the following forms. As shown in FIG. 9A, the winding core 80 has a columnar shape and includes a pair of pins 81 and 84. The pins 81 and 84 are similar to the pins 10 and 20 of the first embodiment, but the pinching portion 82 of the pin 81 is used.
Is thinner than the pinching portion 85 of the pin 84.
The sandwiching surface 83 is a concave curved surface, and the sandwiching surface 86 is a convex curved surface.

In such a winding core 80 as well, the holding surface 8
3, 86 are inclined with respect to the winding axis,
Since 85 is tapered, it has the same effect as that of the first embodiment. Moreover, it is considered that the same effect as that of the second embodiment is achieved by pulling out the thinner pin 81 before the pin 84.

As shown in FIG. 9B, the winding core 90
Consists of a pair of symmetrical pins 91 and 94. Pin 9
The sandwiching portions 92, 95 of 1, 94 have a tapered cylindrical shape. In the winding core 90, the strip-shaped regions (hatched regions in the drawing) that face each other on the outer peripheral surfaces of the sandwiching portions 92 and 95 become the sandwiching surfaces 93 and 96. Such a winding core 90 also has a holding surface 9
3, 96 are inclined with respect to the winding axis,
Since 2 and 95 have a tapered shape, it is considered that the same effects as those in the above-described embodiment are achieved.

Further, in the above-mentioned Embodiments 1 and 2, an example of producing the spirally wound electrode body of the cylindrical nickel-cadmium battery has been shown, but the same is done when manufacturing other types of spirally wound electrode bodies. You can

[0046]

As described above, the core and the method of manufacturing the spirally wound electrode body of the present invention can reduce the occurrence of core breakage as compared with the prior art, and as a result, the production of the spirally wound electrode body. It is possible to improve the sex. Further, it is possible to reduce the winding deviation and the chuck failure, which can also contribute to the improvement of the productivity.

Further, since the diameter of the winding core can be made smaller than in the conventional case, the density of the spirally wound electrode body can be increased,
It also contributes to increasing the capacity of the cylindrical battery.

[Brief description of drawings]

FIG. 1 is a perspective view of a winding core according to a first embodiment.

FIG. 2 is a side view and a plan view showing the shape of the winding core shown in FIG.

3A and 3B are a side view and a top view showing a state where a winding core 1 holds a separator.

FIG. 4 is a perspective view showing one step of manufacturing the spiral electrode body according to the first exemplary embodiment.

FIG. 5 is a diagram illustrating the order of steps of manufacturing the spirally wound electrode body according to the first embodiment.

FIG. 6 is a diagram showing a state of a winding core in the extracting step according to the first embodiment.

FIG. 7 is a diagram showing how the spirally wound electrode body according to the second embodiment is manufactured.

FIG. 8 is a diagram showing how a spirally wound electrode body is manufactured by a core of a comparative example.

FIG. 9 is a perspective view of a winding core according to an embodiment of the present invention.

FIG. 10 is a perspective view showing an example of a conventional split pin-shaped winding core.

FIG. 11 is a perspective view showing an example of a conventional core including a pair of pins.

FIG. 12 is a view showing a cross-sectional shape of an example of a conventional core including a pair of pins.

[Explanation of symbols] 1 core 2 separator 4 Positive plate 5 Negative electrode plate 6 spiral electrode body 10, 20 pin 12,22 clamping part 13,23 clamping surface 30 axes 31 Small diameter part 50,80,90 winding core

Front page continuation (72) Inventor Ryuji Kawase 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd. (72) Inventor Takuya Tamagawa 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Machinery Co., Ltd. (72) Inventor Yoshiyuki Fujimoto 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd. (56) Reference JP-A-8-315830 (JP, A) JP-A-9- 306534 (JP, A) JP 6-150959 (JP, A) JP 63-299059 (JP, A) JP 6-325990 (JP, A) JP 60-40367 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01M 6/02 H01M 6/10 H01M 10/04

Claims (4)

(57) [Claims] 1. A spiral electrode body is manufactured by sandwiching a separator between first and second pins provided facing each other, and winding the separator around the first and second pins as winding cores. In the spiral electrode body manufacturing apparatus, the sandwiching surface formed by the first pin and the second pin is inclined with respect to the winding axis direction of the winding core, and each pin is formed to be thinner on the tip side than on the root side. A spiral electrode body manufacturing apparatus characterized in that. 2. The spiral electrode body manufacturing apparatus according to claim 1, wherein the two pins form a single cylindrical body on the outer peripheral surface of the two pins while sandwiching the separator. 3. A winding method in which a first pin and a second pin are provided so as to face each other and have a facing surface inclined with respect to a winding axis direction, and a separator is sandwiched between the facing surfaces to wind the electrode together. A method for manufacturing a spirally wound electrode body, comprising: a step; and a step of extracting the first pin and the second pin from the spirally wound electrode body after winding. 4. In the winding step, the separator surrounding the first pin and the second pin is wound in a state of contacting more with the second pin than with the first pin, and in the extracting step, the first pin The method for manufacturing a spiral electrode strip according to claim 3, wherein the first electrode is extracted before the second pin.