JP2002222645A - Electrode winding equipment of secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide electrode winding equipment of secondary batteries, which is made capable of being pulled out easily a winding core from an electrode group, after finishing forming of winding fabrication of the electrode group. SOLUTION: The electrode winding equipment of secondary batteries is constituted with the winding core 6, which forms the electrode group, can rotate in the right and reverse directions, and winds up a separator, the positive electrode, and the negative electrode, spirally by turns according to either the directions of the rotation, a pair of pressing rollers 10, which rotate in one direction with the electrode group G, while pressing the electrode group G inserted between the rollers with a prescribed pressing force during the winding fabrication of the electrode group G, and a one-way clutch 20, which inhibits the inverse rotation of the pressing rollers 10, when the winding core 6 is reversed in the rotation after forming winding fabrication of the electrode group G.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a secondary battery electrode winding apparatus for forming a spiral electrode group.

[0002]

2. Description of the Related Art An electrode winding apparatus of this type has a winding core rotatable in one direction, and can be engaged with the winding core by penetrating a sheet-like separator. In this state, when the winding core is rotated, the separator is wound around the winding core. At this time, the sheet-like positive and negative electrodes are fed toward the winding core, respectively.
These positive and negative electrodes are alternately spirally wound around a winding core with a separator interposed between the electrodes, whereby an electrode group is formed.

In order to securely tighten the electrode group with respect to the core during the winding forming of the electrode group,
The electrode group is sandwiched between a pair of pressure rollers from both sides in the radial direction of the winding core, and is in a state of being pressed with a predetermined pressing force by these pressure rollers, and these pressure rollers are held together with the electrode group. It is rotatably supported to rotate. Thereafter, when the winding forming of the electrode group is completed, the electrode group is separated from the core. In this state, the axial movement of the electrode group is prevented by the stripper, and the electrode group is separated from the core. It is implemented by pulling out.

[0004]

By the way, after the electrode group is wound and formed, the separator is tightly wound around the core, and a large pulling force is required to pull out the core from the electrode group. become. For this reason, when pulling out the core, the separator may be dragged out together with the core from the center of the electrode group, or the end face of the electrode group may be deformed by strongly pressing the end face of the electrode group against the stripper, and In the electrode group for nickel-metal hydride secondary batteries,
Since the positive electrode and the negative electrode are thickly coated on the base material with the positive electrode active material and the negative electrode active material, the mechanical bonding strength of the active material to the base material is weak. In addition, problems such as the active substance falling off the base material also occur.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the force of pulling out the core from the electrode group after the completion of the winding forming of the electrode group, and solve the above-mentioned problem. An object of the present invention is to provide an electrode winding device for a secondary battery that can be eliminated.

[0006]

Means for Solving the Problems To achieve the above object, an electrode winding apparatus for a secondary battery as described above includes:
The electrode winding device (Claim 1) of the present invention enables the winding core to rotate in the reverse direction, and when the winding core is rotated in the reverse direction after the winding of the electrode group, each of the pressure rollers is rotated. There is further provided reverse rotation preventing means for preventing reverse rotation.

According to the above-mentioned electrode winding apparatus, when the winding core is rotated in one direction and the electrode group is wound around the winding core, the electrode group is pressed by a pair of pressure rollers with a predetermined pressing force. And the electrode group, that is, the separator, is tightly wound around the core. When the winding forming of the electrode group is completed, the winding core is rotated in the reverse direction by a predetermined rotation angle, and at this time, the pair of pressure rollers reverse rotation of itself by the reverse rotation preventing means, that is, reverse rotation of the electrode group. It is blocking. Therefore, the winding of the separator with respect to the core is loosened by the reverse rotation of the core, and in this state, the electrode group is separated from the core by pulling out the core from the electrode group.

Specifically, the above-described reverse rotation preventing means includes a one-way clutch provided between the roller body of the pressure roller and the roller shaft, and the one-way clutch rotates the roller body in one direction. Only is allowed (claim 2). When the electrode group is wound and formed, the pressure roller can rotate integrally with the electrode group via a one-way clutch, but when the core is reversed, the pressure roller is connected to the electrode group by the one-way clutch. The entrainment is prevented, and only the core rotates in reverse.

[0009]

FIG. 1 shows an embodiment of an electrode winding device suitable for a nickel-metal hydride secondary battery. The electrode winding device of FIG. 1 includes a pair of rotating shafts 2L and 2R, and these rotating shafts 2 are rotatable in forward and reverse directions as indicated by an arrow A in FIG. Further, the rotating shafts 2L and 2R are coaxially separated from each other left and right, and can be moved in a direction in which the rotating shafts 2L and 2R contact and separate from each other by a contacting / separating mechanism (not shown), that is, the direction of arrow B in FIG.

A core half 4L having a semicircular cross section extends from the rotary shaft 2L toward the rotary shaft 2R, while a core half 4R having a semicircular cross section from the rotary shaft 2R toward the rotary shaft 2L. Is extending. When the rotating shafts 2L and 2R are close to each other as shown in FIG. 1, the winding core halves 4L and 4R are combined at a predetermined interval to form a winding core coaxial with the rotating shafts 2L and 2R. The core 6 has a slit 8 formed between the core halves 4L and 4R. The slit 8 penetrates in the radial direction of the core 6 and extends over the entire area in the axial direction of the core 6.

On the other hand, a pair of pressure rollers 10 are arranged above and below the core 6. These pressure rollers 10 are
Are held in parallel with each other in the diameter direction of the core 6, and are rotatably supported by the roller holders 12. Each of the roller holders 12 is connected to a press unit, and these press units can raise and lower the pressure roller 10 via the roller holder 12 in a direction of moving toward and away from the core 6.

More specifically, each pressure roller 10 has a roller shaft 14, and both ends of the roller shaft 14 are supported by the roller holder 12. A roller body 16 is rotatably mounted on the roller shaft 14 via a bearing 18 and a one-way clutch 20. That is, the bearing 18 is located at one end of the roller body 16, and the one-way clutch 20 is located at the other end of the roller body 16.

Here, as is apparent from FIG.
Is a ball bearing, for example, which supports the roller body 16 rotatably in both directions with respect to the roller shaft 14. However, the one-way clutch 20 is, for example, a roller type sprag clutch, and the roller body 16 is
In one direction, and prevents the roller body 16 from rotating in the opposite direction. The rotation directions of the upper and lower pressure rollers 10 blocked by the one-way clutch 20 are different from each other.

Further, in the state shown in FIG. 1, ring-shaped strippers 22 are provided in the vicinity of the rotary shafts 2, respectively. The strippers 22 surround the core 6 from the outside and are concentric with the core 6. Fixedly arranged. Next, a procedure for forming a spiral electrode group of a secondary battery using the above-described electrode winding device will be described.

First, as shown in FIG. 3, a sheet-shaped separator S made of an electrically insulating material is inserted through the slit 8 of the winding core 6, whereby the separator S is
In the rotation direction of the winding core 6,
The movement of the separator S in the axial direction is allowed.
In such a state, the core 6 is rotated by the pair of rotating shafts 2L and 2R.
3 is rotated counterclockwise as shown in FIG. 3, the separator S is wound around the core 6 with this rotation. On the other hand, when the winding of the separator S is started, the positive electrode P and the negative electrode N in the form of a sheet are fed from both sides toward the core 6, whereby the positive electrode P and the negative electrode N Spirally wound around the winding core 6 alternately with the separator S interposed therebetween.
As a result, an electrode group G having a three-layer structure of the positive electrode P, the negative electrode N, and the separator S is formed by winding. Here, the positive electrode P and the negative electrode N are obtained by applying a positive electrode active material and a negative electrode active material to the base material.

On the other hand, during the winding forming of the electrode group G,
As is clear from FIGS. 1 and 4, the pair of pressure rollers 10
Is a state in which the electrode group G is sandwiched from above and below with a predetermined pressing force.
And the electrode group G is tightly wound around the winding core 6. The pressing roller 10 here
Is the rotation direction allowed by the one-way clutch 20, and as the winding forming of the electrode group G proceeds, that is, as the diameter of the electrode group G increases,
It goes without saying that the interval between the pair of pressure rollers 10 is increased.

Thereafter, when the winding forming of the electrode group G is completed, the rotation of the core 6 is stopped, and the core 6 is rotated in a reverse direction by a predetermined rotation angle. In response to the reverse rotation of the winding core 6, the electrode group G also tends to be reversed. However, as described above, the pair of pressure rollers 10 are prevented from rotating in the reverse direction. It will not be accompanied in the opposite direction. Therefore, the pair of pressure rollers 10 sandwich the electrode group G by the pressing force, thereby preventing the electrode group G from rotating in the opposite direction.

Therefore, by the reverse rotation of the core 6 in a state where the rotation of the electrode group G is prevented, the tightening of the center of the electrode group G, that is, the winding core 6 of the separator S is loosened. In this state, when the core halves 4L and 4R constituting the core 6 are moved in a direction in which the core halves 4L and 4R are separated from each other, the core halves 4L and 4R are separated.
L and 4R are pulled out from the electrode group G, respectively, and the electrode group G is separated from the core 6.

Here, when pulling out the core core halves 4L and 4R,
Since the tightening of the separator S with respect to the core 6 is loosened, the pulling force of the core half 4L, 4R is greatly reduced, and the core half 4L, 4R can be easily pulled out from the electrode group G. Therefore, when pulling out the core halves 4L and 4R, the separator S is moved from the center of the electrode group G to the core halves 4L and 4R.
It will not be dragged out with L and 4R.

When pulling out the core half 4L, 4R, the electrode group G
Is moved in the axial direction together with one core half 4, this movement is prevented by the electrode group G contacting the stripper 22 on the corresponding side at its end face, and the core half 4 L, 4 R Is reliably pulled out of the electrode group G. Also, even if the electrode group G comes into contact with the stripper 22, the core half 4L,
Since the pullout force of 4R is greatly reduced, the end face of the electrode group G is not strongly pressed against the stripper 22. As a result, the deformation of the end face of the electrode group G and the falling off of the active substance from the positive electrode P and the negative electrode N are greatly reduced.

Further, prevention of reverse rotation of each pressure roller 10 is realized by a simple structure in which only a one-way clutch 20 is interposed between the roller shaft 14 of the pressure roller 10 and the roller body 16. Is not complicated. The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, although a core having a split structure is employed in one embodiment, an integral core having a slit may be used.

With respect to the pressure roller 10, bearings 18 may be disposed at both ends of the roller body 16, and a one-way clutch 20 may be disposed between the bearings 18. One-way clutches 20 may be disposed at both ends, respectively.
The arrangement and number of 0s can be arbitrarily set. Further, the reverse rotation preventing means is not limited to the one-way clutch 20. A brake is interposed between the roller shaft 14 and the roller body 16, and the reverse rotation of the pressure core 10 is prevented by the brake when the core 6 rotates in the reverse direction. For example, various configurations can be adopted for the reverse rotation preventing means.

Furthermore, the electrode winding apparatus of the present invention is not limited to the electrode group for a nickel-metal hydride secondary battery, but can be applied to the winding forming of another type of electrode group for a secondary battery such as a lithium battery. Needless to say,

[0024]

As described above, according to the electrode winding apparatus for a secondary battery of the present invention (claim 1), after the electrode group is completely wound, the electrode group is prevented from reversing. In the state
Since the core is reversed, the pulling force when pulling the core from the electrode group can be greatly reduced. As a result,
When the core is pulled out, it is possible to prevent the separator from being pulled out from the center of the electrode group, the end face of the electrode group to be deformed, and the active substance from falling from the positive electrode and the negative electrode.

Further, the reverse rotation preventing means for the pressure roller can be realized only by providing a one-way clutch between the roller shaft of the pressure roller and the roller body, which complicates the structure of the electrode winding device. Never.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an electrode winding device according to an embodiment.

FIG. 2 is an enlarged sectional view of the pressure roller of FIG.

FIG. 3 is a diagram for explaining winding forming of an electrode group around a core.

FIG. 4 is a diagram showing a state in which the electrode group is sandwiched between a pair of pressure rollers during winding forming of the electrode group.

[Explanation of symbols]

 4L, 4R Core half 6 Core 10 Pressure roller 12 Roller holder 18 Bearing 20 One-way clutch (reverse rotation prevention means) 22 Stripper S Separator P Positive electrode N Negative electrode

Claims (2)

[Claims] In the process of rotating a core in one direction and winding a sheet-like separator around the core,
A sheet-shaped positive electrode coated with a positive electrode active material and a sheet-shaped negative electrode coated with a negative electrode active material are alternately spirally wound around the core while the separator is interposed between these electrodes. An electrode group is formed, and during the winding forming of the electrode group, the electrode group is sandwiched between a pair of pressure rollers with a predetermined pressing force, so that the pressure roller rotates together with the electrode group in one direction. In the electrode winding device for a secondary battery, the winding core is also rotatable in a reverse direction, and when the winding core is rotated in the reverse direction after the winding forming of the electrode group, each of the pressure rollers An electrode winding device for a secondary battery, comprising a reverse rotation preventing means for preventing reverse rotation. 2. The reverse rotation preventing means includes a one-way clutch provided between a roller body of the pressure roller and a roller shaft, and the one-way clutch allows the roller body to rotate only in one direction. The electrode winding device for a secondary battery according to claim 1, wherein: