JP2002324554A - Production device of electrode plate lattice for storage battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage battery which is lighter and has superior performance in operation life compared to the former storage battery by preventing a cross-sectional area near a bond of bar's intersection from becoming smaller than the other areas. SOLUTION: The invention comprises that a cutter is shaped in simple trapezoid and the cutter with the shape whose angle between a cutting surface and a metal sheet surface becomes wider as deep as the cutter is inserted into is used in a production system of an electrode plate lattice for the storage battery to cut and develop a metal sheet by the cutter reciprocating up and down.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus for manufacturing a grid for a storage battery.

[0002]

2. Description of the Related Art At present, a method for producing a grid for a lead-acid battery is as follows.
The casting method or the expanding method has become mainstream.

[0003] The advantage of the casting method is that a grid of an arbitrary shape can be formed, including a shape having a small electric resistance.
Since a frame that surrounds the periphery of the grid can be formed, a grid that is not easily deformed mechanically can be made.

[0004] Disadvantages are that the batch type is inferior in productivity because it is inferior in productivity, that it is difficult to form an integrated line connected to a post-process such as active material paste filling, and that inferior strength alloy such as lead-calcium alloy is used. In such cases, casting is difficult.

[0005] On the other hand, in the expanding method, a lead alloy sheet produced by rolling or the like is developed to form a mesh grid. There are two main types of unfolding systems: a rotary system that cuts a sheet with a rotating blade and then stretches it, and a reciprocating system that cuts and stretches the sheet with a V-shaped blade that moves up and down.

[0006] Both types can be continuously produced and can be installed in a line consistent with the active material paste filling and drying processes, so that they are characterized by extremely high productivity compared to the casting method. . Further, a lead alloy sheet can be easily produced even with a lead-calcium-based alloy or a lead-calcium-tin-based alloy which is inferior in castability, and the weight of the lattice can be reduced as compared with the casting method.

[0007] A disadvantage is that, since a rolled or cast sheet of a lead alloy is formed into a mesh shape by post-processing, processing distortion is likely to occur during production.

[0008]

In the case of the reciprocating type, in order to aim for a lighter grid (current collector), the number of meshes is reduced, that is, the angle of the blade at the time of deployment is increased as much as possible, and the height is increased. It is desirable to reduce the number of squares in the direction. However, in this case, the processing strain increases, and when this is adopted for the positive electrode grid, the service life of the battery may be shortened.

Particularly, in the reciprocating method, conventionally, as shown in FIG.
As a tool, a blade having a single cutting and deploying angle has been used. In the drawing, reference numeral 2 denotes a blade surface of a flat portion forming a bond portion, and reference numeral 2a denotes a blade surface of a rising portion from the bond portion forming portion. FIG. 5 shows a cross-sectional observation view of a grid bar developed by using the blade (D and E).
As shown in the figure, the elongation was concentrated on the bar 4a in the vicinity of the bond portion 3, which is the intersection of the bars 4, and the cross-sectional area of this portion became smaller than that of the other portions.

[0010] This is considered to be due to slippage between the blade and the lead alloy sheet surface during the development, and the elongation being concentrated on the first cut and developed portion. Since the positive electrode corrosion of the grid formed by cutting and expanding the lead alloy sheet proceeds almost uniformly, the corrosion rupture of the crosspiece, which may cause a life, is caused by the bond portion 3 having a small cross-sectional area.
Was concentrated on the pier near.

In order to extend the life, it is important to increase the cross-sectional area in the vicinity of the bond. For this purpose, the number of meshes in the height direction is increased, and the elongation of the bar, that is, the sheet, is suppressed. To do that. However, with this method, it was difficult to reduce the mass, which is one of the characteristics of the expanded grating.

[0012]

According to the first aspect of the present invention, there is provided an apparatus for manufacturing an electrode grid for a storage battery, which cuts and unfolds a metal sheet with a blade that reciprocates up and down.
An apparatus for manufacturing an electrode plate grid for a storage battery using a blade having a substantially trapezoidal shape, wherein the angle between the blade surface of the blade and the metal sheet surface gradually increases as the blade enters.

According to a second aspect of the present invention, in the apparatus for manufacturing an electrode grid for a storage battery according to the first aspect, the angle between the blade surface of the blade and the metal sheet surface is in the range of 10 to 60 °. Is used.

According to a third aspect of the present invention, in the apparatus for manufacturing an electrode grid for a storage battery according to the first or second aspect, the blade surface of the blade is substantially curved.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a blade having a substantially trapezoidal shape and an angle between a blade surface of the blade and a metal sheet surface increases as the blade enters.

Further, a blade having an angle between the blade surface of the blade and the metal sheet surface in the range of 10 to 60 ° is used.
Further, a blade having a substantially curved blade surface is used.

The present invention has been made to solve the conventional problems, and has a small number of steps while suppressing the extension near the bond.
That is, it is possible to manufacture a grid that can be reduced in weight. By using this manufacturing apparatus, it is possible to obtain a storage battery which is lighter than the conventional one and has excellent life performance.

[0018]

An embodiment of the present invention will be described below in detail.

FIG. 1 is a schematic diagram of a reciprocating expansion device. The knives 1 are displaced by a width (step width) corresponding to the crosspiece width from the vertically moving table and are arranged in a line. The blades 1 are attached at an interval of 1.5 times the mesh width of the mesh sheet 6. The lower blade 1a is flat. Blade 1 and lower blade 1a
In between, the lead alloy sheet 5 is inserted, and the blade 1 is moved up and down, thereby being cut and developed, and the mesh sheet 6 is formed. After filling this with the positive or negative electrode paste,
Cut into a predetermined shape to obtain a positive and negative electrode plate.

One embodiment (A, B) of the blade shape according to the present invention
And C) are shown in FIG. In order to suppress the elongation concentrated near the bond portion, the present blade has a relatively small angle from the blade surface 2 of the flat portion forming the bond portion to the blade surface 2a of the rising portion from the bond portion forming portion. In this embodiment, three types of blades are shown.

In the blade A, the angle of the blade surface 2a at the rising portion from the bond portion forming portion is 10 °, and the blade surface 2b following it is 60 °. In the blade B, the angle of the blade surface 2a at the rising portion is 40 °, and the angle of the subsequent blade surface 2b is 55 °. In each case, a chamfer of about R = 1 was applied where the angle was changed. The blade C has an elliptical surface such that the angle of the blade surface 2a at the rising portion is 10 ° and the blade surface 2c is 60 ° at the blade surface 2c at the maximum entry portion of the sheet.

FIG. 4 shows details of a conventional blade. The conventional blades D and E have a uniform angle of the blade portion for cutting and developing. The angle of the blade D is 45 °, and the angle of the blade E is 50 °.
°.

These blades A to E were mounted on the developing device shown in FIG. 1 and a developing test was performed. Knife A of the present invention
FIG. 3 shows a cross-sectional observation view of the grid bar developed using C.
Each showed a uniform cross section. On the other hand, as shown in FIG. 5, when observing the cross section of the grid developed with the conventional blades D and E, the cross section of the bar 4a near the bond portion 3 is thinner than the bar 4 of the other portion. Was. This is when blade 1
It is considered that slippage occurred between a and the surface of the lead alloy sheet 5, and the bar 4a near the bond portion 3, which was initially cut and developed, was particularly greatly elongated.

The grid prepared by the present invention and the conventional knife and the grid prepared by the present invention are used as a positive grid,
Five types of batteries shown in Table 1 were obtained. The mass of the lattice is also shown.

[0025]

[Table 1]

The batteries 1 to 3 use the grid developed by the blades A, B, and C of which the development angle changes in the middle of the present invention as the positive grid, and have a smaller number of development stages and are lighter than the conventional one. .

The battery 4 uses a conventional grid developed by a blade D having a single development angle, and the weight of the grid is heavier than that of the present invention. The battery 5 uses a conventional grid developed by a blade E having a single deployment angle, similar to the battery 4, but the blade angle is increased so that the number of deployment stages can be reduced. It is as light as the present invention.

Here, a rolled sheet made of a Pb-0.07 mass% Ca-2 mass% Sn alloy was used as a lead alloy sheet for the positive electrode, and was developed immediately after rolling. Also,
Its thickness was 1.8 mm.

A test battery was prepared by the following method. The positive electrode grid obtained as described above was filled with a predetermined positive electrode active material paste, aged and dried to obtain an unformed positive electrode plate.

Here, as the positive electrode active material paste, a mixture obtained by dripping water and diluted sulfuric acid into a mixture of red lead, lead powder and a reinforcing material and kneading the mixture was used. Lead tin is usually added for the purpose of improving the initial discharge capacity of the completed battery or improving the chemical conversion, and its amount is 0 (lead powder only) to 10
The manufacturer can arbitrarily select between 0% (lead only).
Usually, about 5 to 20% is added. As the reinforcing material, fine glass fibers or organic fibers are used, and are added for the purpose of improving the handleability of the electrode plate after filling with the paste, and usually about 0.1% is added.

The negative electrode plate is prepared by filling a predetermined negative electrode active material paste into an expanded grid developed in the same manner as the positive electrode,
Obtained by drying. Here, the lead alloy sheet used for manufacturing the negative electrode grid was different from that of the positive electrode, and was Pb-0.09% by mass.
The rolled sheet was made of a Ca-0.5 mass% Sn alloy and had a thickness of 0.8 mm. Since the negative electrode grid does not cause corrosion, the sheet thickness can be made smaller than that of the normal positive electrode grid. On the other hand, since the sheet strength is reduced due to the thinness, the sheet strength is increased by increasing the amount of Ca added to the alloy. The blade B in FIG. 2 was used as the deployed blade at this time.

As the negative electrode active material paste, a mixture obtained by kneading lead powder, an organic expander, an inorganic expander, carbon, a reinforcing material, water and dilute sulfuric acid was used. The organic expander is added to suppress a phenomenon in which the negative electrode active material shrinks during use of the battery. Usually, lignin or a derivative thereof obtained as a by-product during wood pulp production is used. Recently, there are cases where synthetic organic substances are used. The inorganic expander also suppresses the contraction of the active material like the organic expander,
For this, barium salts are most often used.
The amount of these additives is about 0.1 to 0.3%, but about 2% may be added for special applications.

The positive and negative electrode plates thus obtained were laminated via an elastic separator mainly composed of fine glass fibers to obtain an element of three positive electrode plates and four negative electrode plates. The positive electrode plate group and the negative electrode plate group of this element were welded, respectively, and these six elements were housed in a battery case made of ABS resin.

At this time, the positive and negative electrode plates were pressed by the separator at about 30 kPa in the battery case. The higher the compression force, the better the life performance, but if it is too high, the battery case may be deformed. Usually, the pressure is about 20 to 80 kPa and is selected depending on the intended use. The separator is preferably capable of maintaining this compression, and silica powder, organic fibers, or the like may be blended for this purpose.

After being stored in a battery case, A
A lid made of BS was adhered, and the positive and negative electrode terminals were treated. After pouring a predetermined diluted sulfuric acid through a hole in the lid and attaching a safety valve and a valve retainer, a chemical treatment was performed, and a nominal voltage of 12 V and a capacity of 7
A control valve type lead storage battery of Ah was obtained.

The five kinds of batteries thus obtained were subjected to a trickle life test. That is, a humidity of 30 ° C. in a 65 ° C.
%, 2.23 V per cell, 13.38 per battery
The battery was charged at a constant voltage of V, and the discharge capacity of 1 CA was examined every two months. At the 10th month or when the 1 CA discharge capacity reached 60% of the initial value, disassembly inspection was performed to examine the corrosion state of the positive electrode current collector. FIG. 6 shows the transition of the 1CA discharge capacity.

The batteries 1 to 3 according to the present invention were all superior to the conventional products 4 and 5. Unfolding at a high angle with a conventional blade,
The battery 5 employing the positive electrode grid whose weight was reduced by reducing the number of stages reached a life of 8 months. Here, when this battery was disassembled and the state of corrosion of the positive electrode grid was examined, the bar 4a near the bond portion was extremely thin, and some of the bars were broken. Battery 4, which is a conventional product that has not been reduced in weight, has reached the end of its service life at the tenth month. A disassembly survey revealed that the area near the bond was similarly narrow. It was considered that the increase in resistance in this portion became the resistance at the time of 1CA discharge and caused a decrease in discharge capacity.

On the other hand, the battery according to the present invention showed about 85% of the initial capacity even after 10 months. As a result of the dismantling survey,
The one using a blade whose angle changes in the middle of the present invention is different from the conventional blade with a single angle,
It is considered that each part is uniformly corroded and that a part of resistance is increased is avoided.

The above results are not limited to the control valve type battery, and the effect is not changed even when applied to the open type (liquid type) battery. It can contribute to weight reduction and improvement of life performance.

In the above embodiment, the description has been made mainly of the case where the mesh grid formed by developing the lead alloy sheet is used for a lead storage battery. However, a metal sheet such as copper other than the lead alloy is expanded and formed into a mesh grid. Even when this grid is used for a lead storage battery or a storage battery other than a lead storage battery, the same applies, for example, in that the cross-sectional area of the grid bar can be more uniformly processed. Things.

[0041]

As described above, by applying the grid obtained by the present manufacturing apparatus to a storage battery, a storage battery which is lighter than the conventional one and has excellent life performance can be obtained. It is enormous.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an expanding type developing device.

FIG. 2 is a view showing an embodiment of a blade shape according to the present invention;

FIG. 3 is a cross-sectional observation view of a grid bar developed using the blade according to the present invention.

FIG. 4 is a diagram showing an example of a conventional blade shape;

FIG. 5 is a cross-sectional observation view of a grid bar developed using a conventional blade.

FIG. 6 is a diagram comparing changes in 1CA discharge capacity.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 blade 1a lower blade 2 blade surface of flat portion forming bond portion 2a blade surface of rising portion from bond portion forming portion 2b blade surface following blade surface 2c blade surface of maximum penetration into sheet 3 bond portion 4 beam 4a Bar near bond part 5 Lead alloy sheet 6 Reticulated sheet

Claims (3)

[Claims] 1. A manufacturing apparatus for an electrode grid for a storage battery, which cuts and unfolds a metal sheet with a blade that reciprocates up and down, wherein the shape of the blade is substantially trapezoidal, and the blade surface of the blade and the metal sheet surface are formed. An apparatus for manufacturing an electrode grid for a storage battery, wherein a blade having a shape whose angle gradually increases as the blade enters is used. 2. The apparatus according to claim 1, wherein an angle between the blade surface of the blade and the metal sheet surface is in the range of 10 to 60 °. 3. The apparatus according to claim 1, wherein the blade has a substantially curved blade surface.