JP2002050361A - Manufacturing method of expanded mesh sheet and manufacturing method of lead acid storage battery grid and lead acid storage battery using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To resolve the problem of fluctuations in the dimensions of the expanding process that occurs when the part of the frame sections composing the expanded mesh is more stretched than the other frame sections and the task that the frame sections that are more stretched than the other frame sections and the joint section adjoining these stretched sections are corroded prior to the other sections and thereby shorten the battery life in the manufacturing method of the lead acid storage battery grid using the expanded mesh sheet. SOLUTION: In the angles which are formed between the blade top end face of the protruding blade top end 11 of the dice blade 7c which is used for the expanding process and the sheet metal 4 which is the material to be processed, the angle of the feeding side blade top end face 12 to the sheet metal 4 in the feeding direction is made larger than the angle of the delivered side blade top end face 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an expanded mesh sheet, particularly an expanded mesh sheet applied to a grid for a lead-acid battery, and a lead-acid battery provided with the grid for a lead-acid battery obtained by the manufacturing method. is there.

[0002]

2. Description of the Related Art In general, there are a casting method and an expanding method as a method of manufacturing a grid of a lead-acid battery. However, a calcium battery grid recently developed in response to a maintenance-free requirement has an expanded productivity. It tends to be produced by processing. As the expanding process, a method is used in which a slit portion is formed in a lead alloy sheet by using a reciprocating die cutter and the slit portion is developed to form an expanded mesh.

In recent years, it has been practiced to reduce the grid size of expanded networks for the purpose of improving the voltage characteristics during rapid discharge of lead storage batteries.

When the grid size of the expanded mesh is reduced, it is necessary to increase the number of slits per area of the expanded portion of the sheet metal. In this case, it is necessary to increase the reciprocating speed of the die cutter or increase the number of slits formed in one reciprocation of the die cutter.
In the former case, it is necessary to reciprocate a relatively heavy die cutter at a high speed, which requires a large-capacity press machine, which causes an increase in manufacturing cost.

The latter case can be dealt with by increasing the number of blades of the die cutter. As shown in FIG. 5, two convex blades 3 are provided on the die blades 2 constituting the die cutter 1, respectively. The feed pitch of the sheet metal 4 is set to 2.5 times the grid pitch of the expanded mesh. According to such a method, the number of slits formed in one stroke of the die cutter can be doubled, so that the operating speed of the press can be reduced.

[0006] However, when the expanding mesh processing is performed by the method as shown in FIG. 5, some of the bones 5 are stretched more than the other bones 6, and as shown in FIG. It was confirmed that it became uniform.

[0007] Such non-uniformity of the developed state causes a variation in the expanded width of the expanded mesh, resulting in a large variation in the height of the electrode plate.

Further, the more stretched bone portion 5 and the nodal portion 5-1 between this bone portion 5 and another bone portion 6 are compared with the nodal portion 6-1 formed by other bone portions 6. There is a problem that this portion is subjected to corrosion preferentially when subjected to stress during the expanding process, particularly when used for the positive electrode, and the battery life is shortened.

[0009]

SUMMARY OF THE INVENTION According to the present invention, there is provided a dice cutter in which a plurality of dice blades each having a plurality of convex cutting edges as described above are arranged so as to have a step so that the blade surface of the dice blade is stepped. In a reciprocating expanded mesh sheet in which a slit is formed in a sheet metal by reciprocating motion of a sheet and a method of manufacturing a lead-acid battery grid body using the same, a part of a bone part of a grid forming the expanded mesh part is formed of another bone. This solves the problem that the expanded dimensions of the expanded portion caused by stretching from the part and the bone part stretched over other bone parts and the nodules connected to it are preferentially corroded, shortening the battery life. The purpose is to do so.

[0010]

The invention according to claim 1 of the present invention as means for solving the above-mentioned problems is as follows.
A plurality of intermittent slits are formed in the sheet metal in parallel with each other by a dice cutter in which a plurality of dice blades reciprocating in the vertical direction with respect to the intermittently fed sheet metal are arranged so that the blade surface is stepped. A method of manufacturing an expanded mesh sheet in which slits forming parallel adjacent intermittent slits are formed in a staggered manner and a slit portion formed in the sheet metal is developed and extended, wherein the die blade has the same intermittent slit. A plurality of convex cutting edges are provided so as to simultaneously form a plurality of slits on the strip, and the angle between the cutting edge surface of the convex cutting edge and the sheet metal is on the material input side with respect to the feeding direction of the sheet metal. The angle of the cutting edge is set to be larger than the angle of the cutting edge on the material output side.

According to a second aspect of the present invention, the method for producing an expanded mesh sheet according to the first aspect is a method for producing a grid for a lead-acid battery.

According to a third aspect of the present invention, there is provided a lead-acid battery according to the second aspect, wherein the sheet metal is a rolled sheet made of a lead-calcium alloy and the obtained expanded mesh sheet is a grid mesh portion. A method of manufacturing a lattice was used.

According to a fourth aspect of the present invention, the lead-calcium alloy according to the third aspect has a calcium content of 0.04 mass% to 0.10 mass% and a tin content of 0 mass%. It was set to 0.8% by mass to 2.0% by mass.

According to a fifth aspect of the present invention, there is provided a lead-acid battery provided with the lead-acid battery grid manufactured by the method for manufacturing a lead-acid battery grid according to any one of the second to fourth aspects. did.

[0015]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a view showing a process of manufacturing an expanded mesh sheet according to an embodiment of the present invention. Die blade 7
a, a dice blade 7b, a dice blade 7c, and a dice blade 7d are arranged with the respective blade surfaces 8a, 8b, 8c, and 8d provided with a stepped step 9 to form a die cutter 10. I have. This step 9 is a cutting width at the time of the expanding process,
That is, it is equivalent to the width of the lattice bone and can be changed as needed.

The die blade 7a, which is the first blade on the material input side, is the outermost portion of the expanded mesh, and usually has a trapezoidal shape to correspond to the bottom of the lattice. The subsequent die blades 7b, 7c and 7d are provided with two convex cutting edges 11, respectively. These two convex cutting edges 1
Numerals 1 are on the same blade surface, and two slits that are on the extension of each other in one stroke, that is, on the same line can be formed.

FIG. 2 is a view showing the convex cutting edge 11. In the present invention, the relationship between the angle of the cutting edge surface 12 on the material input side and the cutting edge surface 13 on the output material side of the convex cutting edge 11 is defined with respect to the sheet metal 4 surface. That is, when the angle between the blade edge surface 12 on the material input side and the sheet metal 4 surface is x, and the angle between the blade edge surface 13 on the material output side and the sheet metal 4 surface is y, x> y. is there. Here, if both x and y exceed 90 degrees, no cutting edge is formed, so it goes without saying that the angle is less than 90 degrees. The range of x and y usually used is 30 degrees to 50 degrees, and the value of xy is most preferably about 2 to 5 degrees. With such an angle relationship, the tip of the convex cutting edge 11 is eccentric toward the material input side.
As shown in the figure, the developed length of the bone part 14 on the input side is shorter than the developed length of the bone part 15 on the output side. Conventionally, when there are a plurality of cutting edges, this bone portion is excessively large and stretched downward, so that the square changes from a regular rhombus to a square shape. Thus, the length of the bone after the expanded mesh 16 is developed can be made uniform, and the grid shape can be made a uniform rhombus shape. Therefore, it is possible to suppress the variation in the developed width (W) of the expanded mesh, which has conventionally occurred. In addition, since the excessively stretched bone 5 as shown in FIG. 6 cannot be generated, stress at the bone 5 and the nodule 5-1 connected to the bone 5 can be reduced. If the stress at the time of processing becomes excessive, cracks occur in the bones and nodules, and the strength of the expanded mesh part is reduced, but according to the method of the present invention, it is possible to suppress such a phenomenon that has occurred conventionally. it can.

Since the first die blade 7a on the material input side corresponds to the outermost side of the expanded mesh, there is a case where a trapezoidal blade is provided as shown in FIG. 1 without a convex blade. However, in such a case, the relationship between the angle between the cutting edge surface and the sheet metal may be applied to at least the second die blade 7b and thereafter.

When an expanded mesh formed by using a lead-calcium alloy as a sheet metal is used as a grid of a lead-acid battery, variations in the expanded width of the expanded mesh, that is, variations in the electrode plate height can be reduced. In particular, when applied as a positive electrode expanded grid, oxidative corrosion at bones and nodules can be suppressed, and battery life can be improved.

Further, in the composition of the sheet metal 4, when the calcium content is 0.04% by mass to 0.10% by mass,
When the content of tin is increased to a range of 0.8% by mass to 2.0% by mass, the elongation percentage of the sheet metal 4 decreases. FIG. 6 due to processing stress due to the decrease in elongation
, The incidence of cracks at the bones 5 and the nodules 5-1 increases, which adversely affects the battery life. Therefore, 0.04% by mass to 0.10% by mass of calcium is used as the sheet metal 4.
When it is contained, the effect of the present invention can be more remarkably obtained by using a rolled lead-calcium-tin alloy containing 0.8% by mass to 2.0% by mass of tin.

Then, the expanded grid body thus obtained is filled with a positive electrode active material paste for a lead storage battery, aged and dried to form a positive electrode plate, and this positive electrode plate, a conventional separator, and a conventional negative electrode plate are used. To form the electrode plate group, and thereafter, the lead storage battery of the present invention can be formed according to a usual method.

Although an example has been described in which the number of die edges of the die blades is two, this number can be three or more. In this case, the production speed can be further improved.

[0024]

EXAMPLES <Example 1> Expanded mesh sheets were produced according to the method of the present invention, conventional examples and comparative examples, and evaluated. In addition, in the present invention example, the conventional example, and the comparative example, as the sheet metal, lead-0.06 mass% calcium-1.
A rolled lead alloy sheet obtained by rolling a cast slab of 8% by mass tin alloy was used. The thickness of the cast slab before rolling was 10
mm, and the thickness of the rolled lead alloy sheet after rolling is 1.0 mm.

Inventive Example An expanded network was formed according to the above-described embodiment of the present invention.

The angle x between the sheet metal 4 and the cutting edge surface 12 on the material input side of the convex cutting edge 11 shown in FIG. 1 and FIG. The angle y with the metal 4 was formed at 40 degrees to form an expanded mesh.

Conventional Example An expanded mesh was produced using the die cutter 1 shown in FIG. At this time, the angle x between the cutting edge surface on the material input side of the convex cutting edge 3 and the sheet metal 4 and the angle y between the cutting edge surface on the material output side and the sheet metal 4 were all constant at 42 degrees.

Comparative Example An expanded mesh was produced using the die cutter 17 shown in FIG. Die blades 18a, 18b, 18c, 18d, 18e, 18 constituting this die cutter 17
f has a single cutting edge, and the cutting edge surface 2 on the input side of the convex cutting edge 19 after the second cutting edge (after the die blade 18b).
The angle x between 0 and the sheet metal 4 and the angle y between the cutting edge 21 on the material discharge side and the sheet metal 4 were all set to a constant value of 42 degrees.

As shown in FIG. 3, in the expanded mesh according to the present invention, the lengths of the bones constituting the mesh were uniform, and there was no variation in the shape of the diamond-shaped squares forming the mesh. In addition, the expanded mesh of the comparative example had the same uniform bone length as the expanded mesh of the example of the present invention shown in FIG. 3, and there was almost no variation in the shape of the grid.

On the other hand, as shown in FIG. 6, the expanded mesh according to the conventional example has long and short bones constituting the mesh, and the mesh constituting the mesh has a square shape from a regular diamond shape to a substantially square shape. Variation was observed up to.

The expanded widths (expanded width (W) dimensions in FIG. 3, design value is 120 mm in FIG. 3) of the expanded meshes of the present invention example, the conventional example, and the comparative example are measured at 500 points at intervals of 100 mm. The maximum, minimum and standard deviation were determined. Table 1 shows the results.

According to the results shown in Table 1, the standard deviation of the developed width of the expanded mesh of the conventional example was 1.058, while the standard deviation of the developed width of the comparative example and the example of the present invention was 0.244. . From these results, it can be seen that according to the configurations of the present invention and the comparative example, variations in the developed width can be reduced and the precision can be improved as compared with the conventional example.

[0033]

[Table 1]

As shown in FIG. 5, according to the configuration of the present invention and the comparative example, it can be seen that the variation in the developed width can be reduced as compared with the conventional example. When the developed width corresponds to the electrode plate height, it is possible to suppress variations in the electrode plate height. The expanded network of the comparative example has no problem as in the conventional example, and a good expanded network with little variation can be obtained. However, the expanding processing time is doubled, which is not preferable. This problem of doubling the processing time requires doubling the processing speed of the press machine for reciprocating the die cutter, which is not preferable in terms of manufacturing cost.

Example 2 The expanded meshes of the present invention, the conventional example and the comparative example in Example 1 were filled with an active material paste for a lead storage battery, cut into a predetermined shape, and then aged and dried. After that, a positive electrode plate for a lead storage battery was produced.

Further, in the expanded meshes of Example 1 of the present invention, the conventional example and the comparative example, the calcium content of the sheet metal was fixed at 0.06% by mass.
Tin content of 0.3%, 0.8% and 2.0%
A sample having a mass% was prepared. Here, each of these expanded networks was filled with a positive electrode active material paste for a lead storage battery, and then aged and dried to prepare a positive electrode plate.
A 12V48Ah automotive lead-acid battery was constructed by combining these positive electrode plates with a conventional microporous polyethylene separator and a conventional negative electrode plate. Table 2 shows the configurations of these batteries.

[0037]

[Table 2]

The batteries shown in Table 2 were subjected to a light load life test (JIS D5301) in a gas phase at 75 ° C. Table 2 also shows the results of the light load life test. In addition, the life test result was shown by the index which made the life cycle number of the battery D of a conventional example 100.

From the results shown in Table 2, the batteries A,
It can be seen that B and C can obtain better life characteristics compared to the conventional batteries D, E and F, respectively. In particular, regarding the batteries of 0.8% by mass and 2.0% by mass, in which the tin concentration in the lattice is increased, the effect of improving the life by increasing the tin concentration is given by the batteries of the present invention in the batteries E and F of the conventional examples. It was smaller than B and C. When these conventional batteries were disassembled and examined, corrosion progressed at the bone portion 5 shown in FIG. 6 and the nodule portion 5-1 connected to the bone portion 5 in the positive electrode expanded lattice body, which were stretched more than the others. 5-1 had been cut. Further, corrosion of the bone portion 5 itself progressed, and a decrease in the cross-sectional area of the bone was observed.

Therefore, when the present invention is applied to a battery in which the tin concentration of the positive electrode grid is increased from 0.8% by mass to about 2.0% by mass for the purpose of improving the service life, the use of tin in comparison with the conventional battery is improved. Since the life extension effect can be obtained more remarkably,
It can be seen that it is preferable to apply the present invention to a battery having such a tin concentration.

Further, the battery of the comparative example has the same life characteristics as the example of the present invention, but is not preferred because productivity such as an expanding speed is inferior.

[0042]

As described above, according to the present invention, in an expanded grid used for a lead-acid battery, the variation in the grid size can be reduced by uniforming the expansion size of the grid, and a highly accurate electrode plate can be maintained at a high productivity. Can be manufactured. Also,
When used as a positive electrode grid, it is easy to improve the life of the battery, and its industrial value is great.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a manufacturing process of an expanded mesh according to the present invention.

FIG. 2 is a front view showing a die blade used in the manufacturing method according to the present invention.

FIG. 3 is a front view showing an expanded mesh according to the present invention.

FIG. 4 is a schematic view showing a die cutter used for expanding according to a comparative example.

FIG. 5 is a schematic view showing a conventional expanding network manufacturing process.

FIG. 6 is a front view showing an expanded mesh according to a conventional method.

[Explanation of symbols]

1,10,17 Die cutter 2,7a, 7b, 7c, 7d, 18a, 18b, 18
c, 18d, 18e, 18f Die blade 3, 11, 19 Convex cutting edge 4 Sheet metal 5, 6 Bone 5-1, 6-1 Knot 8a, 8b, 8c, 8d Blade surface 9 Step 12, 20 Cutting edge surface 13, 21 Cutting edge surface on output side 14 Bone section on input side 15 Bone section on output side 16 Expanded mesh

Claims (5)

[Claims] A plurality of intermittent slit strips are formed in a sheet metal by a die cutter in which a plurality of die blades reciprocating in a direction perpendicular to a sheet metal fed intermittently are arranged so that a blade surface is stepped. The method of manufacturing an expanded mesh sheet, wherein the slits forming the intermittent slits adjacent to each other in parallel and parallel to each other are formed in a staggered manner, and the slits formed in the sheet metal are developed and extended. The blade is provided with a plurality of convex cutting edges so as to simultaneously form a plurality of slits on the same intermittent slit, and the angle between the cutting edge surface of the convex cutting edge and the sheet metal is in relation to the feeding direction of the sheet metal. Manufacture of an expanded mesh sheet characterized in that the angle of the cutting edge on the input side is formed larger than the angle of the cutting edge on the output side. Method. 2. A method for manufacturing a grid for a lead-acid battery, wherein the method for manufacturing an expanded mesh sheet according to claim 1 is a method for manufacturing a grid for a lead-acid battery. 3. A method for manufacturing a grid body for a lead-acid battery, wherein the sheet metal according to claim 2 is a rolled sheet made of a lead-calcium alloy and the obtained expanded mesh sheet is a grid mesh portion. 4. The lead-calcium alloy according to claim 3, having a calcium content of 0.04% to 0.10% by mass and a tin content of 0.8% to 2.0% by mass. The method for producing a grid for a lead-acid battery according to claim 3, wherein: 5. A lead-acid battery, comprising a lead-acid battery grid manufactured by the method for manufacturing a lead-acid battery grid according to any one of claims 2 to 4.