JP4069674B2 - Manufacturing method of expanded grid for lead-acid battery - Google Patents

Description

【００２２】
表１に示したように、本発明の構成によれば、鉛合金シートの組成によらず、エキスパンド加工幅のばらつきを抑制できることがわかる。また、本発明例によれば比較例で発生していたような変形部８も発生していなかった。このような寸法ばらつきの抑制により、寸法精度に優れた極板を得ることができ、極板群製造工程における生産性を低下させることがない。
【００２３】
（実施例２）
前記の実施例１で作製した本発明例と従来例のエキスパンド網目に活物質ペーストを充填し、切断加工して単一極板とした後、熟成乾燥を行い、未化成の正極板とした。なお、鉛合金シート組成として実施例１のＰｂ−０．０６質量％Ｃａ−１．４０質量％ＳｎおよびＰｂ−０．０６質量％Ｃａ−０．６０％質量Ｓｎに加えて、Ｐｂ−０．０６質量％Ｃａ−０．８０質量％Ｓｎ、Ｐｂ−０．０６質量％Ｃａ−１．００質量％ＳｎおよびＰｂ−０．０６質量％Ｃａ−１．２０質量％Ｓｎのものを用い、それぞれ本発明例および比較例により正極板を作製した。
【００２４】
これらの正極板７枚と定法による負極板７枚とを組合せて極板群を構成し、この極板群を用いて８０Ｄ２６形の自動車用鉛蓄電池（以下、電池という）を作製し、これらの電池について寿命試験を行った。寿命試験としてはＪＩＳ−Ｄ５３０１で規定されている軽負荷試験を７５℃気相雰囲気で行った。その結果を図３に示す。
【００２５】
図３に示した結果から本発明例によれば寿命サイクルが従来例より向上していることがわかる。これらの寿命試験終了後の電池について分解して調査し、正極格子体の状態について観察した。
【００２６】
その結果、比較例の製造法によるものはエキスパンド網目部で腐食断線が顕著に発生していた。特にその傾向は鉛合金シート中の錫濃度に影響され、錫濃度が１．０質量％を越えて高くしたものに一層顕著に腐食断線が発生していた。一方、本発明例によるものは錫濃度が１．０質量％を越えた領域でも安定した寿命特性を有していた。
【００２７】
【発明の効果】
このように本発明のエキスパンド格子体の製造法によれば、エキスパンド展開寸法のばらつきを低減させて寸法精度の高い極板を供給することが可能となる。さらにエキスパンド網目部の部分的な変形と、これによる腐食を抑制することによって、この格子体を正極に用いた時の寿命特性を改善できることから、工業上、極めて有用である。
【図面の簡単な説明】
【図１】 本発明のエキスパンド格子体製造法に用いるダイスカッターとエキスパンド網目を示す説明図
【図２】 本発明の製造法によるエキスパンド網目の部分拡大正面図
【図３】 本発明例および比較例の製造法による格子体を用いた鉛蓄電池の寿命サイクル数を示す図
【図４】 従来のダイスカッターを用いてエキスパンド網目を形成する状態を示した説明図
【図５】 従来のエキスパンド網目の部分拡大正面図
【符号の説明】
Ａ₁〜Ａ_n，Ｂ₁〜Ｂ₁₈ 加工刃
１，１０ ダイスカッター
２，２a，２b，２c 側面
３ 鉛合金シート
４ スリット
５ 線条部
６ 網目
７，７a 辺
８ 変形部
９ 非展開部 [0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing an expanded lattice for a lead storage battery.
[0002]
[Prior art]
In order to improve productivity, lead storage battery grids are expanded by casting molten lead alloy into a mold and casting lead or lead alloy into a thin sheet by rolling, etc., and then expanding the sheet. Processing methods are becoming widely used.
[0003]
As a expanding process, a reciprocating die cutter is used to leave a non-expanded portion 9 in the center in the width direction of the lead alloy sheet , and to form slits on both side ends , and at the same time, expand and stretch the linear portions surrounded by the slits. There is a so-called reciprocating expanding method for forming a lattice network.
[0004]
The die cutter 1, as shown in FIG. 4, the tip (the where n is a natural number) machining blade A ₁ to A _n of the substantially V-shape is arranged in a row. Each side 2 of the processing blade A ₁ to A _n are adjacent sides 2a, side 2b, forms sequentially stepwise from the side 2c ..., the step size corresponds to the width of the linear portions.
[0005]
Wherein the die cutter 1 of lead alloy sheet Irizai side of the machining blade A ₁ disposed at both side ends _{(hereinafter,} referred to as a first blade) is formed on both side ends of the lead alloy sheet 3 as shown in FIG. 4 Corresponds to the slit 4 to be made. As shown in FIG. 5, the linear portion 5 outside the slit 4 is formed in a trapezoidal shape so as to correspond to the side of the lattice when the slit is expanded and stretched. In order to form the diamond-shaped mesh 6 after the second blade, the tip is formed in a V shape corresponding to the sides 7 and 7a of the mesh 6.
[0006]
Conventionally, it has been common knowledge that the edge angles (α) of the die blades after the second blade are the same, and the die blade shapes after the second blade are the same. However, when the expansion process is performed with such a die cutter, a part of the expanded mesh is deformed and a deformed portion 8 is partially formed, so that the expanded dimension of the expanded mesh varies, resulting in variations in the electrode plate dimensions. This was a cause of problems in the plate assembly process. In particular, when the pole plate height varies and is lower than the specified value, in the strap manufacturing process of collective welding of the electrode plate ears, the ear length included in the strap is less than the specified value, As a result, there exists a problem that the welding strength of an ear | edge part falls.
[0007]
Furthermore, in recent years, the lead alloy sheet tends to be thinned for the purpose of reducing the weight of the storage battery. Furthermore, the tin concentration in the lead alloy may be 1.0% by mass or more for the purpose of improving the corrosion resistance. Although such a rolled lead sheet containing 1.0 mass% or more of tin is excellent in the corrosion resistance of the sheet material itself, cracks are likely to occur in the deformed portion 8 due to a decrease in elongation. When the tin content is less than 1.0% by mass, cracks do not occur due to the deformation as described above. However, when the tin content exceeds 1.0% by mass, cracks occur due to the deformation. When the expanded lattice body in which such cracks are generated is used as a positive electrode, there is a problem in that corrosion proceeds from the deformed portion and the life of the storage battery is reduced.
[0008]
[Problems to be solved by the invention]
The present invention provides a method for manufacturing a grid for a storage battery using the reciprocating expand method described above, and suppresses variations in grid dimensions due to partial deformation of the expanded mesh, and also prevents partial deformation and cracks in the grid caused by the deformation. An object of the present invention is to obtain an expanded lattice body having excellent life characteristics by suppressing the generation.
[0009]
In order to solve the above-mentioned problem, the invention according to claim 1 of the present invention is the lead alloy obtained by repeatedly pushing a die cutter having a plurality of processing blades arranged in a row from one side of the lead alloy sheet to the other side. A method for producing a grid for a lead storage battery using a so-called reciprocating expand in which a staggered slit is formed on a sheet, and a linear portion surrounded by the slit is expanded and extended by a tip of the processing blade, the die cutter the is arranged to form a slit in the inner direction of the sequential lead alloy sheet from a slit located in the first blade and the both side edges to form a slit located on both side ends of the lead-acid battery alloys sheet with 2 blades to N-th blade (where N is a natural number of 3 or more), the cutting edge angle α of any k-th k blade except for said first blade (where a 2 ≦ k ≦ N-1) And it is characterized in any flies more than k th (k + 1) -th alpha _k in edge angle alpha _{k + 1 <it} was alpha _{k + 1} and.
[0010]
The invention according to claim 2 of the present invention shows that the lead alloy sheet used in claim 1 is composed of a lead-calcium-tin alloy containing at least 1.0% by mass or more of tin.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The object of the present invention can be achieved by employing the configuration described in each claim as an embodiment. Hereinafter, the embodiment will be described specifically and in detail with reference to the drawings.
[0012]
FIG. 1 is a front view showing a die cutter 10 used for reciprocating expanding used in the present invention. The die cutter 10 is composed of processing blades B ₁ to B ₁₈ arranged in series. FIG. 1 shows an example in which the die cutter 10 is composed of 18 processing blades B, but the number of processing blades is appropriately determined according to the desired lattice size and mesh size.
[0013]
B ₁ that is the first blade on the input side of the lead alloy sheet has a trapezoidal shape, and is not different from the conventional configuration. In the present invention sequentially increased constituting toward the exit material side cutting edge angle of the B ₂ subsequent processing blade is a second blade from Irizai side. That is, the blade edge angle α _k of any k-th k-th blade (except 2 ≦ k ≦ N−1) excluding the first blade and the (k + 1) -th blade edge angle α _{k that is the} most larger than the arbitrary k-th blade. _{In +1} , α _k <α _{k + 1} is set as a feature condition.
[0014]
By reciprocating and expanding the lead alloy sheet using the die cutter 10 having such a configuration, as shown in FIG. 5, it is possible to develop without generating the locally deformed portion 8 of the expanded mesh that has conventionally occurred. By making the state uniform as shown in FIG. 2, it is possible to suppress variation in the mesh development dimension and improve the dimensional accuracy of the electrode plate.
[0015]
Here, as the lead alloy sheet, a lead-calcium-tin alloy sheet having a tin content set to 1.0 mass% or more for the purpose of improving corrosion resistance can be used. When a lead-calcium-tin alloy with a tin content of 1.0 mass% or more is used and a reciprocating expansion process is performed with a conventional die cutter, a crack is generated in the deformed portion 8 and such a crack is generated. When the expanded lattice body was used for the positive electrode, there was a problem that the crack was preferentially corroded and the battery life was extremely shortened. In the present invention, since the deformation of the expanded mesh itself that causes cracks can be suppressed, the short life of the storage battery can be suppressed. However, if the tin content is 2.2% by mass or more, the elongation amount of the lead alloy sheet is lowered and is not suitable for the expanding process.
[0016]
【Example】
An expanded grid for a positive electrode, a positive electrode plate and a lead-acid battery using the same were manufactured by the method for manufacturing an expanded grid for a lead storage battery according to the present invention and a comparative example.
[0017]
Example 1
According to the above-described embodiment of the present invention, an expanded lattice for positive electrode and an expanded lattice by a conventional example were manufactured. As a lead alloy sheet, the composition is Pb-0.06 mass% Ca-1.40% mass Sn, the thickness is 0.9 mm, the tensile strength just before the expanding process is 70 N / mm ² , and the composition is Pb-0. A material having a mass of 0.9 mm and a tensile strength of 37 N / mm ² immediately before the expansion process was used.
[0018]
In the present invention example, the blade edge angle α ₂ of the second blade is set to 86 ° from the input side of the lead alloy sheet, and thereafter the blade edge angle is gradually increased by 2 ° toward the output material side, and the blade edge angle α of the final 18th blade is increased. ₁₈ was 118 °.
[0019]
In the comparative example, as in the present invention example, a die cutter composed of 18 machining blades is used, but all the blade edge angles β from the second blade from the lead alloy sheet input side to the final 18th blade are all included. Constant at 102 °.
[0020]
Using these dice cutters according to the present invention and comparative examples, expand processing is performed to produce 10000 sheets of grids, and the standard deviation of the processing width varies when the expanded width of these grids is set to 120 mm. The results are shown in Table 1.
[0021]
[Table 1]

[0022]
As shown in Table 1, according to the configuration of the present invention, it can be seen that the variation in the expanded width can be suppressed regardless of the composition of the lead alloy sheet. Further, according to the example of the present invention, the deformed portion 8 as occurred in the comparative example was not generated. By suppressing such dimensional variations, an electrode plate with excellent dimensional accuracy can be obtained, and productivity in the electrode plate group manufacturing process is not reduced.
[0023]
(Example 2)
The active material paste was filled in the expanded mesh of the present invention example and the conventional example prepared in Example 1 and cut into a single electrode plate, followed by aging and drying to obtain an unformed positive electrode plate. In addition to Pb-0.06 mass% Ca-1.40 mass% Sn and Pb-0.06 mass% Ca-0.60 mass% Sn of Example 1 as a lead alloy sheet composition, Pb-0. Using 06 mass% Ca-0.80 mass% Sn, Pb-0.06 mass% Ca-1.00 mass% Sn, and Pb-0.06 mass% Ca-1.20 mass% Sn, respectively. A positive electrode plate was prepared according to the invention example and the comparative example.
[0024]
An electrode plate group is configured by combining these seven positive electrode plates and seven negative electrode plates by a regular method, and an 80D26 type lead acid battery for automobiles (hereinafter referred to as a battery) is produced using these electrode plate groups. The battery was subjected to a life test. As a life test, a light load test defined in JIS-D5301 was performed in a gas phase atmosphere at 75 ° C. The result is shown in FIG.
[0025]
From the results shown in FIG. 3, it can be seen that according to the example of the present invention, the life cycle is improved over the conventional example. The batteries after the end of the life test were disassembled and investigated, and the state of the positive electrode grid was observed.
[0026]
As a result, in the case of the production method of the comparative example, corrosion breakage occurred remarkably in the expanded mesh part. In particular, the tendency was influenced by the tin concentration in the lead alloy sheet, and corrosion breakage occurred more significantly in the case where the tin concentration was higher than 1.0 mass%. On the other hand, the sample according to the present invention had stable life characteristics even in the region where the tin concentration exceeded 1.0 mass%.
[0027]
【The invention's effect】
Thus, according to the method for manufacturing an expanded lattice body of the present invention, it is possible to supply an electrode plate with high dimensional accuracy by reducing the variation in expanded dimensions. Further, by suppressing the partial deformation of the expanded mesh portion and the corrosion caused thereby, the life characteristics when this lattice body is used for the positive electrode can be improved, and thus it is extremely useful industrially.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a die cutter and an expanded mesh used in the expanded grid manufacturing method of the present invention. FIG. 2 is a partially enlarged front view of the expanded mesh produced by the manufacturing method of the present invention. Fig. 4 is a diagram showing the life cycle number of a lead-acid battery using a grid according to the manufacturing method of Fig. 4. Fig. 4 is an explanatory diagram showing a state in which an expanded mesh is formed using a conventional die cutter. Fig. 5 is a portion of a conventional expanded mesh. Enlarged front view [Explanation of symbols]
_{A 1 ~A n, B 1 ~B} 18 processing blade 1, 10 die cutter 2, 2a, 2b, 2c side 3 lead alloy sheet 4 slit 5 linear portions 6 mesh 7,7a sides 8 deformable portion
9 Non-deployment part

Claims (2)

A die cutter having a plurality of processing blades arranged in a row is repeatedly pushed from one side of the lead alloy sheet to the other side to form a staggered slit on the lead alloy sheet, and the linear portion surrounded by the slit the to a method of manufacturing a grid for a lead storage battery according to the so-called reciprocating expand to deploy stretched by the tip of the machining blade, the die cutter first cutting edge for forming a slit located on both side ends of the lead alloy sheet When the a second blade to N-th blade arranged to form a slit in the inner direction of the sequential lead alloy sheet from a slit located at both side ends (where N is a natural number of 3 or more), the in any of the k-th k-th blade (where 2 ≦ k ≦ a N-1) included angle alpha _k and flies more than any of the k-th (k + 1) th edge angle alpha _{k + 1,} except for the first blade _{k <α k + 1} and to the preparation of expanded grid for a lead-acid battery, characterized in that the. 2. The method for producing an expanded lattice for a lead-acid battery according to claim 1, wherein the lead alloy sheet is composed of a lead-calcium-tin alloy containing at least 1.0% by mass or more of tin.

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