JP3185337B2 - Manufacturing method of lead storage battery - Google Patents

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 a lead-acid battery, and more particularly to the life characteristics of a maintenance-free type (Ca battery) using a lead-calcium-tin-based alloy for an anode grid. An improved lead-acid battery manufacturing method.

[0002]

2. Description of the Related Art In recent years, a maintenance-free lead-acid battery in which a slab of a lead-calcium-tin alloy is cold-rolled, and the rolled sheet is expanded to be used as a grid of electrode plates has been frequently used.

[0003] This type of battery is generally considered to have difficulty in use in a high temperature environment and in use of deep discharge, and as a method of solving this drawback, an alloy containing a large amount of tin or antimony on the surface of a rolled sheet. Techniques have been developed to address the problem by increasing the amount of tin and calcium in the alloy of the slabs that provide the layers and form the substrate to increase the tensile strength.

[0004] The composition of this high tensile strength is 6 in terms of tensile strength.
kg / mm ² and sometimes even 7 kg / mm ² .
The technology utilizing this high tensile strength composition has basically become an important technology for improving the life of maintenance-free batteries, but on the other hand, if the tensile strength is increased by increasing the content of calcium and tin, the tensile strength will increase. In response to the increase in elongation, the elongation until fracture is reduced, it is easy to break during expansion processing, stress remains at the intersection of the mesh body, corrosion tends to occur, and the protective layer on the surface peels off It has been found that, in addition to the occurrence of the expected long life, an abnormal short life phenomenon sometimes occurs.

[0005] A detailed examination of this situation reveals that storage conditions and periods between the rolling process and the expanding process are deeply related.
It has been found that there is an appropriate period for each storage temperature, and the relationship between the appropriate temperature and period is complicated, so that the current production plan cannot be established. For example, when stored at a low temperature, it takes time to obtain appropriate hardness, and when the storage is too short, it is too soft and easily deformed by paste application and subsequent electrode plate handling. Conversely, if stored at high temperature, the hardness will be adequate in a short time, but if the appropriate period is short, beyond that period, it will be too hard and cause trouble at the time of high tensile strength. This property causes great confusion in managing actual production. Conventionally, when using a composition in a region where the tensile strength of age hardening is low, unlike high temperature treatment for accelerating age hardening and quickly reaching an equilibrium state,
It is extremely important to appropriately control the hardness in the middle of the process in which the age hardening is not completed, in actual production control.

[0006]

That is, in applying a lead-calcium-tin alloy to an expanded lattice with an alloy composition in a high tensile strength region, a rolled sheet in a process in which the tensile strength is changing toward a high equilibrium value. It is a practically important task to ensure stable elongation and tensile strength suitable for the expanding process for as long as possible and to optimize production control. The present invention solves such a problem, and by actively utilizing the age hardening phenomenon, it is possible to secure an appropriate period for long-term processing, stably maintain the quality of the electrode plate, and easily perform production control. An object of the present invention is to provide a method for manufacturing a lead storage battery.

[0007]

In order to achieve the above object, a method for producing a lead-acid battery according to the present invention comprises casting a lead-calcium-tin alloy having a tensile strength after age hardening of 6 kg / mm ² or more. In a grid manufacturing process of an electrode plate for expanding a rolled sheet obtained by subjecting a slab to cold rolling to a rolling process, after rolling, the rolled sheet has a tensile strength of 5 kg / m.
stored at 35 ° C. or higher until m ^2, then 25 ° C. or less
In is intended to include storing step.

[0008]

[Action] This manufacturing method, in the case of rolling processing, and stored at 35 ° C. or higher until anti tension 5 kg / mm ² to promote age hardening, slow the age hardening and store the subsequent 25 ° C. or less and, by extending the period until the tensile strength 6 kg / mm ² of an upper limit that is suitable for expanding process, by a sufficient period of tensile strength 5~6kg / mm ² which is suitable for the expansion work, the pole plate grid The production control in the manufacturing process can be easily performed, and a grid of stable quality electrode plates can be manufactured in which cracks hardly remain at intersections of lattice bones and peeling of a dissimilar alloy layer on the surface does not easily occur. In summer high temperature environment (35 ℃ or more environment)
In the case of rolling at the bottom), tensile strength 5kg / m
and stored until the m ^2, this store in the subsequent 25 ℃ below
With the above, the period of the tensile strength of 5 to 6 kg / mm ² is sufficiently provided.
Can be secured.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a lead storage battery according to an embodiment of the present invention will be described below with reference to the drawings.

Referring to FIG. 1, the relationship between the storage temperature and the storage period after rolling of a lead-calcium-tin alloy using a high tensile strength composition is shown as an example. 2% rolled sheet lead-calcium-
An example of a tin-based alloy will be described.

In FIG. 1, a region [L] indicates a region where the tensile strength of the alloy is too soft and lower than 5 kg / mm ² , and a region [H] indicates a region where the tensile strength of the alloy is too hard and higher than 6 kg / mm ^2. .

Here, the curve A shows the relationship between the environmental temperature at which the rolled sheet is stored after rolling and manufacturing and the storage period at which the upper limit tensile strength 6 kg / mm ² suitable for expanding is reached, and the curve B is also suitable for expanding. Lower limit tensile strength 5kg
4 shows the relationship with the storage period that reaches / mm ² .

The rolled sheet immediately after the cold rolling of the cast slab has a tensile strength (area [L]) of about 4.5 kg / mm ² , and the expanded grid is too soft for pasting. Yield is poor due to deformation at the time of handling of electrode plates. Therefore, in general, a rolled sheet is generally subjected to expansion processing after accelerating and stabilizing age hardening in a high-temperature environment and then expanding.

However, the final tensile strength of this alloy sheet after age hardening is 7.2 to 7.6 kg / mm ² (area [H]).
And if this rolled sheet is expanded,
Not only cracks and stress abnormalities occur at intersections of lattice bones at the time of processing, peeling of dissimilar alloy layers easily occurs, but even at first glance what seems to be good products, corrosion progresses at intersections of lattice bones during use,
An abnormal short life may occur. From these viewpoints, it is believed that a range of tensile strength suitable for processing would be 5-6 kg / mm ² . That is, the curve between the curve A and the curve B is appropriate, but in a high temperature environment, the tensile strength is 5 to 6 kg / mm ^2.
The appropriate period of time is short, and at a low temperature, the appropriate period can be lengthened, but the period until processing can be extended, and the stock must be increased.

That is, this is an essential problem that has made production management of this type of rolled sheet and the expanding process difficult.

In the present embodiment, the storage of the rolled sheet is simply left to the natural environment temperature, and the properties of the rolled sheet are not stabilized by age hardening during that time. The purpose of the present invention is to positively utilize the property of promoting age hardening to secure the appropriate expanding processing time for a long time.

(Example 1) In FIG. 1, when the rolled sheet is rolled at, for example, 20 ° C. in a normal temperature environment, when the rolled sheet is stored as it is at 20 ° C., the lower limit tensile strength 5 kg / mm ² suitable for the expanding process is obtained. Since an age hardening period of about 10 days (a period between the curve B and the X axis) is required until that time, the expanding process cannot be performed during that period. By accelerating, the period until the tensile strength becomes 5 kg / mm ² can be shortened to about 1 day (the period between the curve B and the X axis), and thereafter, by expanding at a low temperature, for example, at 20 ° C. Upper limit tensile strength 6kg / mm ² suitable for
About 10 days suitable for expanding processing with a tensile strength of 5-6 kg / mm ² until reaching (the period of S between curves A and B)
As the age hardening period can be ensured, production control of the electrode plate grid manufacturing process can be easily performed, and stress and cracks hardly remain at the intersections of the lattice bones, and the dissimilar alloy layer on the surface can be removed. It is possible to produce a grid of electrode plates of stable quality that is unlikely to occur.

(Example 2) In FIG. 1, when the rolled sheet is rolled at 35 ° C. in a high-temperature environment in summer, for example, the rolled sheet is stored at 35 ° C. for about 2 days (the curve B and the X-axis 5 kg / mm ²
In addition, the tensile strength becomes 6 kg / mm ² in about 3 days (the period of R between the curve A and the curve B), so that the period during which the expanding process can be performed is limited to a very short period. To improve this, after rolling, the rolled sheet is cooled to a low temperature, for example,
By storing at 0 ° C., the period until the tensile strength reaches 5 kg / mm ² can be extended to about 10 days (the period between the curve B and the X axis). Further, by keeping the storage at 20 ° C., the period of the tensile strength of 5 to 6 kg / mm ² is secured for about 10 days (the period of S between the curve A and the curve B) to control the production of the electrode plate grid manufacturing process. In addition to being easily implemented, a grid of stable quality electrode plates can be manufactured in which stress and cracks hardly remain at intersections of lattice bones and peeling of a dissimilar alloy layer on the surface does not easily occur.

[0019]

As is apparent from the above description of the embodiment, according to the method of manufacturing a lead-acid battery of the present invention, the production plan is not confused with the properties of the alloy sheet exhibiting the age hardening phenomenon, but the properties are reduced. By proactively utilizing it, it is possible to secure an appropriate period for long-term processing, stabilize electrode plate quality and enhance production management, and its industrial value is extremely large. .

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between storage temperature and storage period of tensile strength of a rolled sheet of a lead-calcium-tin alloy in a method of manufacturing a lead storage battery according to an embodiment of the present invention.

Continuation of the front page (72) Inventor Hiroshi Yasuda 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (58) Field surveyed (Int. Cl. ⁷ , DB name) H01M 4/68-4/74

Claims (1)

(57) [Claims] (1) Tensile strength after age hardening has tensile strength of 6 kg / m.
In a grid manufacturing process for an electrode plate, in which a rolled sheet obtained by cold rolling a cast slab of a lead-calcium-tin alloy having a m ² or more is expanded, the tensile strength of the rolled sheet after rolling is 5 kg / mm ^2. 35 until
A method for producing a lead storage battery, comprising a step of storing at a temperature of not lower than 25 ° C. and then at a temperature of not higher than 25 ° C.