JPH06338328A - Manufacture of expand grid unit for lead-acid battery - Google Patents

Abstract

PURPOSE:To provide a battery excellent in a life characteristic while improving productivity and stabilizing quality by reducing a grid break and a grid crack at the time of expand working, in a method of manufacturing an expand grid unit for the lead-acid battery. CONSTITUTION:In an expand working cutter, as viewed from its side surface, in a point end part of the first blade 1 of a tooth form having a trapezoidal part in the point end part, an R is respectively provided in two points of a crossing part with the bottom surface and a sloped surface into contact with the bottom surface, and in the point end part of the second blade 2 thereafter, an R larger than that of the first blade 1 is provided in the topmost end part between the sloped surfaces, to perform working by using this cutter. By the method of manufacturing an expand grid unit, by reducing breaking and cracking a grid, productivity can be improved and quality can be stabilized to obtain a lead-acid battery excellent in a life characteristic.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an expanded grid for a lead storage battery, and more particularly to improvement of a blade shape of the cutter.

[0002]

2. Description of the Related Art In recent years, automobiles have been rapidly improved in performance and electronics, and as a power source for these automobiles, lightweight and long-life automobile batteries having excellent liquid-reducing characteristics have been demanded. To meet this demand, lead acid batteries for automobiles using low antimony-based or calcium-based lattice alloys are currently on the market. There are two methods of manufacturing the grid of these batteries, a casting method and an expanding method.
There are streets, but generally calcium-based alloy lattices are produced by the expand method, which has good productivity.

This expanding system has a large number of blades having different blade die shapes from the first blade, which is the blade die for forming the frame bone at the bottom of the lattice, and the second blade and later blades, which are the blade die for forming the mesh portion. The cutter is repeatedly moved up and down, the belt-shaped lead alloy sheet is fed in a certain direction in conjunction with the vertical movement of the cutter, and the belt-shaped lead alloy sheet is sequentially arranged from the outside to the inside of the sheet width at a predetermined interval on one side of the sheet thickness. A notch is made from this and the notch is expanded to form a mesh portion of the lattice. It should be noted that the shape of the cutter here is such that the tip of the blade has a trapezoidal portion and the trapezoidal bottom has a square shape when viewed from the side.

[0004]

However, in order to develop a long-life lead-acid battery, in order to improve the lattice strength and the corrosion resistance, a lead-calcium-tin (Pb-Ca-Sn) alloy in the base sheet is used. When the Sn content was increased, a lead alloy sheet with a high tensile strength was formed, and a large number of broken bones were generated during the expanding process. Further, when the battery having a short life was disassembled after the evaluation, the bone of the lattice was broken (cut). The cause of the bone breakage of the grid during use of this battery was that cracks were generated in the grid during the expansion process, and corrosion was promoted from the cracked portions.

As a result of detailed examination of the causes of bone breakage and cracks in these lattices, bone breakages and cracks were found at the lattice portions which hit the corners of the tip of the blade die. This is because stress concentrates on the squared portions, and therefore it is required to eliminate stress concentration on this one point and perform the expanding process.

The present invention solves the above-mentioned problems, and an object of the present invention is to stabilize the quality of the grid and to extend the life of the battery.

[0007]

In order to solve these problems, a method for manufacturing an expanded grid for a lead storage battery according to the present invention uses a plurality of blades having different blade shapes from the first blade to the second blade. Repeatedly move the cutter with the cutter up and down, feed the lead alloy sheet in conjunction with the up and down movement of this cutter, and cut the lead alloy sheet from the outside to the inside of the sheet width sequentially from one side of the sheet thickness at predetermined intervals. This is a method of manufacturing an expanded lattice in which the notches are expanded, and the cutter has a trapezoidal portion at the tip when viewed from the side, and the tip of the first blade of the blade type has a bottom surface and two left and right slopes in contact with the bottom surface. A cutter is provided with R at each of the two intersecting points, and the tip of the blade die after the second blade is provided with a larger R than the first blade at the tip end between the slopes of the trapezoidal portion. Using extract It is intended to command processing.

[0008]

According to the manufacturing method of the present invention, the bone breakage (cutting) of the lattice caused by the stress concentration at the cornering of the blade die tip during the expanding process is reduced by adding R to disperse the stress. Therefore, it is possible to improve productivity. At the same time, since the generation of cracks in the lattice due to stress concentration is reduced, the number of lattice breakages during use of the battery is reduced, and a lead storage battery having excellent life characteristics can be obtained.

[0009]

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

FIG. 1 (A) is a side view of a part of a cutter used in the expanding process of this embodiment, as seen from the side.
(B) is a view of this from below. The tip shape of the cutter is different between the first blade and the second and subsequent blades,
It is arranged with a constant gap from the outside to the inside. The blade die 1 of the first blade is a blade die for forming the lowermost frame of the expanding lattice, and the blade die 2 after the second blade is a mesh portion forming blade die.

FIG. 2 is an enlarged view of the tip of the blade die of the cutter of the above embodiment. FIG. 2A is a first blade, and FIG. 2B is a side view of the tip of the blade die after the second blade. First blade on 3 (A),
(B) shows a blade type perspective view after the second blade. Figure 4
As a conventional example, (A) is a first blade, (B) is a side view of the tip of the blade die after the second blade, and (A) is a first blade, (B).
The perspective views after the second blade are shown in FIG. In the embodiment of the present invention, the tip portion of the first blade of the blade die is rounded at two intersections of the bottom surface of the trapezoidal portion and the left and right slopes contacting the bottom surface.
The tip of the blade die after the second blade is provided with a radius R larger than that of the first blade at the most distal end between the left slope and the right slope of the trapezoidal portion. Therefore, when the lead alloy sheet is expanded, the stress is not concentrated on the squared portion unlike the conventional blade type, but is distributed on the entire R portion, preventing the lattice from breaking and cracking. it can.

Further, in order to disperse the stress more uniformly, as the R to be attached to the die after the second blade, the straight line portions of the left and right slopes constituting the tip portion are tangential lines of R provided at the tip end portion. It is good to

If the radius R of the tip portion is small, the radius becomes sharp and the lattice is broken. Therefore, as shown in FIG. 6, the punching portion of the blade-shaped lead alloy sheet after the second blade has an arc length Q of the R portion provided at the tip end with respect to the punching length P of the blade die. When the ratio of Z is Z, it is preferable to determine R so that Z becomes 0.3 or more.

By using the cutter of the above-mentioned embodiment and the conventional cutter, a high tensile strength Pb-C containing a large amount of Sn is used.
The a-Sn-based lead alloy sheet was expanded by 10,000 for each electrode plate, and the incidence of bone breakage was measured. The result is shown in FIG. 7. As can be seen from the results of FIG. 7, compared with the expanded lattice using the conventional blade die, the expanded lattice using the blade die of this embodiment has almost no bone breakage, and the lattice can be efficiently produced. Became.

[0015]

As described above, according to the method for manufacturing an expanded lattice for a lead storage battery of the present invention, it is possible to remarkably reduce the occurrence of broken bones and cracks in the lattice during the expanding process, and to improve the productivity. It is possible to stabilize the quality. Further, the reliability of the lead storage battery in the market can be secured.

[Brief description of drawings]

FIG. 1A is a side view of an expanding cutter according to an embodiment of the present invention, and FIG. 1B is a view seen from below.

FIG. 2 (A) is a side view of the first cutting blade type of the expanding cutter according to the embodiment of the present invention (B) is a side view of the second and subsequent blade types.

FIG. 3A is a perspective view of a first blade blade die according to an embodiment of the present invention. FIG. 3B is a perspective view of blade blade die after the second blade.

FIG. 4 (A) is a side view of a first blade blade type cutter for an expanding process of a conventional example. (B) is a side view of a blade blade type after the second blade.

FIG. 5A is a perspective view of a conventional first blade blade die, and FIG. 5B is a perspective view of a blade die of the second blade and thereafter.

FIG. 6 is a side view of the expanding alloy cutter according to the embodiment of the present invention when the lead alloy sheet is cut open.

FIG. 7 is a diagram showing a bone fracture occurrence rate of the expanded grid.

[Explanation of symbols]

 1 First blade (frame bone forming blade type) 2 Second blade (mesh portion forming blade type) 3 Lead alloy sheet P Cutting edge length of blade die Q Arc length Z Q / P

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Yasuda 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Katsuhiro Takahashi 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (3)

[Claims] 1. A strip-shaped lead alloy sheet is fed in conjunction with the vertical movement of the cutter by repeatedly moving up and down a cutter having a large number of blades having different blade shapes from the first blade and the second blade and thereafter, The lead alloy sheet of the sheet width from the outer side to the inner side in order to make a notch from one side of the sheet thickness at a predetermined interval, and a method for manufacturing an expanded lattice to expand the notch, the cutter, the table At the blade tip portion of the first blade having a shape portion at the tip portion, R is provided at each of two intersections of the bottom surface and the left and right slopes contacting the bottom surface.
The lead storage battery is characterized in that the blade tip portion after the second blade is expanded using a cutter provided with R larger than the first blade at the tip end portion between the left and right slopes. For manufacturing expanded grids for automobiles. 2. The expanded grid structure for a lead storage battery according to claim 1, wherein the blade die after the second blade has a straight line portion of a slope forming a tip portion thereof as a tangent line of R provided at the most distal end portion. Production method. 3. The ratio Z of the arc length Q of R provided at the tip end to the punching length P of the blade die is 0.3 in the portion where the blade-type lead alloy sheet after the second blade is punched. It is above, The manufacturing method of the expanded grid body for lead acid batteries of Claim 1 or 2.