JP3339109B2 - Method of manufacturing expanded grid for lead-acid 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 an expanded grid for a lead-acid battery, and more particularly to an improvement in the blade shape of a cutter.

[0002]

2. Description of the Related Art In recent years, the performance and electronics of automobiles have been rapidly increasing, and as such power sources, there is a demand for long-life automobile batteries that are lightweight and have excellent liquid reduction properties. In order to satisfy this demand, lead-acid batteries for automobiles using a low antimony-based or calcium-based lattice alloy are currently on the market. There are two methods for manufacturing these battery grids: a casting method and an expanding method.
Although there are various ways, lattices of calcium-based alloys are generally produced by an expanding method with good productivity.

The expanding system has a number of blades having different blade shapes from a first blade, which is a blade for forming a frame bone at the lowermost portion of the lattice, and a second blade and subsequent blades, which are blades for forming a mesh portion. The cutter is repeatedly moved up and down, and the band-shaped lead alloy sheet is fed in a fixed direction in conjunction with the vertical movement of the cutter, and the band-shaped lead alloy sheet is sequentially shifted from the outside to the inside of the sheet width at predetermined intervals on one side of the sheet thickness. And a notch is formed, and the cut portion is developed to form a mesh portion of the lattice. The shape of the cutter here has a trapezoidal portion at the tip of the blade shape when viewed from the side ,
It has a corner on the upper bottom surface .

[0004]

However, in order to develop a long-life lead-acid battery, the lead-calcium-tin (Pb-Ca-Sn) -based alloy of the base sheet must be used to improve the lattice strength and corrosion resistance. When the Sn content was increased, the lead alloy sheet had a high tensile strength, and many fractures of the lattice occurred during the expanding process. In addition, when a battery having a short life was disassembled among the batteries after the evaluation, the lattice was cut (cut). This at the time of this battery use
The cause of the fracture of the lattice was that cracks were generated in the lattice during the expanding process, and corrosion was promoted from the cracks.

[0005] As a result of a detailed examination of the causes of the cuts and cracks in these lattices, bone cuts and cracks were found in the portions of the lattice which corresponded to the corners of the tips of the blade dies. This is because stress concentrates on the squared portion, and therefore, it is required to perform the expanding process without the stress concentration at one point.

An object of the present invention is to solve the above-mentioned problems and to stabilize the quality of the lattice and to prolong the life of the battery.

[0007]

In order to solve these problems, a method of manufacturing an expanded lattice body for a lead-acid battery according to the present invention comprises a method of manufacturing a plurality of blades having different blade shapes from a first blade and a second blade. Repeatedly moving the cutter up and down, feeding the lead alloy sheet in conjunction with the vertical movement of this cutter, cutting the lead alloy sheet from one side of the sheet thickness at predetermined intervals sequentially from the outside to the inside of the sheet width A method for manufacturing an expanded lattice that expands the cut portion, wherein the cutter has a trapezoidal upper bottom surface and a trapezoidal shape at the tip end of a first blade of a blade type having a trapezoidal portion at the tip end when viewed from the side.
An R portion is provided between the left and right slopes in contact with the bottom surface, and the tip of the second and subsequent blades is provided at the tip of the first blade.
Expanding is performed using a cutter provided with an R portion larger than the R portion .

[0008]

According to the manufacturing method of the present invention, the lattice cutting (cutting) caused by the stress concentration at the corner of the edge of the blade during the expanding process is reduced by dispersing the stress by adding R. And productivity can be improved. At the same time, the occurrence of cracks in the grid due to stress concentration is also reduced, so that the grid breakage during use of the battery is reduced, and a lead-acid battery having excellent life characteristics can be obtained.

[0009]

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

FIG. 1A is a side view of a part of a cutter used in the expanding process of the present embodiment, viewed from the side.
(B) is the figure which looked at this from the bottom. The tip of the cutter has a different blade shape between the first blade and the second and subsequent blades,
They are staggered from the outside to the inside at regular intervals. The blade die 1 of the first blade is a blade die for forming the lowermost frame of the expanded lattice, and the blade dies 2 for the second and subsequent blades are blade dies for forming a mesh portion.

FIGS. 2A and 2B are enlarged views of the tip of the blade die of the cutter according to the above embodiment. FIG. 2A is a side view of the first blade, and FIG. 3 (A) first blade
(B) shows a blade type perspective view of the second and subsequent blades. FIG.
FIG. 5A shows a side view of a first blade as a conventional example, FIG. 5B shows a side view of a tip portion of a blade die after a second blade, and FIG.
2 shows a perspective view of the second blade and thereafter. In the embodiment of the present invention, the tip of the first blade of the blade form has R at each of two intersections of the bottom surface of the trapezoidal portion and the left and right slopes contacting the bottom surface.
The tip of the second and subsequent blades is provided with a radius R larger than that of the first blade at the foremost portion between the left and right slopes of the trapezoidal portion. For this reason, when expanding the lead alloy sheet, the stress is not concentrated on the squared portion as in the conventional blade type, but is distributed over the entire R portion, thereby preventing the bone from cracking and cracking of the lattice. it can.

Further, in order to disperse the stress more evenly, the straight line portions of the left and right slopes constituting the tip portion are provided as tangents to the R at the foremost end. Good to be.

If the radius of the tip portion is small, the tip becomes sharp and the lattice is broken. For this reason, as shown in FIG. 6, the portion where the lead alloy sheet of the blade die after the second blade is punched out has an arc length Q of the R portion provided at the tip 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 embodiment and the conventional cutter, a high tensile strength Pb-C with a large amount of Sn is added.
The a-Sn-based lead alloy sheet was expanded for 10,000 sheets of each electrode plate, and the rate of occurrence of lattice fracture was measured. FIG. 7 shows the result. As can be seen from the results of FIG. 7, compared to the expanded lattice using the conventional blade, the expanded lattice using the blade of the present embodiment has almost no bone fracture, and the grid can be efficiently produced. It became.

[0015]

As described above, according to the method of manufacturing the expanded grid body for a lead storage battery of the present invention, it is possible to remarkably reduce bone breakage and cracks in the grid during the expanding process, thereby improving the productivity and improving the productivity. Quality can be stabilized. Further, the reliability of the lead storage battery in the market can be ensured.

[Brief description of the drawings]

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

FIG. 2A is a side view of a first blade edge of an expanding cutter according to an embodiment of the present invention; FIG.

FIG. 3A is a perspective view of a first blade type according to an embodiment of the present invention. FIG. 3B is a perspective view of a second and subsequent blade types.

FIG. 4 (A) is a side view of a conventional first example of a blade for expanding processing, and FIG. 4 (B) is a side view of a blade after the second blade.

FIG. 5A is a perspective view of a first blade type of a conventional example. FIG. 5B is a perspective view of a second and subsequent blade types.

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

FIG. 7 is a diagram showing the rate of occurrence of bone breakage in an expanded grid.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 First blade (blade for forming frame bone) 2 Second blade (blade for forming mesh portion) 3 Lead alloy sheet P Punching length of blade type Q Length of arc Z Q / P

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Yasuda 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Katsuhiro Takahashi 1006 Kadoma Kadoma Kadoma, Osaka Matsushita Electric Industrial Co., Ltd. (56) References JP-A-57-44428 (JP, A) JP-A-56-15563 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01M 4/64-4 / 82 B21D 31/04

Claims (3)

(57) [Claims] 1. A cutter having a number of blades having different shapes from a first blade and a second blade is repeatedly moved up and down, and a strip-shaped lead alloy sheet is fed in conjunction with the up-down movement of the cutter. A method of manufacturing an expanded grid in which the lead alloy sheet is cut from one side of the sheet thickness at predetermined intervals sequentially from the outside to the inside of the sheet width, and the cut portion is developed. In the blade tip of the first blade having a shape portion at the tip, the trapezoidal portion
Rutotomoni respectively provided to two intersections R portion of the left and right slant in contact with the upper bottom surface and the upper bottom surface, of the second blade after blade tip
Method of manufacturing a lead-acid battery for expanded grid, characterized in that the expanding process using a cutter having a greater R portion than R portion of the first Ichiha tip in part. 2. The expanded lattice body for a lead-acid battery according to claim 1, wherein in the blade dies subsequent to the second blade, the straight portion of the slope forming the tip portion is tangent to the R portion provided at the foremost portion. Manufacturing method. 3. The cutting die of the second blade and later, the R portion of the arc provided to the blade-type <br/> tip against the cutting die punching length P of the portion punched the lead alloy sheet length Q 3. The method for producing an expanded grid body for a lead-acid battery according to claim 1, wherein the ratio Z is 0.3 or more. 4.