JPH0419669B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electrode plate for a lead-acid battery using an expanded lead or lead alloy sheet as a grid.

Structure of conventional examples and their problems Conventional electrode plates are obtained by filling a paste-like active material into a lattice made by expanding a sheet of lead or a lead alloy such as lead-calcium, and then cutting it into a predetermined size and shape. Although the workability of manufacturing the electrode plate is superior to that of electrode plates using cast grids, there are no frame ribs (vertical bones) on the left and right sides, and the active material often falls off from the cut surface during the manufacturing process. Ta.

The actual production of electrode plates using this type of expanded grid is to expand the lead or lead alloy sheet on both sides, leaving the central part, and then continuously applying A paste-like active material was filled, and then a protective sheet was attached to both the front and back sides, and then cut into a predetermined size using a cutter.

FIG. 1 shows the cross-sectional state of the electrode plate with this protective sheet attached to its surface. In this figure, an active material support frame 1 made of expanded lead alloy is covered with a paste active material 2, and the front and back sides of the active material support frame 1 are covered with a protective paper 3. However, if a continuous strip of electrode plates is simply cut into a predetermined size with a cutter, there is no material to protect the active material on the cut surface, and the active material may fall off during the electrode plate assembly manufacturing process, resulting in defects. It was the cause of When the lattice is manufactured by casting, there are lead frame ribs on the left and right sides, so this problem does not occur, and is a peculiar phenomenon that occurs with the expanding method. In addition, there are examples of reinforcing the cut surfaces of electrode plates with resin etc. in the expanding method in order to improve their strength, but since the expanding method itself is a continuous production method, processing of each electrode plate is virtually impossible. It was difficult.

Purpose of the invention The present invention solves these conventional problems,
In the process of continuously manufacturing electrode plates using an expanded lattice by cutting them to a fixed size with a rotary cutter, the pasty active material is effectively prevented from falling off from the left and right cut surfaces.

Structure of the Invention The present invention involves filling an expanded continuous sheet with a paste-like active material, pasting protective sheets on both the front and back surfaces, and using a rib-shaped cutting blade with a chevron-shaped cross section of a rotary cutter to cut into a predetermined size. The fibers that make up the protective sheets placed on the front and back sides of the electrode plate to prevent the active material from falling off are loosened and then pressed onto the cut surface of the electrode plate to prevent the active material from falling off.

Description of examples The details of the present invention will be explained below using Examples.

An expanded continuous sheet made of lead or lead alloy is filled with a paste-like active material, and a protective sheet is attached to the front and back of the sheet. This protective sheet is mainly used to prevent the active material from falling off in subsequent steps. Generally, paper with a basis weight of 10 g/m ² or less, which is mainly composed of linter pulp, is used. Attaching this paper to the electrode plates increases the electrical resistance and deteriorates the battery's discharge characteristics, but by using a material that does not have acid resistance, it can be removed or melted from the front and back of the electrode plate during the electrode plate formation, and can be put into practical use. Sometimes it is done so that it does not affect performance in any way. The role of this protective sheet is only to prevent the active material from falling off when assembling the battery after filling the paste-like active material. The material may be a nonwoven sheet made of acid-resistant fibers such as polyethylene or polypropylene. Further, there is no particular restriction on the basis weight.

In practice, when unit electrode plates of a predetermined size are continuously manufactured from expanded sheets, they are cut using a rib-shaped cutting blade with a chevron-shaped cross section of a rotary cutter.The cut surface at this time is shown in Figure 2. As shown above, the inclination angle of the rib-shaped cutting blade 4 having a chevron-shaped cross section directly becomes the inclination of the cutting surface, and the electrode plate 5 is cut in such a manner as to be pushed through. Therefore, at this time, the fibers 6 of the protective sheet 3 are stretched in the pressing direction 7 of the rib-shaped cutting blade 4, and as shown in FIG. Pressure bonding enhances the active material support function of this part and protects the cut surface of the electrode plate.

The length of the fibers loosened at this time is, for example, 2 to 6
mm and the thickness of the electrode plate is longer than 1 to 2 mm, so the entanglement of the loosened fibers further increases the ability to support the active material and is effective in preventing the active material from falling off.

For this reason, it is appropriate for the protective sheet to be a binder-free type or a sheet using a water-soluble binder such as starch or PVA.

Effects of the Invention As described above, in the present invention, the cut surface of the electrode plate using the expanded lattice is protected by the cutting edge having a chevron-shaped cross section.
This is done using the loosened fibers of the protective sheet placed on both the front and back sides of the electrode plate, and in the pressing process, the cutting blade cuts the electrode plate and at the same time strengthens the cut surface, allowing the paste-like active material to be removed from the cut surface. was able to prevent it from falling off.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of an expanded electrode plate filled with a paste-like active material and paper is placed on both the front and back sides as a protective sheet. Figure 3 is a schematic view of the cut surface of the electrode plate being held by the fibers of the protective sheet during cutting. 1... Expanded lead alloy active material support bone, 2... Paste active material, 4... Cutting blade with chevron-shaped cross section, 5... Cut electrode plate, 6... Fiber with the cut surface crimped.

Claims (1)

[Scope of Claims] 1. An electrode plate in which a paste-like active material is filled in a lattice formed by expanding a lead or lead alloy sheet, and paper or synthetic fibers are coated on both the front and back sides of the electrode plate to prevent the active material from falling off. An electrode plate for a lead-acid battery, in which a protective sheet made of non-woven fabric is pasted, and fibers loosened by pushing and spreading the protective sheet using a rib-like cutting blade with a chevron-shaped cross section of a rotary cutter are pressed onto the left and right cut surfaces of the electrode plate. 2. The electrode plate for a lead-acid battery according to claim 1, wherein the length of the fibers constituting the protective sheet is longer than the thickness of the electrode plate.