JPH02276155A - Strap forming mold of lead-acid battery - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to a so-called CO3 battery which forms a strap on the current collecting tab of a stack of positive and negative electrode plates and a plurality of separators.
This invention relates to the improvement of a mold for forming a strap of a lead-acid battery according to a method and method.

2. Description of the Prior Art and its Problems Conventionally, a CO8 method has been used as a means for forming a slap on the current collector ears of a group of electrode plates of a lead-acid battery.

The CO8 method is a scraping group consisting of multiple stacked positive and negative electrode plates and separators, which is reversely opened, and the collector tabs of the electrode plates are inserted into a mold for forming laps into which molten lead has been poured. This is a method in which the strut and tab are integrally molded on the tip of the electric ear, and is excellent in terms of automation, labor saving, mass production, and uniform quality. However, since the current collecting lug of the electrode plate is immersed in molten lead poured into a mold and waited for it to solidify, the immersion level of the current collecting lug is an important point related to welding quality.
The boundary between the current collecting ear and the strap cannot be completely welded over the entire surface due to temperature distribution, etc., so if the tip of the current collecting ear touches the bottom of the mold, ,
The melting of the current collecting lug and the strap may become incomplete, and the strength of the cast strap may be insufficient, causing the strap to break at the joint with the 13th current collecting lug, and in the worst case, the battery may explode. It causes. There would be no problem if the thickness of the strap could be made sufficiently thick, but the reality is that it cannot be made sufficiently thick due to constraints on battery case size and cost. Therefore, we go up to the machine 111 adjustment and adjust the immersion height of the current collecting ear, but there are variations and the tip of the @computer may hit the bottom of the mold.

In order to solve this problem, a protrusion is formed on the bottom of the strap-forming recess of the mold to intersect with the current collecting lug of the electrode plate, and when the current collecting lug of the electrode plate group is inserted into the mold, It has been proposed that the protrusions contact the tips of the current collecting ears to prevent the tips of the current collecting ears from coming into contact with the bottom of the mold, thereby making it possible to cast a strap with sufficient strength. However, in the conventional mold, the projections are continuously provided along the entire length of the strap forming recess, so when molten lead is injected into the recess, the molten lead flows over the projections, At this time, when air is trapped and solidified as a strap, air bubbles are often formed inside the strap, leading to a decrease in the strength of the strap.Additionally, the presence of such air bubbles makes it susceptible to corrosion by the electrolyte. occurs.

Means for Solving the Problems The present invention forms a plurality of intermittent protrusions on the bottom surface of the strap forming recess in a staggered manner in a direction intersecting the current collecting ears, so that molten lead flows smoothly. This is what I did.

Example An embodiment of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 1 denotes a strap forming mold according to the present invention, and on the bottom surface of a strap forming recess 2 of the mold, there are two intermittent protrusions 3 in the direction intersecting the current collector ears of the electrode plate group, which will be described later. 4 is provided.

Short protruding strips 3 constituting the two interrupted protruding strips 3.4
a, 3 b, 3 C...and 4a, 4b.
. . . are arranged alternately in a staggered manner, and are arranged so that no matter where the current collecting ears of the electrode plate group are located, the tips always come into contact with one of the protruding strips.

The protrusion 3.4 is for spreading the molten lead alloy over the tips of the plurality of current collecting ears when forming the strap, and the height should be 1 to several 11111 and the width should be as narrow as possible. Good.

Reference numeral 5 denotes an electrode plate group in which a plurality of positive and negative electrode plates are stacked with separators in between, and current collecting ears 6 of the positive and negative electrode plates protrude from both ends thereof. Note that only one of them is shown in the drawing. 7
is a strap integrally formed on the current collecting lug, and two interrupted grooves 8.9 formed by the protrusions 3 and 4 of the mold 1 are formed on the upper surface.

To form the strap 7 on the current collecting tab of the electrode plate group using the mold 1, molten lead alloy is poured into the strap forming recess 2 of the mold, and the electrode plate group 5 is opened from above in a reverse-open state.
The current collecting ears 6 are lowered and inserted into the strap-forming four parts 2. At this time, the tip of the current collecting lug 5 is regulated by the protrusion @3 or 4 provided on the bottom of the four strap forming parts 2, and there is always melting between the tip of the current collecting lug and the bottom of the strap forming recess. A layer of lead alloy will be present.

Next, when the molten lead alloy is cooled and solidified, a strap 7 is attached to the tip of the current collecting lug 6 of the electrode plate group, as shown in FIG.
is formed.

Effects of the Invention As mentioned above, the strap forming mold of the present invention has a plurality of intermittent protrusions formed in a staggered manner on the bottom of the strap forming recess of the mold, so that the tips of the current collecting ears are on the bottom of the mold. Since they do not contact each other and are buried in the 't8 molten lead alloy, the current collector ears and the strap are more completely fused together, and when molten lead is injected into the recess for forming the strap, the molten lead is It flows smoothly through the gaps between the protrusions and all the way to every corner, without entrapping air, resulting in a strap with no casting defects, and the strength of the strap is greatly improved compared to conventional ones. .

[Brief explanation of drawings]

Fig. 1 is a partially cutaway perspective view showing a state in which the current collector ears of the electrode plate group are inserted into the mold for forming a strap according to the present invention, Fig. 2 is a sectional view showing a state in which a strap is formed with the above mold, and Fig. 3
The figure is a perspective view of a main part of a group of electrode plates in which straps are formed on a collector roof using the mold of the present invention. 1...Mold 2...Four parts for forming straps 3.4...Protrusions 5...Pole group λ flash

Claims (1)

[Claims] A mold for forming a strap on a current collecting lug of an electrode plate group, characterized in that a plurality of intermittent protrusions are formed in a staggered manner in a direction intersecting the current collecting lug on the bottom surface of the strap forming recess. Strap-shaped substitute mold for lead-acid batteries.