JPH1031994A - Lead storage battery and method of manufacturing the same - Google Patents

Abstract

(57) Abstract: The present invention reduces the presence of welding defects at a portion where electrode poles of an electrode group that are in contact with a partition 1 of a battery case 7 of a lead storage battery and are adjacent to each other via the partition 1 are welded in a through hole 10. I do. A portion of the partition wall where the pole is in contact is a concave portion having a width substantially equal to the width of the pole column, and a battery case in which the thickness of the partition wall of the concave portion is 1 to 2 mm is used. The poles are welded to each other in the through hole 10 with the poles fitted in the recesses 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lead storage battery and a method for manufacturing the same.

[0002]

2. Description of the Related Art As shown in FIG. 3, pole columns of a lead storage battery adjacent to a partition of a battery case are connected to through-holes 10 formed in the partition.
In the so-called inter-cell connection technique, the pole 3 is brought into contact with the partition 1 so as to sandwich the through hole 10 of the partition 1,
The pole 4 is deformed by the electrode 4 attached to the jaw 5 with a predetermined pressing force, and the poles 3 are brought into contact with each other in the through hole 10 for a predetermined time to be integrated by welding.

[0003]

The poles 3 are connected to each other through the through-hole 1.
When the contact is made within 0, a space 6 is formed in the through hole 10 as shown in FIG. In this state, when a welding current is applied to generate heat and melt the contact portion, the air in the space 6 solidifies while being taken in the molten lead, and after the welding is completed, a bubble-like welding called a blow hole is performed. It becomes a defect. If a large blowhole is present, a sulfuric acid solution as an electrolytic solution may enter the blowhole and corrode the welded portion to cause breakage. In addition, due to the presence of the large blow hole, the welding strength of the welded portion, that is, the mechanical strength is reduced. The problem to be solved by the present invention is to reduce the presence of welding defects in the portion where the poles adjacent to the partition wall of the battery case of the lead storage battery are welded through the through holes.

[0004]

In order to solve the above-mentioned problems, in order to solve the above-mentioned problem, the poles 3 of the electrode group 8 which abut on the partition 1 of the battery case 7 and are adjacent to each other via the partition 1 are formed into the partition 3. In the lead storage battery formed by welding in the provided through-holes 10, the portion of the partition wall 1 shown in FIG. 1 where the pole 3 abuts is a recess 9 having a width substantially equal to the width of the pole 3. The thickness of the partition 1 is 1 to 2
mm. By employing the above configuration, the size of the space 6 when the poles 3 adjacent to the partition wall 1 of the battery case 7 of the lead storage battery are brought into contact with each other through the through holes 10 as shown in FIG. Is smaller than the size of the conventional space 6 shown in FIG. Therefore, the amount of air taken into the molten lead during welding is reduced, and the size of the blowhole and the volume occupied by the weld are also reduced. As a result, a lead storage battery having a high mechanical strength at the welded portion can be obtained. Here, the reason why the whole of the partition wall 1 is not thinned but the concave portion 9 is formed only in a part thereof to be thinned and the other parts are thickened is as follows.
Due to the stress applied to the partition 1 during welding, the partition 1 and the battery case 7
This is to prevent the whole from being deformed.

[0005] Further, the concave portion 9 in FIGS.
Is substantially equal to the width of the pole 3, the concave portion 9 serves as a guide for the pole 3 in the welding operation, and there is an advantage that the control of the positioning of the pole 3 is easy. If the alignment of the poles 3 is misaligned, the contact state between the poles 3 varies, and if the contact state is not good, the welding portion generates abnormally sudden heat during welding, and the lead in the boiling state is welded. A phenomenon called so-called "scatter" spouting from the part occurs. When the "scattering" occurs, a gap is naturally generated in the welded portion. Therefore, the control of the alignment between the concave portion 9 and the pole 3 is one of the important factors for solving the problem of the present invention.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below. The battery case 7 was formed by molding polypropylene. At the time of the molding, a mold designed to have the shape of the partition wall 1 shown in FIG. 1 was used. The above-mentioned shape means that the partition wall 1 has the concave portion 9, and the through hole 1 is provided substantially at the center of the concave portion 9 in the width direction.
It is a shape having 0. The thickness of the part other than the recess 9 of the partition wall 1 is 3.5 mm, the thickness of the recess 9 is 1.5 mm,
The diameter of 0 was 9.5 mm. The pole 3 is manufactured by a cast-on-strap method and has a composition of Pb-1.
65Sb-0.05As, a thickness of 4.5 mm, and a width substantially equal to the width of the recess 9 of the partition wall 1. The poles 3 adjacent to the partition 1 of the battery case 7 are connected to each other through the through-holes 9 provided in portions where the poles 3 of the partition 1 abut as shown in FIG. In the fitted state, the poles 3 were welded to each other in the through hole with a pressing force of 580 kg for the jaw 5 and the electrode 4, a pressurizing time before energization of 0.2 seconds, a welding current of 9.5 kA, and an energizing time of 4 cycles. The pole 3 used after 3 minutes from the cast-on strap.
Thereafter, a lead storage battery was manufactured through a heat sealing process of a battery case cover, a conductive connection process from the bipolar electrode to the battery external terminal, a process of injecting an electrolytic solution composed of a sulfuric acid solution into the battery case 7, and the like.

[0007]

EXAMPLES The thickness of the recess 9 described in the above embodiment of the present invention was varied from 0.5 mm to 3.0 mm at 0.5 mm intervals to prepare six types of battery cases. At the stage where the welding process between the poles 3 was completed under the same conditions as in the embodiment, the following experiment was performed. (Experiment 1) The cross section of the weld was observed to evaluate the presence of blowholes (voids) in the weld. Table 1 shows the results. In the table, the symbol “○” means that there is no void. In the table, the symbol △ indicates the existence of fine voids. The symbol "x" in the table indicates the presence of large voids.

(Experiment 2) The mechanical strength of the weld was evaluated. The evaluation method is based on twisting the welded portion until it breaks, and measuring the maximum torque value at that time. The results are also shown in Table 1.

[0009]

[Table 1]

As is apparent from Table 1, when the thickness of the concave portion 9 is 0.5 mm, the contact area between the poles 3 in the through hole 10 becomes large, and sufficient heat generation cannot be secured during welding. Insufficient. Therefore, the welding strength was low and fine voids were present. Further, when the thickness of the concave portion 9 is 2.5 mm and 3.0 mm, the pole 3 cannot be sufficiently deformed, and the scattering at the time of welding occurs because the contact state between the poles 3 is not good, or Since the space 6 is large, air space is generated due to the air in the space 6 being taken into the molten lead and solidified as it is during welding, and the space is large. Therefore, the mechanical strength is somewhat inferior. The thickness of the recess 9 is 1.0 mm,
In the case of 1.5 mm, no void was observed at all, and the mechanical strength was good. The thickness of the recess 9 is 2.0 mm
In the case of the above, it was found that although very small voids were present, the mechanical strength of the welded portion could be maintained high. Further, the extremely fine voids were of such a size that it would not affect the infiltration of the electrolyte after the battery was produced. From the above results, it was found that the problem of the present invention can be solved by setting the thickness of the concave portion 9 to 1 mm to 2 mm.

[0011]

According to the present invention, it is possible to reduce the presence of welding defects at the portions where the adjacent poles are welded to each other in the through hole of the partition via the partition of the battery case of the lead storage battery. Also,
Positioning of the pole during the welding step is also facilitated.

[Brief description of the drawings]

FIG. 1 is a perspective view of an example of a battery case used for a lead storage battery of the present invention.

FIG. 2 is a diagram showing a state in which pole columns adjacent to a partition wall of a battery case are brought into contact with each other in a through hole in a manufacturing (welding) process of the lead storage battery of the present invention.

FIG. 3 shows a conventional lead-acid battery manufacturing (welding) process.
It is a figure showing the state where poles adjacent to a partition of a battery case were contacted in a through-hole.

[Explanation of symbols]

 1. Partition wall 3. Pole 4. Electrode 5. Joe 6. Space 7. Battery case 8. Electrode group 9. Recess 10. Through hole

Claims (2)

[Claims] 1. A lead-acid battery in which a pole of an electrode group adjacent to a partition of a battery case is welded to a through hole provided in the partition via the partition, wherein the pole of the partition is The contacted portion is a concave portion having a width substantially equal to the pole width, and the thickness of the partition wall of the concave portion is 1 to 2 mm.
A lead-acid battery characterized by the following. 2. A method of manufacturing a lead-acid battery in which a pole of a group of electrode plates which is in contact with a partition of a battery case and is welded through a through hole provided in the partition via the partition, wherein the pole of the partition is A concave portion having a width substantially equal to the width of the pole is provided in the contacting portion, and the thickness of the partition wall of the concave portion is 1 to 1.
A method for producing a lead-acid battery, wherein the poles are welded to each other in a through hole in a state where the poles are set to 2 mm and the recesses are fitted in the poles.