JPH0982306A - Lead-acid battery and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a battery small, lightweight, and realize high output by forming a positive terminal and a negative terminal at one end of a strap of a cell chamber, practically filling a through hole of a partition wall, and connecting the terminals with an intercell connector. SOLUTION: A plurality of cell chambers 1a partitioned with a plurality of partition walls 2 are formed in a battery container 1, and an electrode group 4 is arranged in each cell chamber 1a. Straps 7a, 7b, 7c are arranged practically in parallel in the upper part of the cell chambers 1a so as to perpendicularly cross to the electrode group in the cell chamber 1a. A positive terminal 8a and a negative terminal 8b are formed at one end of the straps 7a, 7b, and adjacent cells are connected through the partition wall 2. High current is let flow to the contact part of the terminals 8a, 8b with resistance welding electrodes to melt the contact part by joule heat. The terminal 8a and the terminal 8b are connected with an intercell connector 11 formed so as to fill an elliptic through hole 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead storage battery, and more particularly to an improvement in the inter-cell connecting portion and a method for manufacturing the lead storage battery.

[0002]

2. Description of the Related Art Among conventional storage batteries, lead storage batteries are widely used as inexpensive and highly reliable batteries, and lead storage batteries are superior to other storage batteries in terms of economical efficiency and easy handling. It has excellent characteristics. Generally used lead-acid batteries are composed of a positive electrode plate, the same number or more negative electrode plates, a separator sandwiched between the electrode plates, an electrolytic solution, etc., arranged inside a synthetic resin battery case. Has been done. This battery case is sealed by a lid provided with a safety valve for releasing gas into the atmosphere when the battery internal pressure rises abnormally and a bushing for forming terminals for external connection of the positive electrode and the negative electrode. In a conventional lead-acid battery, a perfect circular through hole is formed in the upper part of a partition wall that partitions the inside of the battery case into a plurality of cell chambers. The positive electrode plate and the negative electrode plate disposed in each cell chamber are connected by a strap at the upper part thereof, and the strap of the adjacent cell chamber has a positive terminal or a negative electrode at one end facing the through hole of the partition wall. The terminals were connected. In a conventional lead storage battery, a positive terminal and a negative terminal that face each other with a partition wall in between are connected by an inter-cell connecting portion that fills the inside of a perfect circular through hole of the partition wall.

[0003]

In the conventional lead-acid battery constructed as described above, the positive terminal and the negative terminal in the adjoining cell chambers are in a circular through hole formed in the upper part of the partition wall. The cells are connected through the inter-cell connecting portion that satisfies the above condition, and a large space for the inter-cell connecting portion is required above the battery case. For this reason, the conventional lead-acid battery cannot be made sufficiently small in its height dimension, and the volume efficiency (Wh / m
³ ) was hindering improvement. Further, since the positive terminal or the negative terminal for forming the inter-cell connecting portion is welded to the side surface of each strap and arranged in a stepwise manner, many members for inter-cell connection are required. , This member was heavy and the current path was long. Therefore, the conventional lead-acid battery has a problem that the weight efficiency (Wh / kg) is low and the current path is long, so that the resistance component is large and the output characteristic is also low. The present invention has been made to solve the above problems, and an object of the present invention is to provide a highly reliable lead acid battery that achieves size reduction, weight reduction, and high output.

[0004]

In order to achieve the above object, the lead-acid battery of the present invention comprises a substantially box-shaped battery case having an open upper portion, and the inside of the battery container is partitioned into a plurality of cell chambers. A partition wall having an elliptical through hole having a major axis in the horizontal direction in the vicinity of the upper edge, and an electrode plate group which is disposed in the cell chamber and includes a plurality of positive electrode plates, a negative electrode plate, and a plurality of separators separating the both electrode plates, A substantially linear first strap that is disposed above the electrode plate group and that is connected to the positive electrode plate, and that is disposed above the electrode plate group in parallel with the first strap, The substantially linear second strap connected to the negative electrode plate and the second strap, which are arranged to face each other with the partition wall in between, are provided in the adjacent cell chambers. A positive terminal and a negative terminal formed at one end of each, and the partition wall Substantially fills the circular through-hole comprises the positive polarity terminal and intercell connectors for connecting the negative terminal, and a lid for sealing an opening of the battery jar.

Further, in the method for manufacturing a lead storage battery of the present invention, an electrode composed of a plurality of separators for separating a plurality of positive electrode plates, negative electrode plates and bipolar plates is provided in a plurality of cell chambers in a battery case partitioned by partition walls. A group of plates is housed, a positive terminal is formed at one end of a substantially linear first strap connected to the positive electrode plate, and a substantially linear second strap connected to the negative electrode plate. In a method of manufacturing a lead storage battery in which a negative terminal is formed at one end of an adjacent one of the partition walls adjacent to each other with an elliptical through hole having a major axis in the horizontal direction formed near the upper edge of the partition wall. A step of sandwiching the positive terminal and the negative terminal that fit together with a resistance welding electrode having a protrusion of an elliptical pressure contact surface having a major axis in the horizontal direction and applying pressure to bring the positive terminal and the negative terminal into contact with each other. And the positive end under pressure And a step of forming an inter-cell connection body that substantially fills the inside of the elliptical through hole by resistance welding in which a high current is applied by the resistance welding electrode at a contact portion between the negative terminal and the negative electrode terminal, and in the upper opening of the battery case. A step of heat welding the lid. In the lead acid battery of the present invention configured as described above, each strap connecting the positive electrode plate or the negative electrode plate in each cell chamber is formed with a large cross-sectional shape in accordance with the increase of the current flowing therethrough, the partition wall The positive and negative terminals adjacent to each other are electrically connected via an inter-cell connector having a flat shape and a substantially elliptical cross section.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the lead acid battery of the present invention will be described below with reference to the drawings. 1 is a side sectional view showing an embodiment of the lead acid battery of the present invention, and FIG.
It is a top view which shows the state which removed the cover 14 of the lead acid battery of FIG. As shown in FIGS. 1 and 2, a box-shaped battery case 1 having an upper opening is integrally formed with a partition wall 2 described later from a thermoplastic resin such as polypropylene. Battery case 1
An electrode plate group 4 having a plurality of positive electrode plates 41 and a plurality of negative electrode plates 42, which are arranged to face each other with a plurality of separators 40 in between, is housed inside. In the present embodiment, the separator 40 uses a mat-shaped liquid retaining material (for example, glass retainer mat) manufactured from glass fiber or the like. The positive electrode plate 41 is a grid formed of a Pb-Ca alloy coated with lead paste, and the negative electrode plate 42 is P
A lead paste is applied to a grid formed of a b-Ca alloy. A separator 40 which is the electrode plate group 4,
A diluted sulfuric acid electrolytic solution is held on the positive electrode plate 41 and the negative electrode plate 42.

As shown in FIG. 1, ear portions 41a and 42a are formed on the positive electrode plate 41 and the negative electrode plate 42 of the electrode plate group 4, respectively. A plate-shaped first strap 7a that is a conductor is connected to each ear 41a of the plurality of positive electrode plates 41, and a plate-shaped first strap 7a that is a conductor is connected to each ear 42a of the plurality of negative electrodes 42. Two straps 7b are connected. As shown in FIG. 2, the third strap 7c having the positive or negative pole column 15 has a positive electrode plate 4 similar to the first strap 7a and the second strap 7b described above.
The one ear 41a or the ear 42a of the negative electrode plate 42 is connected. The pole 15 provided on the third strap 7c is a bushing (not shown) provided on the lid 14.
To form a positive electrode or a negative electrode terminal 13.

As shown in FIG. 2, a plurality of cell chambers 1a partitioned by a plurality of partition walls 2 are formed in the battery case 1, and an electrode plate group 4 is arranged in each cell chamber 1a. . Further, in each cell chamber 1a, a first strap 7a and a second strap 7b or a third strap 7c are substantially parallel to each other on the upper portion of each cell chamber 1a so as to be orthogonal to the electrode plate group 4. It is arranged. First strap 7a and second
A positive terminal 8a and a negative terminal 8b are formed at one end of the strap 7b. The positive polarity terminal 8a and the negative polarity terminal 8b connect adjacent cells via the partition wall 2, and the adjacent cell chambers 1a, 1
The positive terminal 8a and the negative terminal 8b of a are electrically connected by resistance welding described later. FIG. 3 is a front sectional view showing the partition wall 2 of the battery case 1 of this embodiment. On the upper right side of the partition wall 2 shown in FIG. 3, an elliptical elliptical through hole 3 having a major axis in the horizontal direction is formed. In this example, the elliptical through-hole 3 has a major axis of 15 mm and a minor axis of 9 mm. Therefore, the major axis / minor axis ratio is about 1.67. In the battery case 1, an elliptical through hole 3
Are formed on the upper part of the partition wall 2, and are arranged alternately every other left and right. The positive terminal 8a and the negative terminal 8b, which are arranged to face each other with the elliptical through hole 3 of the partition wall 2 in between, are connected by resistance welding described later, and cells adjacent to each other through the partition wall 2 are mutually connected. They are electrically connected in series.

As shown in the plan views of the inside of the battery case 1 shown in FIGS. 1 and 2, the first plate-shaped member having a substantially constant thickness.
The width dimension of the strap 7a and the second strap 7b is
It is formed so that it gradually widens as it approaches the positive terminal 8a and the negative terminal 8b formed at each end. In addition, the width dimension of the plate-shaped third strap 7c having a substantially constant thickness is formed so as to gradually widen as it approaches the pole 15 disposed in the center thereof. Thus, in this embodiment, the first strap 7a,
The second strap 7b and the third strap 7c are formed such that the area of the vertical cross section thereof gradually increases in accordance with the increase of the current flowing therethrough. Thus, in each strap, the current density in the vertical cross section is set to be substantially constant.

The first strap 7a and the second strap 7b in this embodiment are provided with cast and
The positive polarity terminal 8a and the negative polarity terminal 8b are integrally formed by the on-strap method. The cast-on-strap method in this embodiment refers to, for example, integrally casting the first strap 7a and the positive terminal 8a with the ears 41a of the positive electrode plate 41 of the electrode plate group 4 inserted in the mold. It is a construction method. Thus, the first strap 7a and the positive terminal 8a, and the second strap 7b
The negative terminal 8b and the negative terminal 8b are continuously formed in a substantially linear shape. Further, the pole 15 made of a lead alloy is
Like the strap 7a and the second strap 7b, it is integrally formed at the same time as the third strap 7c to which the electrode plate group 4 is connected by the above-described cast-on-strap method. Positive and negative terminals 1 that are output terminals to the outside
A lid 14 having a bushing for forming 3 and a safety valve 12 provided corresponding to each cell chamber 1a is heat-welded to the upper opening of the battery case 1 to seal the battery case 1.

Next, in the method of manufacturing the lead storage battery of the present embodiment, a method of connecting the positive terminal 8a and the negative terminal 8b, which are adjacent to each other and are opposed to each other via the partition wall 2, will be described. The positive terminal 8a and the negative terminal 8b, which are arranged to face each other across the elliptical through hole 3 formed in the partition wall 2 in the battery case 1, are welded by a resistance welding device. FIG. 4 shows a resistance welding electrode 9 made of a copper alloy in the resistance welding apparatus. 4A is a side view of the resistance welding electrode 9, and FIG. 4B is a front view of the resistance welding electrode 9. As shown in FIG. 4, the resistance welding electrode 9 has a substantially flat shape in which the vertical direction is short and the horizontal direction is long, and a projection 9a is formed at the tip thereof. The protruding portion 9a has a front protruding end surface that is an elliptical shape having a major axis in the horizontal direction, and the front protruding end surface serves as an elliptical pressure contact surface 9p that presses the welded portion. In this embodiment, the elliptical pressure contact surface 9p has a major axis of 11 mm and a minor axis of 6.
A mm resistance welding electrode 9 was used. Therefore, the major diameter / minor diameter ratio of the elliptical pressure contact surface 9p of the resistance welding electrode 9 in this embodiment is about 1.83. The screw hole 9b shown in the side view of FIG. 4A is a mounting hole for fixing the resistance welding electrode 9 to the resistance welding device.

FIG. 5 and FIG. 6 are side views showing a method of connecting the positive terminal 8a and the negative terminal 8b, which are opposed to each other with the elliptical through hole 3 of the partition wall 2 therebetween, during resistance welding. FIG. FIG. 5 shows the initial state during resistance welding. In the initial state shown in FIG. 5, a pair of resistance welding electrodes 9 are arranged behind each of the positive terminal 8a and the negative terminal 8b. Next, the positive terminal 8a and the negative terminal 8
b is sandwiched by the resistance welding electrodes 9 and is pressurized, so that the positive terminal 8a and the negative terminal 8b are in contact with each other in the elliptical through hole 3. In the contact state under pressure contact shown in FIG. 6, a high current is instantaneously applied to the contact portion between the positive terminal 8a and the negative terminal 8b by the resistance welding electrode 9,
The Joule heat generated at the contact portion melts the portion near the contact portion. Therefore, the positive terminal 8a and the negative terminal 8b are brought into a connected state by the inter-cell connection body 11 formed by filling the inside of the elliptical through hole 3. As described above, the voltage is applied under pressure so that the positive terminal 8a and the negative terminal 8b are resistance-welded to be electrically connected. In FIG. 7, the positive terminal 8 a and the negative terminal 8 b are the partition wall 2.
3 is a side sectional view showing a state in which the connection is made through the elliptical through hole 3 of FIG. As shown in FIG. 7, elliptical recesses 10 are formed on both side surfaces of the positive terminal 8a and the negative terminal 8b by pressing with a pair of resistance welding electrodes 9. The elliptical pressing surface 10p, which is the innermost surface of the elliptical recess 10.
Has substantially the same shape as the elliptical pressure contact surface 9p of the projection 9a of the resistance welding electrode 9, and the major axis / minor axis ratio is about 1.8.
It is 3.

In this embodiment, the short diameter d ₁ of the elliptical pressure contact surface 9p of the projection 9a of the resistance welding electrode 9 is preferably smaller than the short diameter e ₁ of the elliptical through hole 3 of the partition wall 2. The results are shown. That is, d ₁ <e ₁ . Also,
The inside of the elliptical through hole 3 of the partition wall 2 sandwiched between the positive terminal 8a and the negative terminal 8b is filled with the inter-cell connecting body 11, and the inter-cell connecting body 11 has a substantially vertical elliptical cross section. The shape. And the volume V ₁ of the recess space of oval recesses 10 formed in the positive terminal 8a, the total volume V ₁ plus the volume V ₂ of the concave space of oval recesses 10 formed in the negative terminal 8b Although + V ₂ is substantially equal to the volume V inside the elliptical through hole 3 filled with the inter-cell connecting body 11, it is set to be slightly larger in this embodiment. This takes into account some scattering during resistance welding. Therefore,
If V ≦ V ₁ + V ₂ , the effect of the present invention is achieved.

In this embodiment, an elliptical through hole 3 having a major axis in the horizontal direction is formed in the vicinity of the upper edge of the partition wall 2, and the elliptical through hole 3 has a first strap 7a and a second strap 7b. The inter-cell connector 1 with a vertical cross section that connects the
1 is formed by the resistance welding apparatus, the lead storage battery of this embodiment can have a sufficiently small height.
The volume efficiency (Wh / m ³ ) is significantly improved. Also,
In the present embodiment, the first strap 7a, the second strap 7b, and the third strap 7c are formed such that their vertical cross-sectional shapes are gradually enlarged so as to correspond to the increase in the current flowing therethrough. That is, in this embodiment,
Each strap is formed to have a substantially constant current density with a minimum required vertical cross-sectional area. As a result, in the lead acid battery of the present embodiment, the strap has no unnecessary thick portion, so that the weight efficiency (Wh / kg) is significantly improved. Furthermore, in the lead-acid battery of the present embodiment, each strap (first strap 7a or second strap 7b) and a different polarity terminal (positive polarity terminal 8a or negative polarity terminal 8b) are linearly connected, and The elliptical inter-cell connection body 11 is formed on the different polarity terminal without separating from the extension line of the linear strap. Therefore, the straps of the adjacent cell chambers 1a, 1a and the different polarity terminals are connected in a substantially linear shape, the energization path is shortened, and the lead storage battery of the present embodiment has improved output characteristics as compared with the conventional one. ing.

Next, the relationship between the shape of the elliptical through hole 3 formed in the partition wall 2 in the battery case 1 and the elliptical pressure contact surface 9p of the resistance welding electrode 9 in the resistance welding apparatus will be described. FIG. 8 shows a ratio R of the major diameter / minor diameter ratio H of the elliptical through hole 3 to the major diameter / minor diameter ratio T of the elliptical pressure contact surface 9p of the resistance welding electrode 9.
(Hereinafter, it is abbreviated as R) and the relationship between the defective welding rate n obtained by an experiment are shown. In FIG. 8, the vertical axis represents the welding defect rate n.
[%] Is shown, and R is shown on the horizontal axis. R is the major diameter / minor diameter ratio H of the elliptical through hole 3 of the partition wall 2 divided by the major diameter / minor diameter ratio T of the elliptical pressure contact surface 9p of the resistance welding electrode 9.
It is represented by R = H / T. The major axis of the resistance welding electrode 9 /
Instead of the minor axis ratio T, the major axis / minor axis ratio D in the elliptical pressing surface 10p of the elliptical recess 10 formed on each surface of the positive polarity terminal 7a and the negative polarity terminal 7b after resistance welding may be used. Is the result of. That is, R = H / D.

The welding defect rate n in FIG. 8 shows the occurrence rate of the number of welding defects and is expressed as a percentage. As shown in FIG. 8, when R is about 0.85, the welding defect rate n is the lowest, and R is 0.70 to 0.98.
During this period, the welding defect rate n is 0.01% or less. Incidentally, R in the above-mentioned embodiment is 1.67 (H)
The value was /1.83(T)=about 0.91. According to the experiment in which the table of FIG. 8 is created, when R is set to 0.95 or more, the molten lead alloy contains the partition wall 2 and the opposite polarity terminals 8a and 8a.
There were many welding scattering defects scattered from between b.
When the welding scattering defect occurs, the welding strength between the positive terminal 8a and the negative terminal 8b becomes weak and the vibration resistance performance deteriorates. Also, if the amount of scattered welding is large, there is a risk of short-circuiting between the electrode plates. On the other hand, when R is set to 0.70 or less, the inter-cell connection body 11 to be formed in the elliptical through hole 3 of the partition wall 2 spreads to both ends of the major axis of the elliptical through hole 3. That is, there were many welding defects in which the inside of the elliptical through hole 3 was not completely filled.

As described above, when the positive polarity terminal 8a and the negative polarity terminal 8b are resistance-welded, the major diameter / minor diameter ratio H of the elliptical through hole 3 formed in the partition wall 2 and the resistance welding electrode used during resistance welding. The ratio R (= H / T) of the elliptical pressure contact surface 9p of the protrusion 9a of No. 9 to the major axis / minor axis ratio T is 0.70 to 0.95.
It is preferable to set it in between. By thus setting the shapes of the elliptical through-hole 3 and the protruding portion 9a of the resistance welding electrode 9 as described above, it is possible to significantly suppress the occurrence of defects during resistance welding and to provide a highly reliable lead storage battery. Can be obtained.

[0018]

As described above, according to the present invention, an elliptical through hole having a major axis in the horizontal direction is formed in the vicinity of the upper edge of the partition wall, and the inter-cell connection body in the elliptical through hole is formed. It was configured to electrically connect adjacent cells. Therefore, the height of the partition wall can be formed low, and a small lead storage battery can be obtained. According to the present invention,
The cross-sectional shape of the strap connecting the adjacent cells is formed in a deformed shape so that the cross-sectional shape of each portion has a minimum necessary size corresponding to the current flowing therethrough, thereby reducing the total weight of the strap, It is effective in obtaining a lightweight lead-acid battery. Further, according to the present invention, the shape of the elliptical through hole of the partition wall and the resistance welding electrode are set to a desired elliptical shape, so that there is an effect of obtaining a lead storage battery with significantly improved welding strength and reliability.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a lead-acid battery according to an embodiment of the present invention.

FIG. 2 is a plan view showing a state in which a lid of the lead storage battery of this embodiment is removed.

FIG. 3 is a side sectional view showing a battery case in the present embodiment.

4A and 4B show a resistance welding electrode used in manufacturing the lead-acid battery of the present embodiment, FIG. 4A being a side view and FIG. 4B being a front view.

FIG. 5 is a side sectional view before forming the inter-cell connection body in the method of manufacturing the lead storage battery according to the present embodiment.

FIG. 6 is a side sectional view of the lead-acid battery manufacturing method of the present embodiment during formation of the inter-cell connection body.

FIG. 7 is a side sectional view showing an inter-cell connection body and the like in the lead storage battery of this embodiment.

FIG. 8 shows the relationship between the welding failure rate in the lead-acid battery of the present invention and the ratio R of the major diameter / minor diameter ratio H of the elliptical through hole to the major diameter / minor diameter ratio T of the elliptical pressure welding surface of the resistance welding electrode. It is a figure.

[Explanation of symbols]

 1 Battery Case 1a Cell Chamber 2 Partition Wall 3 Elliptical Through Hole 4 Electrode Plate Group 7a First Strap 7b Second Strap 8a Positive Terminal 8b Negative Terminal 11 Cell-to-Cell Connector 14 Lid 40 Separator 41 Positive Plate 42 Negative Electrode Board

Claims (5)

[Claims] 1. A substantially box-shaped battery case having an open top, a partition wall that divides the battery container into a plurality of cell chambers, and has an elliptical through hole having a major axis in the horizontal direction near the upper edge, An electrode plate group disposed in the cell chamber, the electrode plate group including a plurality of positive electrode plates, a negative electrode plate, and a plurality of separators separating the both electrode plates, disposed above the electrode plate group, and substantially connected to the positive electrode plate. A linear first strap, a substantially linear second strap disposed above the electrode plate group in parallel with the first strap and connected to the negative electrode plate, and a partition wall And facing each other, the positive polarity terminal and the negative polarity terminal formed at one end of each of the first strap and the second strap of the adjacent cell chambers, and the elliptical through hole of the partition wall. Substantially filling and connecting the positive terminal and the negative terminal A lead storage battery comprising: an inter-cell connection body; and a lid that seals the opening of the battery case. 2. The first strap and the second strap are formed such that their cross-sectional shapes gradually increase as they approach the positive terminal and the negative terminal formed at one end of each. The lead storage battery according to 1. 3. An electrode plate group comprising a plurality of positive electrode plates, a negative electrode plate, and a plurality of separators separating the both electrode plates is housed in a plurality of cell chambers in a battery case partitioned by partition walls, and the positive electrode plate is A positive terminal was formed at one end of the connected substantially linear first strap, and a negative terminal was formed at one end of the substantially linear second strap connected to the negative plate. In the manufacturing method of a lead storage battery, the adjacent positive electrode terminal and the negative electrode terminal that are arranged to face each other with an elliptical through hole having a major axis in the horizontal direction formed near the upper edge of the partition wall therebetween. Is sandwiched by a resistance welding electrode having a protrusion of an elliptical pressure contact surface having a major axis in the horizontal direction and pressed, and the positive terminal and the negative terminal are contacted, and the positive terminal under pressure. To the contact area between the negative terminal and Lead having a step of forming an inter-cell connection body that substantially fills the elliptical through hole by resistance welding in which a high current is applied by a resistance welding electrode; and a step of thermally welding a lid to an upper opening of the battery case. Storage battery manufacturing method. 4. The positive electrode and the negative electrode are formed such that the short diameter of the elliptical pressure contact surface of the projection of the resistance welding electrode is shorter than the short diameter of the elliptical through hole of the partition wall and the projection of the resistance welding electrode is sandwiched. Whether the total volume of the space inside the concave portion of the elliptical concave portion formed in the flexible terminal is larger than the volume inside the elliptical through hole of the partition wall,
Or the same, The manufacturing method of the lead acid battery of Claim 3. 5. The ratio of the major axis / minor axis ratio in the elliptical through hole of the partition wall to the major axis / minor axis ratio in the elliptical pressure contact surface of the projection of the resistance welding electrode is 0.70 to 0.98. 3. The method for manufacturing a lead storage battery according to item 3.