JP2003086168A - Method of interconnecting cells of lead-acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of interconnecting the cells of a lead-acid battery enabling a battery with excellent volume efficiency to be manufactured without welding errors. SOLUTION: The method of interconnecting the cells of a lead-acid battery includes using an electrode chip to press the backs of the cell connectors of opposite polarities of groups of plates which are adjacent to each other via the separation wall of a battery jar, to contact the connectors with each other within a through-hole in the separation wall, and resistance welding the connectors to each other. The through-hole is formed to be shorter in the vertical direction than in the horizontal direction and the connectors are pressed by the electrode chip and resistance welded to each other in such a way that the inside diameter of the through-hole is greater after the welding than before the welding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for connecting cells of a lead storage battery.

[0002]

2. Description of the Related Art In a conventional lead-acid battery inter-cell connection method, as shown in FIG. 3, a through hole 8 is provided in a partition wall 7 for partitioning a cell chamber 6 of a battery case 9 and adjacent to each other through the through hole 8. Cell chamber 6,
The inter-cell connection bodies 11, 11 of opposite polarities standing on the straps 10, 10 of the electrode plate groups 12, 12 in 6 are arranged to face each other, and the connection bodies 11, 11 are connected from the back side with the inter-cell connection device. With a method of pushing the electrode chips 1 and 1 into the through hole 8 and then energizing and welding the electrode chips 1 and 1 when these connection bodies 11 and 11 obtain a constant contact area (hereinafter referred to as resistance welding). there were.

In general, when this method is adopted, the shape of the through hole 8 provided in the battery case partition wall 7 is a perfect circle, and the shape of the protrusion 3 of the electrode chip 1 is also a perfect circle as shown in FIG. there were. However, recently, there is an increasing demand for improvement in the volumetric efficiency of the battery, and the height dimension of the connection body 11 is reduced, and the height of the working surface of the electrode plates 13 and 14 is correspondingly increased. One of them is to change the shape of the protrusion 3 of the electrode tip 1 from a perfect circle to an ellipse that is vertically short as shown in FIG.
The shape of the through hole 8 of the battery case partition wall 7 is also changed from a perfect circle to an oval shape. The oval cross-sectional area at this time is not different from the true circular cross-sectional area.

In this way, the connecting member 11 is equal to the difference between the diameter of the true circle and the short diameter of the oval (length in the vertical direction).
Since the height of the battery can be shortened and the height of the working surfaces of the electrode plates 13 and 14 can be correspondingly increased, the discharge capacity of the battery in the same volume can be increased. The shape of the through hole 8 may be an elliptical shape, the shape of the electrode chip 1 is the same as the shape of the through hole 8, and the contact area of the connector 11 is 30 to 60% of the cross-sectional area of the through hole 8. To determine the diameter.

[0005]

However, when inter-cell connection is made in the lead acid battery configured as described above,
After the connection body 11 is pushed into the through hole 8 by the electrode tip 1, the lead melted and expanded by resistance heat fills the space in the through hole when resistance welding is performed, but the molten lead is melted in the subsequent cooling process. Shrinks and solidifies to form voids 4 as shown in FIG. 6 in the through holes, and in the worst case, a welding failure occurs.

The present invention has been made in view of the above problems, and an object of the present invention is to produce a lead storage battery having excellent volume efficiency and to obtain a good inter-cell connection state. It is to provide a method of connecting cells of a lead acid battery.

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an inter-cell connection body of opposite polarities of adjacent electrode plate groups which are adjacent to each other via a partition wall of a battery case from the back surface of the connection body to an electrode. In the inter-cell connection method of a lead storage battery in which the connecting members are brought into contact with each other in a through hole of the partition wall by resistance welding by a chip, the through hole is formed so that the vertical direction is shorter than the horizontal direction, and the connecting body is welded. It is characterized in that the through hole is pressed by the electrode tip and resistance-welded so that the inner diameter of the through hole becomes larger than the inner diameter before welding. And
The force pressed by the electrode tip of the connector is 0.
It is preferably 80 MPa / cm ² or more.

As a result, when the connecting body 11 is pressed by the electrode tip 1 and then resistance welding is performed, the lead of the connecting body 11 is melted and expanded by resistance heat, and then the molten lead is contracted and solidified in the cooling process. Even if a sufficient pressing force is applied to the electrode tip 1, the electrode tip 1 spreads the through hole in the vertical direction and advances in the pressing direction. Therefore, it is possible to prevent the occurrence of holes in the through hole after welding. can do. As a result, a good cell-to-cell connection state can be obtained, the height dimension of the connection body can be reduced, and a lead storage battery manufacturing method with excellent volume efficiency can be provided.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

First, a battery case having six cell chambers 6 as shown in FIG. 2 and having a partition wall 7 for partitioning adjacent cell chambers 6, 6 having an oval through hole 8 whose vertical direction is shorter than the horizontal direction. Prepare 9.

Next, as shown in FIG. 3, each cell chamber 6 of the battery case 9 is
A pole plate group 12 in which polar plates having the same polarity are connected to each other by a strap 10 and a connection body 11 is erected at one end of the strap 10.
To store. At this time, the inter-cell connectors 11, 11 of the adjacent cell chambers 6, 6 are housed so as to have opposite polarities via the through holes 8 of the partition wall 7. In addition, 13 is a positive electrode plate, 14
Is a negative electrode plate.

Next, the tips of the electrode chips 1, 1 are brought into contact with the back surfaces of the inter-cell connecting bodies 11, 11 facing each other through the through holes 8, and the electrode chips 1, 1 are respectively moved by the arms 2, 2.
Are brought close to each other, and the inter-cell connection bodies 11, 11 are connected to the through hole 8
Push it inside. Then, after a lapse of a predetermined time, the movement of the arm is stopped, and a current is passed through the electrode tips 1 and 1 to resistance-weld the connection bodies 11 and 11 in the through hole 8 to complete the inter-cell connection.

Here, the shape of the electrode tip 1 has, as shown in FIG. 5, an elliptic cone-shaped protrusion 3 having a flat tip and an inclination, and becomes thicker toward the arm. The protrusion 3 has an oval shape with the vertical direction being shorter than the horizontal direction, and the fixed seat 16 has a perfect circular smooth surface. Further, in the electrode tip 1, the front surface of the electrode tip 1 is inclined toward the front (front side) toward the upper side, and is fixed to the arm 2 at the back surface.

Next, by changing the pressing force of the electrode tip by the method of the embodiment, the cell-to-cell connection is carried out, and after the cell-to-cell connection, the respective cell-to-cell connection bodies (5 locations per battery) are peeled off, The welding defect rate due to the generation of holes was investigated from the state of the through hole and the welded surface. The result is shown in FIG.

From the results shown in FIG. 1, the pressing force is 0.80 MPa /
When it was less than cm ² , the defect rate decreased with the increase of the pressing force, but the defect rate due to the generation of holes between the inner circumference of the through hole and the upper and lower portions of the welding surface was high. On the other hand, the pressing force is 0.8
When it was 0 MPa / cm ² or more, the shapes of the welding surface and the through holes of the adjacent inter-cell connecting bodies were almost the same, and the welding defect rate due to the generation of voids was 0.01% or less, which was a problem-free level. From the above results, by connecting the cells with a pressing force of 0.80 MPa / cm ² or more, the welding surface 15 of the inter-cell connecting bodies 11, 11 adjacent to each other and the through hole 8 have substantially the same shape, which results in poor welding. Can be significantly suppressed, and a good inter-cell connecting portion can be obtained.

In this embodiment, 0.80 MPa / cm
^Although welding defects can be significantly suppressed by connecting cells with a pressing force of ² or more, even if the pressing force is further increased, the effect of the present invention is the same, so the set value is a manufacturing variation. In consideration of the above, the lower limit may be set to 0.80 MPa / cm ² or more by setting the range. Also,
The pressing force is not limited to the value obtained in this embodiment, and the optimum pressing force changes depending on the design specifications such as the shape of the through hole and the shape of the inter-cell connection body. The effects of the present invention can be obtained by setting conditions and connecting cells.

[0017]

As described in detail above, according to the present invention,
Since the inner diameter of the through-hole after welding is larger than the inner diameter of the through-hole before welding, the connecting body is pressed by the electrode tip to connect the cells, so that there is a hole in the welded portion of the inter-cell connecting portion. It does not occur and a good connection is obtained. Further, according to the present invention, since the shape of the inter-cell connection portion can be an ellipse whose vertical direction is shorter than the horizontal direction, the height of the inter-cell connection body can be lowered,
It is possible to provide a lead storage battery having excellent volume efficiency.

[Brief description of drawings]

FIG. 1 is a graph showing a relationship between a pressing force of an electrode tip and a defective rate in a through hole.

FIG. 2 is a perspective view of a battery case for inter-cell connection according to the present invention.

FIG. 3 is an explanatory diagram of a conventional and present invention inter-cell connection method.

FIG. 4A is a side view of a main part of a conventional electrode tip, and FIG. 4B is a front view of the main part.

FIG. 5A is a side view of a main part showing an electrode tip according to an embodiment of the present invention, and FIG. 5B is a front view of the main part.

FIG. 6 is a cross-sectional view showing a state when holes are generated in a welding surface by a conventional method.

[Explanation of symbols]

1 electrode tip 7 partition 8 through holes 9 battery case 11 Cell-to-cell connection

Claims (2)

[Claims] 1. An inter-cell connecting body of mutually opposite polarities of electrode plate groups that are adjacent to each other via a partition wall of a battery case is pressed from the back surface of the connecting body by an electrode chip to connect the connecting bodies to each other in a through hole of the partition wall. In the lead-acid battery inter-cell connection method of contacting and resistance welding,
The through hole is formed so that the vertical direction is shorter than the horizontal direction, and the connection body is resistance-welded by being pressed by the electrode tip so that the inner diameter dimension of the through hole after welding becomes larger than the inner diameter dimension before welding. A method for connecting lead-acid battery cells, which is characterized in that 2. The method for connecting cells between lead acid batteries according to claim 1, wherein the force of the electrode tip of the connection body is 0.80 MPa / cm ² or more.