JP2003317677A - Lead acid storage battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lead acid storage battery having a lead bushing constituting the terminal part insertion molded in the battery outer package, which does not have a gap between the lead bushing and the resin constituting the battery outer package even by the rotating torque impressed on the terminal, and there is no leaking of the electrolyte in the area of the terminal part by securing airtightness and fluid-tightness in this portion, and which is superior in reliability. <P>SOLUTION: This is a lead acid storage battery which has a plurality of ring-shape protrusions formed in flange shape on the outer circumference of the lead bushing, and in which the ring-shape protrusions are insertion molded on the battery outer package. It comprises a plurality of grooves constituted by mutually adjoining ring-shape protrusions and a first rib for stopping the rotation of the lead bushing is provided at one of the grooves, and a portion in which the angle made by the side face of this first rib and the bottom face of the above groove is an acute angle of less than 90° is provided. <P>COPYRIGHT: (C)2004,JPO

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 terminal structure mainly used for starting an automobile.

[0002]

2. Description of the Related Art Terminals of lead acid batteries for automobiles used for starting are made of lead alloy, and a terminal portion having a truncated cone shape is mainly used. As shown in FIG. 1, the terminal portion 1 is formed by inserting a pole post 4 into a hollow lead bushing 3 insert-molded in a battery case or a cover 2 and welding the lead bushing 3 and the pole post 4 together. It Further, the battery case and the cover 2 are usually made of polypropylene resin (hereinafter, P
P resin) is used. The part of the lead bushing 3 inserted into the PP resin is registered utility model No. 3047, for example.
As described in Japanese Patent No. 311, it has a structure in which a plurality of annular projections 5 are formed on the outer circumference of the lead bushing 3. Normally, a height equal to that of the terminal portion 1 protruding outside the battery is set to P
Airtightness is secured by inserting it in P resin.

In the first place, the adhesion between lead and PP resin is extremely low, and even if insert molding is performed under high pressure, lead bushing and P
There is a case where the P resin does not strictly adhere to the boundary surface. In such a case, the electrolytic solution inside the battery crawls up into a minute gap that is not in close contact, and the electrolytic solution crawls out of the battery. By providing the annular protrusion 5 on the insert portion of the lead bushing 1, the length of the path of the electrolyte to crawl can be lengthened, so that the cradle of the electrolyte to the outside of the battery can be suppressed.

On the other hand, when the battery is mounted on the vehicle, the vehicle-side harness is connected and fixed to the terminal portion. Since a large current of about 100 to several hundreds of amperes flows through this connection portion when the engine of the vehicle is started, the connection and fixing are performed by tightening the bolts and nuts to a specified torque or more.

In order to prevent the insert portion of the lead bushing 3 from rotating due to the tightening force transmitted from the terminal portion at the time of tightening the bolts and nuts, a rotation preventing rib 6 is provided as shown in FIG. Has been done.

[0006]

In recent years, due to streamlining and speeding up of automobile production lines, when assembling a battery into a vehicle, the battery terminal and the vehicle-side harness terminal are instantly tightened using a tightening tool such as an impact wrench. Work to fix is coming to be done.

Conventionally, the bolts and nuts for tightening a vehicle-side harness terminal have been such that when a tightening torque of a certain amount or more is applied, the terminal itself starts to idle, and further tightening cannot be performed. Nowadays, even with a considerable tightening torque, a structure in which a harness terminal is securely fixed to a battery terminal without idling has been adopted.

As a result, a considerably higher tightening force is applied to the battery terminal portion than in the conventional case, and as a result, the lead bushing 3 tries to rotate in the same direction in the PP resin, and the rotation preventing rib 6 rotates. A force acts to crush the PP resin surfaces facing each other in the direction. Due to this force, a large gap of about 0.5 mm is generated between the PP resin surface and the anti-rotation rib 6, resulting in poor airtightness, which causes a problem of crawling up of the electrolytic solution. .

[0009]

In order to solve the above-mentioned problems, the invention according to claim 1 of the present invention has a plurality of collar-shaped annular projections formed on the outer peripheral surface of the lead bushing. In a lead storage battery insert-molded on the battery outer casing, having a plurality of groove portions formed of annular protrusions adjacent to each other, one of the plurality of groove portions is provided with a first rib for stopping rotation of the lead bushing, 1 shows a lead storage battery provided with a portion where an angle formed by a side surface of the first rib and a bottom surface of the groove portion is an acute angle of less than 90 °.

According to a second aspect of the present invention, a second rib for stopping the rotation of the lead bushing is provided in a groove portion other than the groove portion provided with the first rib when the lead bushing is projected from above. 2 shows a lead storage battery provided so that the first rib and the second rib do not overlap each other in the case of doing so.

Further, the invention according to claim 3 of the present invention is
The lead acid battery according to claim 1 or 2, wherein the ratio of the sum of the areas of the one side surfaces of the first ribs or the first ribs and the second ribs to the surface area of the terminal portion is 3%.
The feature is that the above settings are made.

[0012]

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

FIG. 3 is a view showing a terminal portion of the lead storage battery according to the embodiment of the present invention. Note that FIG. 3 shows a state before the pole 4 and the lead bushing 7 are welded.

A lead bushing 7 is insert-molded on a cover 8 joined to a battery case (not shown). In this insert portion 9, annular protrusions 10a, 10b, 10c, 10 formed in a flange shape on the outer peripheral surface of the lead bushing 7.
It has a plurality of d and 10e.

In the present invention, adjacent annular projections 10 are provided.
A first rib 13 for stopping rotation as shown in FIG. 4 is provided in the groove portion 11b constituted by b and 10c. In this example, the first rib 13 is provided in the groove 11b, but it may be provided in the other grooves 11a, 11c, 11d.

In the present invention, the first rib 13 is rotated horizontally with respect to the vertical center axis C of the lead bushing 7 to cover 8.
Of the surface of the first rib 13 that contacts the PP resin, that is, the angle θ formed by the side surface 13b of the first rib 13 and the bottom surface 14 of the groove 11b is 9
A portion having an acute angle of less than 0 ° is provided.

Such a structure of the first rib 13 can be realized by forming it along at least two virtual lines N and N'which are parallel to each other. In such a configuration, if the line L orthogonal to the imaginary lines N and N'and passing through the vertical central axis C is used as the parting line of the lead bushing mold, the die cutting can be performed without any trouble.

According to the structure of the first rib, the side surface 13b of the first rib 13 causes the side surface 13b and the bottom surface 14 when the lead bushing 7 is subjected to a tightening torque in the direction of rotation of the vertical center axis C. Although the PP resin surrounded by is compressed, the repulsive force of the compressed PP resin can suppress the rotation of the lead bushing 7. It should be noted that such a structure in which the first rib of the present invention is provided can be easily obtained by only partially processing an existing casting mold, and an increase in the amount of lead can be extremely small.

Further, as shown in FIG. 5, the first rib 1
Groove portions 11a, 11c, 11 other than the groove portion 11b provided with
Second ribs 12 for preventing rotation can be provided on d and 11e. The second ribs 12 can be provided with the same configuration as the first ribs 13 described above, but can also be provided radially from the virtual center C of the lead bushing 7. In this case, the position where the second rib 12 is provided is set at a position where the parting line (line L) set in the casting mold of the lead bushing 7 does not hinder the die cutting. For example, as shown in FIG. 5, it is provided on a line L set as a parting line and a line M orthogonal to the line L and intersecting the central axis C.

In the structure provided with such a second rib, the first rib 1 is seen when the lead bushing 7 is projected from the upper surface.
It is provided at a position where 3 and the second rib 12 do not overlap. When viewed from above the lead bushing 7, the first rib 13
And the second rib 13 are provided so as to overlap each other, that is, when the tip end surface 13a of the first rib 13 and the tip end surface 12a of the second rib 12 are arranged in a straight line. It is not appropriate because the length of the climbing path in the area becomes short in this part.

Further, the first rib 13 and the second rib 1
As for the size and number of 2, one side surface of each rib
The sum S of the areas of 12b and the side surface 13b (2S₁+ 2S₂+
4S ₃) Lead lead bushing 7 taper terminal portion 15 surface
By setting the ratio to the product S'to 3% or more
Upper limit of tightening torque allowed for taper terminal 15
Can be effectively increased. The side of the rib
Area of the lead bushing 7 on the central axis C in one direction
Consider one side that compresses the resin when rotated
It However, only the first rib 13 is provided, and the second rib 1
When 2 is not provided, one side surface of the first rib 13
Ratio of sum of products S ″ to surface area S ′ of tapered terminal
Is 3% or more.

[0022]

EXAMPLES Lead acid batteries according to the present invention and comparative examples were manufactured and a strength test was conducted on the terminals. In the test, as shown in FIG. 6, the harness terminal 16 on the vehicle side is connected to the terminal portion 1 of the test battery 17.
8 and then apply the torque shown by the arrow D to the harness terminal 16 to make the cover fair and the PP resin and the terminal portion 18
By checking the airtightness of the boundary surface part of, the airtightness limit torque value at which airtightness is poor was confirmed. The shape of the terminal portion conforms to the taper terminal T ₂ shown in JIS-D5301.

Inventive Example A The lead storage battery of Inventive Example A has a terminal portion in which only the first rib shown in FIG. 4 in the embodiment of the invention is formed in the groove portion 11b. The ratio of the sum of the areas of the one side surface 13b of the first rib (2S ₁ + 2S ₂ ) to the surface area S ′ of the taper terminal portion of the lead bushing (hereinafter referred to as the rib side surface area ratio) was changed to 1% to 7%. Created.

Inventive Example B The terminal portion of the storage battery of Inventive Example B has the first rib shown in FIG. 4 in the groove portion 11b and the second rib 13 shown in FIG. 5 in the embodiment of the invention. It is formed in the groove 11a. The ratio (2S ₁ + 2S ₂ + 4S ₃ ) of the areas of the one side surface 13b of the first rib 12 and the one side surface of the second rib 12 to the surface area S ′ of the taper terminal portion of the lead bushing (hereinafter referred to as the rib side surface area). It was created by changing the ratio) from 1% to 7%.

Conventional Example C The lead storage battery of Conventional Example C has a terminal portion in which only the second rib shown in FIG. 5 in the embodiment of the invention is formed in the groove portion 11a. The ratio of the sum of the areas (S ₃ × 4) of the one side surface 12b of the second rib to the surface area S ′ of the taper terminal portion of the lead bushing (hereinafter, rib side surface area ratio) is 1.
It was created by changing to ~ 7%.

Conventional Example D In the lead storage battery of Conventional Example D, only the second rib shown in FIG. 5 in the embodiment of the invention is used as the terminal portion of the groove portion 11a and the groove portion 11.
It is formed in b. The ratio of the sum of the areas (S ₃ × 8) of the one side surface 12b of the second rib to the surface area S ′ of the taper terminal portion of the lead bushing (hereinafter, rib side surface area ratio) is changed to 1 to 7%. Created.

The above-described terminal strength test was conducted on the lead-acid batteries of the present invention example and the conventional example. The result is shown in FIG. 7. From the results shown in FIG. 7, it can be seen that the terminal airtightness limit torque of the lead storage battery according to the present invention is at a higher level than the conventional example. Further, in both the present invention example and the conventional example, when the rib side surface area ratio is increased, the airtight limit torque also tends to increase.

Particularly, in the invention examples A and B, when the rib side surface area ratio is 3% or more, the airtight limit torque tends to remarkably increase. Therefore, in the example of the present invention, it is particularly preferable to set the rib side surface area ratio to 3% or more. Although the present invention does not specify the upper limit of the rib side surface area ratio, even if the rib side surface area ratio is increased beyond 6%, the airtightness limit torque is not significantly increased. The ratio is preferably set to 3% to 6%. Further, it can be seen that the invention sample B can obtain a high airtightness limit torque even when the rib side surface area ratio is reduced as compared with the invention sample A.

Here, if the rib side surface area ratio is increased, a larger amount of lead is required accordingly. If an attempt is made to secure a larger rib side surface area ratio, the outside diameter of the bushing will become extremely large, making it difficult to use the existing resin molding die, and it will be necessary to make major modifications to the bushing insert part of the molding die. Therefore, it is not preferable from the viewpoint of standardization of equipment. A method of increasing the rib side surface area ratio by increasing the number of ribs is also conceivable. However, as described above, from the original purpose of the groove portion 11 to lengthen the path for the electrolyte to crawl, the groove portion 11 is increased. It is not preferable to provide too many ribs in order to prevent the electrolyte from creeping up.

[0030]

As described above, according to the present invention, in the lead storage battery in which the lead bushing serving as the terminal is insert-molded in the battery case, the lead bushing and the battery case are configured also by the rotational torque applied to the terminal. It is possible to provide a highly reliable lead-acid battery that does not crawl up the electrolyte of the terminal part by ensuring airtightness and liquid-tightness in this part without generating a gap between the resin and , Very useful.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a main part of a conventional lead-acid battery.

FIG. 2 is a diagram showing a lead bushing according to a conventional example.

FIG. 3 is a diagram showing a main part of a lead storage battery according to an example of the present invention.

FIG. 4 is a diagram showing a lead bushing cross section of a lead storage battery according to an example of the present invention.

FIG. 5 is a view showing another cross section of the lead bushing of the lead storage battery according to the example of the present invention.

FIG. 6 is a schematic diagram showing a terminal strength test method.

FIG. 7 is a diagram showing a result of a terminal portion strength test.

[Explanation of symbols]

1 terminal 2 cover 3 Lead bushings 4 poles 5 annular protrusion 6 Anti-rotation rib 7 Lead bushings 8 covers 9 Insert part 10a, 10b, 10c, 10d, 10e Annular protrusion 11a, 11b, 11c, 11d, 11e Groove part 12 Second rib 12a (second rib) tip surface 12b Side surface (of second rib) 13 First rib 13a Tip surface (of first rib) 13b Side (of first rib) 14 Bottom 15 Tapered terminal 16 harness terminals 17 test battery 18 terminals

Claims (3)

[Claims] 1. A lead storage battery having a plurality of collar-shaped annular protrusions formed on the outer peripheral surface of a lead bushing, wherein the annular protrusions are insert-molded in a battery case. A plurality of first ribs for stopping rotation of the lead bushing is provided in one of the plurality of groove portions, and an angle formed by a side surface of the first rib and a bottom surface of the groove portion is less than 90 °. Lead acid battery characterized by having a certain portion. 2. The first rib and the first rib when a second rib for stopping rotation of the lead bushing is projected from the upper surface in a groove portion other than the groove portion provided with the first rib. The lead acid battery according to claim 1, wherein the rib is provided so as not to overlap the second rib. 3. The ratio of the sum of the areas of one side surfaces of the first ribs or the first ribs and the second ribs to the surface area of the terminal portion is set to 3% or more. Alternatively, the lead acid battery according to item 2.