JP2001351599A - Device and method for manufacturing lead-acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize strap welding of highly productivity. SOLUTION: In a cast-on strap device in which a mold is immersed in a molten lead bath for heating and supplying molten lead, a cooling unit is allowed to abut on the mold, and in solidification of a strap, a refrigerant is let flow for cooling down the mold. Desirably, the mold and the cooling unit are made of a copper alloy principally consisting of copper, and the mold and the cooling unit are operated in the fixed operation while the molten lead bath and an element are vertically moved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cast-on-strap type plate assembly manufacturing apparatus for a lead-acid battery by welding ears of positive and negative plates constituting an element and casting and forming a pole and a strap. It relates to a manufacturing method.

[0002]

2. Description of the Related Art Conventional cast-on straps (hereinafter, referred to as cast-on straps)
Called COS. ) The apparatus has the following problems, firstly regarding the mold temperature of the pole and strap forming mold (hereinafter referred to as the mold) and secondly regarding the method of supplying molten lead to the mold.

First, the mold temperature will be described.
The OS device has a built-in heater inside the mold to maintain an optimum mold temperature during strap molding, and constantly controls the temperature. In addition, a cooling medium is passed through the inside of the mold to solidify the introduced molten lead. As described above, since a structure in which the heating / cooling mechanism is built in the same mold is applied, a large thermal shock is locally applied, and the life of the mold is often caused by cracks due to thermal fatigue. FIG. 2 shows a cross-sectional view of a conventional general mold and the relationship between crack generation portions A and B.

[0004] In recent years, it has been practiced to minimize the mold volume in order to shorten the strap molding time for cost reduction or to reduce the size of the apparatus. The short life of the mold due to heating and cooling of the mold has become a serious problem.

[0005] Further, in a mold having a built-in heating heater, a difference in engraving surface temperature depending on the distance from the heater causes variation in strap welding quality. ± which is the standard value of many manufacturers
High quality welding by controlling the mold temperature by absorbing multiple phenomena of various factors such as individual difference of heater output of 3% and fluctuation of heat conduction caused by fitting of heater itself and heater mounting hole. Great costs are required to maintain quality.

Next, a method of supplying molten lead to the mold will be described. First, a needle valve method shown in FIG. 3 is one of the methods frequently used in the conventional COS device. In this method of determining the supply amount of molten lead by controlling the opening time of the needle, the effective cross-sectional area through which the molten lead 8 'passes changes due to the adhesion of lead oxide around the needle C and the valve seat D. As a result, it is necessary to frequently adjust the valve opening time.

[0007] The overflow method shown in FIG.
This is a method in which a notch E for overflow is provided in a part of the mold engraving 4 ′ to discharge an excess amount of molten lead from the mold. In this method, the molten lead 8 'flows out of the notch excessively through the notch using the oxide film formed immediately after the completion of pouring, causing a phenomenon that the strap thickness becomes lower than the height of the notch. Since the amount of the outflow is proportional to the temperature of the molten lead and the time until the solidification is completed, it is difficult to avoid partial unevenness of the strap thickness as long as the temperature of the mold cannot be controlled completely uniformly.

As a method for solving the problems of the conventional COS apparatus, Japanese Patent No. 1846821 discloses a manufacturing method including a series of steps including immersing a mold in molten lead and heating the mold uniformly. This method is effective when the heater and cooling mechanism, which are conventional trouble factors, are eliminated from the mold, but there is a problem in mass production as it is, and the related invention thereafter has not solved this problem.

[0009]

One of the problems to be solved in the method of immersing a mold in molten lead is cooling of the mold first. This is because the productivity is extremely low in terms of time and space in the method of cooling a large number of movable molds by leaving them to stand naturally or in the conventional method of cooling on a turntable. Mold cooling is also an important factor affecting quality as it is associated with solidification of the strap. Later related inventions have proposed a cooling method using air blowing or water, but those that directly apply a refrigerant to the mold from the outside have a problem in safety, and those using water especially mold and molten lead tank. Need to be completely isolated, but the method is not disclosed.

[0010] As a second problem, there is an adverse effect on quality which is caused by making the mold which repeats thermal expansion and contraction by heating and cooling movable. First, in the method of circulating and using a plurality of movable molds, individual differences of the molds are unavoidable, and there is a concern about securing quality. Further, in the method in which the mold mechanism inside the COS device is made movable, it is difficult to achieve both the measures against the heat of the movable part and the securing of the positional accuracy, and product defects due to insufficient positional accuracy are likely to occur.

The present invention relates to an apparatus and a method for manufacturing a lead-acid battery electrode group by the COS method, which mainly relates to a strap forming mold and cooling thereof, thereby improving productivity and stabilizing quality.
Another object of the present invention is to solve a problem related to safety.

[0012]

Means for Solving the Problems In order to solve the above-mentioned problems, the first invention of the present application is to heat a pole and strap forming mold and introduce molten lead into the mold, and place the mold in a molten lead tank. A lead-acid battery manufacturing apparatus, characterized in that a cooling unit is in contact with the mold in a cast-on-strap apparatus performed by immersion. The cooling unit has a structure through which a refrigerant can flow.

According to a second aspect of the present invention, in the first aspect of the invention, the material of the mold and / or the cooling unit is made of a copper alloy containing copper as a main component. Device.

Further, the third invention of the present application relates to a method of manufacturing a lead-acid battery, wherein a mold portion in which a cooling unit is in contact with a pole and a strap forming mold is horizontally installed, and a molten lead tank is raised from below. A step of heating the mold and introducing molten lead by immersing the mold portion,
When the mold reaches the heating set temperature, the process of lowering the molten lead bath, the process of removing excess lead on the upper surface of the mold with a scraper, and the process of lowering the element previously introduced at a predetermined position above the mold to reduce the current lug of the electrode plate Having a step of immersing in the molten lead in the mold, a step of flowing a coolant through the cooling unit to cool the cooling unit and the mold, and a step of elevating the element when the mold reaches the cooling set temperature and the molten lead solidifies. By raising the element, the pole and the strap formed by the mold are discharged from the mold together with the ears of the element.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, first, in order to improve the shortening of service life due to thermal fatigue of a pole and a strap forming mold, a heating / cooling mechanism is eliminated from the mold. The method was carried out by immersion, and at the same time, a method capable of introducing molten lead into the engraving of the mold was adopted. However, it has been found that it is difficult to solve the problems relating to productivity, quality and safety as described above by the method of immersing a movable mold in a molten lead bath as conventionally proposed.

In the present invention, in order to solve these problems,
First, a cooling unit was brought into contact with the mold to cool the mold by heat conduction. The cooling unit was provided with a cooling hole so that the coolant could flow, so that the mold could be cooled efficiently in a short time. Since the refrigerant flows through the cooling holes inside the cooling unit and does not directly act from the outside of the mold as in the conventional case, there is no need to worry about contact with the molten lead, and the refrigerant is safe.

The material of the mold and / or the cooling unit is preferably a copper alloy mainly composed of copper having high thermal conductivity and high-temperature hardness. A mold having a high high-temperature thermal conductivity quickly rises to a predetermined temperature when immersed in a molten lead bath, and has good cooling efficiency. Furthermore, it is resistant to immersion in molten lead, which rises to about 400 ° C. after melting, and its high-temperature strength is stable.

In the manufacturing method of the present invention, the mold and the cooling unit that comes into contact with the mold are of a fixed type, and an apparatus structure that is immersed together in the molten lead tank is used. However, in the sense that it does not work with the fixed type here, the installation method was a structure with relief with one side fixed. As a result, it is easy to cope with stress generation due to thermal expansion and contraction of the mold, and the positional accuracy of the mold can be secured. In addition, a handle and a detachable structure often seen in a movable mold are not required and a simple mold structure can be obtained.

The scraper for removing excess lead on the upper surface of the mold is preferably made of an elastic thin plate.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments.
FIG. 1 is an embodiment of a cast-on-strap type lead storage battery manufacturing apparatus according to the present invention.

The pole and strap forming mold 1 (hereinafter referred to as the mold 1) is a cooling unit mounting stand 3
The cooling unit 2 was installed in contact with the upper surface of the cooling unit 2.
As a material of the mold 1 and the cooling unit 2, a copper alloy containing copper as a main component, which is generally called a mold material for high cycle molding, was used, and a required engraved portion 4 was provided on the upper surface of the mold 1. The cooling unit was provided with a cooling hole 5 and water was piped. As the scraper 6 for removing excess lead on the upper surface of the mold 1, a nickel-white plate having a thickness of 0.5 mm was used.

Next, the operation of the lead storage battery manufacturing apparatus according to the embodiment will be described step by step.

The mold part formed by the pole and strap forming mold 1 being in contact with the cooling unit 2 is fixed horizontally,
The molten lead bath 7 is raised from below and the mold part is immersed. The molten lead 8 is introduced into the mold engraving section 4, and when the mold 1 reaches the set temperature, the molten lead tank is lowered. At this time,
The set temperature of the molten lead bath is 380 ° C, and the measured temperature of the molten lead bath is 38.
It was 0 ° C. ± 5 ° C.

The mold set temperature was 340 ° C., and the maximum mold temperature during strap welding was 345 ° C. When the upper surface of the mold is separated from the molten lead tank 7, the scraper 6 removes excess lead on the upper surface of the mold. Next, the element 9 previously introduced at a predetermined position above the mold is lowered, and the current lug of the electrode plate is immersed in the molten lead 8 in the mold. At the same time, water is flowed into the cooling unit 2 to cool the mold part. Note that the cooling operation is controlled so that the cooling operation cannot be performed while the cooling unit is immersed in the molten lead bath. When the mold 1 reaches the cooling set temperature, the element 9 is raised, discharged from the mold 1 and returned to the beginning.

According to the present embodiment, the cycle time is shortened, and the productivity is greatly improved as compared with the conventional COS system.

[0026]

As described above, according to the present invention, since the cooling efficiency of the mold is increased, the productivity is improved, a product of stable quality can be obtained, and the lead-acid battery which is reliable from the viewpoint of safety can be obtained. A manufacturing device can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic view of a cast-on strap device according to an embodiment.

FIG. 2 is a cross-sectional view of a conventional general mold.

FIG. 3 is a schematic view of molten lead supply by a needle valve system.

FIG. 4 is a schematic diagram of molten lead supply by an overflow method.

[Explanation of symbols]

 A, B Crack generation part C Heater and heater hole D Refrigerant passage hole E Needle F Valve seat G Notch 1 Strap molding mold 2 Cooling unit 3 Cooling unit mounting stand 4 Engraved part 5 Cooling hole 7 Scraper 8 Molten lead tank 9 Molten lead 10 elements

Claims (3)

[Claims] 1. A cast-on strap apparatus for heating a pole and strap forming mold and introducing molten lead into the mold by immersing the mold in a molten lead bath, wherein a cooling unit is brought into contact with the mold. Lead-acid battery manufacturing apparatus characterized by the following: 2. The apparatus according to claim 1, wherein the mold and / or the cooling unit are made of a copper alloy containing copper as a main component. 3. A mold part in which a cooling unit is abutted on a pole and strap molding mold is horizontally installed, and a molten lead tank is raised from below to dipped the mold part, thereby heating the mold and melting the molten lead. A step of lowering the molten lead bath when the mold reaches the heating set temperature, a step of removing excess lead on the upper surface of the mold with a scraper, and lowering the element previously introduced to a predetermined position above the mold. Immersing the current lug of the electrode plate in the molten lead in the mold, flowing a coolant through the cooling unit to cool the cooling unit and the mold, and removing the element when the mold reaches the cooling setting temperature and the molten lead solidifies. And elevating the lead-acid battery.