JP2003109577A - Strap forming method and device for lead storage battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a strap forming method and a device for a lead storage battery by which, highly reliable joined state can be obtained with good productivity. SOLUTION: A strap forming method for a lead storage battery includes the process of injecting melt M of a material for a strap inside a mold 11 which can be heated and cooled, heating the mold 11, immersing an end part of a lead 2a or a lead 2b in the mold 11, and forming a protrusion of solidified strap by cooling the mold 11 afterwards. When heating the mold 11, a ring- shaped belt plate material 20 made of magnetic material is arranged at the outer periphery of a heating skirt part 14 of the mold 11 made of the material with high heat conductive property, and the ring-shaped belt plate material 20 is heated by supplying high frequency current to a high frequency induction heating coil 18, by the above, the mold 11 is effectively and quickly heated, and prevented from the generation of the unevenness of the temperature.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method and apparatus for forming cast-on straps in lead acid batteries.

[0002]

2. Description of the Related Art Conventionally, in a lead storage battery, a jig called a comb type has been used as a method for integrally connecting electrode plates having the same polarity in each cell and forming a strap for connecting an electrode plate group between cells. A method of projecting the ends of the leads extended from the electrode plate into the gap of, melting and welding with a strap material with a burner, and further welding a connecting part for inter-cell connection to one side of the ends, for example, Japanese Patent Laid-Open No. 60-1388
48, JP-A-6-290770, and Patent No. 2
As disclosed in Japanese Patent No. 958857, a molten metal of a strap material is injected into a mold in which a cavity corresponding to a strap shape is formed, leads of an electrode plate group are immersed, and the mold and the molten metal are heated by a heating means. A cast-on-strap method is known in which the mold is cooled to solidify the strap material and form a strap.

Although the strap formed by the welding method is likely to cause lead connection failure and may adversely affect the discharge characteristics and the life characteristics, the cast-on-strap method can reliably bond the lead and the strap. it can. However, the cast-on-strap method requires uniform and rapid heating of the mold in order to ensure its reliability and productivity. Therefore, the above-mentioned JP-A-60-
Japanese Patent Laid-Open No. 138848 and Japanese Patent Laid-Open No. 6-290770 disclose that rapid heating is realized by high-frequency induction heating.

An example of the structure of the apparatus for heating the mold by the high frequency induction heating to form the strap will be described with reference to FIGS. 4 and 5.

In FIG. 5, reference numeral 1 denotes an electrode plate group in which a positive electrode plate and a negative electrode plate are laminated with a separator interposed therebetween, and leads (called ears) 2a and 2b of the positive electrode plate and the negative electrode plate are projected on one end face thereof. Has been done. The ends of the leads 2a and 2b are joined by a lead alloy strap 3 of the same type as the electrode plate. The strap 3 is provided with a joining portion 3a for joining the ends of the leads 2a and 2b and a connecting piece 3b for connecting between cells protruding upward in an L shape at one end thereof.

In FIG. 4, reference numeral 31 denotes a mold in which a cavity 32 having an open upper surface corresponding to the shape of the strap 3 is formed, and is heated to about 400 ° C. which is higher than the melting temperature (about 340 ° C.) of the lead alloy which is the strap material. Therefore, it is made of a material having heat resistance against the temperature, a predetermined strength, and good thermal conductivity. The cavity 32 is formed in a shape having a deep groove portion 32b corresponding to the connecting piece portion 3b at one end portion of the shallow dish-shaped portion 32a corresponding to the joint portion 3a.

The mold 31 includes a mold wall 33 along the surface shape of the cavity 32, a heating skirt portion 34 having an appropriate length which is vertically provided integrally with the outer periphery of the cavity 32, and an installation projecting on the outer periphery of the upper end portion thereof. And a flange 35. A guide portion 37 of a push-up pin 36 that pushes up the formed strap 3 from below is provided at a portion corresponding to both ends of the cavity 32.

A coil 38 for high-frequency induction heating of the mold 31 is arranged around the heating skirt portion 34 of the mold 31, and cooling water is sprayed to the mold at the lower part of the center of the mold 31. Cooling nozzle 3 for rapid cooling
9 are provided.

In the above structure, when the strap 3 is formed on the electrode plate group 1, the cavity 3 of the mold 31 is formed.
A lead alloy melt M is injected into the inside of the electrode 2 as indicated by a phantom line, and the electrode plate group 1 is turned upside down and held by a moving means (not shown) so that the lead 2a or 2b is placed in the cavity 32. Along with the immersion, a high-frequency current is passed through a coil 38 with a high-frequency power source (not shown) to mainly induction-heat the heating skirt portion 34. Since the mold 31 has high thermal conductivity, the heat of the heating skirt portion 34 is quickly transferred to the mold 31.
Is heated uniformly and the molten metal M of the lead 2a or 2b
The portion immersed in the molten metal is integrated with the molten metal M while being melted, and immediately thereafter, the energization of the coil 38 is stopped and the cooling nozzle 39
Cooling water from the mold toward the mold 31
1 is uniformly rapidly cooled to uniformly cool and solidify the molten metal M to form the strap 3 integrated with the lead 2a or 2b, and then the push-up pin 36 pushes up the electrode plate group 1 by the moving means to move the strap 3 Is taken out from the mold 31.

[0010]

However, in the structure of the cast-on-strap forming apparatus as described above, since the mold 31 needs to have necessary heat resistance and strength and high thermal conductivity, As described above, the copper alloy is used. However, the efficiency of high frequency induction heating is extremely low because of this, it takes longer time to heat compared with the input power, the productivity is lowered, and the location of the mold 31 varies. There is a problem that temperature unevenness may occur.

In view of the above-mentioned conventional problems, the present invention can efficiently and promptly heat by high frequency induction heating, generate no temperature unevenness of the mold, and obtain a highly reliable bonded state with high productivity. An object of the present invention is to provide a strap forming method and device for a lead storage battery.

[0012]

A method of forming a strap for a lead storage battery according to the present invention comprises a step of injecting a strap material into a mold that can be heated and cooled, a step of heating the mold, and a lead end portion of an electrode plate group. In a method of forming a strap for a lead storage battery, which comprises a step of immersing a metal in a mold and a step of cooling the mold and protruding a solidified strap, in a mold heating step, a mold made of a material having high thermal conductivity and a magnetic material is arranged. Is used for high-frequency induction heating of the mold. Since the mold has good thermal conductivity and the magnetic material can efficiently perform high-frequency induction heating, the mold can be heated quickly and efficiently, and temperature unevenness occurs. Instead, the straps bonded to the leads of the electrode plate group with high reliability can be obtained with high productivity. .

The lead-acid battery strap forming apparatus of the present invention is further provided with a mold for injecting a strap material, a mold heating means, a mold cooling means, and an electrode plate group which holds the lead ends of the mold inside the mold. In a lead storage battery strap forming device equipped with electrode plate group moving means that is taken out after being formed by strap formation, a magnetic material is provided in a mold made of a material having high thermal conductivity, and a coil for high frequency induction heating is provided on the outer periphery of the mold. It is arranged, and the effect can be obtained by implementing the above method.

Further, when a magnetic material layer is provided so as to surround the outer surface of the mold continuously or intermittently in an annular shape, and a coil is arranged around the magnetic material layer, the surface facing the coil is heated particularly efficiently in high frequency induction heating. Therefore, by providing the magnetic material layer on the outer surface of the mold, the heating efficiency can be further improved, and since the thermal conductivity of the mold is high, the mold can be uniformly heated quickly and efficiently.

When an annular strip plate material made of a magnetic material is arranged on the outer periphery of the mold and insert-cast, a magnetic material having a uniform composition and thickness can be formed on the coil facing surface of the mold by using the annular strip plate material. The heating efficiency is improved, the magnetic material and the mold are highly integrated, the heat transfer performance between them can be improved, and the mold can be uniformly heated quickly and efficiently.

Further, by fitting and fixing the annular band plate body made of a magnetic material to the outer periphery of the mold, the same operation and effect can be obtained with a structure that can be more easily realized, and the magnetic material is a material having a high thermal conductivity. Similar effects can be obtained even if the mold is made of an alloy in which

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION A lead storage battery strap forming apparatus according to an embodiment of the present invention will be described below with reference to FIG. Note that the electrode plate group and its strap are the same as those described in the conventional art with reference to FIG. 5, and the description thereof will be incorporated.

In FIG. 1, 11 is a mold in which a cavity 12 having an open upper surface corresponding to the shape of the strap 3 is formed, and heated to about 400 ° C. which is higher than the melting temperature (about 340 ° C.) of the lead alloy as the strap material. Therefore, it is made of an alloy (brass) having copper and zinc as the main components, which is a material having heat resistance to the temperature, a predetermined strength, and good thermal conductivity. The cavity 12 is formed in a shape having a deep groove portion 12b corresponding to the connecting piece portion 3b at one end portion of the shallow dish-shaped portion 12a corresponding to the joining portion 3a.

The mold 11 has a mold wall 13 extending along the surface shape of the cavity 12, a heating skirt portion 14 having a proper length which is vertically provided integrally with the outer periphery of the cavity 12, and an installation projecting on the outer periphery of the upper end portion. And a flange 15. A guide portion 17 of a push-up pin 16 that pushes up the formed strap 3 from below is provided at a portion corresponding to both ends of the cavity 12 so as to extend downward. An annular band plate member 20 made of a ferromagnetic material such as a stainless steel plate is integrally provided on the outer peripheral portion of the heating skirt portion 14 as a magnetic material layer by insert casting.

A coil 18 as heating means for high-frequency induction heating of the mold 11 is arranged around the heating skirt portion 14 of the mold 11, and the mold 1 is also provided.
A cooling nozzle 19 as cooling means for injecting cooling water into the mold to rapidly cool the mold is disposed in the lower part of the center of the mold 1.

In the above structure, when forming the strap 3 on the electrode plate group 1, the cavity 1 of the mold 11 is formed.
Molten lead alloy M is injected into the inside of the electrode 2 as indicated by a phantom line, and the electrode plate group 1 is turned upside down and held by a moving means (not shown) so that its lead 2a or 2b is placed in the cavity 12. Along with the immersion, a high-frequency current is passed through the coil 18 by a high-frequency power source (not shown) to efficiently efficiently induction-heat the annular strip plate member 20 mainly on the outer peripheral portion of the heating skirt portion 14. Since the mold 11 has high thermal conductivity, the heat of the annular strip plate member 20 is rapidly and uniformly heated from the heating skirt portion 14 to the entire mold wall 13, and the portion of the lead 2a or 2b immersed in the molten metal M is uniformly melted. And is integrated with the molten metal M.

Immediately thereafter, the energization of the coil 18 is stopped and the cooling water is sprayed from the cooling nozzle 19 toward the mold 11, whereby the mold 11 is uniformly rapidly cooled and the molten metal M is uniformly cooled and solidified. , The strap 3 integral with the lead 2a or 2b is formed. After that, by pushing up with the push-up pin 16 and pulling up the electrode plate group 1 by the moving means, the electrode plate group 1 and the strap 3 are taken out from the mold 11.

According to this embodiment, the mold 11 is made of brass, which is a material having good thermal conductivity, the annular band plate member 20 as a magnetic material layer is provided on the outer periphery thereof, and the coil 18 is arranged around the annular band plate member 20. Since the high frequency induction heating is performed, a magnetic material layer having a uniform composition and a uniform thickness can be formed on the surface of the mold 11 that faces the coil 18, and the mold 11 can be heated quickly and efficiently and temperature unevenness is generated. , The leads 2a of the electrode plate group 1 with high reliability,
The strap 3 joined to the 2b can be obtained with high productivity.

Further, the annular strip plate member 20 is attached to the mold wall 1
Since insert casting is performed on the outer periphery of the heating skirt portion 14 on the outer periphery of 3, the magnetic material layer and the mold 11 are highly integrated, and the heat transfer performance between them can be enhanced.
Can be uniformly heated quickly and efficiently.

In the above description of the embodiment, the mold 11 is used.
The annular band plate material 2 so as to face the outer periphery of the heating skirt portion 14 of
Although the example of insert casting 0 into the mold 11 is shown,
A magnetic material layer may be formed by spraying a magnetic material onto the outer peripheral surface of the heating skirt portion 14.

Further, as shown in FIG. 2, an annular strip plate member 21 made of a magnetic material such as a stainless steel plate is molded into the mold 11.
It may be fitted to the outer periphery of the heating skirt portion 14 and integrally fixed by using an adhesive having good thermal conductivity. Further, it is preferable that these magnetic material layers are continuously provided in an annular shape on the outer circumference of the heating skirt portion 14, but they may be provided intermittently in some cases.

Furthermore, as shown in FIG. 3, a magnetic material mixing mold 22 made of an alloy in which a magnetic material such as nickel is mixed with a brass material having high thermal conductivity may be constructed. As a material for the mold, in addition to copper alloys such as brass, aluminum alloys or materials having higher thermal conductivity can be used.

[0028]

As is apparent from the above description, according to the method of forming a strap for a lead storage battery of the present invention, a magnetic material is placed in a mold made of a material having high thermal conductivity in the mold heating step, and the mold is subjected to high frequency. This is induction heating, and since the mold can be efficiently induction heated by a magnetic material and the mold has good thermal conductivity, the mold can be quickly and efficiently heated and temperature unevenness does not occur. Can be obtained with high productivity in a state of being bonded to the leads of the electrode plate group with high reliability.

Further, according to the lead storage battery strap forming apparatus of the present invention, the magnetic material is provided on the mold made of a material having high thermal conductivity, and the high frequency induction heating coil is arranged on the outer periphery of the mold. It can be carried out and the effect can be produced.

Further, when a magnetic material layer is provided so as to continuously or intermittently surround the outer surface of the mold in a ring shape and a coil is arranged around the magnetic material layer, the surface facing the coil is heated particularly efficiently in high frequency induction heating. Therefore, by providing the magnetic material layer on the outer surface of the mold, the heating efficiency can be further improved, and since the thermal conductivity of the mold is high, the mold can be uniformly heated quickly and efficiently.

When an annular strip plate material made of a magnetic material is arranged on the outer periphery of the mold and insert-cast, a magnetic material of uniform composition and thickness can be formed on the coil facing surface of the mold by using the annular strip plate material. The heating efficiency is improved, the magnetic material and the mold are highly integrated, the heat transfer performance between them can be improved, and the mold can be uniformly heated quickly and efficiently.

Further, by fitting and fixing the annular strip plate body made of a magnetic material to the outer periphery of the mold, the same operational effect can be obtained with a structure that can be more easily realized, and the magnetic material can be added to the copper alloy or the aluminum alloy. Even if the mold is made of the mixed alloy, the same effect can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a schematic configuration of a strap forming device according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing a schematic configuration of a strap forming device according to another embodiment of the present invention.

FIG. 3 is a vertical cross-sectional view showing a schematic configuration of a strap forming device according to yet another embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view showing a schematic configuration of a conventional strap forming device.

FIG. 5 is a perspective view of a main part of an electrode plate group having a strap formed thereon.

[Explanation of symbols]

1 plate group 2a, 2b lead 11 Mold 18 coils (heating means) 19 Cooling nozzle (cooling means) 20 Annular strip material (magnetic material layer) 21 Annular strip plate material (magnetic material layer) 22 Magnetic material mixed mold

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takashi Hattori             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Satoshi Kajikawa             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F term (reference) 5H022 AA01 BB14 BB28 CC15 CC19                       CC23 CC24 EE04

Claims (8)

[Claims] 1. A step of injecting a strap material into a heatable / coolable mold, and a step of heating the mold,
A lead storage battery strap forming method comprising a step of immersing a lead end portion of an electrode plate group into a mold and a step of cooling the mold to project a solidified strap, which is made of a material having high thermal conductivity in a mold heating step. A method for forming a strap for a lead storage battery, characterized in that a mold in which a magnetic material is arranged is used and the mold is subjected to high frequency induction heating. 2. The method for forming a strap for a lead storage battery according to claim 1, wherein the material having high thermal conductivity is a copper alloy or an aluminum alloy. 3. A mold for injecting a strap material,
A strap forming device for a lead storage battery, comprising: a mold heating means; a mold cooling means; and a pole plate group moving means for holding a pole plate group, immersing a lead end thereof in the mold, and taking out after strap formation. A strap forming device for a lead storage battery, wherein a magnetic material is provided in a mold made of a material having high thermal conductivity, and a high frequency induction heating coil is arranged on the outer periphery of the mold. 4. The lead storage battery strap forming device according to claim 3, wherein the material having high thermal conductivity is a copper alloy or an aluminum alloy. 5. The lead storage battery strap formation according to claim 3, wherein a magnetic material layer is provided so as to continuously or intermittently surround the outer surface of the mold in an annular shape, and a coil is provided around the magnetic material layer. apparatus. 6. The lead storage battery strap forming device according to claim 5, wherein an annular strip plate member made of a magnetic material is arranged on the outer periphery of the mold and insert-cast. 7. The lead storage battery strap forming device according to claim 5, wherein an annular band plate body made of a magnetic material is fitted and fixed to the outer periphery of the mold. 8. The strap forming device for a lead storage battery according to claim 3, wherein the mold is made of an alloy in which a magnetic material is mixed with a material having high thermal conductivity.