JP2008262771A - Lead storage battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lead storage battery in which an As content contained in a terminal formed of a Pb-Sb alloy and exposed out of an outer case of a lead storage battery is reduced and the lowering of the mechanical strength of the terminal caused by the reduction of the As content is controlled, and while an exposed amount of As to an environment is reduced, the mechanical strength of the terminal is kept stable. <P>SOLUTION: An exposed portion of a terminal exposed from a battery outer case is formed of a Pb-Sb alloy containing As 0.095 mass% or smaller, Sn 0.001-0.055 mass%, and Cu 0.001-0.01 mass%. By setting contents of Sn and Cu as above, mechanical strength required for a terminal can be obtained even if an As content is made to be 0.095 mass% or smaller. Moreover, since the As content can be reduced remarkably from a conventional amount of 0.2-0.5 mass%, this can be favorable in terms of an environment. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lead-acid battery.

  As a method for molding lead-acid battery terminals, a terminal bushing made of lead or lead alloy that penetrates the inside and outside of the battery integrally molded with a synthetic resin battery case lid, and a pole that collects the electrode group and penetrates the hole of the terminal bushing A method of connecting a column to a column by welding or other means is widely used including automobile batteries.

  At present, when joining the terminal bushing through the pole pillar with a burner or the like, the terminal body and bushing have a low melting point because of the presence of synthetic resin around the terminal bushing, so the weldability is low. An excellent Pb—Sb alloy is used.

  Further, the terminal bushing is required to have strength against tightening by a harness or the like for connecting to an external load. Therefore, it is common to add about 0.2 to 0.5% by mass of As to the Pb—Sb alloy in the Pb—Sb alloy to supplement the mechanical strength.

  For example, in Patent Document 1, Sb is 1.6 to 3.5 mass%, As is less than 0.2 mass%, Sn is 0.06 to 0.1 mass%, and Cu is 0.002 to 0.01 mass%. Pb-Sb alloy for storage batteries, comprising less than%, 0.006 to 0.1 mass% of Se, and the balance Pb, and can reduce the Sb content and obtain a good cast product without cracking during casting. It is shown.

In Patent Document 2, Sb is 0.5 to 3.5 mass%, As is 0.025 to 0.3 mass%, Se is 0.005 to 0.1 mass%, and Sn is 0.002 to 0.0 mass%. A Pb—Sb alloy for a storage battery is shown which is composed of 05 mass%, Cu is 0.01 to 0.1 mass%, and the balance is Pb, and which reduces contamination by scale during casting.
JP-A-4-2055 JP 50-108125 A

  In general, the amount of As contained in the Pb—Sb—As alloy is 0.2 to 0.5 mass%, and the proportion of the lead storage battery main body is even smaller. Further, from the current situation that most of lead acid batteries are recovered by recycling, As contained in the lead acid batteries is appropriately treated in the recycling process, and it is considered that the influence on the environment is extremely small.

  However, As and its inorganic compounds are very harmful to the human body, laws regarding the identification of specific chemical substances released into the environment and the promotion of improved management, and the identification of specific chemical substances released into the environment, etc. Needless to say, the amount of As in Pb-Sb-As alloy is more preferable from the environmental viewpoint because it is designated as "Class 1 Designated Chemical Substance" in the Enforcement Ordinance on Promotion of Management Improvement. Yes.

  For example, in a lead acid battery for start-up used in automobiles, among Pb and Pb alloys used for lead acid batteries, those used particularly for terminals are different from Pb and Pb alloys used for grids and internal connectors. The lead-acid battery is exposed on the exterior.

  When a Pb alloy containing As is used as a terminal exposed on the battery exterior, there is a concern that the As component may be eluted by touching the user's human body or contact with moisture.

  From the above, the inventors of the present invention have been diligently working to reduce the amount of As in the Pb—Sb—As alloy, but only by reducing the amount of As in the current Pb—Sb—As alloy, Pb— Since the mechanical strength of the alloy is lowered, particularly in the case of a terminal, when it is fastened and fixed by a connecting harness, there is a problem that the terminal is cracked or deformed.

  In view of the situation as described above, the present invention is particularly suitable for lead storage batteries having Pb exposed to the exterior, such as terminals, particularly for the purpose of reducing the environmental load while ensuring the mechanical strength necessary for the terminals. The lead acid battery which employ | adopted the Pb-Sb alloy by which the quantity was reduced is shown.

  In order to solve the above problems, the invention according to claim 1 of the present invention is such that the portion of the terminal exposed to the battery exterior has 0.095 mass% or less As and 0.001 to 0.055 mass%. 1 shows a lead storage battery characterized by being a Pb—Sb alloy containing Sn and 0.001 to 0.01% by mass of Cu.

  ADVANTAGE OF THE INVENTION According to this invention, the lead storage battery which is preferable also from the environmental viewpoint which reduced the amount of As in Pb alloy, ensuring the mechanical strength of Pb alloy exposed to battery exteriors, such as a terminal, can be provided. Has an effect.

  A configuration example of the lead storage battery of the present invention will be described with reference to the drawings. As shown in FIG. 1, the lead storage battery 1 of the present invention has a battery case 2 and a lid 3 that closes the battery case 2. A terminal bushing 4 is integrally formed on the lid 3, and a pole column 5 led out from an electrode plate group (not shown) is inserted into the terminal bushing 4, and both are welded to form a terminal 6. 1 shows a cross-sectional view of the vicinity of the terminal 6 of the lead storage battery 1. FIG.

  The lead alloy exposed from the battery case 2 and the lid 3 as the battery exterior of the lead storage battery 1 is only the surface of the terminal 6. In the present invention, at least a portion of the terminal 6 exposed to the outside is Pb—Sb containing 0.095 mass% or less As, 0.001 to 0.055 mass% Sn, and 0.001 to 0.01 mass% Cu. Alloy.

  In the present invention, in the Pb—Sb—As alloy, the content of As having an effect of increasing the mechanical strength is reduced to 0.095% by mass or less compared to the conventional case. By prescribing the Sn amount to 0.001 to 0.055 mass% and the Cu amount to 0.001 to 0.01 mass%, it is possible to suppress a decrease in mechanical strength due to the reduction in As amount, and as a lead storage battery with an external load. It is possible to obtain a lead-acid battery having a strength that can be safely used for tightening at the time of connection.

  Moreover, since As in the Pb alloy exposed outside the battery can be reduced, elution of As into the environment due to contact with moisture and the like, and exposure of the As-containing substance to the battery user are suppressed, which is preferable in terms of the environment. .

  In the present invention, the amount of As in the Pb alloy exposed to the outside of the battery is reduced. For example, due to the structure of the terminal bushing 4, only the portion of the terminal bushing 4 exposed on the outer surface of the lead storage battery 1 is disclosed. It goes without saying that the Pb—Sb—As alloy shown in FIG. 5 can be used, and the inside (bulk) of the terminal bushing 4 can be a Pb—Sb—As alloy or other Pb alloy containing a large amount of conventional As. Nor.

  Moreover, in this embodiment, although the example applied to the lead acid battery for start-up, especially the terminal of truncated cone shape was described, also in the terminal of lead acid batteries other than such a shape, generally for external connection It is obvious that the present invention is effective for a lead-acid battery having a terminal other than the truncated cone shape.

  In addition, what is necessary is just to select as Sb content in a Pb-Sb alloy in the range of 1-5 mass% known conventionally.

  Lead storage batteries using terminal bushings made of Pb—Sb alloys having various compositions shown in Tables 1 to 3 were prepared, and the Vickers hardness (Hv) of the terminals was measured. In this example, the mechanical strength of the lead alloy as an index of the tightening strength of the terminal is 10 gf at the time of measurement in the Vickers hardness measurement specified in JIS Z2244 “Vickers hardness test-test method”. The micro Vickers hardness test was evaluated.

  Tables 1 to 3 show values of Vickers hardness (Hv) of terminals having various compositions obtained by these measurements. In addition, about Vickers hardness, it measured about each five measurement samples. In Tables 1-3, the minimum value and the maximum value of Vickers hardness were shown. In addition, what showed the single value has shown that all the measurement samples showed the same Vickers hardness.

  In Tables 1 to 3, the lead alloy composition and the Vickers hardness for the content (mass%) of each alloy component of As, Sn, and Cu in the Pb—Sb alloy containing 2.5 mass% of Sb in the examples. Table 1 shows the length. The balance other than those listed in Tables 1 to 3 is Pb.

  In the present invention, it is one of the objects that the lead-acid battery terminal can be safely used for tightening when connected to an external load.

  The present inventors take into account the data of terminal tightening strength tests, actual vehicle tests, etc. and the market results of shipped lead storage batteries, and set the reference value of Vickers hardness (Hv) required as a lead storage battery terminal to 10 It was. And Vickers hardness (Hv) was prescribed | regulated as the safe area | region when using as a lead acid battery terminal 10 or more.

  From the results shown in Tables 1 to 3, when the amount of As is reduced from the conventional one to 0.095% by mass or less, the Vickers hardness of the terminal varies greatly depending on the amount of Cu and the amount of Sn. Recognize. In this example, in order to obtain 10 or more, which is Vickers hardness necessary for terminal strength, the Sn content is 0.001 to 0.055 mass%, and the Cu content is 0.001 to 0.01. It turns out that it is necessary to set it as the mass%.

  When the amount of As is 0.095% by mass or less, when the Sn content is increased from 0 to 0.001% by mass and the Cu content is increased from 0 to 0.001, the Vickers hardness is 13 and a sufficient value is obtained. can get. However, when the Sn content is 0.1% by mass or the Cu content is 0.05% by mass, the Vickers hardness tends to vary. As a result, the average Vickers hardness is 10 or more. Although it can be ensured, there was a case where the minimum value of Vickers hardness was less than 10.

  Therefore, when the As content is 0.095% by mass or less, in order to obtain the mechanical strength necessary for the terminal, the Sn content is 0.001 to 0.055% by mass, and the Cu content. It is necessary to satisfy simultaneously 0.001 to 0.01 mass%.

  On the other hand, when the amount of As is 0.2% by mass, which is the conventional level, in this example, the Vickers hardness is 10 or more in all examples regardless of the Sn content and the Cu content. It had the mechanical strength required as a lead alloy.

  In addition, in the present Example, although the result about the case where the amount of Sb in a Pb-Sb alloy is 2.5 mass% was described, also when the amount of Sb is 1.5 mass% and 4.5 mass%, this Results similar to those of the example were obtained. That is, when the Sb content is 1.5% by mass and 3.5% by mass, the Sn content is 0.001 to 0.055% by mass and the Cu content is 0.001 to 0.01% by mass. Thus, it was possible to obtain 10 or more Vickers hardness required for the lead storage battery terminal including variation. In addition, when the Sn and Cu contents are 0.001 to 0.055% by mass and the Cu content is not 0.001 to 0.01% by mass, a Vickers hardness of 10 or more can be stably obtained. I could not.

  From the above, the present invention remarkably suppresses the decrease in mechanical strength that occurs when the As content in the Pb—Sb alloy used for the lead-acid battery terminal is limited to 0.095 mass% or less. Can do. As a result, the amount of As in the terminal exposed on the lead-acid battery exterior can be reduced without a decrease in terminal strength, and the environmental load can be significantly reduced.

  The present invention can be applied to a lead storage battery in which a portion exposed from the lead storage battery exterior of the terminal is made of a Pb—Sb alloy, and can be applied to lead storage batteries for various uses including a start lead storage battery.

The figure which shows the structural example of the lead acid battery of this invention

Explanation of symbols

1 Lead Acid Battery 2 Battery Case 3 Lid 4 Terminal Bushing 5 Polar Column 6 Terminal

Claims (1)

Pb-Sb alloy in which the portion of the terminal exposed on the battery exterior contains 0.095 mass% or less As, 0.001 to 0.055 mass% Sn, and 0.001 to 0.01 mass% Cu Lead acid battery characterized by being.

Images