MXPA97007011A - Anticorrosion border with short anchor, without union lines, for accumulated batteries - Google Patents

Abstract

The present invention relates to an anticorrosion terminal with short anchor, without connecting lines, for accumulator batteries of the type constituted by an upper portion preferably of conformation according to a frustoconical hollow body emerging from the battery cover, which is distinguished by comprise in adjacencies of the end of greater section of said frustoconical hollow body, a hollow lower portion whose internal cavity is coaxial with the cavity of said frustoconical body, said hollow lower portion having a first both of cylindrical configuration and greater diameter than that of the greater end section of the frustoconical hollow body, which is continued with a second section of frustoconical configuration, in adjacencies of whose end of greater section, are formed anchoring means of the terminal constituted by a circumferential projection whose wall defines a plurality of perimetral cavities alternately open towards up and towards ba

Description

ANTICORROSION BORDER WITH SHORT ANCHOR. NO LINES OF UNION. FOR BATTERIES OF ACCUMULATORS DESCRIPTION The main purpose of the present invention is an anticorrosion terminal with short anchor, without connecting lines, for accumulator batteries that provides important advantages resulting from its minimal corrosion due to the migration of the internal electrolyte, its weight being significantly lower than that of the terminals manufactured. to the present, and of the lower maintenance required during the operation of the batteries in which said terminal is used. More specifically, the present invention covers a terminal of the type specified for use in accumulator batteries, which has been conceived and developed as a result of the experience acquired in the use of these devices to generate electrical energy, and laboratory tests intended for to study the highly damaging corrosion process of the lead alloy terminals, generated by the migration of the electrolyte towards the external surface of the metal, during the operation of the battery. In this sense, the invented terminal minimizes this migration and, consequently, its external surface remains clean, maintaining a good electrical contact with the terminal of the external circuit to which it is linked. Likewise, the substantial reduction of the aforementioned corrosion allows the operation of the battery, practically without the need of the usual maintenance tasks aimed at cleaning the terminal. On the other hand, having a smaller amount of material than that of the terminals used up to the present, it is noticeably lighter, with the additional advantage of its lower production cost due to the material savings and simplicity of the tooling used in its manufacture. As is known, the battery of accumulators comprises a box -generally of thermoplastic material-, inside which the electrolyte and lead plates of positive and negative polarity are housed. For its upper part, said box has a lid or cover -also made of thermoplastic material- through which, in most battery designs, the upper portion of two lead terminals is projected. This upper portion can adopt various configurations, but is generally constituted by a hollow body of frustoconical shape whose dimensions are fixed by DIN, SAE, SETIA and others. In adjacencies of its lower end of greater diameter, said hollow frustoconical body extends into a lower portion, also hollow, which is immersed in the thermoplastic material, and constitutes the portion of the terminal intended for anchoring in the cover or cover. On the other hand, the inner cavity of the frustoconical upper body and the lower portion of said terminals form the housing space of respective rods, respectively linked to the internal plates of positive and negative polarity.

Each inner stem is linked to the respective lead terminal, in adjacencies of its upper end, by means of a process of welding with lead or alloy of this metal, thus achieving the necessary electrical continuity. As it is known, the manufacturing technology of the battery covers consists of the use of injection machines, by means of which the thermoplastic material is injected into the matrix for forming the cover. In a first operation, the terminals are positioned, manually or automatically, in respective holes of said matrix, and after the injection at high pressure of the molten plastic material, said terminals are adhered to the cover, by its lower portion partially immersed in the thermoplastic material. The battery manufacturers and the vehicle terminal companies establish the minimum axial effort and torque that each terminal must support, without breaking the metal and / or the thermoplastic material of the cover. In order to satisfy this requirement of mechanical fixation, various designs of the lower portion of the terminal have been developed, all of which ensure the anchoring of said portion in the material of the lid. These designs generally consist of a plurality of circumferential and parallel projections that prevent axial displacement, while the means for blocking the rotation movement can have various configurations, such as for example a plurality of cavities where the injected plastic material is housed. , and which are formed in the perimeter of the side wall, or also a plurality of protrusions or teeth projecting radially, etc. Examples of configuration of these anchoring means of the lower portion of the terminal, can be seen in the illustrations of US Patents 5,296,317 and EP 261 .31 1. As seen in the cited patents of invention, the configuration of the lower portion of the terminal is such that in the process of manufacturing this metal element should be used dies-in the case of cold stamping and also presofusion-or molds -in the casting case - that, once the piece is finished, due to its geometry must necessarily be opened horizontally, that is to say, perpendicularly to the axis of symmetry of the terminal, in order to remove it from its housing cavity in the tool. These matrices or molds must then be constituted by two or more moving parts that, once displaced radially, leave on the lateral surface of the lower portion of the formed terminal, burrs or lines of union of the material parallel to their axis of symmetry, in correspondence with faces facing and in contact with adjacent parts of the die or mold. The thickness of these burrs or lines of union increases as the matrix or mold ages, as a consequence of the continuous opening and closing operations of its components. By means of tests carried out with penetrating inks, it has been determined that said burrs or junction lines constitute paths through which the electrolyte flows to the outside, favoring the corrosion of the terminal, and consequently affecting its electrical contact with the terminal to which it is located. linked. To this migration of the electrolyte through the burrs or lines of union, the migration by capillarity generated by the internal porosity of the lead alloy is added, when the terminal is manufactured by the casting or presofusion procedures. All the terminals used up to the present in the covers or covers of thermoplastic material for batteries fulfill the requirement of the aforementioned anchoring or mechanical fixing, by means of a lower portion immersed in the cover, whose conformation requires the use of matrices or molds, which they must necessarily be opened by moving their constituent parts perpendicular to the axis of symmetry of the terminal, for their extraction once finished. These terminals, in addition to the drawback of owning burrs or longitudinal lines of connection, which have a very important effect on the corrosion process of their external surface, have the additional drawback that their lower portion -whose length can reach 1/3 of The total length of the terminal has an amount of lead alloy, which in addition to not fulfilling any function from the electrical point of view, unnecessarily increases the total weight of the terminal. The aforementioned drawbacks are solved with the anticorrosion terminal with short anchor, without connecting lines, for batteries of accumulators i nventado, which in addition to satisfying the requirement of anchoring or mechanical fixation in the material of the lid, with an amount of lead significantly lower - up to 40% of the total weight - than that of similar terminals known, has the important advantage of not having in its lower portion, the burrs or longitudinal bond lines that favor corrosion, ensuring a hermetic seal that prevents the migration of the electrolyte to the outside. The latter is possible because of the configuration of said lower portion, which allows the manufacture of the terminal with the use of dies or molds that do not require its radial opening, to extract the terminal already finished. Another aspect of utmost importance to take into account, is the fact of not needing the lead alloy used in the manufacture of the invented terminal, no percentage or content of arsenic -component highly dangerous to health- to avoid deformation of the material, under the high injection pressures of the molten plastic. This is a consequence of the configuration or design of the lower portion of the terminal immersed in the cover, which has a high resistance to deformation caused by said pressures. In order to completely eliminate corrosion, the lead plug invented will be preferably formed by the known cold stamping process, starting from a piece of solid lead or hollow extrudate, thereby eliminating the internal porosity that facilitates the migration of the electrolyte by capillarity to the outside.

The aforementioned results are a direct consequence of the particular configuration and conformation of the anti-corrosion terminal with short anchor, without connecting lines, for batteries of invented accumulators, which comprises an upper portion emerging from the cover or cover of the battery, preferably constituted by a hollow body of frustoconical shape, in adjacencies of which end of greater section, has a lower hollow portion -of anchoring in the thermoplastic material- whose internal cavity is of conical truncated conformation. This lower portion is constituted by two sections whose external configuration is such that the axial movement of the terminal is prevented or blocked. The first section is of cylindrical configuration and diameter greater than the end of greater section of the frustoconical body, while the second section is of frustoconical configuration, adjacent to whose end of greater section, means of blocking the rotation movement are formed of the terminal. In order to specify the advantages thus briefly commented, and to facilitate the understanding of the constructive, constitutive and functional characteristics of the anti-corrosion terminal with short anchor, without connecting lines, for batteries of accumulators invented, a preferred embodiment is described below, which is illustrated schematically and without a specific scale in the attached sheets, with the express clarification that, precisely because it is an example, it is not appropriate to assign to it a limiting or restrictive character of the scope of protection of the present invention patent , but simply a purely explanatory and illustrative intention of the basic conception on which it is based. Figure 1 illustrates a perspective view of the anti-corrosion terminal with short anchor, without connecting lines, for invented accumulator batteries. Figure 2 shows a longitudinal section of the same terminal of the previous figure, anchored in the cover of the battery. Figures 3 and 4 illustrate the invented terminal with different variants of the means for blocking the rotation movement of the terminal. In all the figures, to the same reference numbers correspond the same or equivalent parts or constituent elements of the assembly, according to the embodiment chosen for the present explanation of the anti-corrosion terminal with short anchor, without connecting lines, for batteries of invented accumulators.

As can be seen in Figure 1, the invented terminal comprises a top portion which, in the illustrated example, is constituted by a hollow body 1 of frusto-conical shape, in adjacencies of which end of greater section, has a lower hollow portion, indicated globally with reference 2, and which is intended for anchoring the terminal in the thermoplastic material. Said lower portion 2 is constituted by a first section 3 of cylindrical configuration, and diameter greater than that of the end of greater section of the frustoconical body 1, which is continued with a second section 4 of frustoconical configuration. As seen, in adjacencies of the end of greater section of the section 4, is formed a circumferential projection 5, whose wall defines a plurality of perimetric cavities 6 open alternately up and down, and in which the thermoplastic material is housed during the injection, constituting a means of blocking the rotation movement of the terminal. Figure 2 shows a longitudinal section of the same terminal of the previous figure, molded in the cover or cover 7 of the battery. As can be seen, the hollow lower portion 2 has an internal cavity 8 of truncated conical shape, and coaxial with the internal cavity of the frustoconical body 1. A circumferential groove 9 formed in the lower face increases the path of a possible migration of the electrolyte to along the contact surface between the lead alloy and the thermoplastic material. As observedsaid lower portion 2 is completely immersed in the thermoplastic material, so as to prevent axial movement of the terminal, while the perimetric cavities 6 block the rotation movement. Likewise, this portion 2 has such a configuration that it is highly resistant to the deformation caused by the high injection pressures, and consequently a lead alloy without any arsenic content can be used. Figure 3 illustrates the invented terminal with means for blocking the rotation movement, formed by a plurality of circumferential notches 10, while Figure 4 shows the same terminal, in whose lower portion 2 is formed a plurality of holes 1 1 , in which molten thermoplastic material is deposited or housed. The scope of protection of the present invention is defined, in addition to the variants of embodiment of the example illustrated above, by the claims detailed below.

Claims (5)

R E I V I N D I C A C I O N S

1. - Anti-corrosion terminal with short anchor, without connecting lines, for batteries of accumulators of the type constituted by an upper portion preferably of conformation according to a frustoconical hollow body that emerges from the cover of the battery characterized by the fact that it comprises in adjacences of the end of the greater section of said frustoconical hollow body a hollow lower portion whose internal cavity is coaxial with the cavity of said frustoconical body; said lower hollow portion having a first section of cylindrical configuration and diameter greater than that of the end of greater section of the frustoconical hollow body, which is continued with a second section of frusto-conical configuration, in adjacencies of whose end of greater section, are formed means of anchor of the terminal constituted by a circumferential projection whose wall defines a plurality of perimetral cavities alternately open upwards and downwards.

2. Terminal, according to claim 1 and 2, characterized in that said lower hollow portion has the internal cavity of truncated conical shape.

3. Terminal, as claimed in claims 1 and 2, characterized in that said lower hollow portion has on its lower face formed at least one circumferential groove.

4. Terminal, according to claim 1, characterized in that the means of anchoring the terminal are constituted by a plurality of circumferential notches.

5. - Terminal, as claimed in claim 1, characterized in that the means of anchoring the terminal are constituted by a plurality of holes whose centers are arranged along a circumference.