CS209651B1 - Fuse fuse and method of its production - Google Patents

Abstract

A fuse fusible link with a constant cross-section over the entire length, optionally provided with a narrowed cross-section in places, which is made at least in part of its length of a metal binary alloy having an ordered structure, the content of both components being 25, 50 or 75 atomic % and the sum of the contents of both components being 100 atomic %. The invention can be used in particular in low-voltage power fuses.

Description

In particular, the invention is applicable to low voltage power fuses. 209651 209651

BACKGROUND OF THE INVENTION The present invention relates to a fusible fuse conductor and to a method for producing it. For modern fuses, their users require the current-time characteristics to be maintained in order to ensure safe and reliable protection of the appliances in which the fuse is connected. The required characteristics are mandatory in national and international standards. Years ago, it has been recognized that in order to achieve the desired characteristic, mere conductor shaping is not sufficient in many cases, but that special design measures are needed, especially in the overload area of the fuse. These special measures are implemented by applying a substance to a fusible conductor that only becomes active when the fusible conductor is heated to a certain temperature by an overcurrent. According to the principle of action, we talk about metallurgical and chemical phenomena. In the metallurgical phenomenon, an additional metal of lower melting temperature is applied to the fusible conductor than the parent metal of the fusible conductor. Upon reaching the melting point, the applied metal melts and begins to diffuse intensively into the parent metal of the fusion conductor. The resulting alloy has a higher resistivity than pure parent metal. The resistance of the fusible conductor increases locally with the subsequent increase in electrical losses, accompanied by a rise in temperature. The described phenomenon occurs until the solid conductor is remelted, but this occurs at a temperature below the melting point of the parent metal. Similarly, in the chemical phenomenon, an additional non-metallic substance is applied to the fusible conductor, which starts to react with the metal of the fusible conductor at a certain temperature, with the emerging compound or compounds having a higher electrical resistance than the parent metal of the fusible conductor. A number of substances with the above-described effects are known from the produced fuses and literature. The use of low-melting metals or solders, such as Sn, Pb, binary, ternary or multicomponent Cu, Pb, is the most widespread use of the metallurgical phenomenon, which is used almost exclusively in fuse construction. Cd, Zn, In, Bi, further In, Ti, Se, Te and Mg, the chemical phenomenon is realized by depositing S, CaTe, InSe, compounds Se or Te, SrSC> 4, KCl and the like.

A common disadvantage of the described fuse conductors is the need to include sufficient operations in the production cycle, as well as equipping the production equipment with special preparations, exact dosage and composition of the active substance, which is associated with increased costs.

The above-mentioned drawbacks are eliminated by the fuse fuse of the invention.

The essence of the invention is that the fusible conductor is made of at least a part of its length from a metal binary alloy having an ordered structure, the content of both components being 25, 50 or 75% atomic and the sum of the contents of both components being 100% atomic. Under certain conditions, these alloys are in a state where the atoms of the individual components are arranged more or less regularly

Claims (4)

OBJECT A fuse-type fuse having a fixed cross-section over its entire length, optionally provided with tapered cross-sections, made of at least a portion of a metal binary alloy, characterized in that the alloy has an ordered structure, the contents of both components being 25, 50 or 75 of atomic and the sum of the contents of both components is 100 atomic. 2. Fuse-link fuse according to claim 1, characterized in that the structured alloy is based on copper and AuCu or AuCu'j, or nickel and manganese base NigMn or preferably CuPd copper and palladium bases. or CujPd. the degree of arrangement / at certain nodal points, so that the structure of such an alloy is close to that of a perfect crystal. Arranged temperature-increasing alloys change the ordered state to disordered. The electrical properties, ie in particular the electrical resistivity of the alloy, depend on the state in which the alloy is located. In the ordered state, the resistive electrons are provided with a small resistance between the lattices of arranged atoms, and the electrical resistivity is low. Conversely, in a disordered state, the probability of a collision of a passing electron with the alloy atoms increases, resulting in an increase in resistivity. A first embodiment of the invention is a melt conductor of a non-variable cross section made of an alloy having an ordered structure of AuCu, AuCu3, CuPd, Cu3 Pd, AgPt, Ni ^ Mn, preferably CugPd. In a second exemplary embodiment, the fusible conductor is in the form of a strip of copper as the parent metal but is provided with a tapered cross section. At the point of the constricted cross-section, a Pd coating is applied to the Cu base metal as a second component of the future Cu3Pd alloy, with the Cu and Pd thickness ratio corresponding to the composition of the Cu alloy with Pd with an ordered structure. The alloy is formed after subsequent diffusion annealing in a protective atmosphere. The function of the fuse conductor according to the invention is that by passing the fault overcurrent through this conductor, it increases its temperature against the rated current. As the temperature of the fusible conductor increases, its ordered structure also changes to disordered, which also increases its electrical resistance. Depending on the type of alloy used, these changes occur either continuously or by jump. The increased resistance of the fusible conductor will cause a further increase in its loss and further increase in warming. This procedure is repeated avalanche until the fusion conductor is remelted. If the fusible conductor is made of an alloy that is subjected to a step change in electrical resistance, the current passing through it will suddenly increase when the ordered structure disappears. In addition to the properties of the melt conductor itself, the magnitude of the increased current is also determined by the characteristics of the external circuit, and the current can be reduced by a fuse with the fuse according to the invention before it is reflowed. Losses on the fusible conductor can drop here so that the fusing does not occur at all. Such a fuse is capable of multiple functions in a particular overcurrent field, which would be very economically advantageous. The main economic benefit of the invention is the simplification of the production of fusible conductors by the discharge of operations involving the deposition of substances causing a metallurgical or chemical phenomenon. Furthermore, the alloying metal can be economically utilized by applying it only to the functional sites. The invention also opens the way to repeatable fuses in a limited range of currents. THE INVENTION 3. Fuse conductor according to claim 12, characterized in that the structure-structured alloy is a constricted point. 4. A method for producing a fuse conductor according to any one of claims 1 to 3, wherein a second component of the future alloy is electroplated unilaterally or bilaterally on the molten conductor made of parent metal, wherein the ratio of the parent metal to the second component of the future alloy corresponds to the composition ratio. alloys with an ordered structure and subsequent diffusion annealing in a protective atmosphere will form an alloy with an ordered structure. Srvfroprafia. n. p. zivod 7, Most