DD201072A1 - UNIFORM MELT FOR ELECTRICAL FUSES - Google Patents

Abstract

The invention relates to a one-piece fusible conductor for electrical fuses with at least one agent depot in a groove and reduced cross-bottlenecks. The object of the invention is to provide a low-energy dissipation, age-resistant, characteristic-fixed and technologically advantageous manufacturable fusible link. A fusible conductor is developed which, by selectively generating flows in the liquid agent and utilizing precipitates, rapidly melts away at temperatures just above the melting point of the active ingredient and breaks the flow of current by perpendicularly extending a local area of the half-active substrate web to surface and simultaneously dissolved over the entire width of the web. Such fusible elements are used in particular in low-voltage and high-performance fuses. Fig. 1

Description

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Title of the invention

One-piece fuse element for electrical fuses

Field of application of the invention

The invention relates to a one-piece fusible conductor for electrical fuses having at least one active substance depot in a channel and cross-section reduced bottlenecks.

Such fusible conductors are used in particular in low-voltage high-voltage fuses.

Characteristic of the known technical solutions

DE-OS 292-6βΟ discloses a fusible conductor which is intended to achieve a specific switch-off characteristic and low aging with a soft solder application and cross-section reduced bottlenecks of different recess width, by applying the active substance directly to a constriction and the maximum temperature by additional cross-sectional constrictions into the active substance-carrying body This fusible conductor has the disadvantage that the temperature required for melting is far above the melting point of the active ingredient as a result of unfavorably chosen dissolution conditions.

This high heating reduces the aging resistance and leads to large energy losses, since even at liennstrom already a high operating temperature is reached.

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From DE-PS 2428569 melt conductor are known which have arranged at least one active ingredient accumulation in front of the current-carrying Sngstelle and only a portion of the active ingredient is applied to zones of high temperature.

A disadvantage here is that the active ingredient must be transported in the dissolution of the accumulation of active ingredient to the reaction site on the Sngstelle, which is made difficult especially by prolonged operation by the reduced wetting ability of the support · Another disadvantage is that the current-carrying cross-section parallel to the drug center radially outward is dissolved to the surface, whereby the ratio of the attack surface of the active substance to be dissolved volume of the substrate necessary for the interruption is very small and the Abschmelzvorgang is delayed thereby ·

At the same time, as a result of the release of the active ingredient to the reaction site, cooling thereof occurs, which additionally lengthens the decay process.

Xn of US Pat. No. 4,227,167, a fusible conductor is finally described in which the active ingredient is directly adjacent to the snatch site intended for switching off. A disadvantage of this variant is that the active ingredient is not geometrically fixed in a channel, which is an undefined one Wide flow and thus on the one hand strongly scattering Abschmelzcharakteristiken conditions and on the other hand leads to drug cross-sections that are very unfavorable for the dissolution process ·

Furthermore, it should be noted that the position of the active ingredient on the fusible link was not chosen so that the temperature distribution favors the Abschmelzvorgang optimal. Finally, it can be stated for all of the patent literature reviewed that the influence of external forces (e.g., gravity, centrifugal force) on the dissolution process by promoting or obstructing flows within the drug is not recognized, and thus, especially with fusible links with only one side of the temperature maximum

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the reaction point located Lotdepot the Abschmelzcharakteristik is essentially dependent on the installation position.

Object of the invention

The object of the invention is to provide a low-loss, age-resistant and characteristic-resistant and technologically advantageously producible fusible conductor.

Explanation of the essence of the invention

The object of the invention is to provide a fusible link which melts as quickly as possible at temperatures which are only slightly above the melting point of the active substance and interrupts the flow of currents. For this purpose , the current-carrying cross sections of all Engestellen a Engestellenreihe must be resolved perpendicular to their surface and very locally on the Sngestellen. With this local resolution is achieved that only one зе'п? small volume of the carrier is dissolved in proportion to the amount of viral substance. By applying a 'part of the drug to each half of the Engesteller, a Engestellenreihe which faces the Lotrinne, which in turn is arranged perpendicular to the direction of flow, it is achieved that the active ingredient is constantly directly on the reaction site, this reaction site itself but in The edge of the vaccine depot and on the Engestellen the corresponding Engestellenreihe and the drug retains its Porm and position even after melting, ie a Kintransport to the reaction site is not required, a cooling effect of the active ingredient does not occur and the favorable flow arrangement of the Y / material remains intact.

Crucial for the shutdown process is the saturation of the active ingredient with dissolved carrier material. By suitable arrangement of the fusible conductor in an external force field (gravity, centrifugal force, etc.) currents are promoted, which lead there in conjunction with the colder part of the drug supply there to excretions, so that

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the agent flowing back to the reaction site continuously maintains its solubility

According to the invention, the object is achieved in that, according to FIGS. 1 a and 1 b, the active substance 3 is located in at least one channel extending transversely over the carrier material 1 with a fluidically favorable shape and size, the ratio of average width b to depth t being 1, and the groove on the fusible conductor is to be arranged so that in each case the half surfaces of all Engestellen 2 Engestellenreihe protrude into the drug channel so that the drug in the ITähe the reaction parts a sufficiently large flow cross section 4 is guaranteed. According to FIG. 1c, the side of the row of extensions is selected for this purpose, in which case the temperature in the operating case of the fuse decreases away from the row of bearings and thus the greater part of the plastic depot is at lower temperatures than the reaction point 5.

Advantageously, this temperature difference should as far as possible form the basis of the classification. It is the purpose of the invention to use only one of the active substances of the invention so that the center of gravity of the active substance is always viewed from the half-line of active substances in the direction of the force (eg 3. F .. vertical installation, Fp horizontal installation of the fusible conductor in the use of gravity) · If, however, several V / hkstoffdepots arranged on the substrate, it must be ensured that all drug depots the above requirements in the same Suffice it »

The active substance used is advantageously a solder which reacts with the carrier material and has a low melting interval, in particular pure metal or eutectic mixture.

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Ausfuhrun ^ SExample

The invention will be explained in more detail with reference to an embodiment and the accompanying drawings.

The one in Pig · 1 and Pig. 2 consists of a strip-shaped carrier material 1 made of a material with good electrical conductivity (eg silver, copper or combinations of corresponding materials), which has a plurality of rows of restricts 6, 7 and at least one active ingredient depot. The active substance is located in a channel whose ratio of middle channel width b to channel depth t (see Pig. 1Ъ) is one.

At least one Engestellenreihe 6 protrudes so far into a drug depot 3 in that each one's Engestelle this Engestellenreihe is covered up to half with V / uhkstoff, so that at the same time in the ITähe the Realrtionsstelle a sufficient otrömungsquerschnitt 4 is guaranteed. In this case, the drug depot is located on the side of Engestellenreihe 6, which, based on the fuselage ends, has the smaller electrical resistance.

Advantageously, rows of resistors having different electrical resistances are arranged on the fuse conductor so that the rows of electrical resistance 7 are located farther outward than the rows of higher electrical resistance. The different resistance contributions of the rows of frames 6 and 7 are realized by different shapes of embossment Cross section at the narrowest point of each Engestelle but the same size. The one in Pig. 2 and 3 indicated distance a may optionally be chosen equal to zero, so that the fusible conductor can aufv / iron both an even and an odd number of Engestellenreihen. The positioning of the in Pig. 2 illustrated fuse in the fuse has to be done so that when operating the fuse the center of gravity of the active substance of the half covered with active substance Engestellen-

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row always seen in the direction of force (e.g., when utilizing the force of gravity.: .. vertical installation, F ₂ horizontal mounting F) is located.

If two drug depots are placed on the fusible link to make it largely independent of the mounting position, it must be ensured by arranging according to FIG. 3 that the individual drug fins correspond in shape, size and position to the half-line covered with active substance row in each case, that one of them optimally fulfills the conditions for the shut-off mechanism to be represented in the following.

In the case of release of the fuse, the active ingredient is transferred by the 7 / iderstandsbeiträge the Engestellen in the liquid state, whereby the arrangement of the active ingredient on the fusible link and the Teir.peraturvert training hurrying due to the arrangement and shape of the Engesteilreihen the greater part of the Jirkstoffes a has lower temperature than the drug part, which is located at the reaction site. The object of the invention is promoted by the fact that the different resistance contributions of the various Enstellellenreihen increase this temperature difference even further.

It comes under the action of the external force to a flow process 8 (Fig. 1a) within the drug, which forms due to the flow of the carrier material at the reaction site 5 turbulence, which cause a particularly good removal of the dissolved carrier material and thus a much faster resolution the local very limited reaction site than at other sites covered with active substance of the carrier material. This local, rapid dissolution of the carrier material is favored by the fact that carrier-rich active substance flows through colder active ingredient zones and there precipitates the carrier material components. The further flowing back to the reaction site drug has constantly a large solvent power and its reactivity is maintained. The

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inventive Sciimelzleiter enforces these optimal flow conditions and thus reaches the required melting times at very low temperatures, i. at temperatures just above the melting point of the active ingredient «

With electric currents up to the small test current, however, the active ingredient remains solid and there is no reaction between the active ingredient and the carrier material, nor do currents develop in the active ingredient. The fusible conductor is thus very resistant to aging. At the same time, these low temperatures also mean low-energy-loss working of the fuse.

Claims (4)

я- 23Д694 2 Invention claim 1 · One-piece fuse element for electrical fuses in the form of a metal strip with reduced cross-bottlenecks, at least one drug depot in a gutter and a drug with low melting interval, preferably pure metal or eutectic mixture, characterized in that the drug depot 3 has such a shape and size, the internal currents 8, the Engestellen a Engestellenreihe protrude up to half in the drug depot that a sufficiently large flow cross-section 4 is ensured in the active ingredient at the bottom of the reaction site 5 and the drug depot is on the side of Engestellenreihe 6, the ends of the Schmelsleiterenden With respect to the smaller electrical resistance, the positioning of the fusible conductor in the fuse must be such that the center of gravity of the active substance is seen in front of the semi-active substance covered in the direction of force (eg gravity, centrif fugal force) is located. 2 · integral fusible link for electrical fuses according to item 1, characterized in that the ratio of average gutter width to gutter depth is 1, but the absolute width is at least so large that the Ströraungsvorgänge are not significantly impaired in the liquid /, but at most so it is great that a flow away of the liquid active substance from the drug depot under the influence of external forces (z · B, gravity, centrifugal force, shocks) is avoided. 23D694 2 3 · One-piece fuse element for electrical fuses according to item 1 and 2, characterized in that the Abschal tvorgang is favored in that recesses are arranged with different geometry such that current carrying Engestellenreihen arise whose smallest cross-sections are the same size, but the effective resistance at room temperature the power carrying Engestellenreihen is so different that the Snehnellen with lower electrical resistance "are arranged farther out on the fusible conductor, as the Engestellen with greater electrical resistance, 4 · One-piece fusible conductor for electrical fuses according to item 1,2 and 3, characterized in that at least two active substance depots according to Fig. 3 are arranged on the fusible conductor, that the individual drug troughs in ororm, size and location for each half covered with active ingredient Are in accordance with the principles of enlightenment and are formed opposite to each other
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