SU675480A1

SU675480A1 - Electric circuit protecting fuse

Info

Publication number: SU675480A1
Application number: SU752196539A
Authority: SU
Inventors: Кемаль Кадырович Намитоков; Андрей Абдуллович Харисов
Original assignee: Предприятие П/Я А-7147
Priority date: 1975-11-03
Filing date: 1975-11-03
Publication date: 1979-07-25

Description

ческих цепей, содержащий корпус, заполненный кварцевым песком, контактные выводы, закреплейнь1е на корпусе, и легкоплавкий элемент, подсоеднненный к контактным выводам, выполненный в виде полос из алюмини или его сплавоЬ с участками уменьшенного поперечного сечени (3.circuits, comprising a body filled with quartz sand, contact leads fixed on the body, and a low-melting element connected to the contact leads, made in the form of strips of aluminum or its alloy with areas of reduced cross-section (3.

Однако в указанных предохранител х вследствие очень малой толщины, большой величины отношени широкой токоведущей и узкой плав- to кой части, л также невысокой механической прочности алюминиевых материалов вообще, такие плавкие элементы станов тс непрочными и . при монтаже в корпусе и засьшке корпуса наполнителем часто повреждаютс . Обнаружить пов-15 реждение плавкого элемен1а в оборванном 1фёдохранителе , например, то, что плавкий элемент надорван практически невозможно, в то же врем этот дефект может настолько изменить,характеристики предохранител , что он не смойсет 20 выполн ть свои функцин.However, in these fuses, due to the very small thickness, the large ratio of the wide current-carrying and the narrow fusible part, and the low mechanical strength of aluminum materials in general, such fusible elements become fragile and. when mounted in and out of the body, the filler is often damaged. It is practically impossible to detect the fusible element position in a dangling fuse, for example, that the fusible element is torn, at the same time, this defect can change the characteristics of the fuse so much that it does not carry out its functions.

Кроме того, такие плавкие элементы могут сильно повреждатьс и в процессе эксплуатации предохранителей, что также может сушественно изменить характеристики предохранител .25In addition, such fusible elements can be severely damaged during the operation of the fuses, which can also drastically change the characteristics of the fuse .25

Целью изобретени вл етс повышение надежности работы предохранител .The aim of the invention is to improve the reliability of the fuse.

Достигаетс зто благодар тому, что в плавком предохранителе, содержащем корпус, запол- . ненный кварцевым песком, контактные выводы, 30 закрепленные на корпусе, и легкоплавкий элемент , подсоединенный к контактным выводам, вьщолненный в виде полос из алюмини или его сплавов с участками уменьшенного поперечного сечени :, кажда из полос плавкого элемента в 35 наиболее широкой токоведущей части имеет отношение ширины к толщине в пределах 2:1 -100:1 , а отношение массы кварцевого песка к массе алюминиевого материала плавкого элемента , размещенного в кварцевом песке, находитс 40 в пределах 40:1-200:1.This is achieved due to the fact that the fuse that contains the case, the cap-. quartz sand, contact leads 30 fixed to the housing, and a fusible element connected to the contact leads, finished in strips of aluminum or its alloys with areas of reduced cross section: each of the fusible element strips in the 35 widest current-carrying part is related widths to thickness are in the range of 2: 1 to 100: 1, and the ratio of the mass of quartz sand to the mass of aluminum material of the fusible element placed in quartz sand is 40 in the range of 40: 1-200: 1.

Такое соотношение злементов конструкции предохранител с алюминиевым плавким элементом , создава в предохранителе услови максимальной эффективности дугогашени кварцевым 45 песком при применении сравнительна толстых плавких элементов, позвол ет одновременно уменьшить подверженность плавких элементов механическим повреждени м в процессе изготовени и эксплуатации предохранителей и исклю- so ить случаи разрыва корпуса предохранителей ри отключении аварийных токов.Such a ratio of the elements of the design of the fuse with an aluminum fusible element, creating in the fuse the conditions for maximum quenching of 45 quartz sand with comparatively thick fusible elements, simultaneously reduces the susceptibility of fusible elements to mechanical damage during manufacture and operation of the fuses and eliminates rupture fuse boxes when disconnecting emergency currents.

На фиг. 1 дан обший вид предохранител с астичным вырезом стенки корпуса; на фиг. 2- - варианты выполнени алюмнниёврго или 55 пренмушественно алюминиевого, плавкого элеента . .FIG. 1 Dan is a general view of a fuse with an asthical cut-out of the housing wall; in fig. 2- - embodiments of aluminum or 55 pre-musically aluminum fusible element. .

Предохранитель содержит корпус 1, заполненый , кварцевым песком 2, закрепленные на корпусе контактные выводы 3 и размещенный в корпусе и соединенный с контактными вывод,ми 3 плавкий элемент 4, преимущественно ил ПОЛНОСТЬЮ состо щий из алюмини или его сплвов . Дл обеспечени необходимой прочности, лучшего охлаждени и достаточно равномерного размещени массы алюмини по объему квацевого песка 2 плавкий элемент 4 вьшолнен в виде полос 5, имеющих отношение ширины в наиболее широкой токоведущей части 6 к толщине не менее 2:1 и не более 100:1. Отношени массы кварцевого песка 2, заполн ющего корпус 1, к массе алюмини плавкого элемента 4, размещенного в кварцевом песке, в предохранителе находитс в пределах 40:1-200:1., С меньшим соотношением указанных масс предохранитель не способен обеспечить во всем диапазоне аварийных токов надеишое дугогашение. С большим отношением его вьшолн ть нецелесообразно , так как это не дает заметного выиграша в дугогасительной способности конструкции, а толко увеличивает габариты предохранител .The fuse includes a housing 1 filled with quartz sand 2, contact leads 3 fixed on the case and placed in the case and connected to the contact leads, fuse 4, mainly silt consisting entirely of aluminum or its alloy. To provide the necessary strength, better cooling and sufficiently uniform mass distribution of aluminum throughout the volume of quartz sand 2, the fusible element 4 is formed in the form of strips 5, having a ratio of the width in the widest current-carrying part 6 to a thickness of at least 2: 1 and not more than 100: 1. The mass ratio of quartz sand 2 filling the case 1 to the aluminum mass of the fusible element 4 housed in quartz sand in the fuse is in the range of 40: 1-200: 1. With a lower ratio of these masses, the fuse is not able to provide emergency currents hope arc. With a great attitude, it is inexpedient to implement it, since it does not give a noticeable gain in the arcing capacity of the structure, but only increases the size of the fuse.

Корпус 1 предлагаемого предохранител может быть выполнен из изол ционного материала, например фарфора, кордиерита, термостойкой пластмассы, или из металла, например, алюмини или его сплавов.The housing 1 of the proposed fuse may be made of an insulating material, for example, porcelain, cordierite, heat-resistant plastic, or of metal, for example, aluminum or its alloys.

Контактные выводы 3 дл устранени возможности возникновени в местах соединени с алюминиевым плавкши элементом 4 электрохимической коррозии целесообразно также выполн ть из алюмини .Contact pins 3 to eliminate the possibility of occurrence at the junctions with the aluminum smelting element 4 of electrochemical corrosion, it is also advisable to perform from aluminum.

Кварцевый песок 2 в предохранителе должен быть достаточнр чистым, а величинь гранул должны, преимущественно, находитьс в пределах 0,1-1,2 мм.The quartz sand 2 in the guard should be clean enough, and the size of the granules should preferably be in the range of 0.1-1.2 mm.

Claims

Depending on the magnitude of the rated current, technological requirements, and j: q). the fuse allows different versions of the fusible element 4, made in the form of strips 5. In FIG. 2 shows the simplest fusible element 4, made in the form of a single strip 5. The cross section of the strip should be selected depending on its thickness so that in the widest conductive part 6 the ratio of its width to thickness is not less than 2: 1-100: 1. In particular, when the thickness of the strips is 0.1-0.3 mm, it is recommended to choose their cross section within 0.3-0.7 mm. The limits of the ratio of the cross section of the strips in the wide conductive part 6 to the cross section in the narrow fusible part 7 are selected in accordance with the required protective characteristics. From the point of view of ensuring an optimal ratio between. high current-limiting capacity of the fuse and the mechanical strength of the strips, it is advisable to choose the specified ratio of cross-sections in the range from 2.5-1 to 6-1. The length of the strip 5 and the number of sections with a reduced cross section on it determine the magnitude of the rated voltage of the fuse. In the fuse for big. but1 “our current individual strips 5 can be connected in parallel on the contact leads 3 and form a fusible element 4 in the form of several strips 5 or in the form of several rows of strips 5. To reduce the complexity of the installation of fusible elements 4 made in the form of several strips 5, such fusible elements can be made of sheet or tape by cutting out of them parts of the metal so that the floor) D1 are separated by a gap of strips connected between (by Yourself only in places 8 directly connected to the contact terminals. This type of fusible element T 4 is depicted in Fig. 3. In some other cases, it may be useful to use plra elements 4 in the form of strips 5 connected not only at the points 8 connecting to the contact terminals, but also at the places 9 located in the middle part of the fusible element A similar fusible element 4 is shown in Fig. 4. The fuse operates as follows: At rated currents and permissible short-time overload currents in the circuit, the fuse operates as a normal conductor. Good corrosion resistance and sufficiently high electric and thermal conductivity of the material of the fusible element ensures long-term operation, low superheat and small power losses in these modes. With unacceptable emergency currents in the circuit, the fuse element of the fuse is destroyed, and the electric arc arising in the fuse is reliably quenched by quartz sand. The possibility of breaking the fuse body and the overlapping of the poles of the circuit is completely eliminated by the exothermic reaction of the aluminum fusible element with quartz sand resulting from the design, due to the fairly uniform dispersion of the aluminum mass over the volume of silica sand and the optimum mass ratio of 45 silica sand and fusible aluminum element, which quartz sand, despite the exothermic reaction with aluminum, in the whole range of emergency currents It is also maximally capable of intensively absorbing and dissipating in its volume the energy released in the fuse and to perform the functions of an effective arc-suppressant. The increased reliability of all the specified characteristics of the safety device in the intended design is ensured through the use of. It has fusible elements in the form of relatively thick aluminum conductors, which increase the resistance to mechanical damage during the manufacture and operation of the fuse, which in turn was made possible by ensuring that the fuse quarantine sands are maximally efficient in the fuse, eliminating the cases of fuse cases breaking as a result of in a fuse exothermic reaction. Tests have shown that such fuses in a circuit with a nominal voltage of 660 V can reliably cut off the current of 100 kA eff. Value {1i and withstand shock and vibration loads of third degree of rigidity without changing the performance characteristics. However, these data are not yet the limit for such 1-fuses, but the limit of the capabilities of the test equipment on which the samples were tested. Improving the reliability of operation of aluminum fuse-element fuses opens up wide possibilities for using such fuses in the national economy, which allows saving tons of extremely scarce silver and copper and obtaining a huge economic effect. The application of the invention only in fuses of the series PP31, the serial production of which is currently being carried out by the enterprise, will save an estimate for the use of aluminum in fuses of more than 1 million rubles, Formula of the invention Fuse for protection of electrical circuits, comprising a case filled with quartz sand, contact leads mounted on the housing, and a low-melting element connected to the contact terminals, made in the form of strips of aluminum or its alloys with areas of reduced pope River section, characterized in that, in order to increase reliability of operation, each of the fusible element strips in the widest current-carrying part has a width-to-thickness ratio of 2: 1-100: 1, and the ratio of the mass of quartz sand to the fusible-aluminum material housed in quartz sand, is in the range of 40: 1 -200: 1. Sources of information taken into account in the examination 1. UK Patent No. 1031836, class H2, 1965.

2.PRZEGLAD ELEKTROTECHNICZNY (Poland), R.XLI, Z.7, p. 253-254, lhZ, JAN, NASILOWSKI „Badania piasku kworcowego do bezpiecznikow topikowych

3. The patent of Switzerland N5019, cl. H 01 H85 / 04, 1971.