DE1054520B - Process for embedding electrically conductive wires in ceramic glaze mass, in particular for the production of wire resistors - Google Patents

Description

The invention relates to a method for embedding electrically conductive wires in ceramic Glaze mass, in particular for the production of wire resistors.

In the manufacture of glazed electrical wirewound resistors, the resistance wire is attached to a ceramic carrier body and the resistance winding produced in this way in several operations Covered with a glaze (enamel) in several layers, so that this winding is completely embedded in the glaze is. The connection elements are attached to it and the resistors with an indication of provided the resistance value.

In this known method for the production of resistors, it is necessary to put the glaze in adapt their expansion coefficient to that of the ceramic support body, so that the individual Materials sit on top of each other without tension and this causes cracks and cracks in the the glaze is avoided even when the heating and cooling of the resistor change frequently.

There are limits to the process in the area of the required resistance values, namely in the case of very high resistance values by using the thinnest resistance wires and the smallest winding spacing required in each case. A winding turn by turn is not possible because each individual turn should be embedded in glaze. As is known, the glaze is applied either by spraying on or by dipping with subsequent drying and baking and is continued in many operations until all the turns are completely embedded in the glaze. Due to the much greater expansion coefficient of the resistance wire compared to the expansion coefficient of the ceramic carrier body, in particular hard porcelain and the glaze (enamel), there is an increase in the diameter of each individual wire turn due to its own weight when the glaze is heated up before the glaze melts sags. As a result of this increase in diameter, the initially tightly wound resistance wire loosens, the individual turns shift under the influence of the liquid glaze, with the individual turns approaching one another and others moving away from one another. This is called "bundling", so-called "hot spots" arise on the resistance surface, caused by a greater accumulation of individual wire windings to form groups. Achieving small resistance limits in this way fails because of the requirement to completely embed each individual turn in the glaze. Fulfilling this requirement becomes more and more difficult, the larger the resistance wire through method for embedding electrical
conductive wires in ceramic
Glaze mass, especially for

Manufacture of wirewound resistors,

Applicant:

Rosenthal isolators

Company with limited liability,

Selb (OFr.)

Dr.-Ing. Oskar Paul and Hermann Haase, Selb (OFr.), Have been named as inventors

knife will. This is the reason that one usually has resistance limits of about 3 to 100 ohms depending on the size of the resistance body, the minimum value cannot fall below.

These disadvantages are eliminated in that, according to the invention, the wire is made on a carrier ceramic glaze mass is wound, whereupon the carrier with winding between cover parts from the put the same mass and the whole thing is heated so high that the cover and support body, the wire tight enveloping, to be united by fusing to form a single body.

A particularly advantageous modification of this process is in the manufacture of low-resistance Given resistances, if a brought into the desired shape, z. B. zigzag curved Resistance wire placed between two bowl-shaped cover bodies made of ceramic glaze mass and the whole thing is heated so high that the melt envelops the resistance wire and the cover body be united in a unified body.

In the method according to the invention, the usual ceramic support for the resistance winding is omitted and a support is used Replaced glaze mass, which in particular is difficult to reach and continuously monitored Exact adaptation of the glaze to the ceramic carrier body is not necessary, because how exact Investigations have shown that the coefficient of expansion of the ceramic carrier bodies, depending on the batch, is also evident fluctuate a little and thus an ongoing adaptation of the glaze to the one used Make ceramic bodies necessary.

809 789/352

Claims (1)

3 4 It is known that glazed wire resistors can be produced. The slots 7 can be expanded inside have to deliver by sliding a glass tube over the stanchions. Instead of the one shown in the figure with winding provided ceramic body and connection wires 2 can also be differently shaped, for. B. melting the pipe. However, this is also used for connecting elements stamped in advance from sheet metal Settlement that, in order to avoid crack formation, find 5 and press it into the plate 5 or between the winding support and the glass during which they are work-hardened. The wrapped plate 5 prepared in this way moderately alternating high heating and re-becomes between two shell-like, out of the same fetched cooling the coefficient of expansion of the mass molded halves 3, 4 placed (Fig. 5). The on- Glass tube adapted to that of the winding carrier, the stacked parts are now fired, got to. ίο where the whole thing rests on a pad. the It is also known an electrical resistance, both in particular shell-like halves 3, 4 verder made of metallic conductors embedded in glass flux bind with each other and with that of the same consists, the type of wire glass in a glass material existing middle plate 5 and embed the bodies are inserted. Since glass in melted wire winding applied well on all sides. To stand diverges very easily, the manufacture is 15 the fire has the finished resistance shown in Fig. 6 in the resistances difficult and the mechanical and view and in Fig. 7 in section indicated shape, Insufficient thermal load capacity. On the other hand, the side of the resistor, which is used as a support surface About being served in the method according to the invention during the fire is finished with Ceramic glaze used, which was clearly visible. Resistors can be produced that also have a 20 The production of a flat resistor according to the withstand shock loads. Process according to the invention can also be entirely There is also a known method in which reverse generally applies to the manufacture of other electrical Stand wires are surrounded by a quartz mass. Structural elements that are conductive embedded in glaze Here, however, only an edge fusion of wires takes place, in particular coils and glazed ones Intermediate body and cover body instead. It is also possible to apply 25 wirewound resistors of any shape, known to be fused together cover Characterized that the ceramic carrier body through Shells made of plastic for wrapping against opponents are replaced by those made of glaze mass, the Use standing wires. Even if the progress achieved is particularly clear, which is in When heat and pressure are applied, the result is that of the simpler glaze composition and envisaged phenolized asbestos a uniform 30 thus the production of favorable conditions for the Body generally not formed, since before manufacture and use according to the invention Melting a disintegration occurs. With this resistance provided coils and glazed resistors allows It is therefore also provided that the individual body with It is also possible to wrap the carrier after it has been wrapped hold together a mounting bracket, so that in the usual way at least once by diving not from a single body in the sense of pre-glazing or spraying and firing. lying invention can be spoken. As a special simplification of the new procedure The method is highlighted in more detail with reference to the drawing that has always been explained in place of the above. It shows necessary application and melting of the glaze Fig. 1 and 2 schematically one with connecting wires in two to four or more layers depending on the thickness provided, zigzag curved resistance 40 of the winding jet according to the new process wire for a low resistance in elevation, only one fire is sufficient, after which the resistance is and floor plan, already finished. It is therefore no longer Fig. 3 shows the resistance to a particularly low resistance that, through repeated burning-in, the glaze Stacked parts to cause failures, d. H. Resistances with under- 4 shows a solidified broken winding produced from glaze mass. Plate, wrapped with resistance wire and with contact The occurrence of failures will continue to connecting wires provided, prevented by that in the examples shown Fig. 5, the resistance to each other - the entire resistance in the glowing state none layered parts before firing, solid components, but exclusively a soft one Fig. 6 is a top view of the finished resistor 50 containing ground. according to Fig. 5, The resistance range can be 7 shows a cross-section through the finished event according to the invention, expanding upwards because according to the line IV-IV of Fig. 6, the wire diameter for such resistances was A thick resistance wire 1, in particular, can be considerably reduced and it is possible a resistor with a very small ohmic value, e.g. B. 55, even higher resistance values in a small space 1 ohm or less, will accommodate in the form of a zigzag,
line curved and with connection wire ends 2 electrical well connected. The so prepared counter-claims:
Stand wire is placed between shell-like parts 3 and 4 60 1. Method for embedding electrically conductive materials melted. Wires in ceramic glaze, in particular In the embodiment according to FIGS. 4 to 7, wire resistors are thereby produced for the production of higher-ohmic resistors marked that the wire on a carrier Unfired plates 5 formed from glaze powder, wound from ceramic glaze mass, sinters or fired after cooling with an 65, whereupon the carrier with winding between end elements 2 provided and then placed with counter-cover parts made of the same mass and the stand wire 6 of a certain length and a certain whole is heated so high that cover and Wrapped in diameter. The plate 5 is advantageously provided with a carrier body, tightly enveloping the wire Slots or recesses 7, in which the connection merging verelemente into a single body or connecting wires 2 must be fixed in the same way.