EP0315845B1 - Process for manufacturing electrical and mechanical connections from sheath-thermo-conductors - Google Patents

Description

The invention relates to a method according to the preamble of patent claim 1.

In gas turbine engine construction u. a. Sheathed cables of the type mentioned are used to transfer electrically measured values, e.g. from pressures and temperatures on engine assemblies such as compressors, combustion chambers or turbines for test and design purposes as well as for example for control and regulation in the form of relevant engine variables (parameters).

Repairs and partial dismantling of the engine often force a separation of the respective sheathed lines and, in the case of the engine assembly, the reestablishment of the relevant connections of related wiring harnesses, which is also referred to in technical terms as "shanking" or "shanking". A "stock" is often necessary because sheathed cable strands become unusable due to the ingress of atmospheric moisture and must therefore be replaced by new cable strands.

Already proposed business concepts require a relatively large expenditure of time and construction, in order to frequently connect several separate electrical lines of different polarity precisely and reliably for long-term use without electrical and mechanical connections.

An already proposed business concept sees u. a. a sleeve made of Teflon to be shrunk onto the sheathed cable ends to be connected. This concept is already ruled out from the point of view of a lack of temperature resistance, namely at temperatures above about 260 ° C (long-term use) or about 350 ° C (short-term use).

Another proposal provides for the sheathing of two sheathed cables on a substrate insulated with high-temperature cement; Already from the point of view of an enormous expenditure of time, this proposal can be described as not practicable, since different layers of cement each have to be hardened for at least 1 hour at a temperature of approximately 180 ° C; it should also be regarded as disadvantageous in the above-mentioned proposal that the heat to be applied externally to provide the hardening flows out comparatively quickly from the shaft assembly, which in turn directly adjacent components of the engine can be heated inadmissibly.

A method for producing an electrical and mechanical connection between assigned ends of sheathed thermal lines, in which wires are electrically insulated and embedded in metal sheaths in a manner which protects the environment, is already known from EP-A-0 220 918.

The invention has for its object to provide a method with which sheathed cable ends can be connected in a relatively simple manner in such a reliable manner that external environmental criteria such as comparatively high temperatures and air humidity can be mastered.

The object is achieved in a method according to the type mentioned by the features specified in the characterizing part of patent claim 1 according to the invention.

• 1. Eindeutige parallele Fixierung der Drahtenden innerhalb der Schäftung mittels des kapillarartigen keramischen Einsatztes mit Längsbohrungen. Keine Möglichkeit für einen Masseschluß.
• 2. Die einwandfreie Drahtführung im keramischen Einsatz ermöglicht exzellente Schweiß- bzw. Lötverbindung an den parallel liegenden Drähten.
• 3. Äußerst geringer Platzbedarf bei unkomplizierter Verarbeitung. Bei Notwendigkeit kann die Verbindung weiter miniaturisiert werden.
• 4. Durch die Wahl der geeigneten Lote für die Außenhülse ist eine Anpassung der Schäftungen an Temperaturen bis 900°C möglich. Durch den Einsatz eines Nickellots wären auch Temperaturen über 900°C beherrschbar.
• 5. Die Verbindung ist hermetisch gekapselt und somit gegen Luftfeuchte, Öl und aggressive Medien unempfindlich.
• 6. Alle Schäftungen sind mit Teilen aus Meterware herstellbar. Es sind keine komplizierten Hilfsmittel oder Werkzeuge erforderlich, somit ist die Durchführung der Arbeiten auch unter Freifeldbedingungen möglich.
• 7. Die Verbindungen können vor dem endgültigen Verlöten der Außenhülse visuell und elektrisch in ihrer mechanischen Endlage geprüft werden.
• 8. Durch die "fliegende Anordnung" kann die Schäftung an jeder beliebigen Stelle am Triebwerk, also auch an örtlich heißen Stellen untergebracht werden, ohne konstruktiv eine Unterbringung in kühleren Bereichen schaffen zu müssen.
• 9. Außer den zuvor erwähnten Punkten ergeben sich folgende Möglichkeiten für den Einsatz dieser Verbindungen bzw. Schäftungen:
  • 9.1 Bei schwierigen Montageabläufen (kein direktes Herausziehen der Leitungen möglich) können die verschiedenen Bauteile oder Baugruppen bzw. Module eines Gasturbinentriebwerks vorinstrumentiert werden, während die Schäftung unmittelbar vor der mechanischen Verbindung der Bauteile, - gruppen oder Module erfolgt. So sind Leitungsführungen möglich, die sonst nicht ausgeführte werden können.
  • 9.2 Bei Teilzerlegungen können Meßleitungen an vorgesehenen Trennstellen gekappt und bei erneuter Montage an den eingelegten Loslängen geschäftet werden. Dadurch entfallen bei Modulbauweise Montageschritte längs der Leitungsführung.

This results in the following advantages for a parallel connection or a longitudinal connection:

• 1. Clear parallel fixation of the wire ends within the shaft by means of the capillary-like ceramic insert with longitudinal bores. No possibility for a ground short.
• 2. The perfect wire routing in ceramic applications enables excellent welding or soldering connections on the parallel wires.
• 3. Extremely small space requirement with uncomplicated processing. If necessary, the connection can be further miniaturized.
• 4. By selecting the suitable solders for the outer sleeve, the shafts can be adapted to temperatures up to 900 ° C. By using a nickel solder, temperatures above 900 ° C would also be manageable.
• 5. The connection is hermetically encapsulated and therefore insensitive to air humidity, oil and aggressive media.
• 6. All shafts can be made with parts from yard goods. No complicated aids or tools are required, so the work can also be carried out under free field conditions.
• 7. The connections can be visually and electrically checked in their mechanical end position before the final soldering of the outer sleeve.
• 8. Due to the "flying arrangement", the shaft can be accommodated at any location on the engine, that is to say also at locally hot locations, without constructively accommodating in cooler areas to have to create.
• 9. In addition to the points mentioned above, there are the following options for using these connections or shafts:
  • 9.1 In the case of difficult assembly processes (no direct pulling out of the lines possible), the various components or assemblies or modules of a gas turbine engine can be pre-instrumented, while the stocking takes place immediately before the mechanical connection of the components, assemblies or modules. In this way, cable routing is possible that would otherwise not be possible.
  • 9.2 In the case of partial dismantling, measuring lines can be cut at the designated separation points and, when reassembled, can be used on the inserted lot lengths. This eliminates assembly steps along the cable routing in the case of modular construction.

In particular with regard to a parallel connection or shank, the invention enables connections running transversely to the engine axis or transversely to the component axes without great loops (risk of kinking!) Of the sheathed lines or shafts, taking into account relatively small spatial distances between the engine assemblies or modules.

Fig. 1

eine Parallelverbindung bzw. -schäftung zwischen zwei Mantel-Thermo-Leitungsenden, teilweise aufgeschnitten dargestellt,

Fig. 2

die gegenüber Fig. 1 um 90° verdrehte Ansicht der Parallelverbindung oder -schäftung, im Sinne der genannten Verdrehung teilweise aufgeschnitten dargestellt,

Fig. 3

eine Längsverbindung oder -schäftung an zwei Mantel-Thermo-Leitungsenden, teilweise aufgeschnitten dargestellt und

Fig. 4

einen Schnitt gemäß III - III der Fig. 3

The invention is further explained, for example, with the aid of the drawings; show it:

Fig. 1

a parallel connection or shank between two sheathed thermo cable ends, shown partially cut away,

Fig. 2

the view rotated by 90 ° relative to FIG. 1 of the parallel connection or shaft, partially cut away in the sense of the aforementioned rotation,

Fig. 3

a longitudinal connection or shaft on two jacket thermo cable ends, partially cut open and

Fig. 4

a section according to III - III of FIG. 3rd

A method for producing an electrical and mechanical connection between assigned ends of sheathed thermal lines is specified, in which wires 1, 2, 3, 4 are electrically insulated and embedded in metal sheaths 5, 6 to protect them from the environment; in principle, in the process, ends of the wires projecting from the metal sheaths 5.6, e.g. 2.4 or 1.3, passed through longitudinal bores 7, 8 of a ceramic insert 9, held thereon without mass connection and welded or soldered to one another along overlapping sections 9 of the same polarity protruding from the insert (welding points 10) Insert 9 containing electrical connection by means of a metallic outer sleeve 11 pushed onto the metal shells 5, 6 can be hermetically sealed by soldering (solder seams 12 or at the gap end 15).

Eg. the ends of the wires 2, 4 can be preformed with the aid of pliers with a view to the opposite arrangement of the longitudinal bores 7, 8 of the insert 9 and then, if necessary, cut to the required length. As illustrated, for example, at the end of the wire 2, it must be bent inwards (FIG. 1) and outwards (FIG. 2) to match the position of the associated bore 7 and be straightened at the rest of the end so that it can be aligned with the bore 7 in the longitudinal direction.

Within the scope of the aforementioned features - insofar as they match the features according to patent claims 1 and 2 - the invention is also extremely practical for a longitudinal shaft, which will be explained in more detail later.

In order to facilitate the connection arrangements, it is advantageous in the case of a parallel connection or shanking of sheathed thermal lines according to FIGS. 1 and 2 that, before carrying out the mounting and connection of the wire ends on the ceramic insert 9, first two end sections of the metal sheaths 5, 6 are used a fixing sleeve 13 immovable and fixed to each other in common length adjustment. The fixing sleeve 13 is mechanically clamped to the metal sleeves 5, 6 and then soldered to the sleeves 5, 6 (solder seams 14); After preferably joint soldering 14 or 12 of the fixing sleeve 13 as well as the one end part of the outer sleeve 11 with the two end sections of the metal sheaths 5, 6, an open end part 15 remaining on the opposite side on the outer sleeve 11 can also be compressed like a duck foot and then by welding or Soldering to be hermetically sealed. The compression can be carried out by means of suitable pliers, the pliers jaws of which have preformed shapes in accordance with the desired compression.

According to FIG. 3, in the case of a longitudinal connection or shank of sheathed thermal lines, end sections of the metal sheaths 16, 17 to be positioned opposite one another opposite to one another are to be soldered (soldered seams 18, 19) and wall-reinforcing metallic inner sleeves 20, 21, to which a common joint metallic outer sleeve 23 is pushed on, after the electrical connection to the ceramic insert 24 has been established beforehand.

Expediently and advantageously, the outer sleeve 23 should already have been loosely placed on one of the two metal shells 16 and 17 before the electrical connection to the insert 24 is made.

After being pushed onto both inner sleeves 20, 21, the common outer sleeve 23 is to be soldered to the latter (solder joints 25, 26) and so the electrical connection and insert 24 are to be hermetically sealed from the external environment.

In order to simplify the method, the latter can only be soldered to the relevant end sections of the metal shells 16, 17 after the common outer sleeve 23 has been pushed onto the inner sleeves 20, 21 (solder seams 18, 19). In other words, the solderings 18, 19 and 25, 26 (FIG. 3) can be carried out after the outer sleeve 23 has been pushed on.

According to the method, the inner sleeves 20, 21 can be pushed or placed onto the end sections of the two metal shells 16, 17 opposite each other according to FIG. 3 in such a way that the end parts of the metal shells 16 provided with the protruding wires 26, 27 and 28, 29 , 17 slightly project beyond the mutually facing end faces of both inner sleeves 20, 21.

3 and 4, ends of the wires 26, 27 of different polarity of an end section of the one metal jacket 16 provided with the inner sleeve 20 can first be separated by associated longitudinal bores 30, 31 (FIG. 4) of the insert 24 be pushed through; thereupon the ends of the wires 28, 29 of different polarity of an end section of the rest of the metal jacket 17 provided with the other inner sleeve 21 can be pushed through the already mentioned longitudinal bores 30, 31 of the insert 24 to such an extent that sections 24 which overlap each other on both sides of the insert 24 are guided the wires 26, 28 and 27, 29 of the same polarity are present, at which a local spot weld connection P takes place.

As can also be seen from FIGS. 3 and 4, the outermost ends 32, 33 and 34, 35 of the wires 26, 27 and 28, 29 protruding from the insert 24 on both sides can be used to form the local spot weld connection with respect to an immediately adjacent continuous wire 28.29 or 26.27 of the same polarity are laterally curved.

As can be seen from FIG. 3, the wire ends welded or soldered to one another at or near the insert 24 can be embedded in a dielectric 24 'before the outer sleeve 23 is slid on.

In a further embodiment, the invention is characterized by the use of a ceramic insert 9 or 24 formed in the manner of a capillary in the way of the aforementioned longitudinal bores 7, 8 (FIGS. 1 and 2) or 30, 31 (FIGS. 3 and 4) and corresponding to the number the ends of the wires to be connected in pairs spatially separated and at equal intervals parallel to one another and / or one above the other longitudinal bores or openings, or in the form of a multi-hole capillary.

In order to ensure optimum soldering and a permanently hermetically sealed connection with regard to variable operating temperatures, the same or similar metallic materials with the same or very similar should also be used Coefficients of thermal expansion are provided for the outer sleeve and for the metal shells in question, including, if appropriate, the inner sleeves.

It has proven to be advantageous that the outer sleeve and the metal shells in question are made of nickel or a nickel alloy, this also in the given case including the inner sleeves.

With regard to high-temperature applications, it is advantageous that the outer sleeve, possibly inner sleeves (if present) and metal shells can be made of platinum or a predominantly platinum-containing material or coated with one of these materials.

• Abisolieren, Befestigen der Innenhülse 20, Formbiegen der Drähte 26,27,Polkennzeichnung (+Pol), Auffädeln des Einsatzes 24 auf die Drähte 26,27 (hier links);
• Polrichtiges Einführen der Drähte 28, 29 (hier von rechts), nachdem diese ebenfalls zuvor durch Formbiegen angepaßt worden sind, Nachausrichten der Drähte 26,27 bzw. 28,29,die aus dem Einsatz 24 herausragen, Punktschweißen P sowie Abtrennen von jeweiligen Drahtüberlängen;
• Aufbringen des jeweiligen Dielektrikums 24′;
• Aufschieben der Außenhülse 23 und Verlötung gemäß Lötnähten 18,19 bzw. 25,26.

A longitudinal shaft according to FIGS. 3 and 4 can be represented according to the invention in working steps, for example as follows:

• Stripping, fastening the inner sleeve 20, shaping the wires 26, 27, marking the pole (+ pole), threading the insert 24 onto the wires 26, 27 (here on the left);
• Correct insertion of the wires 28, 29 (here from the right), after these have also been previously adapted by bending them, re-alignment of the wires 26, 27 and 28, 29, which protrude from the insert 24, spot welding P and cutting off respective wire excess lengths;
• Application of the respective dielectric 24 ';
• Slip on the outer sleeve 23 and solder according to the solder seams 18, 19 and 25, 26.

Claims (16)

1. A method of establishing an electrical and mechanical connection between associated ends of heat-resisting sheathed conductors in which wires are electrically insulated and embedded in metal sheaths to protect them from the environment, characterised in that ends of the wires (2, 4, 1, 3) protruding from the metal sheaths (5, 6) are passed through longitudinal bores (7, 8) in a ceramic insert (9) on which they are supported in a non-earthing manner and while overlapping one another, portions of like polarity projecting from the insert (9) are welded or soldered to one another, whereupon the electrical connection containing the insert (9) is hermetically sealed by soldering, using an external metal sleeve (11) which is pushed onto the metal sheaths (5, 6).
2. A method according to Claim 1, characterised in that the ends of the wires (2, 4) are preformed in the light of the predetermined disposition of the longitudinal bores (7) in the insert (9).
3. A method according to Claim 1 or 2, particularly for the parallel connection or splicing of heat-resisting sheathed conductors, characterised in that prior to the measures according to the method of the invention being performed in order to support the wire ends on the ceramic insert (9), initially two end portions of the metal sheaths (5, 6) are by means of a fixing sleeve (13) secured to one another immovably and in such a way that their lengths are adapted to each other.
4. A method according to Claim 1 or 2, particularly for the longitudinal connection or splicing of heat-resisting sheathed conductors, characterised in that wall-reinforcing metallic inner sleeves (20, 21) are fitted onto end portions of the metal sheaths (16, 17) which have to be positioned opposite each other and onto which a common metallic outer sleeve (23) is pushed once the electrical connection at the ceramic insert (24) has been established.
5. A method according to Claim 4, characterised in that the outer sleeve (23) is pushed onto one of the two metal sheaths (16, 17) even prior to the electrical connection being established at the insert (24).
6. A method according to Claim 4 or 5, characterised in that the common outer sleeve (23), after it has been pushed onto the two inner sleeves (20, 21), is soldered to these latter and in this way the electrical connection together with the insert (24) is hermetically sealed in respect of the outer environment.
7. A method according to Claim 6, characterised in that only after the common outer sleeve (23) has been pushed onto the inner sleeves (20, 21) are these latter soldered to the relevant end portions of the metal sheaths (16, 17).
8. A method according to Claim 3, characterised in that after preferably common fixing or soldering (12, 14) of an end part (8) of the outer sleeve (11) and the fixing sleeve (13) to the two end portions of the metal sheaths (5, 6) an open end part (15) remaining on the opposite side on the outer sleeve (11) is compressed like a duck's foot and then hermetically sealed by soldering or welding.
9. A method according to Claim 4, characterised in that the inner sleeves (20, 21) are so pushed onto the end portions of the metal sheaths (16, 17) that the end parts of the metal sheaths (16, 17) which have the protruding wire ends project beyond the associated end faces of the inner sleeves (20, 21).
10. A method according to Claim 4, characterised in that firstly ends of wires (26, 27) of different polarity of an end portion of one metal sheath (16) which is provided with an inner sleeve (20) is passed through associated but separate longitudinal bores (30, 31) in the insert (24) and only then are the ends of wires (28, 29) of different polarity of an end portion of the other metal sheath (17) which is provided with the other inner sleeve (21) passed through the said longitudinal bores (30, 31) in the insert (24) sufficiently and in such a way that on either side of the insert (24) there are mutually overlappingly extending wires (26, 28; 27, 29) of like polarity, on which a localised spot-welded connection (P) is made.
11. A method according to Claim 10, characterised in that whichever are the outermost ends (32, 33 and 34, 35) of the wire portions projecting from both sides of the insert (24) are bent over laterally opposite an immediately adjacent continuous wire (28, 29 or 26, 27) of like polarity in order to make the localised spot-welded joint (P).
12. A method according to one of Claims 1 to 11, characterised in that the wire ends soldered or welded to the ceramic insert (24) are embedded in a dielectric material (24') before the outer sleeve (23) is pushed over them.
13. A method according to one or more of Claims 1 to 12, characterised by the use of a capillary-like ceramic insert (9, 24) in which there are the said longitudinal bores (7, 8; 30, 31), said insert being constructed as a multi-bore capillary or having spatially separate and equidistantly disposed parallel adjacent and/or superposed longitudinal bores or apertures corresponding in number to the ends of wires which have to be connected in pairs.
14. A method according to one or more of Claims 1 to 13, characterised in that identical or similar metallic materials having the same or very similar coefficients of heat expansion are provided for the outer sleeve, the inner sleeves and for the respective metal sheaths.
15. A method according to Claim 14, characterised in that the outer sleeve, the inner sleeves and the relevant metal sheaths are made from nickel or from a nickel alloy.
16. A method according to Claim 14, characterised in that outer sleeve, inner sleeves and metal sheaths are made from platinum or a predominantly platinum-containing material or are coated with one of these materials.

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