DE2706989A1 - Tube with complex shape made by electroforming - and suitable for mfg. rocket thrust nozzles - Google Patents

Abstract

Tubes are made, esp. with a changing cross-section and/or an undulating or bent shape, e.g. to make a tunnel consisting of a rocket combustion chamber followed by a thrust nozzle contg. a constriction. A core is made of metal, or of a nonmetallic material with an electrically conducting surface layer; and the tube is made by electroforming a metal onto core, or deposition of metal by electrochemical means; core is then removed. Core is pref. made by casting a low m.pt. alloy, esp. Cerrobend (RTM). Several cores are pref. mounted on a jig, esp. a shaft fitted with disks between which the cores are located; and the jig is immersed in the electro(less) forming bath. The cores are then melted out of the tubes. An inexpensive method of mfg. tubes with complex shape.

Description

Process for the production of pipes and devices

device for performing part of the method The invention relates focus on a method of making tubes, particularly with changing Cross-section and / or corrugated or curved, z. B. for one of them formed hollow body, preferably a tunnel-like body from a rocket burning pellet and an adjoining thrust nozzle with a constriction.

Object according to the invention is a little expensive, cheap Process for the manufacture of the tubes, often tubes, to be found.

To solve this problem, the invention is that a dem Inside the tube the same metal core or non-metal core with electrically conductive Surface layer is made of the pipe by coating the core with metal produced by galvanic means with an external power source or by electrochemical means and the core is removed from the tube. This procedure requires no expensive tools. Furthermore, reproducibility is possible without great expense possible with tight tolerances. With the help of this core or this process any desired pipe or tube contour can be produced. Several or many Tubes or tubes can be used individually, but also easily together or at the same time can be produced by said coating.

The core can be produced by casting or in a casting process will. This is cheap and requires little effort.

In particular, the core is melted out of the tube.

In particular, the core is made of low-melting material, such as z. B. Cerrobend manufactured. This can be melted out very easily.

A surface layer mentioned generally consists of metal.

During the above-mentioned pulling on by galvanic means with an external power source it is about electrolysis, in the electrochemical way it is the immersion process or the settlement process, but especially the contact process. One can at the invention of an electroplating, in particular electroplating Process or speak of electroplating (Galvanostegie).

In particular for the production of a named hollow body or tunnel-like body is proceeded with advantage so that a large number of cores a support device for the cores arranged and together with this support device is immersed in a bath used for said coating. Such a carrying device is a device for the series production of pipes or hollow bodies or tunnel-like Body.

In particular, the core is melted out of the tube or tubes.

The process according to the invention is economical and technical exceptionally good or best possible solution, z. B.

also for the production of many pipes or tubes or one named Hollow body, preferably the tunnel-like, for driving or controlling a Combustion chamber thruster unit consisting of many tubes or tubes, serving as rockets, generally in tubular lightweight construction, or other tubular heat exchangers or complex cooling channel devices or geometries.

Only through the method according to the invention or this and the method according to the invention Device it is possible to have many, e.g. B. hundred or more Manufacture tubes or tubes in a single operation. You can all up be immersed once in a named bath. There is advantageously one said support device essentially consists of a shaft, in particular a drive shaft, and on this at a mutual distance attached discs, on which the kernels arranged or set, z. B.

be hooked. There are generally two discs.

A named core made of such a material or

such materials are made that after electroplating this core is removed chemically, if necessary with the addition of heat or can be dissolved, decomposed or etched out.

In the drawing, the invention is exemplified in context indicated schematically with a rocket combustion chamber with a thrust nozzle.

Fig. 1 of the drawing shows the rocket combustion chamber with thrust nozzle in Side view, a tubular core in longitudinal section and three cross sections of the associated Rohrs.

Fig. 2 of the drawing shows the tube in a view from direction I.

A number of identical, metallic tube cores are made by casting manufactured, one of which is a tubular core of FIG. 1; it is crosshatched shown and denoted by 10.

This number of cores is equal to the number of tubes 18 - see FIG. 2 -, which to form the consisting of the combustion chamber 12 and the thrust nozzle 14, A circular unit is required in all cross-sections; all pipes 18 are the same and soldered or welded to this unit. Is this unity in operation, a coolant flows through the tubes 18. In the axial direction 11, each tube 18, like each core 10, has a varying cross-section and corrugated in such a way that the combustion chamber 12 converges slightly and the subsequent one Thrust nozzle 14 first has a constriction 13 and then diverges relatively strongly. The approximately triangular pipe cross-section located at the inlet end of the combustion chamber 12 is here 15 continuously in the one located at the narrowest point of the constriction 13, relatively to the pipe cross-section 15 small, also approximately triangular pipe cross-section 16 and this continuously again into a larger pipe cross-section, with a reduced cross-section Area of the tube 10, the speed of the coolant is greater and thus there the heat is dissipated faster; the pipe cross-section 17 at the outlet end of the The thrust nozzle 14 is wider and radial as seen in the circumferential direction of the unit 12, 14 slightly smaller than the pipe cross-section 15.

Accordingly, the shape of each core is 10. The wall thickness of the Rohrs 18 is at least roughly the same over its length and everywhere else. It will the cores 10 made of low-melting material by casting and the tubes 18 by Covering these cores 10 with the desired tubular metal in one of the cores 10 containing electroplating bath and by subsequent melting out of the cores 10 manufactured.

Claims (7)

Method for the production of pipes, in particular with changing cross-section and / or wavy or curved, z. B. for a hollow body formed from them, preferably a tunnel-like body from a Rocket combustion chamber and an adjoining thrust nozzle with a constriction, characterized in that a metal core (10) identical to the interior of the tube (18) or a non-metal core is produced with an electrically conductive surface layer, the Rchr (18) by coating the core (10) with metal in a galvanic way external power source or by electrochemical means and the core (10) is removed from the tube (18). 2. The method according to claim 1, characterized in that the core (10) is made by casting. 3. The method according to claim 1 or 2, characterized in that the Core (10) is made of low-melting material. 4. The method according to claim 3, characterized in that the core (10) is made from Cerrobend. 5. The method according to claim 1, 2, 3 or 4, characterized in that that a plurality of cores (10) are arranged on a support device for the cores (10) and together with this carrying device in a bath used for said coating is dived. 6. The method according to claim 1, 2, 3, 4 or 5, characterized in that that the core (10) is melted out of the tube (18). 7. Carrying device for DurciIführung the method according to claim 5, characterized in that it consists essentially of a shaft and on this spaced apart disks on which the cores (10) are fixed will exist.