JPS6158957A - Manufacture of combustion chamber for pocket engine - Google Patents

Abstract

PURPOSE:To eliminate regulation of a filler in a groove during electroforming of an outer cylinder, by a method wherein a nickel electroforming layer is formed on the whole of the outer surface of an inner cylinder made of copper, heating is effected after electroforming to form a cooling passage, and electrolessly plating is applied on the inner surface of the cooling passage. CONSTITUTION:A groove processing 2 is applied on the outer size side of an inner cylinder 1 made of copper, and the interior of the groove is filled with a soluble inconductive filler 3. After conductivity is provided on the surface of the filler 3, nickel electroforming layer 5 is formed on the whole. The filler 3 is molten for removal to form a cooling passage 8. After an outer cylinder 6 made of an alloy is attached to the outer surface of the nickel electroforming layer 5, electrolless plating 9 is applied on the inner surface of the cooling passage 8. This eliminates regulation of a filler in a groove during electroforming, and enables a hydrogen bristleness preventing layer to be formed at one time.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing a rocket engine combustion chamber that can be applied to manufacturing regeneratively cooled liquid rocket engine combustion chambers, heat exchangers, and the like.

(Prior art) Since the inner surface of the regeneratively cooled liquid rocket engine combustion chamber is exposed to high-temperature, high-pressure combustion gas, a cooling passage is provided on the inner wall and a part or all of the high-pressure propellant is used to cool the combustion chamber. There is. Conventionally, a double wall structure, a brazed elongated pipe structure, or a brazed groove structure has been used as a manufacturing method for this cooling passage.

However, as combustion pressures become higher, a combustion chamber with a groove structure where the inner cylinder and outer cylinder are more perfectly joined has become essential.

One example that has been proposed so far is SSME (Space Shuttle Main Engine). As shown in FIGS. 6 to 8, a cooling passage 1 is provided on the outside of the inner cylinder 10 with copper mtJ.
1, a nickel jacket 12 is provided by electroforming. Further, in order to prevent the nickel from becoming brittle due to high-pressure hydrogen, which is a cooling liquid, electrolytic copper plating 13 is applied in advance under the nickel layer. Furthermore, high-strength alloy steel (Inconel, etc.)! I! It was also necessary to separately provide a protective layer on the inner surface of the peripheral member 14. Also, when electroforming the second layer, it was necessary to adjust the electrical conductivity of the filler in the groove.

(Problems to be Solved by the Invention) The present invention solves problems such as the need to provide a conventional protective layer and adjust the electrical conductivity of the filler in the groove. The present invention aims to provide a method for manufacturing a combustion chamber of a rocket engine that does not require adjustment of the filler in the groove and can apply a hydrogen embrittlement protection layer and a layer at the same time.

(Means and operations for resolving the problem) Therefore, the present invention provides a method in which a groove is formed on the outer diameter side of the copper inner cylinder, a soluble nonconductor filler is filled in the groove, and the surface of the filled filler is After finishing the filler to be flush with the outer diameter surface of the inner cylinder and imparting conductivity to the surface of the filling agent, a nickel electroforming layer is formed on the entire outer surface of the inner cylinder, and then the filler is melted and removed. A cooling passage is formed here, a protective layer is provided on the inner surface of the passage by electroless plating, and the above-mentioned nickel electrode &i? An outer cylinder made of alloy steel is attached to the outer surface of one layer.

(Example) Examples of the present invention will be described below with reference to the drawings. FIGS. 1 to 5 show examples of the present invention. First, a groove 2 is formed on the outer diameter side of the copper inner cylinder 1, and a soluble nonconductor filler (wax) 3 is filled in the groove so that it is flush with the outer diameter surface 1a of the inner cylinder 1.

Next, conductive powder (silver powder) 4 is rubbed onto the surface of the wax 3 to give it conductivity, and then a nickel electroformed layer 5 is applied to the entire surface.
Apply to the required thickness. The cooling passage 8 can be formed by heating after electroforming, melting the wax 3, and removing it. Next, the outer shape and the like are finished by machining, etc., and high-strength alloy steel members (outer cylinder 6, manifold 7, etc.) are attached by welding, etc., and then the inner surface of the cooling passage 8 is electroless plated (copper plate 9).

(Effects of the Invention) The present invention is configured as described above, and since nickel is electrodeposited on a smooth copper surface, a uniform high-strength bond can be obtained. In addition, after installing the manifold etc.
By carrying out i\copper coating, a hydrogen brittle protective layer can be provided by electroless plating on the entire surface of the part that comes into contact with hydrogen. Moreover, if silver powder is used to impart conductivity to the wax surface, delicate adjustment of the conductive wax is not necessary.

The present invention electrodeposit nickel directly onto the machined surfaces of the canal tube, resulting in a complete bond. Furthermore, a hydrogen embrittlement protective layer can be provided on the inner surface of the cooling passage, including the inner surface of peripheral parts such as a manifold, in one step.

[Brief explanation of drawings]

Fig. 1 is a side cross-sectional view showing the steps up to forming a nickel electroformed layer in a method showing an embodiment of the present invention, Fig. 2 is a cross-sectional view taken along A-A Ili in Fig. A side sectional view of the combustion chamber manufactured by the method of the invention, FIG. 4 is B in FIG.
-B sectional view, Fig. 5 is a detailed view of C section in Fig. 4, Fig. 6 is a side sectional view of a conventional rocket engine combustion chamber, and Fig. 7 is a sectional view of C section in Fig. 4.
FIG. 8 is a detailed view of section E in FIG. 7. Explanation of the main parts of the diagram 1 - Copper inner cylinder ° 1a - Inner cylinder outer diameter surface 2 - Grooving 3 - Soluble nonconductor filler 4 - Conductive powder 5 - Nickel electroforming Layer 6 - outside? F18-Cooling passage 9--Electroless plating patent applicant Mitsubishi Heavy Industries, Ltd. Figure 1
Figure 2 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] A groove is machined on the outer diameter side of the copper inner cylinder, a soluble nonconductor filler is filled in this groove, and the surface of the filler is finished to be flush with the outer diameter surface of the inner cylinder, and the surface of the filler is After imparting conductivity, a nickel electroforming layer is formed on the entire outer surface of the inner cylinder, and then the filler is melted and removed to form a cooling passage there, and a protective layer is applied to the inner surface of the passage by electroless plating. A method of manufacturing a combustion chamber for a rocket engine, further comprising: providing an outer cylinder made of alloy steel on the outer surface of the electroformed nickel layer.