Forming method of variable cross-section special-shaped single tube for thrust chamber of liquid rocket engine

Abstract

The invention discloses a forming method of a variable cross section special-shaped single tube of a thrust chamber body of a liquid-propellant rocket engine. The method comprises the following stepsthat (1), bend shaping is conducted, specifically, a single tube workpiece in the annealing state and filled with filling materials is placed in a bend shaping tool for bend shaping machining, so thatthe workpiece can be bent along an inner molding surface curve of a theoretical single tube; (2) preforming is conducted, specifically, the single tube workpiece is placed in a preforming tool of a hinge pressing plate structure, the preforming tool is adopted to press the single tube workpiece in an oblateness shape with plane included angles of two sides being the same as the theoretical singletube; (3), hydraulic bulging is conducted, specifically, an internal high pressure forming mold with a high pressure forming inner cavity being completely attached to the outer surface of the theoretical single tube is adopted to apply high pressure from the interior of the single tube workpiece to the outside to conduct bulging; (4), annealing is conducted and the single tube workpiece is back into the annealing state; and (5), the step (3) and the step (4) are repeated until the single tube workpiece is completely attached to the wall surface of the high pressure forming inner cavity, and asingle tube finished product is obtained. Machining accuracy and yield of single tube products can be obviously improved with the method.

Description

technical field [0001] The invention relates to a liquid rocket engine thrust chamber, in particular to a forming method for a liquid rocket engine thrust chamber body with variable cross-section and special-shaped single tube. Background technique [0002] The tube bundle type is one of the main structural forms of the regenerative cooling body of the thrust chamber of the liquid rocket engine. It is assembled by a certain number of formed tubes and welded into a whole by brazing and welding methods. [0003] Tube bundle regenerative cooling body can use round tubes, semicircular parabolic tubes, and rectangular tubes. Among them, the round tubes fill the grooves and reduce the cooling capacity. etc., resulting in heavier weight and higher cost of the semicircular tube. Further research shows that the use of rectangular tubes with small aspect ratios is the best solution taking into account rigidity, cost, and weight. [0004] The technical difficulty of tube bundle regen...

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Problems solved by technology

[0006] 2) It is easy to appear in the single tube forming process: irregular depressions on the side; the tube is closed asymmetrically, and the uneven force on both sides affects the forming dimensional accuracy; the part is long and the tube diameter is small, and it is easy to produce abnormal deformation during the forming process. hydrofill forming

[0007] 3) The internal cavity volume of the part is small and the pressure bearing capacity is poor. The traditional pressurization method is very easy to instantly increase the hydraulic pressure in the internal cavity, exceeding the yield limit of the tube, resulting in abnormal deformation or blasting;

[0008] 4) The elongation rate of the tube is low, limited by the structure of the Laval nozzle, the elongation rate of the single tube part exceeds 100% at most

[0009] In addition, such parts adopt traditional processing technology, which has low material utilization rate, high processing cost, and low pass rate

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