Air inlet machine casing

Abstract

The invention discloses an air inlet machine casing. A fixing support plate, long-strip-shaped ice preventing holes, an inner ring front section and a machine casing shell are included. The fixing support plate is formed through welding of a first fixing support plate body and a second fixing support plate body. The structure of the first fixing support plate body and the structure of the second fixing support plate body are symmetric left and right with the plane passing through the center line of a rectification blade in the length direction as the symmetric plane. Each of the first fixing support plate body and the second fixing support plate body comprises a rectification blade part and a support plate head part which are integrally formed. The long-strip-shaped ice preventing holes are formed in the surface of the rectification blade in a penetrating manner. The inner ring front section is welded to the end, away from a support plate head, of the fixing support plate. The machinecasing shell is welded to the support plate head. According to the air inlet machine casing, the problems about super-plastically formed fixing support plate surface swelling, ice preventing hole cracks and welding triangular areas can be solved; and in addition, integral design is adopted in the fixing support plate and the support plate head, argon arc welding lines between the fixing support plate and the support plate head are eliminated, so that the problem about welding line cracks at the position is basically solved.

Description

technical field [0001] The application belongs to the field of aero-engine structural design, in particular to an air intake case. Background technique [0002] The intake casing of the small bypass ratio aero-engine is located at the front end of the engine, and is composed of a fairing assembly, an intake casing assembly assembly, etc. The casing is equipped with bearings to withstand the front fulcrum load and vibration load of the low-pressure rotor, etc. It is one of the main bearing frames of the engine. In order to prevent the front end parts of the engine from freezing in low temperature environment, the air intake case also needs to have anti-icing function. [0003] Commonly used structures for air intake casings include assembly structures and welded structures. Among them, welded air intake casings have a simple structure, do not need to be connected by fasteners, reduce assembly difficulty, have a smaller overall weight, and have higher processing efficiency. ...

AI Technical Summary

Problems solved by technology

[0006] First of all, the hollow rectifying blade assembly processed by superplastic forming / diffusion bonding process using four-layer titanium alloy plate has welding problems such as poor welding rate and triangular area between layers due to the limitation of forming process. Some non-destructive testing methods cannot effectively check for welding defects, resulting in problems such as bulges and cracks in the triangular area and the rear end surface of the blade.

[0007] Secondly, at present, the anti-icing holes on the rectifier blades are electro-machined. Due to the limitation of the structure and molding process, manual polishing is required to remove the re-melted layer on the electro-machined surface. Due to the limitation of the operator's technical level and stability, the re-melted layer will appear thick Uneven phenomenon, and the excessive thickness of the remelted layer will bring about hidden dangers of cracks

At the same time, due to the limitation of the molding process, it is impossible to round the edge of the anti-icing hole in the inner cavity of the support plate, and there is a phenomenon of stress concentration at the edge of the hole

Under the influence of the above two factors, the fixed support plate is prone to cracks at the sharp edge of the anti-icing hole under various loads

[0008] Thirdly, the front part of the inner ring of the air intake case and the support head of the outer ring are all made of castings. Due to the current domestic casting level, the geometric dimensions and geometric tolerance accuracy of the castings often cannot meet the assembly and welding requirements of the components.

Airfoil misalignment and deflection, airfoil thickness out of tolerance, and wall thickness out of tolerance will lead to serious misalignment after welding, poor welding consistency, large welding deformation and residual stress, and subsequent defect repair welding further increases welding deformation and residual stress Level

At the same time, defects such as loose structure and trachoma of the casting reduce the load-carrying capacity of the entire casing. Crack

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