Device and device for rounding sharp corner of inner wall of air film hole of air-cooled hollow blade

Abstract

This application belongs to the technical field of engine blade processing, and in particular relates to a device and a method for rounding the inner wall of an air film hole of an air-cooled hollow blade. The device comprises an electrolyte circulation module and a power circuit; the electrolyte circulation module comprises an electrolyte tank and a working fluid pool; an electrolyte is introduced from the electrolyte tank to the upper part of the working fluid pool through a spray pipe, and returns through a return pipe; a nozzle of the spray pipe is aligned with the air film hole of the air-cooled hollow blade in the working fluid pool; the power circuit comprises a power supply, an electrode rod, and a conductive plate; the electrode rod is used for extending into the air film hole ofthe air-cooled hollow blade, and leave a gap with the inner wall of the air film hole; the surface, except for a corresponding processing area in the air film hole of the blade, of the electrode rod is coated with an insulating layer; and the conductive plate is arranged in the working fluid pool for being electrically connected with the air-cooled hollow blade. During the processing, the sharp corner in the air film hole comes into contact with fresh electrolyte, causing the metal at the sharp corners to dissolve much faster than other parts on the anode surface, so that the sharp corners arequickly dissolved and removed.

Description

technical field [0001] The application belongs to the technical field of engine blade processing, and in particular relates to a device and method for rounding the sharp corners of the inner wall of an air film hole of an air-cooled hollow blade. Background technique [0002] With the increasing requirements of aero-engines on the thrust-to-weight ratio, the temperature before the turbine of the engine is also gradually increasing. In the future, the temperature before the turbine of the next-generation aero-engine will be higher and higher. Aircraft engine requirements. Therefore, advanced film cooling technology must be used to improve the temperature resistance of turbine blades and achieve long-term reliable operation. my country has designed a variety of mature air-cooled hollow blades. There are dozens to hundreds of air film holes distributed on the surface of the blades, which are regularly arranged along the direction of the blade body, and the spatial position dis...

AI Technical Summary

Problems solved by technology

[0012] 1. The mechanical method is mainly used for large-sized parts. Tools such as brushes cannot enter the inner cavity of the hollow blade, and there is no operating space, and it is impossible to remove the sharp corners on the inner surface of the air film hole of the blade; at the same time, the mechanical method has poor control accuracy and is not suitable for blades. Precision Machining

[0013] 2. The magnetic grinding method can still be used for large-sized turbine guide vanes without complicated cooling channels. The inner cavity of the blade is polished as a whole and the sharp corners of the air film holes are removed, but the rounding effect cannot be controlled

Moreover, because the magnetic needle is limited by the inner cavity space of the blade, the range of motion is small, the moving speed is low, and the force generated when it collides with the surface of the inner cavity is small, and the removal effect is not good.

[0014] 3. Abrasive flow method and abrasive jet method are mainly to deburr and polish the inner cavity of the blade as a whole, not only for rounding the sharp corners of the air film holes. Since the abrasive flow method belongs to the overall treatment process, it cannot consider the blade gas Due to the difference of film holes, the amount of removal of sharp corners and the effect of rounding cannot be controlled; the size of abrasive particles is not easy to control, and the selection of smaller abrasive flow particles is not effective in removing sharp corners of film holes. Granular flow particles are easy to block the tiny air film pores; additives used in the abrasive flow process contain some substances that will chemically react with the blade material and have unknown effects on the blade

[0015] 4. The chemical method is mainly used for stainless steel, copper and copper alloy, etc., and the polishing effect is not as good as electrochemical polishing

Turbine blades are generally manufactured by casting process, and the casting alloy will have composition segregation, which will lead to localized corrosion due to different local potentials

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