Disassembling of aerotechics

Creation of the technological process of disassembly depends on the type of AT(airplane, helicopter, turbojet engine, piston engine) and constructive peculiarities. In spite on huge amount of factors that influence on the disassembly process, it is necessary to take into account the general principles which provide qualified and highly productive fulfillment of disassembly and further aircraft repair.

1. Before disassembly the specimen is installed in such way, that his mass is separated on the support.

2. Installation of aircraft or engine, arranging of the equipment and tool should provide maximum scope of works and minimal time spending for auxiliary operations. It is reached with the help of optimal planning of technological process and usage of highly effective equipment and tools.

3. Disassembly should be done determined technological process, which is suitable for this specimen.

Disassembly of the aircraft. The volume of disassembly works is determined by the number of flight time and additional fault detection (correspondently for the information). Besides that, the volume of disassembly works is depending on repair manufacturability of the construction, which is determined in such way:

- access for overlooking and control of main constructive elements;

- rational construction, joints and accommodation of aggregates, links and blocs, which give possibility not to remove one aggregate because of another aggregate;

- interchangeability of details, links and aggregates of the airplane.

The process of disassembly of aircraft comes into removing of:

-power plants (PP) (engine with elements of its joints, bonnet, jet nozzle and all aggregates, devices, links and communications which provide the work of engine and placed in his compartment);

- disconnecting (DPW) middle (MPW) and parts of the wing;

- ailerons, dashboards of flaps;

- rudder and fin;

- fuel tanks;

- removing equipment of fuselage and center section;

- landing gear.

Further disassembly of removed parts is performed in corresponding department territory and districts of the plant. Label with number of aircraft are hanged up on removed details and links.

For landing gear removal the airplane is posted up on hydrolift. Instead of removed landing gear the driving “false” landing gear is installed.

During disassembly, assembly and repair in the hangar the special unified docks are used. Dock (pic 1.5) is the combination of some stationary and moving platforms, which clasp the plane around the contour and give possibility for access of all his parts. Platforms are installed on different heights depending on the construction of the aircraft.

Dock is equipped with systems that provide his autonomy:

- electrical system of industrial voltage- for lighting and feeding of dock’s aggregates;

- electrical system of direct current (24 V) – for feeding of aircrafts network;

- system of pressed air supply under pressure 0,5 – 0,8 MPa and distributive points near working places;

- system of signalization of talkative devices.

Under the platforms of dock there are:

– universalhydro installationunderpressure 25 МPa;

– hydro installationforpumping of breaking system;

– installation for hermetic checking under the pressure 0,04 MPa;

– hydrolift complex of the aircraft;

– vacuum cleaners;

– installation for lubrication of bearings and so on.

Docks are equipped with overhead crane beams, cantilever-pivoting cranes, monorails and hoists.

Features of helicopters disassembly. Features of helicopters disassembly are determined by the system presence of the driving and tail propellers. Before disassembly it is necessary to make work checking and fault detection of hinged connections of driving and tail rotors.

Before disassembly the helicopter is washed up, hanged on the lifts, proceed leveling and disassembly of systems.Disassembling begins with the removal of the tail rotor.Dismantling of tail rotor is performed while blades are taken off. Then the speed reducer is removed.

Disassembly of aviation engines. Disassembly of engines is carried out according to adopted method of repair. Current method of engine disassembling is performed on mechanized production lines.Such productive line (for example as for Ai-24 engine) may consist of five stands (three horizontal and two vertical). On the first stand all fixtures and aggregates are removed from the engine. Aggregates are sent to the repair shop units.

On the second stand the speed reducer is removed and on the third – turbine. Than the engine is installed into vertical position. After this, on the fourth stand the crankcase is removed and on the fifth – compressor. After the release of the first stand another engine is installed.

To improve the productivity of work, disassembly of the links is performed on specialized work places.

Each link is disassembled on special stand which allow installing it in comfortable position for disassembling.

Pneumatic and electric wrenches, mechanical and hydraulic strippers and other devices are used for disassembling of the engine.

Mail rules of AT disassembly are such:

– Locksmiths-disassemblers should know well the product design, engineering usage techniques of equipment, devices and strippers, sequence of folding operations;

– at first all complex products are disassembled on separate aggregated, then the aggregates are disassembled on links, and links – on details; such order allows to expand the collapsible front work to create specialized working places and to increase productivity;

– disassembly of engine should be done in strict order, according to the technology with minimal time spending;

– usage of tools which cause the damage of details is forbidden;

–details which operated during exploitation and available for further operation shouldn’t be discompleted during disassembling; before removal they should be labeled with keeping their positioning;

– heavy aggregates and links should be removed with special tap, keeping all safety rules.

Дата добавления: 2014-01-05