Study On Cylinder Wear Behaviors Of Engine In Light UAV

In recent years,the technology of UAV becoming mature.In the process of development to high power and long stroke,the lightweight requirements of cylinder materials are increasingly rapid.The lightweight materials in UAV Engine can improve the power performance,bearing capacity of UAV,economy and reduce exhaust pollution.At the same time,the cylinder-piston is the core part of the engine,its friction loss accounts for 40%-50% of the whole loss of UAV.Therefore,reducing the friction damage of the cylinder – piston is an effective way to improve the efficiency of UAV.The friction mechanism of the cylinder-piston has been studied.By adjusting the structural parameters and surface coating technology,the wear has been reduced.The cylinder surface used in the study has been coated.When the coating on the surface of the UAV engine cylinder is damaged,the friction between the aluminum and magnesium alloy cylinder and the piston ring will occur.In order to extend the life of cylinder,it is necessary to study the tribology of lightweight cylinder materials.At present,the research on lightweight materials for UAV Engine Cylinder mainly focuses on adding alloy elements and adjusting heat treatment process,and there are few reports on the tribology research under the lubrication state(normal operation),dry friction state(oil shortage state),sand containing lubrication state(sand particles enter the cylinder due to air filter damage).At the same time,in order to further improve the lubrication state of aluminum and magnesium lightweight materials,it is necessary to study lubricating system suitable for aluminum and magnesium alloy.Therefore,this paper tests the performance of different ratio of gasoline and engine oil according to the lubrication characteristics of two-stroke UAV Engine.Two kinds of aluminum alloy(ZL104 and ZL111)and two kinds of magnesium alloy(ZA81M and Elektro21)are selected as the materials.Commercial oil,68# oil and 10W-30 oil are selected as the lubricating medium.ZDDP is selected as the additive.The wear failure mechanism of loads,lubricating medium and reciprocating frequencies are carried out.The physical properties of the mixed oil and the materials in dry friction,oil lubrication and sand-oil lubrication are analyzed.It is found that the lubricating performance of 68# oil is better,the best ratio with gasoline is 30:1;the tribological properties of magnesium alloy is better than aluminium alloy,and ZL111 is better than ZL104;and the ZA81 M is better than that of aluminum alloy under dry friction and low frequency oil lubrication;the tribological properties of Elektro21 is worst under oil lubrication;the optimal volume fraction of ZDDP in 68# oil is 4%;the abrasive wear produced by adding sand particles will damage the surface reaction layer and intensify the wear.The research of this paper will provide theoretical support for the selection of cylinder materials and lubricating oil types of UAV Engine under different working environments.It is of great significance for the research of improving the life of UAV Engine Cylinder under different working environments,and it will be helpful for the developments of UAV engine friction theoretical system.