Research On Wear Model Of Valve And Valve Seat Based On Slip Quantity

The popularity of automobiles has brought convenience to people's lives.At the same time,it has brought about various problems such as environmental pollution and shortage of fossil resources.People are increasingly demanding the engine's power and fuel economy.The valve train is one of the important components of the engine.It regularly opens and closes the intake and exhaust valves to ensure timely intake of fresh air and exhaust gas.The valve and valve seat are extremely important in the valve train.The components are closely related to the dynamic characteristics of the valve train,so the wear of the valve and valve seat has always been the focus of the optimization of the valve train.In order to effectively reduce the valve and valve seat wear,this paper deeply explores the wear mechanism of the valve and valve seat,and constructs the wear calculation model.The main influencing factors of valve seating characteristics and slippage are studied by software simulation,and the valve and valve seat wear model based on slip amount is constructed based on Archard wear model.The main work and conclusions are as follows:1.Through the software modeling and simulation of the valve train,the valve seating characteristics were studied in depth.The influence of engine speed on the speed of valve movement is analyzed.Generally,the faster the speed,the greater the maximum speed of the valve,which leads to an increase in valve seating force.At the same time,the effects of speed,speed fluctuation,valve spring preload and stiffness and valve clearance on valve seating force are also studied,which provides a direction for optimizing the valve train and reducing the wear.Generally,the maximum valve seating force gradually increases with the increase of the rotational speed:the rotational speed fluctuation will have a certain influence on the seating force of the intake and exhaust valves.In addition to the fluctuation of the speed,the seating force of the intake and exhaust valves will increase;as the preload of the spring increases,the maximum seating force of the intake and exhaust valves will increase as a whole,and the seating force of the intake valve is generally higher than that of the intake valve.The exhaust valve is large;the seating force of the inlet and exhaust valves varies irregularly with the spring stiffness of the valve,and sometimes decreases when it rises and there is no obvious change trend.2.Through the simulation of finite element software,the temperature field and stress field distribution of the valve and valve seat are studied,which shows that the stress on the contact surface between the valve and the valve seat is concentrated,which is easy to wear.The relationship between valve cone angle,explosion pressure,valve seating force and sealing width and the amount of valve and valve seat slip is studied.Generally speaking,the larger the valve cone angle,the larger the explosion pressure,the larger the valve seating force and the sealing width.The smaller the valve,the greater the slippage of the valve and valve seat.3.The main wear mechanism of the valve and valve seat is studied,and the slip calculation formula is fitted with the simulation results.Combined with the Archard wear model,the valve and valve seat wear model is constructed to provide a valve and valve seat wear.Approximate calculation formula.