A Moving And Self-locking Permanent Magnet Electromagnetic Valve Actuation For Internal Combustion Engine

With the pressure of global energy crisis, the electromagnetic valve actuation(EMVA) has become an important research direction on internal combustion engine.As it can simplify the structure of engine and reduce manufacturing cost, fuel andvalve driving energy consumption, besides, each EMVA can be controlled separatelyto regulate the valve timing which makes it easy to select the valve position. With theuse of EMVA, the internal combustion engine can improve the combustion efficiency,fuel economy and emission performance effectively.Many technical problems still exists during the research of traditionalelectromagnetic valve actuation, such as the valve soft landing, the reliability ofelectromagnetic device and the quick response of the valve, etc. Thus, a newelectromagnetic valve actuation which can be used in internal combustion engine isproposed in the paper, the stator and the armature of new EMVA use the insulationiron powder soft magnetic composite material which has the property of highpermeability and low electrical conductivity. Some parameters of new EMVA wereoptimized, such as the stator chamfering structure, the size of the permanent magnet,the "L" shape air gap size and so on. According to the results of the finite elementsimulation of electromagnetic field, the electromagnetic force, the coil inductance andsoft-land problem were analyzed respectively.On the basis of traditional electromagnetic valve actuation with double springdouble coil, the new EMVA added a permanent magnet into the structure, whichmakes it like a DC linear motor when working. The operating principle of new EMVAis similar to the traditional electromagnetic valve actuation, the difference is thearmature of new EMVA can realize self-locking in the upper or lower limit positionwith the electromagnetic force produced by permanent magnet, and there is no needfor holding current, which reduced the copper loss. The new EMVA adopts the doubleclosed loop control system with speed loop and current loop, during operative mode.The new EMVA, as a kind of permanent magnet DC linear motor, can provide anaxial force which can supplement damping energy to make the moving part beharmonic vibration effectively, which make it is easy to implement the control ofvalve and soft landing. With the static field finite element analysis, the new EMVAelectromagnetic relationship and some beneficial conclusions can be obtained. Thetransient field simulation results show that it can achieve soft landing effectively.