关于气门油封唇口结构对泄漏量影响的研究

Research on the Influence of Valve Seal Lip Structure on Leakage

通过计算机辅助工程(CAE)仿真分析,研究单橡胶密封唇结构和多橡胶密封唇结构气门油封在不同气压载荷条件下,主唇口与气门杆接触宽度、径向抱紧力的变化情况。通过气门油封专用泄漏量试验台,测量不同橡胶密封唇结构气门油封在交变气压载荷条件下的泄漏量。通过发动机台架试验,研究匹配不同橡胶密封唇结构气门油封的气门的积碳情况。根据CAE分析结果,具有二道唇和气唇结构的三唇口气门油封,对气压载荷的承载能力最好,主唇口与气门杆接触宽度、径向抱紧力随正负交变气压载荷的变化最小。在0.4 MPa气压载荷条件下,三唇口气门油封主唇口与气门杆接触宽度变化率为0%,径向力减小2.5%;在-0.4 MPa气压载荷条件下,三唇口气门油封主唇口与气门导管接触宽度变化率为0%,径向力增加0.5%。根据泄漏量和发动机台架试验结果,三唇口气门油封泄漏量稳定,不同试样的泄漏量变差可以控制在0.5 mg/h以内,匹配该油封的气门经2 000 h发动机台架试验后,几乎没有积碳。研究结果可以为气门油封的选型和匹配设计提供指导。

Through CAE simulation analysis,the variation of the contact width and radial holding force between the main lip and the valve rod of the valve oil seal with single rubber seal lip and multiple rubber seal lips under different pressure loads was studied.The leakage of valve oil seals of different rubber seal lip structures under the condition of alternating air pressure was measured by a special valve oil seal leakage test rig.The carbon accumulation of valves with different rubber seal lip structure was studied by engine bench test.According to the CAE analysis results,the three-lip oil seal with two lips and two lips has the best bearing capacity to the pressure load,and the contact width between the main lip and the valve rod and the radial locking force change the least with the positive and negative alternating pressure load.Under the pressure load of 0.4 MPa,the change rate of the contact width between the main lip of the three-lip valve seal and the valve rod is 0,and the radial force decreases by 2.5%.Under the pressure load of-0.4 MPa,the change rate of the contact width between the main lip of the three-lip valve seal and the valve guide is 0,and the radial force increases by 0.5%.According to the leakage amount and engine bench test results,the leakage amount of three-lip valve oil seal is stable,and the leakage variation of different samples can be controlled within 0.5 mg/h.After 2000 h engine bench test,the valve matching the oil seal has almost no carbon deposition.The research results can provide guidance for valve seal selection and matching design.