异常工况下双进双排气门-导管许用间隙值研究

为提高双进双排气门的使用寿命,以气门-导管间隙ΔD为特征变量,采用有限元法分析ΔD、锥面角β对气门应力特性的影响,并探讨了在异常工况下双进双排气门的许用ΔD。研究表明:当ΔD≤0.22 mm时,最大应力及第二热点应力变化较稳定,而当ΔD>0.22 mm时,其随ΔD增大而急剧增大;此外,当ΔD=0.22mm时,最大表面应力随β的增加而增大,而第二热点应力随β的增加呈现先减小后增大趋势,且β=45°时,气门第二热点应力最小。研究有助于异常工况下双进双排气门的失效分析和气门结构的优化设计。

Allowable Gap between Double Intake-exhaust Valve and Valve Guide under Abnormal Working Conditions

In order to improve the life of the double intake-exhaust valve,the effect of the valve-valve guide gaps(ΔD) and cone angles(β) on the stress characteristics of the valve were analyzed and the allowable ΔD was also investigated under abnormal working conditions by taking ΔD as the characteristic variable and using finite element method.The research results show that when ΔD is smaller than 0.22 mm,the maximum stress and the second hot spot stress present a stable value,whereas,when ΔD is beyond 0.22 mm,the stresses above sharply increase with the increase of ΔD.Furthermore,when ΔD is 0.22 mm,the maximum stress increases while the second hot spot stress firstly decreases then increases with the increase of β,meanwhile,when β is 45°,the second hot spot stress is the smallest.The research is useful to the failure analysis of the double intake-exhaust valve in abnormal working conditions and its structural optimization design.