双金属垫内压自紧密封性的有效计算压力解析分析

Analysis of Effective Calculating Pressure in Determination of Self-sealingPerformance of Double-metal Gasket under Internal Pressure

为了分析双金属波齿复合垫的内压自紧密封性,根据垫片所承受的预紧最小压紧力、操作最小压紧力以及金属环张开力的作用,把双对称的实物模型构建为简化的力学模型,通过垫片压紧力的4种取值条件展开推导,全面分析了内压作用下金属环张开的力学原理,并揭示了计算压力存在最大有效值的物理意义,结果表明,当内压只充满金属环之间的无效密封宽度,任何结构材料的双金属垫具有内压自紧密封的条件是计算压力小于8.3倍垫片系数除以垫片系数加上0.5的商,只与垫片系数有关联,而与垫片预紧密封比压无关。当内压充满金属环之间的整个宽度,双金属垫具有内压自紧密封的条件是计算压力小于垫片的密封比压除以两倍垫片系数的商,该条件只与垫片特性参数有关,而与垫片宽度无关,在最高有效计算压力的前提下,对于一定宽度的双金属垫,其两层金属环之间能充满内压的宽度越大,则双金属垫就能获取越大的内压自紧性。

In order to analyze the self-lock tightness of double-metal wave-serrated composite gaskets, simplified mechanics modelwasbuilt from double-symmetrical solid model under minimum pre-tightening force, minimum operating tightening force andopening force of metal ring. Based on mechanics principles, metal ring opening force under internal pressurewas analyzed in actionsof four kinds of different gasket tightening forces. The physical meaning of the maximum effective pressure for calculating pressurewas revealed. It was shown from the result that when internal pressure only acts on the ineffective sealing width between metal rings,theself-lock tightening condition for any double-metal gasket isthat the calculating pressure should be less than 8.3 times gasketfactor divided gasket factor plus 0.5, which is only correlate to gasket factor but not to gasket pre-tightening sealing load;when theinternal pressure acts on the whole width of the metal rings, theself-lock tightening condition is that the calculating pressure shouldbe less than sealing specific pressure divided by two times gasket factor, which is only related to gasket characteristic parameter butnot to the width of the gasket. With the maximum effective calculating pressure, and for constant double metal gasket with specificwidth, the more width between the two metal rings for acting pressure, the larger internal self-lock tightening can be obtained for thedouble metal gasket.