液压垫平行度调整方案研究

本文对液压机液压垫上平面对工作台上平面平行度(简称液压垫平行度)超差且无法调整的原因进行了分析论证,推导了液压垫铜导板导向面相对理想位置重合、内倾、外倾,工作台固定导板导向面相对理想位置重合、内倾、外倾的九种组合工况下的液压垫平行度和导向面总间隙公式。结论为:最恶劣的两种工况是液压垫铜导板导向面和工作台固定导板导向面相对理想位置同时内倾或外倾,将会使液压垫铜导板导向面相对液压垫上平面垂直误差和工作台固定导板导向面相对工作台上平面垂直度误差两者按推导出的公式相互叠加而增大液压垫平行度误差。针对这两种工况,制定了提高导向面加工精度等级和只允许工作台固定导板导向面相对理想位置内倾和液压垫铜导板相对理想位置外倾等措施,使得只剩下4种可接受的工况发生,大大减小了生产操作难度。并据此制定相关文件,在生产实践中严格按此执行。经过两年多的实践验证,证明措施可靠,找到问题症结,基本消除了液压垫平行度超差和无法调整的现象。

Study on parallelism adjustment method for hydraulic cushion

The causes of exceeding specification and unable being adjusted for parallelism tolerance of hydraulic cushion's top surface relative to the workbench's top surface (hereinafter hydraulic cushion parallelism tolerance) have been analyzed and demonstrated.The formulas of hydraulic cushion parallelism and total clearance between guide surface under nine kinds of combined conditions have been deduced,including when the guide surface of hydraulic cushion's copper guide plates relative to ideal position is overlapped,introversion and extroversion,and when the guide surface of workbench's fixed guide plates relative to ideal position is overlapped,introversion and extroversion.It is concluded that the two worst cases exist when both of the guide surface of hydraulic cushion's copper guide plates and the guide surface of workbench's fixed guide relative to ideal position are introversion or extroversion in the same time.They would cause the mutual superposition between perpendicularity of the guide surface of hydraulic cushion's copper guide plates relative to top surface of hydraulic cushion and perpendicularity of the guide surface of workbench's fixed guide plates relative to top surfaces of workbench deduced by the formula,which would increase the parallelism tolerance of hydraulic cushion.Aiming at the two worst cases,the measures that improve guide surface machining accuracy level and only allow introversion of workbench fixed guide surface relative to ideal place and extroversion of hydraulic cushion's copper guide plates guide surface relative to ideal place have been drawn up.Thus in this way,only four left acceptable conditions could occur,which can greatly reduce the difficulty of the operations.The related paper has been formulated accordingly and carried out the implementation strictly in production practice.It is proved by more than two years' practice that the measure is feasible and the reason of problem has been found out.The exceeding specification and unable being adjusted for the parallelism tolerance of hydraulic cushion have been eliminated.