李正现1，2，刘伟达1，2，刘近报1，2，程祥军1，2，高进1，2

1.内燃机可靠性国家重点实验室，山东 潍坊 261061；

2. 潍柴动力股份有限公司发动机研究院，山东 潍坊 261061

摘要：为解决市场配套柴油机机油冷却器盖频繁出现裂纹的故障，分析2种不同流量的水泵，测量不同转速下水泵的水压及水压波动。测量结果表明：水流量大、转速高的水泵易引起水压大幅度波动，最大水压超过500 kPa，波动幅度约为250 kPa。对测量的水压进行有限元分析可知，水压及水压波动大是导致机油冷却器盖裂纹的根本原因。对机油冷却器盖进行改进，增大倒角，计算分析表明改进后的机油冷却器盖可承受500 kPa水压。改进后机油冷却器盖在使用中未出现裂纹现象。计算分析及使用结果表明：在满足散热、冷却和热平衡等情况下，应优先选用流量小的水泵；用瞬时水压代替平均水压，分析结果更准确；防冻液刚进入机体的位置为水压测点，测量结果更精确。

关键词：水压；波动；机油冷却器盖；节温器；冷却系统；水泵

Abstract:In order to slove the crack failure of oil cooler cover frequently occured in a diesel engine ,two pumps with different flow are selected for analysis. The pressure and fluctuation of pressure of water are measured at different speeds. The measurement results show that pumps with larger water flow and higher speed are easy to cause larger fluctuation of water pressure.The maximum water pressure could exceed 500 kPa, and the fluctuation rang is 250 kPa.Finite element analysis is used and it is found that cracks appear because of such high water pressure and water pressure fluctuation. Increasing the chamfering of the cold cover could improve its performance under 500 kPa water pressure.No cracks appear in the oil cooler cover after use. Calculation, analysis and application results show that considering heat dissipation,cooling and heat balance,water pump with small flow is preferred.Replacing average water pressure with instantaneous water pressure will get more accurate analysis results.The position near the antifreeze inlet of the water pump could give reliable data for pressure measurement.

Keywords:hydraulic pressure; fluctuation; oil cooler cover;thermostat; cooling system; water pump