组合活塞连接螺栓预紧力控制的试验研究
王星全1，2，贾艳1，2，石小明1，2，王占宜1，2，徐涛1，2，常飞翔1，3
1.滨州渤海活塞有限公司，山东 滨州 256602；2.山东省先进发动机活塞组件重点实验室（筹），山东 滨州 256602;
3.江苏科技大学机械工程学院，江苏 镇江 212003
摘要：为提高大缸径发动机组合活塞螺栓预紧力的控制精度，以某缸径250 mm发动机组合活塞的螺栓连接为研究对象，分析螺栓预紧力的计算方法，设计螺栓拧紧操作流程，使用转矩–转角法对螺栓预紧力进行试验验证，并分析可能影响螺栓预紧力的因素。结果表明：实测的预紧力与理论计算预紧力高度吻合，其相对误差基本控制在±10%之内，满足设计目标；螺纹及相关接触表面的磨合处理、接触面良好润滑等措施，可有效降低摩擦因数，显著提高螺栓预紧力的控制精度；螺纹紧固胶兼具防松和减小螺纹表面摩擦因数的双重作用，对提高螺栓预紧力控制精度具有积极效果。
关键词：组合活塞；螺栓；转矩–转角法；预紧力
Experimental study on preload control of connecting bolts for combined pistons
WANG Xingquan1,2, JIA Yan1,2, SHI Xiaoming1,2, WANG Zhanyi1,2, XU Tao1,2, CHANG Feixiang1,3
1.Binzhou Bohai Piston Co., Ltd., Binzhou 256602, China;
2.Shaodong Province Key Laboratory of Engine Piston Cylinder Kites(Under Preparation), Binzhou 256602, China;
3.School of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China
Abstract: To improve the control accuracy of bolt preload for assembled pistons in a large-bore engine, the calculation method of bolt preload is analyzed for a combined piston in an engine with a cylinder diameter of 250 mm, the bolt tightening operation procedure is designed, the experimental verification of bolt preload using the torque-angle method is conducted, and the potential factors affecting bolt preload is investigated. The results show that the measured preload is in high agreement with the theoretical calculation results, with the relative error basically controlled within ±10%, which meets the design objectives. Running-in treatment of threads and related contact surfaces, as well as sufficient lubrication of contact interfaces, can effectively reduce the friction coefficient and significantly improve the accuracy of bolt preload. Thread locking adhesive not only provides anti-loosening function but also reduces the friction coefficient of thread surfaces, thus exerting a positive effect on improving the control accuracy of bolt preload.
Keywords: combined piston; bolt; torque-angle method; preload
