商用车发动机横腔拧紧工艺研究

Tightening Torque Research for Transverse-Cavity Nut of Diesel Engine

为确定商用车柴油发动机燃油系统安装工艺,采用电阻应变片对进油横腔装配轴力进行测试,解决在使用过程中横腔头部压溃的问题。先根据缸盖三维结构确定应变片连接线引出位置并打孔,再使用有限元方法计算横腔应力、应变分布并确定打磨和贴片位置,最后采用应变片测试出横腔在缸盖上装配的轴力数据。根据加载扭矩和测试轴力数据,结合横腔设计许用轴力值,确定推荐安装扭矩为47 N·m较为合适,轴力值分布范围为1.33×10^(4)~2.04×10^(4)N。

Promoting domestic production of fuel supply system used on heavy-duty enging,satify sealing requirements and avoid the seal structure yield while engine running.Simulation the situation of transverse cavity with FEA,and according to stain distribution arrange where strain gage layout,polish transverse cavity and paste strain gage,prepare for strain testing.Finding out an appropriate channel on engine head for stain gage wire to extend out of fuel return channel,drilling through engine head top tray.Measurement real strain with resistance strain gauge is applying specific torque while transverse cavity nut.According to experimental results and design axial force,recommand mounting torque apply on transverse cavity nut is 47 N·m,while transverse cavity axial force range from 1.33 ×10~4to 2.04 × 10~4N.