1.乌鲁木齐城市轨道集团有限公司，新疆 乌鲁木齐 830000；
2.新疆工程学院，新疆 乌鲁木齐 830000
Abstract：In order to solve the problem of oil leakage caused by poor sealing of exhaust manifold of diesel engine for a subway diesel locomotive under low speed and low load conditions, the cause of oil leakage is analyzed, and a method is proposed to increase the load of the diesel engine under the idling condition after starting the locomotive, which makes the engine temperature rise rapidly, and quickly forms an effective seal at the exhaust manifold to eliminate leakage. The control program of programmable logic controller (PLC) is optimized, and the brake cylinder pressure switch is added. The test of the improved locomotive on the testing line and the load operation on the main line are carried out. The results show that the optimized diesel engine can quickly reach the normal working temperature after starting, the piston ring expands fully, and the seals on the diesel engine exhaust manifold play an effective role, oil leakage no longer occurs.
Keywords:internal combustion engine;leakage;automatic loading; exhaust manifold ;improvement