Faults and causes caused by overheated operation o

Faults and causes caused by overheated operation of crane engine

in order to keep the engine in thermal equilibrium, 20% - 30% of the heat should be taken away with cooling water to keep the water temperature in the cooling water jacket at 80-90 ℃. Operation when the engine water temperature exceeds 95 ℃ is called overheated operation

(1) during operation with high water temperature, pay attention to the readings of water temperature gauge and torque converter oil temperature gauge. If it is found that the engine is overheated, the operation should be stopped to make the software go out of the laboratory level of domestic peers and reduce the engine speed to medium speed (1000~1100r/min). Do not add cooling water directly when it is overheated. The cylinder head with temperature up to 400~500 ℃ is prone to hot cracking when it drops sharply. Let the engine idle for a few minutes before the hot engine stops, so as to prevent the oil film of high-temperature pistons and other parts from sticking and coking

(2) the faults easily caused by overheated operation are: a) the inflation coefficient decreases, the mixture combustion is abnormal, causing cylinder knocking, deflagration and power reduction. b) The mechanical properties of cylinder head, valve, cylinder liner, piston and piston ring are more important than other physical properties. The thermal stress of heated parts increases, and hot cracks often occur. c) Destroy the normal clearance of sliding fit, dilute the oil film, and cause piston cylinder pulling. d) Burn out the waterproof rubber ring of the cylinder liner. E engine oil deteriorates in the early stage, resulting in poor lubrication and easy Bush burning. This new water-based adhesive scheme has obvious advantages in the following aspects: good adhesion, long storage time, flexible viscosity and safer operating environment

the causes of engine overheating are: a) excessive heating. The reason is: the engine timing is poor, the ignition is too late: the engine oil is channeled into the combustion chamber or excessive diesel oil is injected: after adding the test piece for a long time, the room is overloaded; High transmission oil temperature caused by torque converter or transmission failure: high hydraulic oil temperature. b) Insufficient heat dissipation. The reasons are: insufficient water, lack of water operation; Poor water quality, water mixed with engine oil, reducing thermal conductivity; The water quality is too hard to produce a lot of scale, which seriously affects the heat dissipation effect; Mixing bubbles into water reduces its cooling capacity; The thermostat is poor and the large circulation opening is not enough; Mud, sand, rust, scale and other impurities block the water tank; The water tank grille is blocked by branches, mud and sand, and sundries; Poor water pump, loose fan belt, fan blade deformation, resulting in insufficient forced refrigeration, etc