Look, smoke checks for wear. Two see carbon deposition check condition. Three, look at the water temperature check cooling. Four look at the gas distribution valve.
five look at the cylinder pressure check leak. Six see smoke smoke check. Seven see chaca injection lag. Eight see fire check sooner or later.
look at the smoke and check for wear.
work in the engine, open the oil cap, such as strands of smoke emitted from the cover, that excessive wear or overrun each cylinder piston ring gap, if the gap does not meet the requirements should be promptly repaired. Open the valve cover, such as a blue, white smoke from the root valve (the valve face) out, that the valve or valve seat wear is too large or ablation, or the valve clearance is too small or no gap, at this time, which can directly see which valve cylinder leak, should be promptly repaired.
two look at carbon deposits to check the working conditions. When the
diesel engine is out of flame, the exhaust pipe is removed and the carbon deposits at the exhaust port are checked to determine the working conditions of the diesel engine. Coke is dark gray, like surface covered with a layer of white carbon layer is very thin, the diesel engine in good working condition; carbon black color, but not wet, the diesel engine burning oil slightly, should be excluded; the thickness of exhaust port deposition was higher than that of the other cylinder exhaust port, the cylinder or cylinder seal bad injector worse, should be repaired or replaced; individual exhaust wet or oil, the oil cylinder row, should be repaired; the cylinder exhaust port deposition layer is thicker and darker color, because of low working temperature, caused by injection or too late, should be used correctly and timely adjustment.
three look at the water temperature and check for cooling.
engine cooling system when the water temperature is too high (more than 100 DEG C, the engine overheating, resulting in insufficient air intake, and the friction loss of piston and cylinder wall to rise sharply, the mechanical efficiency decreased obviously. Therefore, in order to maintain the cooling system in time, after the engine is working 1000h, the scale in the cooling system should be removed, and the thermostat and the water pump fan should be kept in good technical condition. If there is any trouble, it should be eliminated in time.
four look at the gas distribution valve. The
engine in the long-term work, crankshaft, camshaft impact is not normal and distortion, timing gear, cam surface, servo and tappet column will wear, the intake and exhaust valve opening and closing time delayed and deviate from the valve timing, the charging efficiency is reduced, reduction of engine power. Therefore, the engine timing should be checked regularly, if not meet the requirements, should be adjusted in a timely manner.
five look at the cylinder pressure check leak. The cylinder compression force of
engine is the key factor that affects the power shortage. The method of judging compression force is simple. Taking S195 diesel engine as an example: it is not the case in the decompression crank crankshaft, when shaking to the compression force, to shake it, relax the handle, but the hands do not leave the handle, at this time, if there is a big rebound, indicating good compression, and compression the poor. Check the cause of the leak again. The main reason for the leak is that the cylinder is not sealed. In order to narrow the search range, when the engine is working, can be close to the air cleaner to listen, whether there is a hissing sound, such as that, with the open valve leakage; add oil cover again, if there is a unit of smoke, that the cylinder and the piston and piston ring leakage. Six see smoke smoked
engine in the normal working hours, generally do not smoke or take some light gray and white smoke, sometimes with the naked eye is difficult to see, such as the engine smoke engine is faulty, the failure will affect the drop of engine power, it should check the color of smoke. As the smoke is less oil gas cylinder, incomplete combustion performance; blue smoke is cylinder liner and piston, valve and valve guide wear gap is too large, the sump oil combustion chamber channeling people burning oil; white smoke is water and fuel completely without burning diesel after vaporizing tube at from the exhaust, the diagnosis should be ruled out. Seven see
injection chaca lag. Take a look at the
injection is good, good fuel is not deflected, drop of oil, oil mist, uniform range is appropriate, can hear the ringing in the outside of the body "Puchi Puchi, sound, and touch the fuel high-pressure tubing can feel vibration sense. This method can also diagnose the multi cylinder machine "vibration" force size and no "vibration" force of each cylinder work, if necessary, can also be combined with broken cylinder inspection, in order to symptomatic exclusion. Eight see
head check sooner or later.
head refers to the injection is, that is to say whether accord with the fuel supply advance angle. Each model diesel engine in the manual indicate their respective oil supply advance angle is how much?. Such as S195 diesel engine fuel supply advance angle of 15 degrees -18 degrees. This is because the diesel injection into the cylinder after a short period of air mixing, heating before self ignition, so the fuel injection into the cylinder should be in the compression stroke, piston before reaching the top dead point. The time ahead is indicated by the crank angle. Too late (fuel supply advance angle is too small), diesel engine difficult to start, incomplete combustion, exhaust smoke, machine temperature is too high, insufficient power supply; early (advance angle is too large), the diesel engine is knocking, easily damaged parts, easily overturned when starting, but also affect the power of the engine. Therefore, look at the meaning of ignition, mainly to check whether the oil is too late or too early. Taking S195 diesel engine as an example, check the fuel supply advance angle is in accordance with the technical requirements, the specific steps are: (1)
high pressure pipe chimney removed one end of the nozzle;
(2) loosen the nut end high pressure oil injection pump, high
Excavator running deviation2017-04-14