Where dose the weird sounds of 4 stroke electric starting diesel engine set come from?

When abnormal noise occurs in the power supply process of the high quality 6 cylinder diesel engine, it is necessary to determine where the noise comes from, such as the valve chamber, the front cover plate, the joint between the generator and the diesel generator set, the inside of the engine body and the inside of the cylinder. After determining the fault location, the fault must be judged and eliminated according to the working principle.

 

When the diesel generator set is running at low speed, the sound of "click, click" is heard.

Fault analysis:

This kind of noise generally belongs to the valve knocking sound. When the rotational speed of the powerful 12 cylinder diesel engine increases, the noise will also increase. This kind of failure is usually caused by incorrect valve clearance adjustment and loose fit between piston pin and bushing or pin seat.

Fault handling:

Carry out oil cut-off tests on the 6-cylinder high-pressure oil pipe on the fuel injection pump respectively to see if any abnormality is found.

Remove the valve chamber cover and check the push rod of the intake valve of the first cylinder of the 4 stroke turbocharger diesel engine. In case of abnormality, replace the push rod and adjust the valve clearance.

 

If a rhythmic ringing metal knock can be heard in the cylinder after the diesel generator set is started, the diesel engine generator has abnormal smoke exhaust.

Fault analysis:

During the operation of the diesel generator set, the premature injection time will cause the diesel oil to be injected into the combustion chamber at a lower temperature and pressure, resulting in the extension of the ignition time of the diesel oil and the accumulation of more diesel oil in the combustion chamber. Once ignited, the temperature and pressure will rise sharply, which will produce knocking sound. Judging whether the oil injection time of the diesel generator set is too early in the operation process has two noise characteristics: first, the new staionary 12 Cylinder Diesel Engine emits sharp, crisp and continuous sounds similar to metal knocking when accelerating rapidly; Second, it is accompanied by organism vibration at idle speed or at low load, while the noise is relatively reduced and the operation is relatively stable at high load.

Fault handling:

l Remove the high-pressure oil pipe of the first cylinder on the upper part of the high-pressure oil pump and then check the oil supply advance angle of the high quality 6 cylinder diesel engine generator.

l pry the flywheel of the diesel generator set with a screwdriver according to the operation direction of the new motor 6 cylinder diesel engine until the fixed pointer on the diesel generator set body is aligned with the 28-degree scale line on the flywheel. Then tighten the two locking screws on the transmission connecting plate.

l After the diesel generator unit is restarted to the rated speed, it is found that the abnormal phenomena of metal knocking and smoke exhaust in the cylinder disappear and the fault is eliminated.

 

After starting the low-noise diesel generator set, a rhythmic heavy knock was heard in the cylinder.

Fault analysis:

This kind of failure is usually caused by excessive valve clearance, excessive clearance between valve stem and valve guide, valve spring rupture or too small oil supply advance angle, etc.

Fault handling:

l First turn the flywheel to the "0" scale line. At this time, the first cylinder of the powerful 12 cylinder diesel engine should be located at the top dead center of the compression stroke. Then, use a feeler gauge to check the clearance between the intake and exhaust valves of the first, second and third cylinders respectively. If abnormality is found, adjust the corresponding cylinder clearance. After adjustment, restart the diesel generator set until the rotation speed reaches 700 rad/min.

l According to various requirements of 4 stroke electric starting diesel engine set, check the advance angle of oil supply. The results show that when the first cylinder of the high-pressure oil pump starts to supply oil, the oil supply advance angle of the diesel generator set is 10. Then loosen the two fixing screws on the driving plate of the high pressure oil pump and turn the plate unit back until the pointer is aligned with the flywheel scale by 28 degrees. The heavy knocking sound in the cylinder disappears after restarting the diesel engine.