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Causes and prevention of cylinder pulling of diesel generator set
Article source:this site | Issuing time：2019-04-07
Cylinder pulling is a major engine accident, mainly due to obvious scratches, scratches and other wear phenomena on the inner wall of the cylinder, which cause the diesel generator set to start difficult or self-extinguish.
The main reason for cylinder pulling is that dry grinding occurs due to poor lubrication in the cylinder. Quark motor summarizes through experience and mainly causes the cylinder pulling due to the following three problems:
Improper maintenance of the piston group:
The piston ring clearance is too small. Piston ring gap, side gap or back gap is too small, causing the piston ring to be thermally expanded and jammed during operation, and it is tightly pressed against the cylinder wall, or the piston ring is broken, and the groove is pulled out on the cylinder wall.
Piston pin sprang out. Because the piston pin circlip is not installed or falls off or breaks, the piston pin bounces out during the movement, it is easy to strain the inner wall of the cylinder, causing the cylinder to blow-by to the crankcase.
The clearance between the piston and cylinder is too small or too large. If the material of the piston is poor, the manufacturing size error is too large, or the piston is deformed after the piston pin is assembled, the clearance between the piston and the cylinder is too small, the piston will be stuck after being heated and expanded, and the cylinder wall will be strained.
Severe carbon deposits on the piston ring. Excessive carbon deposits cause the piston ring to stick or seize in the ring groove. At the same time, the carbon deposits are a hard abrasive, which will grind into longitudinal grooves on the cylinder wall.
The piston is severely offset from the cylinder. Due to the bending and twisting of the connecting rod, the deviation of the parallelism and coaxiality of the connecting rod journal, main journal, and piston pin seat is too large, causing the piston to be obviously biased, which will accelerate the wear of the piston ring, piston and cylinder wall, and destroy the oil film Formation.
Improper cylinder set:
The roundness and cylindricity tolerances of the cylinder liner exceed the allowable range, which greatly reduces the sealing performance of the piston and the cylinder liner. The high-temperature gas in the cylinder moves downwards, destroys the oil film between the piston and the cylinder wall, and causes cylinder pulling.
The cylinder liner is deformed during assembly. For example, if the upper end surface of the cylinder liner protrudes too much, the cylinder liner will be deformed after installing the cylinder head; the cylinder liner water blocking ring is too thick, and the cylinder liner will be deformed after being pressed into the body, which will easily cause the cylinder to pull.
Reasons for improper use:
The air filter is not sealed, which makes the filtering effect worse. The dust, sand and other impurities in the air are sucked into the cylinder to form abrasive wear. Tests have shown that if a few grams of dust is sucked in every day, the wear of the cylinder liner will increase by more than 10 times.
Poor running-in. There are many microscopic unevennesses on the surface of cylinder liners, pistons, piston rings and other parts of the new or overhauled engine, and the lubricant film is difficult to form. If it is put into high-load operation immediately without running-in, it is easy to cause accidents such as cylinder pulling.
Start at low temperatures often. When the engine is started at low temperature, the lubricating oil has high viscosity and poor fluidity, and it is difficult to form an effective oil film on the inner wall of the cylinder. According to tests conducted by the research department, the wear of the cylinder liner and other parts of the diesel engine where the cooling water temperature is below 30°C is 5 to 7 times that of the normal water temperature.
The engine is overheating. When the cooling system is poorly maintained or overloaded, the excessively high machine temperature not only reduces the mechanical strength of the parts, but also prevents the formation of a lubricating oil film on the inner wall of the cylinder. After the piston and other parts are heated and expanded, they are easy to get stuck in the cylinder liner. The consequence is often that the piston is partially melted and the inner wall of the cylinder liner is damaged, forcing the engine to stall.
In actual use, cylinder pulling is often the result of several factors. For example, if an engine that has not been run-in is started, it will be put into full-load operation immediately after it is started. At this time, cylinder pulling accidents are prone to occur.
The main reason for cylinder pulling is that dry grinding occurs due to poor lubrication in the cylinder. Quark motor summarizes through experience and mainly causes the cylinder pulling due to the following three problems:
Improper maintenance of the piston group:
The piston ring clearance is too small. Piston ring gap, side gap or back gap is too small, causing the piston ring to be thermally expanded and jammed during operation, and it is tightly pressed against the cylinder wall, or the piston ring is broken, and the groove is pulled out on the cylinder wall.
Piston pin sprang out. Because the piston pin circlip is not installed or falls off or breaks, the piston pin bounces out during the movement, it is easy to strain the inner wall of the cylinder, causing the cylinder to blow-by to the crankcase.
The clearance between the piston and cylinder is too small or too large. If the material of the piston is poor, the manufacturing size error is too large, or the piston is deformed after the piston pin is assembled, the clearance between the piston and the cylinder is too small, the piston will be stuck after being heated and expanded, and the cylinder wall will be strained.
Severe carbon deposits on the piston ring. Excessive carbon deposits cause the piston ring to stick or seize in the ring groove. At the same time, the carbon deposits are a hard abrasive, which will grind into longitudinal grooves on the cylinder wall.
The piston is severely offset from the cylinder. Due to the bending and twisting of the connecting rod, the deviation of the parallelism and coaxiality of the connecting rod journal, main journal, and piston pin seat is too large, causing the piston to be obviously biased, which will accelerate the wear of the piston ring, piston and cylinder wall, and destroy the oil film Formation.
Improper cylinder set:
The roundness and cylindricity tolerances of the cylinder liner exceed the allowable range, which greatly reduces the sealing performance of the piston and the cylinder liner. The high-temperature gas in the cylinder moves downwards, destroys the oil film between the piston and the cylinder wall, and causes cylinder pulling.
The cylinder liner is deformed during assembly. For example, if the upper end surface of the cylinder liner protrudes too much, the cylinder liner will be deformed after installing the cylinder head; the cylinder liner water blocking ring is too thick, and the cylinder liner will be deformed after being pressed into the body, which will easily cause the cylinder to pull.
Reasons for improper use:
The air filter is not sealed, which makes the filtering effect worse. The dust, sand and other impurities in the air are sucked into the cylinder to form abrasive wear. Tests have shown that if a few grams of dust is sucked in every day, the wear of the cylinder liner will increase by more than 10 times.
Poor running-in. There are many microscopic unevennesses on the surface of cylinder liners, pistons, piston rings and other parts of the new or overhauled engine, and the lubricant film is difficult to form. If it is put into high-load operation immediately without running-in, it is easy to cause accidents such as cylinder pulling.
Start at low temperatures often. When the engine is started at low temperature, the lubricating oil has high viscosity and poor fluidity, and it is difficult to form an effective oil film on the inner wall of the cylinder. According to tests conducted by the research department, the wear of the cylinder liner and other parts of the diesel engine where the cooling water temperature is below 30°C is 5 to 7 times that of the normal water temperature.
The engine is overheating. When the cooling system is poorly maintained or overloaded, the excessively high machine temperature not only reduces the mechanical strength of the parts, but also prevents the formation of a lubricating oil film on the inner wall of the cylinder. After the piston and other parts are heated and expanded, they are easy to get stuck in the cylinder liner. The consequence is often that the piston is partially melted and the inner wall of the cylinder liner is damaged, forcing the engine to stall.
In actual use, cylinder pulling is often the result of several factors. For example, if an engine that has not been run-in is started, it will be put into full-load operation immediately after it is started. At this time, cylinder pulling accidents are prone to occur.
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Quark motor prompts the main measures to prevent cylinder pulling:
For the new engine and the overhauled engine, it must be run-in first, that is, under the condition of maintaining good lubrication, according to the principle of rotating speed from low to high, and load from small to large, carefully operate in compliance with the regulations before putting into formal load. Running.
According to the provisions of the instruction manual, correctly select the gap between the piston skirt and the cylinder liner, the opening gap and the side gap of the piston ring. In addition, it is necessary to keep the piston off-cylinder in the repair, while ensuring the dimensional accuracy of the cylinder liner.
Keep the normal temperature of cooling water between 70°C and 95°C to avoid overheating of the engine. Preheat measures should be taken before starting in winter.
Operate and use the engine rationally, do not overload the operation, do not slam the throttle indiscriminately, do not start without water.
Strengthen the maintenance of the air filter to prevent dust from being sucked into the cylinder.
Maintain the lubrication system to prevent mechanical impurities and carbon deposits from mixing into the oil and aggravate the wear of the cylinder liner.
Quark Motor specializes in producing diesel generator sets，Volvo diesel generator set，Yuchai diesel generator set，Cummins diesel generator set，Shangchai diesel generator set，400kw Cummins diesel generator setWait for a full range of diesel generator sets, consultDiesel generator set manufacturers,to understandingdiesel generator set offer, welcome to inquire; we are a manufacturer of diesel generator sets, and we will solve your power problems in all aspects!24-hour hotline：400-966-0200,website：en.kuake.biz
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