Because the cylinder pad is washed to varying degrees, the abnormal noise is different. On the basis of Red-120, three groups of cylinder gasket faults of pulse bulldozer engine are displayed and eliminated. Basic information Chinese name Pinyin Chūnggāng Interpretation of collision fault between piston and cylinder liner of internal combustion engine Interpretation of pronunciation Chūnggāng refers to collision fault between piston and cylinder liner of internal combustion engine of motor vehicle. 1, mainly due to the serious shortage of lubricating oil, resulting in a sharp rise in the friction temperature between the cylinder and the piston and connecting rod. At high temperature, due to the drastic change of thermal expansion coefficient of metal objects, the lubrication gap decreases rapidly, which makes the piston locked with the cylinder and connecting rod. Due to the strong inertia force, the cylinder block was seriously damaged by impact and scrapped. If the mechanical lubrication gap between the piston and the inner wall of the cylinder liner is too large, it will also cause the mechanical impact of the piston on the cylinder block. One of the common faults is that the cold start bulldozer makes a "jingle, jingle" sound, and the first one emits white smoke. After smoking, the engine suddenly caught fire, the throttle suddenly struck, and the abnormal sound of the throttle disappeared. If you suddenly push the throttle again and again, there is still a knock at the door. When the storage tank was closed for inspection, they found an abnormal sound in the VI cylinder. Suspected that the syringe needle is eye-catching. Delete the result of checking normal. When deleting the cylinder head of the sixth cylinder, we found that the cylinder gasket was burning and smoking. The cylinder head bolt of this cylinder was originally tensioned (the torque was as high as 250N meters), but the cylinder head and cylinder gasket were not compressed because a water body was blocked above the upper body. Replace the cylinder gasket and get off the plane. After another abnormal sound, the installation height of the water baffle is lost and the engine runs normally. Another phenomenon is that when the bulldozer is idling, the "throat, throat sound" of the engine, that is, when the V-shaped cylinder turns off the oil until it disappears, the sound weakens. It is suspected that V caused the cylinder to idle, but it could not help the small rotation, and the abnormal sound was not obvious when the large and medium throttles were operated. Valve clearance is normal. To start the fuel valve of the engine, there is a knocking sound of "thunk, thunk", and the gas pedal is repeatedly stepped on, and the five-cylinder cylinder gasket smokes. After inspection, the fault was caused by the cleaning of the fuel tank gasket. There is also a bulldozer with obvious loading sound, throttle and no load in primary and secondary schools. Abnormal sound is obvious; By repeatedly loading the application, the sound is obvious, but three or four take the fuel tank between the cylinder heads. Check the display box. Third, pad burning tanks. Replace the cylinder gasket and eliminate the fault. Red-120 bulldozer is equipped with 6 130 diesel engine (one cylinder and one cover). There are fewer failures of cylinder liners, mostly due to unnecessary failures caused by the torque and sequence of cylinder head bolts (divided into 2-3 times) and tightening. Diesel generator set is a complete set of products, including diesel engine, generator, control components, protection devices and so on. The whole machine inspection of export products includes the following contents: (1) product technology and inspection data review; (2) Product specifications, models and main structural dimensions; (3) the overall appearance quality of the product; (4) Unit performance: mainly technical parameters, unit operation adaptability, reliability and sensitivity of various automatic protection devices; (5) Other items specified in the contract or technical agreement. Symptoms of cylinder knocking The symptoms of cylinder knocking in the operation of diesel generator include: heavy cylinder knocking from medium speed to low speed, black smoke from the exhaust pipe of diesel generator set, sometimes shooting or fire, and overheating of the body. The main reasons for cylinder knocking are as follows: 1. The oil supply time is too early. When the piston of the diesel generator set moves upward before reaching the specified fuel injection position, the fuel injector starts to inject fuel, so that the fuel burns ahead of schedule, and the high-pressure gas in the cylinder impacts the piston, making a rhythmic "click, click" clear cylinder knocking sound, reducing the throttle and making the cylinder knocking sound obvious. The elimination method is: adjust the fuel supply advance angle, that is, increase the gasket between the fuel injection pump and the gearbox to delay the fuel supply time to meet the specified fuel injection time. When the gasket is increased by 0. 1mm, the fuel supply advance angle can be delayed by 1.3- 1.7. 2. Poor fuel combustion, low injection pressure, oil dripping from injector, poor atomization of injection and late oil supply time will all cause poor fuel combustion and cylinder knocking. The knocking sound caused by this kind of fault is low and hoarse, accompanied by engine overheating, black smoke or exhaust pipe shooting and fire. The fuel injector should be removed for inspection and adjustment, and the fuel supply time should be adjusted. If necessary, replace it with a new one to make it conform to the regulations. 3. The oil outlet valve is worn. After the oil outlet valve is worn, on the one hand, the fit gap between the pressure relief ring and the inner hole of the valve seat becomes larger, the sealing performance becomes worse, and the pressure relief effect becomes worse; On the other hand, the residual pressure in the high-pressure oil pipe is too high, and the oil supply increases, which leads to fuel explosion and cylinder knocking, especially when the throttle is reduced. Cylinder pulling failure Diesel engine cylinder pulling refers to the phenomenon of excessive wear, galling, scratch, crack or seizure of the working surface caused by the intense interaction between piston assembly and cylinder working surface. Cylinder pulling is different degree of adhesive wear under lubrication conditions. Lightly, the cylinder is pulled, the cylinder liner and piston assembly are damaged, and seriously, it causes a vicious machine damage accident of cylinder biting. And the piston or connecting rod is broken, which damages the machine and causes a major accident. Therefore, it is of great significance to analyze the formation mechanism of diesel engine cylinder pulling failure and find out early prediction and correct countermeasures for improving the correct management and use of diesel engines, improving reliability and prolonging service life, and improving the ability of managers to troubleshoot. Reasonable use and maintenance (regular inspection) can also reduce the cylinder pulling failure of diesel engine. 1. Cylinder pulling phenomenon: The mechanism of cylinder pulling damage is mostly due to the local damage of lubricating oil film at the sliding part. At this time, the two relatively moving surface convex parts first contact with metal, and then a small "melting" phenomenon occurs locally, and the melted part is torn due to the relative movement of the parts. In this process, a hardened layer is formed on the metal surface. When the hardened layer is destroyed, the metal abrasive particles produced will become materials that aggravate surface wear. In a short time when the so-called "burning loss" occurs, uneven wear marks parallel to the center line of the cylinder appear on the surface of the piston and cylinder liner, which is the phenomenon of cylinder pulling. In severe cases, the sliding part is completely stuck or stuck, and even cracks occur in the weak parts of the two surfaces, causing damage to the parts, that is, cylinder seizure. Therefore, the root cause of cylinder pulling is burning and melting wear. 2. Causes of cylinder pulling: The causes of cylinder pulling are very complicated. There are design reasons, such as the selection of materials, the determination of gap size, whether the installation of the device is moderate, whether the structural arrangement is reasonable, whether the surface roughness is appropriate, and whether the lubrication and cooling arrangement is perfect. From the management point of view, it may be caused by the following reasons: (1) Poor cylinder lubrication: insufficient cylinder lubricating oil or oil supply interruption. The causes of poor cylinder lubrication are: too little oil in the oil pan or poor oil quality, too high temperature of diesel engine or damage or failure of piston ring (mainly oil ring). (2) Insufficient running-in: In order to get effective running-in in the shortest time, we must consider running-in time and load distribution. You can't finish running even for a long time under low load, but if you are eager to run under high load, it will cause cylinder pulling. Therefore, during the running-in period of diesel engine, attention should be paid to: increasing the fuel injection amount appropriately during the running-in period; After replacing the piston ring, it should be operated under low load for a period of time; After replacing the piston and cylinder liner, it should be run-in and then run under the condition of increasing load. (3) Poor cooling: Poor cooling will lead to high temperature and poor lubrication of cylinders and pistons; Poor cooling will overheat the piston and cylinder liner, lead to excessive expansion and deformation, lose the original normal clearance and pull the cylinder. The reasons for poor cooling are: insufficient outlet pressure of cooling water pump, insufficient water supply or interruption; Rusty or dirty cooling water cavity; Water contains bubbles, which accumulate in the cooling cavity and cannot be released, resulting in air resistance; The water is too dirty and the water temperature is too high. (4) The piston ring is not working properly: the opening gap is too small, which leads to the piston ring breaking; The gap between heaven and earth is too small, which causes the piston ring to get stuck; Excessive carbon deposition makes the piston ring stuck in the ring groove lose its elasticity, leading to fracture or air leakage; The opening gap is too large or seriously worn, resulting in air leakage. The gas leakage destroyed the lubricating oil film and made the surface temperature too high. After the piston ring is broken, the fragments easily fall between the piston cylinders, causing the cylinder to pull and bite. (5) Burning inferior fuel: Incomplete combustion will bring more combustion residues; After-combustion phenomenon is serious, which makes the exhaust temperature rise, and technical measures are not taken in time; The base of cylinder lubrication is not suitable. In addition, some diesel engines are overloaded for a long time, the thermal load increases, overheating and expansion occur, or the moving parts are poorly aligned, resulting in cylinder pulling. (6) Repair the assembly error: when repairing the assembly error, the piston pin snap ring is missing or not completely installed, and when the diesel engine is working, the piston pin falls off and scratches the cylinder liner, resulting in cylinder pulling. Poor cleaning during installation, bringing metal fragments or hard objects into the cylinder can also cause the cylinder to be pulled. In addition, incorrect installation, reverse installation and leakage of piston ring will cause cylinder pulling. Piston rings are divided into oil rings and gas rings. Oil ring is mainly used to scrape oil and improve the lubrication condition of cylinder liner. The gas ring mainly ensures the seal between the piston and the cylinder liner. According to different working conditions and pressures, the material selection and structural design of each gas ring are also different. If the piston ring is installed incorrectly, reversed or omitted, the seal is not tight or there is no oil scraping effect, the lubrication condition of the inner surface of the cylinder liner will deteriorate, resulting in oil shortage and cylinder pulling.