Pollution and prevention of lubricating oil of the

Pollution and prevention of internal combustion engine lubricating oil (II)

5) polluting energy. Pollution energy refers to the thermal energy of all objects of lubricating oil. The oil temperature is too low, the viscosity of the lubricating oil is high, the fluidity is poor, the oil pump is difficult to absorb oil, and at the same time, it makes it difficult to start the internal combustion engine; If the oil temperature is too high, the lubricating oil becomes thinner, the viscosity decreases, and the leakage increases. Dry friction or semi dry friction occurs between the moving pairs, and even the lubricating oil oxidizes, decomposes and deteriorates

2 basic methods and measures to prevent lubricating oil pollution

1) selection of lubricating oil. The selection of lubricating oil with proper viscosity and excellent quality is of great significance to the normal operation of internal combustion engine and the extension of its service life. Therefore, the basic principles of selecting lubrication are: (1) select according to load and speed. If the load is large and the speed is low, for example, some large diesel engines should choose lubricating oil with high viscosity; For those with low load and high speed, such as gasoline engine, lubricating oil with low viscosity should be selected. (2) Select according to the region, season and temperature. In cold areas in winter, such as northeast and northwest regions, lubricants with low viscosity and low freezing point should be selected; The temperature is high all year round. For example, lubricating oil with slightly higher viscosity should be selected in Jiangnan area. (3) Select according to the wear condition of internal combustion engine. For long service life and large wear of parts, oil with higher viscosity should be selected appropriately, and lubricating oil with lower viscosity can be selected for new internal combustion engines. (4) Internal combustion engines equipped with superchargers should use special lubricating oil. (5) According to the instructions of the internal combustion engine, select the designated brand of lubrication

2) lubricating oil cleaning. When filling lubricating oil, ensure that the oil filler and the oil container are clean to prevent the invasion of dust and sand; Maintain the lubricating oil filter on time; Maintain the air filter and fuel filter on time to prevent impurities from entering the crankcase from the cylinder

3) lubricating oil temperature. The normal operating temperature of lubricating oil is 45~90 ℃. After the internal combustion engine is started, it should be preheated first, and then put into operation or driving when the oil temperature is higher than 45 ℃. When the ambient temperature is high, the working time is long, and the lubricating oil temperature is higher than 90 ℃, it should be idled and work after the temperature drops

4) prevent water from mixing into lubricating oil. Prevent moisture or rain from invading the lubricating oil during refueling. When the oil level of crankcase rises during operation, the cause should be analyzed in time, and the working conditions of water pump water seal, cylinder block, cylinder head and other components should be checked to eliminate the fault

5) prevent fuel from mixing with lubricating oil. Maintain the normal working temperature of the cooling system. The normal water temperature of the water-cooled internal combustion engine is 80 ~ silicide material. Due to the brittleness of the material, the crack expands by 95 ℃, and the temperature of the cylinder head of the air-cooled internal combustion engine should be less than 120 ℃. High temperature will accelerate the oxidation and deterioration of lubricating oil; If it is too low, part of the mixture entering the cylinder will condense into liquid and flow into the crankcase. Keep the fuel system in good working condition, check and adjust the fuel supply advance angle and fuel injection atomization quality of the high-pressure pump and injector in time, so as to avoid poor fuel atomization and vaporization, which will flow into the lubricating oil along the cylinder wall

6) prevent the exhaust gas from polluting the lubricating oil. Install the piston ring correctly; The clearance between piston and cylinder liner and the clearance between valve and guide tube should be appropriate; Keep crankcase well ventilated and seal clean

7) lubricating oil replacement time. The quantity and quality of the lubricating oil should be checked before starting the internal combustion engine of each shift through the digital processing of the original information. It should be considered to replace it in case of one of the following situations: when the dipstick is pulled out, the lubricating oil on the dipstick flows away quickly, or the lubricating oil drops on the paper and diffuses rapidly, indicating that the lubricating oil is too thin; Pinch the lubricating oil with your fingers, feeling no smooth oil film and black, with fuel smell; There are too many metal chips in the lubricating oil

the replacement lubrication is generally after the test run of the new car or the machinery after overhaul; Diesel engine runs every 600H and gasoline engine runs every 400H (about 14000km); In winter or summer, overcome the bad phenomenon of only refueling without changing oil, and replacing oil with replenishment

8) the universal testing machine for lubrication system cleaning has stable display, high precision and convenient use. Clean the lubrication system when changing the lubricating oil. The method is to drain the old lubricating oil of the lubrication system while it is hot, add the mixed oil (4:1) of clean lubricating oil and diesel oil to the lower marking of the dipstick, stop the engine after idling for 3~5min, drain it, and fill the new lubricating oil to the specified oil level