(1) reduce the harmful effects of mechanical impurities. Generally refers to the dust, soil and construction machinery used in their own generated metal shavings, wear and tear and so on. These impurities will accelerate wear and tear parts. It is determined that the mechanical impurities in lubricating oil increased to 0.l5%, the wear rate of the first piston ring will be 25 times larger than normal. temperature. In general, the cooling water temperature is 80 ~ 90 ℃, hydraulic transmission system hydraulic oil temperature is 30 ~ 60 ℃. The test shows that the main drive gears and bearings of all kinds of construction machinery operate at a lubricating oil of -5 ° C and run at a lubricating oil of 3 ° C, which is 10 to 12 times larger than that of the lubricating oil. When the oil temperature exceeds 60 ° C and the oil temperature rises 5 ℃, the oxidation rate of oil will increase l times. Therefore, it is necessary to prevent the machine overload operation at low temperatures, but also to prevent it from working at high temperatures. corrosion. Rainwater, chemicals in the air, etc. enter the interior of the machine, corrode parts and accelerate wear. Use should be based on weather and air pollution, take effective measures. (2) to maintain normal working load test shows that the engine working under unstable load compared with the work under steady load, the cylinder wear increased 2 times. Overloaded, malfunction, low life expectancy. To evenly add and subtract the throttle, to prevent the engine, the working device movements ups and downs. (3) reasonable lubrication According to statistics, more than half of construction machinery failure is caused by poor lubrication. Good lubrication allows the various parts to maintain normal working clearance and the appropriate operating temperature, reduce wear and tear. Reasonable lubrication, a reasonable choice of lubricants, and second, we must always check the quantity and quality of lubricants. If the emergency substitute, after the incident must be handled correctly. (4) timely maintenance of major mechanical failure is often caused by some minor faults, fault size should be promptly ruled out. Daily, one in accordance with maintenance procedures, the machine for regular maintenance and repair, and second, to strengthen the use of regular and irregular inspections. 2. Prevention of Engine Faults (1) Prevention of Low-pressure Gas Resistance The low-pressure oil line is tightly sealed or the oil level in the fuel tank is too low. When the machinery is inclined to park or drive, the air will take the opportunity to enter. When the temperature is high and the fuel evaporates, Low-pressure oil gas resistance formation, resulting in unstable engine, automatic flameout or can not start. Always check the low pressure tubing, fittings and gaskets, pump and hand pump seal status; assembly of diesel engine fine filter cover, fuel pump cover, fuel pump cover, we must first check the seal paper pad is intact and After the burrs and impurities are combined, the screws that fasten the cover and the housing are tightened according to the regulations. When the weather is hot, cover a drip pump with a damp cloth to keep dripping water and slow down the evaporation of fuel. (2) Prevention of oil blockage Common blockages mainly include oil pipes, filters, diesel filters and fuel tank vent holes in the oil tank. The key to preventing blockage is to ensure clean oil and oil seal. 48h precipitation before filling diesel; refueling tools to be cleaned, it is best to use a sealed tube to refuel, do not plug the suction pipe to the bottom of the barrel, the fuel tank filler screen must be intact, the tank should be cleaned often, refueling should be full ; Oil should be regularly maintained, cleaned, and timely replacement filter. (3) Preventive maintenance of fuel pump with qualified diesel; Before each start should check the quantity and quality of oil in the fuel pump to prevent oil water or diesel spoilage, resulting in early wear and corrosion of the plunger and the valve. Periodic inspection and adjustment of the project are as follows: fuel supply advance angle and fuel supply interval angle of each cylinder; camshaft clearance (axial clearance is too large on both sides of the gasket plus adjustment, radial clearance is too large to replace new products); each cylinder fuel supply ( Can be determined by smoke color, sound, exhaust manifold temperature). Periodic inspection items: oil valve sealing occasions, if the multi-cylinder seal is not good, should be thoroughly debug pump maintenance, replacement of parts; related keys, slots and bolts wear; timely replacement of worn plunger coupling; use Standard high-pressure tubing. (4) Precaution of early damage of injector coupling Strict implementation of the requirements of oil selection, oil storage, sedimentation, filtration and refueling; clean the fuel filter on time and replace the damaged filter cartridge and sealing ring on time; install a new fuel injection Even when the device, pay attention to remove the anti-rust oil on its surface, cleaning the needle in the valve body twitching and rotating several times, tighten the injector coupling, the torque is generally 60 ~ 80N? M, the best elastic repeatedly A few times to prevent even the deformation of the coupling; adjust the injection pressure, the first check injector seal, can not leak; with the pressure plate fixed anger, install the pressure plate do not install the anti; keep the injector heat, The washer must be copper pad, and the mounting hole should be 2 ~ 3mm of clearance; fuel supply time, gas phase and cooling water temperature are required to promptly remove carbon deposition; replacement or disassembly of high pressure tubing, diesel filter, plunger pair And the valve and other parts of the oil should be cleaned before installation; high-pressure tubing is not connected to the injector before pulling the throttle should be large, driven by an external force to idle a few laps to clean the high-pressure tubing to prevent impurities into the injector even Pieces. (5) Man-made fault prevention Man-made faults are generally in the repair after the test machine running a mileage found, such as gaskets fell into the intake pipe, gear collision caused abnormal sound, illegal operations lead to exhaust pipe flow oil, hear the alarm Do not dispose of accidents. The main reason is that one is not in accordance with the provisions of the replacement, add oil, cleaning the oil filter, lack of oil or the use of deterioration of lubricants, there is no timely replacement of the air filter; Second, illegal operation or repair assembly poor quality; Third, the quality of parts failed or Added fuel, fuel oil quality is poor; Fourth, barbaric disassembly, poor cleaning cleaning habits; Fifth, do not follow the provisions of mileage cleaning "three filter", replace the oil; Sixth parts missing equipment; Seven illegal use, Such as the new machine or overhaul after the closing period, the implementation does not go together with the rules, do not go together to maintain, with a load in advance, overloaded, over-speed operation; eight is poor repair, inspection is not fine, as in the assembly crankshaft, flywheel and clutch Assembly do not do the balance test, the engine running instability, periodic vibration; nine is the wrong line, the wrong parts. (6) Prevention and control of oil leakage The main reasons for oil leakage are: the quality of the products (parts), the material or the poor workmanship; the poor structural design; the mismatch of the surface with the assembly, the damage of the cushion, the displacement or the failure of the operation rules; Friction nut torque unbalance, slip wire or loose Kuang; seal wear, aging, deformation, failure; excessive oil, oil surface is too high or wrong oil; parts (edge ​​cover, thin-walled pieces) Surface deflection;
