Should pay attention to the hydraulic excavator cooling parts maintenance and repair

Full hydraulic excavators in use should pay attention to the engine radiator and hydraulic oil cooler and heat-related components and parts inspection and maintenance, otherwise it will reduce the cooling efficiency of the engine, so that the oil temperature and water temperature caused by power loss, increased wear and tear , Serious cases can lead to early damage to the engine accident, so we can not ignore the inspection and maintenance of these components. Hydraulic excavator engine cooling is used suction air-cooled, suction-type radiator core air can get a good distribution. To ensure that the hydraulic excavator engine in use in the original cooling effect, it must ensure that the heat-related pieces intact. Affect the cooling effect in the following areas: 1, to prevent the use of heat in the process of return heatsink around the filler, known as "sponge." But it is not any "sponge" can be replaced. Its requirement on the hydraulic excavator is that it must have decay resistance, good temperature resistance and poor aeration, because its function is mainly to prevent the hot gas from flowing back. That is, to prevent the cold air drawn in from the front of the radiator from entering the rear of the radiator (engine compartment) after it rises in temperature and can not be returned to the front of the radiator. If some of the hot gas back to the radiator before, it is inevitable to reduce the cooling effect of the system, causing oil and water temperature increases, so that the engine can not work properly, resulting in early damage. Therefore, the hydraulic excavator should not be neglected during the use of the radiator around the "sponge" inspection and repair of damaged parts to be timely replacement. 2, To ensure the smooth discharge of hot air ① After the radiator engine compartment parts of the partitions are not free to disassemble, otherwise it will cause the formation of hot air in the circulation vortex, affecting the exhaust of hot gas. ② The engine room part of the exhaust vents must be kept open, in particular, the engine and the lower part of the pump exhaust vent holes must not be clogged and placed items, otherwise it will make the exhaust heat blocked. Air intake to reduce the cabin temperature also increases the intake air temperature, electrical components due to high temperature and early damage caused by aging. 3, to ensure that the cooling part of the air circulation area Radiator core ventilation area, due to the air flow in the hydraulic excavator process and a variety of reasons can easily lead to blockage. A protective net to promptly clean up the blockage, there is no protective net in accordance with changes in the environment and construction conditions outside the radiator pollution, timely cleaning and cleaning, or air flow blockage to reduce the ventilation area, will inevitably reduce the heat effectiveness. To prevent the radiator internal pollution is more important, in use must be strictly according to random technical documents, regular replacement of antifreeze and cleaning, can not be added to the contaminated water instead of antifreeze. If the internal liquid flow path caused by blockage, it is difficult to check the second is difficult to clean and remove, only replace the radiator. 4, to ensure that the cooling part of the air volume into the air volume In addition to preventing hot air backflow and ventilation area, the most important is the wind hood and fan. Wind hood at present there are Vindu, ring, box three. Fan and wind shield installation location is a strict requirement, the distance between the fan and the engine are also required. Because windshields are commonly used to improve fan efficiency, air is more evenly distributed over the radiator core and backflow of hot gases in the engine nacelle is prevented. Recommended by Cummins Engine Installation: ① fan from the radiator core distance of 50.8 ~ 101.6mm. ② maximum blade tip speed limit 4000 ~ 5200 m / min range. ③ fan blade tip and wind guide hole clearance for the fan diameter of 1.5%, the smaller the higher the efficiency, when the gap is greater than 2.5% of the fan's air supply will drop sharply. Therefore, the use of maintenance, repair process can not be changed wind shield and fan size and geometry, the radiator and fan can not change the installation location, otherwise it can not guarantee the original cooling effect and reliability. In particular, fans, most of them are made of non-metallic materials, will contact the high temperature deformation, deformation will reduce the fan for the air supply. 5, to ensure that the intake resistance and intake air temperature within the standard range (Cummins 6bt5.9 engine intake resistance standard ≤ 15inh0o, intake air temperature above 38 ℃ for each increase of 6 ℃ engine power decreased by 1%, heat dissipation increased 1.5%) Increase the intake resistance during use are: air inlet filter, cyclone filter and air filter pollution. It is easy to clean and clean the cyclone filter and the inlet filter in time. However, it is not so easy to use the filter cartridge because sometimes it is not possible to buy it directly from the engine manufacturer for various reasons. It is not good to determine whether the purchased air filter can meet the needs of the engine if it is not available at other vendors. If the replacement of the paper filter can not meet the needs of the engine will directly affect the reliability of the engine and reduce the life of the engine, it is necessary to understand and master some of the performance and parameters of the paper filter and the engine needs air filtration accuracy. To know the engine air filtration accuracy and intake resistance requirements are very strict. Imported diesel engine requires air filtration accuracy of 5um, domestic diesel engine also requires air filtration accuracy of less than 20um, while the domestic filter paper filtration accuracy of only 80um, imported common filter paper filtration accuracy of 30um, imported high efficiency filter paper filtration accuracy of 2um. Therefore, the choice of the air filter must be with the original engine power, economy and reliability to match; on the filter paper thickness, tensile strength, the original intake resistance, filtration and other requirements. Filter performance test mainly in the following four aspects: ① flow - resistance test to determine the pressure loss of air flow. ② The original filter efficiency test, filter efficiency can be calculated dust collection. The normal filter dust removal rate should be 99% or more. ③ dust storage capacity test and cumulative efficiency test, the filter dust caused by too much clogging, air intake resistance increased. The air intake resistance at which the engine power is reduced by 5% or the fuel consumption is increased by 5% is a limit value, at which point the filter must be cleaned or replaced. ④ The original intake resistance test, the rated intake air through the filter when the pressure at the import and export (the rated intake air filter is greater than the required intake air intake), should not exceed 3.2kpa or the filter can not meet Need for the engine. Intake air temperature and intake port location and the temperature of the cabin has a close relationship between the intake pipe and intake need to isolate or as far as possible away from the high temperature components, but also to prevent the cabin of hot gas into the intake port, and to ensure The heat of the cabin is evacuated smoothly to keep the temperature of the cabin as low as possible. Engine is the power source of hydraulic excavator, can guarantee the normal operation of the engine, in addition to the engine itself design, manufacturing quality, that is, in the process of using the engine maintenance inspection and scientific and reasonable maintenance. This scientific and reasonable maintenance, is to predict the preventive inspection and preventive maintenance according to the actual work of the engine. In the process of overhauling, we must analyze the engine's heat dissipation, intake air, exhaust gas and lubrication system systematically, and through the interaction and interaction of these four aspects, we can determine whether the parts should be overhauled or replaced, Restore the original reliability and extend the life of the engine.