When the water temperature of the loader maintenance is too high, the oil temperature should be reduced. Generally, the method of "load reduction and low speed" is used. At this time, although the time for the coolant to exchange heat at the high-temperature parts is long, the water flow speed is slowed down, and the time for heat dissipation is extended. At the same time, due to the reduction in load and speed, the heat generated by the collision of various moving parts is also reduced accordingly. Therefore, lowering the oil temperature can not only reduce the amount of heat generated by the engine, but also indirectly reduce the amount of heat absorbed by the coolant, and then also slow the rate of water temperature rise.
Excessive oil temperature will cause great damage to the engine
The so-called high engine temperature means that the oil temperature and water temperature of the engine exceed 90 ℃. When these two temperatures are too high, it will affect the normal operation of the engine and cause certain damage to the engine. Because the level of water temperature mainly indicates the burning of the engine and the heat of high temperature parts such as pistons and cylinder walls. Therefore, excessively high water temperature will lead to deterioration of incineration conditions, thermal expansion of high-temperature parts, and shrinkage of the gap between the piston and the cylinder wall, which constitutes severe wear or "pulling the cylinder." The oil temperature mainly indicates that the crankshaft and the bearing generate heat due to the conflict. The engine oil dissipates most of its heat, and the balance between the amount of heat generated and the amount of heat dissipated (expressed as stable oil temperature) is relative. When the heat generation exceeds the heat dissipation, the temperature of the bearing bush will rise, and part of the temperature will reach the melting point of lead, and the lead in the bearing bush will melt and be separated. When a lot of lead is separated, the bearing surface of the bearing bush becomes smaller and uneven, which increases the wear. In severe cases, the temperature can exceed the melting point of copper (1083 ℃). Copper also begins to melt, which eventually leads to severe ablation or occurrence of crankshaft and bearings The result of the "tile holding shaft". According to the test, when the oil temperature reaches 110 ° C, the temperature of the oil film in the bearing gap can reach 150 ° C. If the temperature of the oil film is as high as 150 ° C or higher, a simple crack will constitute a semi-dry conflict. Because the crankshaft bearing is a copper-lead alloy, if the reduction method is not correct, the bearing temperature will be too high and the lead will be melted and separated, and the result is unimaginable. Therefore, when the oil and water temperatures are too high, the oil temperature should be lowered first.
First, the drop in water temperature has a great influence on the establishment of the oil pressure of the engine main shaft oil passage
As we all know, the temperature of precipitation is generally the method of "load reduction, high speed". When the speed is too high, the inertial force and centrifugal force of the piston Lianxuan group will increase, which will increase the load on the crankshaft bearing. At the same time, the relative conflict speed of the journal and the bearing bush will also increase, so that the heat added in a unit time will decrease the oil pump oil quantity, and a lot of oil will be thrown out from the main oil passage, and then cause the conflict of various parts. Sufficient lubricating oil will increase the wear and the oil temperature will rise further.
When the engine oil temperature is too high, not only the fuel consumption is added (leakage, evaporation, incineration), but also the quality of the engine oil is affected, so that the oil film of the appearance of the conflicting parts of the engine is not easy to form and persist, and the main oil channel oil pressure cannot be established , And then increase the wear of mechanical parts. The effect of water temperature on oil pressure must be achieved through oil temperature. Therefore, it has a certain indirectness and a certain moment in demand.
