Analysis and elimination of overheat fault in cool

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Analysis and elimination of overheating fault of cooling system of internal combustion counterweight forklift requires that rubber materials have necessary physical and mechanical energy. Except for

for the current internal combustion counterweight forklift (hereinafter referred to as forklift), diesel engine or gasoline engine is used as the power source. The piston internal combustion engine is widely used in diesel engines or gasoline engines. The internal combustion engine only uses about 30% of the heat energy. Most of the rest of the heat energy is taken away by the exhaust, and the rest is absorbed by the parts of the internal combustion engine. When the internal combustion engine is working, the temperature in the cylinder can be as high as 1730 ~ 2400 ℃. Therefore, the temperature of those parts directly in contact with high-temperature gas (such as cylinder block, cylinder head, piston, valve, etc.) will rise. If the temperature of these parts is too high: (1) the inflation efficiency is reduced, resulting in the power reduction of the internal combustion engine; (2) The mechanical properties of metal materials are reduced, resulting in the deformation of parts. It reflects the load of the car within a certain range, which can damage the fitting gap between parts, cause rapid wear of parts, and even cause part fracture accidents in serious cases; (3) High temperature will also cause the engine oil on the cylinder wall to deteriorate, making it lose lubricating performance and even coking, intensifying the friction and wear of parts, and even jamming the piston. Therefore, in order to ensure the normal operation of the internal combustion engine, a cooling system must be set up

there are two cooling methods of internal combustion engine: water cooling system (or other liquid coolant) and air cooling system. Due to the low driving speed and structural characteristics of the forklift, the transmission system must be arranged at the tail of the forklift, and the muffler with high temperature is also nearby, so the exhaust is not smooth, the heat dissipation is difficult, and the heat source is concentrated, which determines that the forklift must adopt the closed water cooling system from the structure

however, due to various reasons, it is still possible to make the temperature of the internal combustion engine too high after calculating the sectional stiffness, free height, initial tension, and judging whether the spring is qualified. Therefore, this paper will analyze and discuss the causes of the excessive temperature of the cooling system, that is, the overheating of the cooling system and its countermeasures, combined with its own experience

1 causes of overheating of the cooling system

there are many factors causing poor cooling, mainly in the following aspects

1.1 internal combustion engine system

includes water pump, fan pulley (including active and passive), internal combustion engine (cylinder liner), fan belt, thermostat, etc

if the water pump does not work properly or the center distance between the driving wheel and the driven wheel of the fan pulley is incorrect, resulting in belt relaxation and slipping, which will reduce the speed of the driven wheel, the speed of the water pump and the flow of the water pump; Or the pipeline between the cylinder liners of the internal combustion engine is blocked, so that the water flow is not smooth; Or the thermostat fails, which stops the water circulation of the whole system, etc; All the above factors will make the internal temperature of the internal combustion engine rise sharply. Nine different lower molds can eventually be used in production according to the order of mixed models, resulting in overheating of the cooling system. In addition, the internal combustion engine will overheat the cooling system due to other faults such as incorrect ignition time

1.2 radiator system

radiator system includes radiator, wind shield, etc

radiator is also called water tank, which is composed of water inlet chamber, water outlet chamber and heat dissipation core. The cooling liquid (water) flows in the radiator core, and the air passes outside the radiator core. In this way, the heat absorbed by the cooling water from the internal combustion engine can be transferred to the external air, so that the cooling water temperature decreases to circulate again. The function of the wind shield is to make all the air drawn by the fan pass through the radiator to improve the efficiency of the fan

if the pipe in the radiator core is blocked or there is desoldering or faulty welding between the pipe and the heat sink, the heat dissipation performance will be greatly reduced. At the same time, during the transportation, assembly and use of the radiator, the fins on the radiator core are very easy to be bruised, which reduces the air passing area, increases the wind resistance and reduces the heat dissipation performance. If the air guard is damaged or the gap between the fan and the radiator is too large, the fans cannot all enter the air guard, causing the loss of air volume and also affecting the heat dissipation performance

1.3 fan system

the fan is generally installed in front of the radiator and coaxial with the water pump. The function of the fan is to increase the air flow rate and flow through the radiator to enhance the heat dissipation capacity of the radiator. If the cooling air volume is insufficient or the pulley slips, the heat dissipation effect will be affected

1.4 others

if the air outlet after the counterweight of the forklift is too small, and the hot air cannot be discharged in time and flows back, reheat all parts of the forklift and overheat the cooling system. If the rotation center of the fan is not concentric with the center of the radiator, the utilization rate of the radiator area will decline and the heat dissipation capacity will also decline. If the cooling system leaks and the water in the radiator is insufficient, the full heat dissipation area of the radiator cannot be fully utilized, affecting the exertion of the heat dissipation capacity. When the water volume is reduced to a certain extent, the cooling system will overheat

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