Cooling system

Abstract

The invention relates to a cooling system used for a loading machine. The cooling system comprises a fan, wherein the fan is connected with a constant displacement motor, an electric proportional relief valve, a constant displacement pump and an oil tank in sequence, the electric proportional relief valve is further connected with a controller and a temperature sensor, the temperature sensor is connected with an engine ECU through a CAN bus, and a radiator is further arranged at the front end of the fan and connected with hydraulic oil and bending moment oil through a temperature control valve. The independent hydraulic-controlled cooling fan is adopted in the cooling system, the flow of the hydraulic oil flowing through the radiator and the flow of the bending moment oil flowing through the radiator are controlled by the temperature control valve, the hydraulic oil is matched with bending moment oil, operational use time of the fan is greatly increased, and the performance ratio of the fan is improved; meanwhile, the temperature of engine coolant, the temperature of hydraulic oil and the temperature of bending moment oil are controlled to be within the best temperature interval in the shortest time, overheating and supercooling of media are avoided, and stabilization of the thermal state of the whole machine is guaranteed.

Description

technical field [0001] The invention relates to a cooling system for a loader. Background technique [0002] At present, most of the cooling fans in the engine cooling system of construction machinery are driven by the engine crankshaft, so that the cooling air passes through the radiator to take away the heat of the cooling water. This mechanical driving method makes the cooling capacity of the fan only change with the engine speed, but cannot It changes automatically with the thermal state of the engine and the ambient temperature, so it will inevitably cause serious shortage of cooling capacity at low speed and heavy load, and excessive cooling at high speed and small and medium load, which not only affects the progress of the project, but also increases Reduce fuel consumption and increase operating costs; of course, some large-scale construction machinery adopts an independent heat dissipation system, that is, the speed of the cooling fan is controlled by electro-hydrau...

AI Technical Summary

Problems solved by technology

[0002] At present, most of the cooling fans in the engine cooling system of construction machinery are driven by the engine crankshaft, so that the cooling air passes through the radiator to take away the heat of the cooling water. This mechanical driving method makes the cooling capacity of the fan only change with the engine speed, but cannot It changes automatically with the thermal state of the engine and the ambient temperature, so it will inevitably cause serious shortage of cooling capacity at low speed and heavy load, and excessive cooling at high speed and small and medium load, which not only affects the progress of the project, but also increases Reduce fuel consumption and increase operating costs; of course, some large-scale construction machinery adopts an independent heat dissipation system, that is, the speed of the cooling fan is controlled by electro-hydraulic drive. Relief valve, the system detects the engine coolant temperature by the coolant temperature sensor, and sends the coolant temperature signal to the micro control unit ECU. After processing the signal, the ECU sends a control signal to adjust the input of the pilot electromagnetic proportional relief valve. The current can change the adjustment pressure of the relief valve, and the fan speed can be changed by changing the flow rate of the hydraulic motor, so that the fan speed can be automatically adjusted with the temperature of the engine.

However, when the hydraulic oil and torque converter oil are concentrated together for heat dissipation, the limitations of this system are revealed.

If the engine temperature is high, but the hydraulic oil and torque converter oil temperature is low, according to the control method, the fan speed will increase, and the hydraulic oil temperature and torque converter oil temperature will increase slowly, which will affect the loader work efficiency

Images