HYDRAULIC SELF-ADAPTATION VARIABLE VALVE TIMING SYSTEM FOR DIESEL ENGINE AND CONTROL METHOD THEREFOR

摘要

The present invention discloses a self-adaptive hydraulic variable valve timing system for an internal combustion engine, comprising an oil pump provided on the power output shaft of the engine, wherein the oil pump is connected with a pressure regulating reversing valve, a main lube oil passage of the engine is connected with the oil pump via an oil inlet tube of the oil pump, and the pressure regulating reversing valve is further connected with an oil line and an oil return tube, and the oil line is connected with an oil supply main tube; the working medium of the system is the engine oil of the engine; the oil inlet tube of oil pump draws oil from the main lube oil passage of the engine; the oil pump is connected with the power output of the engine; the pressure regulating reversing valve regulates the pressure oil pressurized by the oil pump to a proper operating pressure and switches the flow direction thereof so as to complete the switch of the operating states of the system; and the oil supply main tube, the oil line and the working cylinders of the engine are connected via a self-adaptive pushrod length changing mechanism. Meanwhile, the present invention further discloses a control method for the aforesaid system. The variable valve timing system of the present invention may work in an operating mode or a non-operating mode according to the requirement, and it can not only meet the actual need of the engine but also serve the functions of energy conservation and environmental protection.