1, high pressure pump

The supply of high-pressure oil pump design criteria must be guaranteed in any circumstances, the diesel engine fuel injection quantity and control of oil and demand, and to accelerate the start-up and the demand for oil changes. The injection pressure in the common rail systems in the fuel injection process have nothing to do, and the injection timing was no high-pressure pumps from the cam to ensure that, the high pressure pump oil pressure according to the peak torque cam minimum, the smallest and most contact stress tolerance Mill design principles to the design of the cam.

Bosch companies from diesel-driven triplex radial piston pump to generate up to 135 Mpa pressure. In each of the high-pressure pump oil pressure unit used in a number of oil pressure cam to reduce peak torque to the traditional high-pressure pumps 1 / 9, also load more evenly, and reduce operating noise. The high-pressure common-rail system in the cavity pressure control through the cavity of the common rail fuel in China to achieve the release, in order to minimize power loss in the fuel injection quantity is smaller, will be closed triplex radial column Cypriot pump oil pressure in one unit to reduce supply.

Denso Corp., introduced a three-line role cam to generate high-pressure pump, as shown in Figure 2. The high-pressure fuel pumps on the low-pressure control used to control fuel oil into effective method.

A plunger down, control valve opened, the low pressure fuel control valve plunger cavity flows;

B plunger up, but not yet in the control valve electricity, in the open state, low fuel by the return of low pressure control valve cavity;

C reach of regular supply, the control valve electricity, closed, returning Circuit was cut, and the plunger cavity compressed fuel, fuel oil, as a high-pressure valve oil into the orbit. Use control valve closing time of the different control access to the high-pressure fuel oil track of how much control high-pressure oil to achieve the purpose of rail pressure;

D-cam or a maximum after the plunger into the fall trip, reducing the pressure on the plunger cavity, filling valve closed, and stop oil supply, the control valve then stop electricity, in the open state, low fuel into the plunger cavity to the next a cycle.

The method of high-pressure pumps do not produce additional power consumption, but the need to identify the control pulse width and pulse control and high-pressure pump cam phase relationships, the control system is rather complicated.