High-pressure common rail system oil inlet metering valve flow control system and control method

Abstract

The invention discloses a high-pressure common rail system oil inlet metering valve flow control system and a control method. A flow calculation module, a variable structure PID module, a displacementcalculation module and a drive calculation module are in signal connection with a fuel oil temperature sensor, a rail pressure sensor, a rotating speed sensor, an accelerator opening degree sensor and a barometric pressure sensor which are arranged inside an electronic control diesel engine. The high-pressure common rail system oil inlet metering valve flow control system and the control method have the advantages that no special position sensor or flow sensor needs to be adopted, the existing fuel oil temperature sensor, the rail pressure sensor, the rotating speed sensor, the accelerator opening degree sensor and the barometric pressure sensor of the electronic control diesel engine are directly used as signal sources for oil inlet metering valve flow control, no existing system structure needs to be changed, convenience and feasibility are achieved, cost is low and implementation can be facilitated.

Description

technical field [0001] The invention relates to the technical field of a control strategy and a control method for oil inlet metering of a high-pressure common rail diesel engine, in particular to a flow control system and a control method for an oil inlet metering valve of a high pressure common rail system. Background technique [0002] The aggravation of environmental pollution and the increasing exposure of the energy crisis, the increasingly stringent emission regulations have promoted the development of electronically controlled diesel engines. Due to the precise and flexible adjustment of fuel injection pressure and fuel injection law, the high-pressure common rail system has become the development direction of the diesel engine fuel system in the future. The fuel inlet metering valve of the high-pressure common rail fuel supply pump is one of the important components of the high-pressure common rail system. The amount of fuel input makes the amount of fuel delivered...

AI Technical Summary

Problems solved by technology

In order to consider the cost, when the oil inlet metering valve of the high-pressure common rail oil supply pump does not include a position sensor or a flow sensor, it cannot calculate the flow accurately in real time

[0004] Existing control methods, such as patent application number CN201410366774.6, use the target value of the rail pressure as the input of the mathematical model, and the mathematical model outputs the operation of the injector at the target pressure value and the value of the fuel flow leaking out of the common rail as the flow rate The target value of the target value; the measured rail pressure is used as the input of the mathematical model to calculate the estimated value of the output flow; since the above only considers the influence of the rail pressure, although the implementation is simple, the accuracy of the model will be greatly reduced, resulting in the insignificant feedforward effect; When the flow target value and estimated value with a large error are used as the calculation of the subsequent drive control, such as the input of the nominal function, the stability and responsiveness of the rail pressure will be poor; because only the proportional integral (PI) controller is used to generate feedback Contribution item, when the engine operating condition changes suddenly, resulting in a sudden change in the rail pressure target value or the fuel injection target value, the responsiveness of the proportional integral (PI) controller may be insufficient, resulting in a large error between the target value and the actual value of the flow rate. ;Because only the adjustable parameter current of the metering valve is controlled, and the driving frequency is not controlled, in some engine operating conditions, such as multiple injections at certain speeds, it may cause rail pressure oscillations

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