Digital Control Function Variable Pump Axial Piston

Swash plate axial piston variable displacement pump is widely used inengineering machinery and injection molding machine. Energy saving, lownoise and electro-hydraulic proportional technology have become to animportant development direction of the axial piston variable displacement pump.However, the key technology of axial piston variable displacement pump is stillmonopolized by large foreign companies. The domestic research andmanufacturing are still remaining in the initial development phase. The defectsof the piston pump such as noise, poor-stability, slow response, short life spanand low-reliability are mainly due to the technological gap. Therefore, it'sabsolutely necessary to improve the international competitiveness of ourhydraulic components by means of carrying out the technology analysis of axialpiston variable displacement pump and it will also bring us great economicsignificance, social significance and engineering significance.1. As variable pump used in the injection molding machines requires betterperformance on energy-saving and the stability of the system, it has greatsignificance to study the stability of pressure control and flow rate control ofthe electro-hydraulic proportional axial piston variable displacement pumpunder variable operating conditions.2. Analysis of variable displacement mechanism of axial piston pump.According to the schematic of piston variable pump, the mathematical modelwill be built and the key factors affecting the dynamic characteristics of pressureand flow rate will be analyzed. The relevant parameters of the pump will beadjusted in simulation station in order to improve the system performance and toreduce the pressure and flow rate fluctuation which is caused by thelow-instability of the swash plate.3. Digital control multi-function axial piston variable displacement pump,the variables agencies of which is manipulated by power-mechanicalconversion and proportional valve, is based on the original variable pump A4VSO added electro-hydraulic proportional valve and a variety of sensordevices. This will not only simplify the construction of the pump and alsorealize the stability of the system by means of changing the control policy underdifferent working conditions.4. The corresponding models have been selected according to theperformance requirements of the A4VSO variable displacement pump and thecharacteristics of the servo proportional valve and sensor requirements. Themathematical models have been established according to the control principlefor pressure control, flow rate control, power control and composite control ofthe variable displacement piston pump.5. In this paper, the minimum controller is designed with PID control mode.The characteristics of the system under variety of conditions including pressurecontrol,flow rate control, power control, compound control and transform ofcontrol mode have been analyzed in the MATLAB/SIMULINK simulationenvironment. The parameters of the controller have been defined and thepurpose of steady-state switching and multi-function variable results has alwaysbeen achieved.6. Controller module of variable displacement pump has been transformedto source code which has characteristics of readable, high efficiency and betterreal-time by the MATLAB/RTW based on the SIMULINK simulation. Thisrapid development methods reduce costs, save a lot of programming time andimprove the speed of product development greatly.