The Research And Design Of Control System For DP80-3 Diaphragm Pumps With Three Cylinder And Oneleacting

Since the 70s of last century ,as the rapid development of slurry transportation equipment, the application of diaphragm has been increasingly common in mining, power plants, metallurgy, petroleum,chemical and other industries. In current, most of the traditional diaphragm pump driven by a conventional mechanical crank slider mechanism, which makes the pump flow pulsation,vibration and noise greater, large volume and high manufacturing costs. Therefore, a cost-effective new power port instead of the traditional mechanical power port has become the trend of diaphragm pump in the future.The study of this subject was based on the current conventional diaphragm pumps to carry out analysis and design from the power port of DP80-3 type diaphragm, find and solve the problems on the traditional diaphragm pump. Designed diaphragm pump power end hydraulic system, it provides a theoretical reference for the study of hydraulic diaphragm pumps.The subject design a load sensing hydraulic power end by analyzing the current commonly used cylinder speed control loop,mainly consists of three single-rod hydraulic cylinders and a main variable pump. There are many advantanges, such as lower throttle loss, the structure more simple, the one-time manufacturing cost low, easy to install and mainten, smaller footprint, competitive market and so on. At the same time, we select the required specifications and dimensions of hydraulic components, established a linear mathematical model of proportional directional valve controlled hydraulic cylinder and electro-hydraulic servo valve control variable pump. In the last, we complete the theoretical study and MATLAB / Simulink simulation to the speed control of hydraulic cylinder and the variable pump pressure control pump of system, the simulation results are in good agreement with expected . This subject is also depth study the speed curve of the hydraulic cylinder in diaphragm pump working process. Studies have shown that the three hydraulic cylinders only by maintaining 120 degphase angle and accordance with the provisions of the velocity curve working ,the diaphragm pumps can effectively reduce the flow pulsation, vibration and noise. Hardware and software of the hydraulic diaphragm pump power end control system also be studied in the subject, selected the required PLC and the corresponding hardware modules in the control process and study the way of speed curve of the hydraulic cylinder stored in the PLC controller, ultimately determine the principle that speed curve be stored at time 20ms variable address in the PLC user memory. Hydraulic cylinder working speed, position and angular displacement measured by Incremental Rotary Encoder, with high accuracy, high resolution, reliability and do not need A/D conversion characteristics, and the realization of a sensor to measure a variety of variables.