Design Of Automotive Engine Cylinder Head Valve Seat Pressing Control System

At present, some domestic engine manufacturers don’t monitor pressure anddisplacement, due to the technical limitation and cost restrict in the production processing line.PLC is chosen to control the pressure value by some manufacturers, in view of the productionline control system which PLC build monitor real-time differential, it cannot accuratelycontrol the pressure value, resulting in low precision of cylinder head valve seat pressingmachine. With the development of car in the industry, new products are studied and improvedby many manufacturers and research institute, which promote the development of technologyon the domestic cylinder head valve seat pressing machine rapidly. In order to meet therequirement of high precision, reliability production on pressing machine, the design ofcontrol system for cylinder head valve seat pressing machine has been completed in thisthesis.Based on the analysis of working principle for the automobile engine cylinder head valveseat pressing control system, the cylinder head valve seat pressing machine is researched as aobject, a control device is developed based on STM32f103VET6chip, which monitors,analyzes and processes for the pressure signal, in order to control the pressing processaccurately and improve the production efficiency of enterprises. This design usesSTM32f103VET6as the control chip which reduces the cost and ensures the stability of thesystem and uses RS232communication technology to finish data transmission of controlprocess, LCD touch screen is used as the user interface, realizes the setting of pressure anddisplacement value. The change curves of displacement and stress are displayed in thepressing process, monitors the change of pressure.The main research contents:(1) the design of controller, the controller uses STM32as the main control chip, the chipintegrates FLASH, RAM, TIMER, USART, and the chip has the advantages of small volume,low price. The controller mainly completes serial communication with AC servo motor andLCD touch screen, realizes the data transmission of control process. (2) the control of AC servo motor, both position model of the AC servo motor and themaximum torque limit are controlled by the STM32, for precision press of the press head. Theposition model of AC servo motor control pressure displacement, setting maximum torquelimits pressure of the press head.(3) the design of man-machine interface, operator inputs stress and displacement valueon the LCD touch screen interface, real-time changing signal of stress and displacement in thepressing process will be displayed in the LCD screen.(4) the design of pressure signal acquisition system, the strain type pressure sensoracquires pressure simulation signal of pressing head, obtains the real-time pressure changesby A/D conversion.