Research On Submicron Precise Grinding Device For Servo Valve Spool Throttling And Working Edge

In the manufacturing process of electrohydraulic servo valve, the overlap value grinding of spool and valve sleeve is the key process in servo valve manufacturing process. Overlap value grinding process is actually to repeat process of measurement and actual grinding of valve spool, until meeting the designed requirements. The grinding accuracy is directly related to the result of the servo valve grinding. At present servo valve’s overlap value grinding is mainly conducted on Studer S20 grinding machine. T he problems existing in the current method include human judgment for tool clamping error, objective and strong interference, low machining efficiency and precision of the grating ruler can no longer meet the requirements of grinding. The main research goa l of this dissertation is based on the acoustic emission technology and the theory of micro feed technology to develop precision grinding device that can be used for grinding throttling and working edge of spool. This device will reach the sub-micron precision to solve the above problems.This dissertation analyzes the current tool problems aimed at grinding machine, and puts forward the method by using acoustic emission technology and driving the hand wheel by motor to achieve the automatic tool clamping, using piezoelectric ceramic to achieve the micro feed as the overall design scheme. It identifies the part of the whole device, makes the subject clear, which included mechanical system, electrical system, the console and control software, the error analysis, etc. In the other hand, it analyzes the key technology when developing this device.Then this dissertation introduces the overall device both in each part of hardware and software. In the part of design of mechanical system, the improvement design of micro feeding system includes micro driving morse’s taper and the sliding tailstock, designing the structure of the micro feed handwheel driven by the motor with automatically tool clamping. In electrical aspect, according to the functions of all parts of t he overall system, the circuit diagram is designed and device console is built. And in software’s aspect, according to the whole grinding process, this dissertation uses LABVIEW graphical programming way to write the grinding control software of the system.Transporting the designed precision grinding equipment to the processing site, it’s installation and debugging are done in S20 grinder to guarantee the mechanical error of morse’s taper, after that, analyzing the displacement error of piezoelectric ceramic feed, then finishing the acoustic emission of cutter error test experiment, through the experiment, finding the right judgment tool clamping point, controlling cutter error in the allowed range, after the overall error analysis and validation. At last, this dissertation process servo valve spool, measures machined part of overlap value and validate the conclusion of this topic.