Research On Measurement Of Ring Groove Type Large-flow Spool Valve And Evaluation Of Static Characteristics

In the aerospace field,servo valves are required to have small size and high power.In order to meet this requirement,a scientific research institute uses an ring groove type spool valve in Servo valve because the power amplification stage is design for large flow gain.The ring groove type slide valve has the advantages of good linearity of flow gain and large rated flow rate;however,the inner ring groove of the sleeve valve needs to adopt the milling processing mode with ultra high precision.After the inner ring groove of the valve sleeve is processed,it is required to perform grinding processing with the spool valve shoulder so that the throttling control performance of the valve port meets the requirements.The spool valve grinding is the last process of the slide valve machining.After the completation of the grinding,it is forward to the servo valve assembly shop for assembling.This thesis makes a deep study on the detection and evaluation methods of slide valve performance during the grinding process of the ring groove slide valve.The static characteristic equation of the slide valve is deduced according to the size of the edge of the slide valve.The relationship between the no-load flow characteristics,pressure characteristics and static consumption characteristics of the slide valve is deeply analyzed.FLUENT simulation analysis was conducted on the valve port flow characteristics,and the relationship between valve port flow,valve opening,and valve port geometry was studied.According to the analysis of the static characteristics of the slide valve,the static performance of the slide valve after grinding is evaluated in conjunction with the processing requirements of the servo valve.It is determined that the processing evaluation index of the slide valve includes the overlap amount and the numerical requirements of the characteristic points related to the static characteristics.According to the definitions of the overlap and static characteristics of the slide valve,the measuring principle of overlap value and static characteristics was studied respectively.Based on the measuring principle,a comprehensive testing circuit was designed with the determination of switching that can test the overlap value and static characteristics of the slide valve.ball valve control method was adopted for the oil circuit testing.A test system was designed that can detect the amount of overlap of the slide valve and evaluate the static characteristics of the slide valve.Special fixtures required for the test process are designed to realize the slide valve clamping and spool valve displacement.According to the characteristics of the large flow rate of the slide valve,an oil source is designed to meets the detection requirements,the hardware system was designed to release data acquisition and control instructions for the inspection process realization.The software system was designed for the test function.The test system was subsequently assembled and debugged,including sensor calibration and software test system changes.Finally,the test bench is completed by assembling and commissioning to test the ring groove slide valve specimens.Including overlap measurement test,system accuracy and repeatability;static performance test,performance of the slide valve no-load flow curve,pressure curve and the test performance of static consumption curve.Taking multiple measurements result into account,the selected feature points are used to test for repeatability of test performance.