Research On Servo Valve Nozzle Eyelet Flow Character Measurement System

Electro-hydraulic servo valve is the core component of servo system and nozzle is one important part of servo valve. The function of servo valve is influenced by the function of nozzle's small hole. But now, the measurement of the flow of servo valve nozzle is still stay in the low level of pressure adjusting and the data recording by hand. It is difficult to meet the production of high precision holes flow efficiency requirements.In this thesis, based on the study of the servo valve nozzle orifice pressure and flow characteristics, and according to the characteristics of nozzle measuring it achieves the automation of pressure controlling and multi-point measurement. And it also can achieve automatic matching. Compare with artificial measurement and matching, it greatly improves the efficiency and accuracy of the measurement and matching.First, it analyzes the influence of the holes flow factor in different sizes by discussing the formula of the rate of orifice flow, and study the principle of nozzle flow and pressure measurement and the methods of matching. It provides the foundation of the development of automatic measuring equipment.Then it describes the overall design of the measuring equipment and analyzes the structure and hydraulic system of the equipment. It also detailed describes the circuit of sensors. In pressure controlling systemic achieves automatic pressure controlling and it's steadily control by using "Pump-proportional relief valve" program. its controller is "PLVC",and it controlled by computer easily. This dissertation works out one set of new software system utilizing the C++ language at the Visual C++ 6.0 programming circumstances. From pressure controlling to the data collection and storage, it can be achieved by the program in small orifice measuring. And it reduces manual labor intensity and human error. The measurement results are handled by"SQL Server 2000" database storage which can handle the result easily.Finally, it tests and analyzes the performance of the measuring equipment in this thesis. Its result says the repeatability error is±3ml/min and the accuracy of pressure controlling is±0.03MPa.It can be say that all the indicators meet the design requirements and it can completely meet the needs of actual production.