The Research On Red Light Ranging Float Pneumoelectric Convertion Technology And Application

The measurement to the overlap of valve sool and valve sleeve of the electro-hydraulic servovalve is an important step in the machining of the servovalve. For pneumatic gauging possess a lot of merits, such as the resolution is high, can achieve non-contact measurement, can do special part of the measurement and less demanding on the measurement conditions, etc, we adopt pneumatic gauging to measure the overlap of the valve core & sleeve of the slide valve. Pneumatic gauging include pneumatic pressure measuring method and pneumatic flow measuring method, in principle, the relation between the measuring pressure of the pneumatic pressure measuring method and opening size of the nozzle is nonlinear, compared with it, pneumatic flow measuring method is linear, so pneumatic flow measuring method is our first choice. For pneumatic flow measurement application, the pressure loss caused by float-type pneumatic measuring instrument is constant relative to other flow sensors and the pressure is equal to the weight of the float, so it can be used to the precision measurement like the measurement of the overlap. but it just can rely on manual readings. In order to achieve pneumatic flow automation overlap measurement, we design float-type pneumatic measuring instrument based on the red lights sensor.Firstly, the text introduces the principle of flow type pneumatic measurement and the principle of float-type pneumatic measuring instrument, analyzes how to use red light range-finding sensors to realize the automation collection of the height of the float in the float-type pneumatic measuring instrument. It provides theory basis to the next step of design work.We transform an ordinary float-type pneumatic measuring instrument by adding a right lights sensor on it and design a suitable float for it through the theoretical calculation and the simulation with Fluent. At last, we do a series of experiments and by the experiments, its nonlinear error is less than the ordinary float-type pneumatic measuring instrument. So the whole instrument is feasible.The final purpose of designing the float-type pneumatic measuring instrument based on the red lights sensor is to measure the overlap of the valve core & sleeve of the slide valve, so we design the whole overlap testboard including mechanical fixture,electric circuit,gas circuit and the software to control the instrument. With the whole instrument we achieve the automation measurement .we test the overlap of a certain servo valve with this testboard, find that the measuring result is reasonable and the repeatability error is only one micrometer at most, so the result meets the demand.