Separation Based On The Throttle - The Interdiction Function Vacuum Failure Breaker Structure And Test Research

In pneumatic automatic vacuum adsorption system, vacuum ejector is used as local vacuum generation device. Usually, a single vacuum generator is used with multiple vacuum suckers. When one or several suckers have air leakage on contact surfaces, the whole vacuum system will work abnormally. At present, the prototype facility of membrane isolating valve is being researched. But there are some problems with the structure. And the dynamic displacement of the membrane is difficult to measure, so that the relationship between the structure parameters and the dynamic response of the isolating valve can't be recognized. These problems have influenced the structure further improvement and product forming. This paper solve these problems starting with the separation of the throttle channel and the flow isolating function, the membrane structure improvement and the displacement measurement by using non-contact method. The main work and achievements are as follows:(1)The membrane of the original isolating valve has two functions-throttle and isolating, so the structure parameters of the membrane are hard to match and the fatigue failure is occurred because of the hole-opening. Therefore, the throttle of the base opening and isolating of the membrane structure, which has separated functions, is put forward. In this way, the throttle opening and the structure parameters of the membrane can be designed respectively. Also, the fatigue failure of the membrane is hardly occurred. (2)The stiffness and sensitivity of the flat diaphragm can't simultaneously satisfy and this has influenced the dynamic characteristics of the isolating valve. So the technical scheme using corrugated diaphragm instead of the flat diaphragm is proposed. The influence of flow structure parameters on the performance of the membrane is studied by using finite element method and the experiments. The membrane, which both has good stiffness and sensitivity is designed. (3)To analyze the performance and optimize the structure parameters of the system, the mathematical model of the vacuum adsorption system is founded. Then, the working characteristics of the system are analyzed by simulation. And this lays a foundation for the parameter optimization and the further experiments. (4)The dynamic displacement of the membrane of the isolating valve is hardly to obtain with the direct measurement method, so the relationship between structure parameters and the dynamic response of the isolating valve can't be recognized. To solve this problem, it's put forward to measure the dynamic displacement with laser non-contact method. A simulation vessel is designed with the clear glass as cover. Then the dynamic displacement of the membrane is measured by the laser displacement sensor. This provides the experimental basis on the further improvement and parameter optimization of the isolating valve.The performance experiments show that the isolating valve with corrugated diaphragm can reliably isolate the leakage branch circuit. The final vacuum can reach 95kPa. Compared with the 93kPa of the principle prototype, it has slightly improvement. The isolating time is less than 0.62s. Compared with the 1.8s of the principle prototype, it decreases by 65.6%. The response time delay rata is less than 10.45%. Compared with the 17.3% of the principle prototype, it decreases by 6.85%. The critical isolating flow is about 6.42L/min, less than the 21.5L/min of the principle prototype, it decreases by 70.1%. These show that the study and improvement have obvious effect.