| Single flow channel ER-valve and multi-flow channel ER-valve ,which realize high frequency switch control, used to control electrorheological (ER) fluid is developed in this paper based on request of the item'Principle and Key Technology Study on Piezoelectric/ER Mixing Extra-Precision Stepper Actuator'. Allocated-use circuit control system was designed. The performance of different ER-valve, whose structure is the main difference, are studied and developed though theory analysis, Fluent simulation and experimental testing. Allocated-use circuit control system was examined simultaneously.1. IntroductionThe item'Principle and Key Technology Study on Piezoelectric/ ER Mixing Extra-Precision Stepper Actuator'is put forward to a method ,which can solve response lag,liquid flowing backwards,low resolution and so on, by ERF (electrorheological fluid) valve, having simple structure,convenient controls processes easily and so on, instead of traditional hydraulic valve, The development trends of ER technology is summarized firstly in the paper. Finally, the research content of this paper was simply introduced.2. The theory and appliance of ER liquidFirstly, the basic knowledge of ERF is summarized, involving composition and characteristic of ERF. And then mechanism of ER effect, and Influencing Factors(involving magnitude of electric field, frequency of electric field, suspended particles, dispersed medium, mechanical properties, temperature, additive and so on) of ER effect are expatiate particularly. At last, the adaptability of ER effect to a project is summarized briefly, as well as the appliance pattern.3. Structuarl design and performance analysis of the ER valveThe influence of the ER valve to the actuation system was analyzed firstly. On this basis, the unsymmetrical single flow channel ER-valve was designed. Then, the structure of the unsymmetrical single flow channel ER-valve was proved to be reasonable. In order to solve the disadvantages of traditional multi-flow channel ER-valve, such as the difficulty in processing valve-body, the finite in increasing flow area, the defect in working principle, the multi-flow channel series-parallel ER-valve was designed. The multi-flow channel series-parallel ER-valve increase immensely flow area by changing the number of the channel. The static stopping point performance was raised by eccentricity adjustment. Importantly, The channel of the multi-flow channel series-parallel ER-valve was in series. The rationality of the multi-flow channel series-parallel ER-valve structure was proved. In the last, by the Fluent simulation analysis about variation in flow and distribution of pressure, the advantages of the unsymmetrical single flow channel ER-valve and the multi-flow channel series-parallel ER-valve were verified.4. The design of the sequential control systemThe sequential control system includes controlling circuit and controlling program. The rational time sequence control system was the condition of the accuracy stepping driving. The equivalent circuit of the ER-valve and working principle of the piezoelectric stack pump were firstly introduced in this chapter. Based on it, controlling circuit of the ER-valve and the piezoelectric stack pump was designed. Then, components of electric circuit were selected and the whole controlling circuit was established. In the last, according to the response time of the ER-valve and the piezoelectric stack pump, the time-delay program was compiled. This could increase the performance of the break over or stopping point. According to the needs of the driving system, the break service was designed, which could realize the stopping driving and changing the subsection number of the voltage exerted on piezoelectric stack pump. Based on the order of the execution components, the sequential control program was compiled.5. Experimental ResearchThe method of ERF which is confected and the experimental equipments are firstly introduced in this chapter. The main parameters of experimental equipments are introduced too. Then,The different experiment platforms for ER-valve are built according to different purpose. The static cut-off performance and the dynamic cut-off performance of the ER-valve were detected respectively. In the last, the curve graphs were drawn according to the date obtained in experiment and the experimental results were amplified based on these curve graphs. |
