scholarly journals Analysis and optimization of the pilot stage of jet pipe servo valve

Author(s):  
Ying Zhang
Keyword(s):  
2010 ◽  
Vol 145 ◽  
pp. 410-413 ◽  
Author(s):  
Jing Wang ◽  
He Yong Han ◽  
Qing Xue Huang ◽  
Jun Wang

The reasons for impact pressure are obtained by the research the hydraulic system of Hydraulic Rolling-Cut Shear. The impact pressure of hydraulic system is divided into direct impact and indirect impact. Based on analyzing the actual situation the measures should be taken to reduce the impact pressure when design hydraulic system. The suitable length of pipeline can improve the performance of the hydraulic system because the length is important for the impact pressure. The accumulator can absorb impact pressure and improve the work situation of servo valve. Therefore, the suitable accumulators should be set in the hydraulic system. The study provides theory basis for the pipe design of large hydraulic servo system.


Author(s):  
Shuai Wu ◽  
Richard Burton ◽  
Zongxia Jiao ◽  
Juntao Yu ◽  
Rongjie Kang

This paper considers the feasibility of a new type of voice coil motor direct drive flow control servo valve. The proposed servo valve controls the flow rate using only a direct measurement of the spool position. A neural network is used to estimate the flow rate based on the spool position, velocity and coil current. The estimated flow rate is fed back to a closed loop controller. The feasibility of the concept is established using simulation techniques only at this point. All results are validated by computer co-simulation using AMESim and Simulink. A simulated model of a VCM-DDV (Voice Coil Motor-Direct Drive Valve) and hydraulic test circuit are built in an AMESim environment. A virtual digital controller is developed in a Simulink environment in which the feedback signals are received from the AMESim model; the controller outputs are sent to the VCM-DDV model in AMESim (by interfacing between these two simulation packages). A LQR (Linear Quadratic Regulator) state feedback and nonlinear compensator controller for spool position tracking is considered as this is the first step for flow control. A flow rate control loop is subsequently included via a neural network flow rate estimator. Simulation results show that this method could control the flow rate to an acceptable degree of precision, but only at low frequencies. This kind of valve can find usage in open loop hydraulic velocity control in many industrial applications.


2013 ◽  
Vol 88 ◽  
pp. 590-598 ◽  
Author(s):  
Songjing Li ◽  
Nay Zar Aung ◽  
Shengzhuo Zhang ◽  
Junzhang Cao ◽  
Xinzhi Xue

2021 ◽  
Vol 3 (144) ◽  
pp. 116-121
Author(s):  
Nikita A. Pen’kov ◽  
◽  
Oleg A. Sidorkin ◽  
Sergey Yu. Zhachkin ◽  
Anatoliy I. Zavrazhnov ◽  
...  

One of the most common reasons for the failure of hydraulic drive systems for agricultural machinery is the working fluid leak in the contact points of the rubbing surfaces of hydraulic blocks. The application of composite coatings based on chromium on the contacting surfaces allows you to restore the defect in the shape of the part caused by wear, as well as reduce the friction coefficient at the contact points, which positively affects the wear resistance of the part. (Research purpose) The research purpose is in developing technologies for restoring parts of agricultural machinery with predetermined operational properties. (Materials and methods) A servo valve, widely used in various hydraulic drive systems, was used as an experimental sample. Its working surface was restored with a composite coating applied by electroplating to increase the wear resistance of the servo valve. (Results and discussion) Authors conducted a series of direct measurements under the same conditions. The article presents the de-pendence of the microhardness on the parameters of the electrolysis mode and the thickness of the applied coating using the method of least squares. The nature of changes in microhardness and residual stresses was evaluated to determine the quality of the coatings. The article presents the dependences of these indicators on various control parameters (current density, temperature, tool pressure). The equations of the regression of the main qualitative and accuracy characteristics of the parts were deter-mined using the apparatus of the theory of experimental planning. (Conclusions) The article presents the method for predicting coatings of a given quality, taking into ac-count the influence of the current density and the temperature of the electrolyte during electrolysis on the nature of the precipitation obtained. The influence of the tool pressure on the depth of deformation of the formed layers was estimated. This approach allows us to evaluate the nature of the stress distribution in the formed coating and the quality of the restored parts.


2017 ◽  
Vol 55 (9) ◽  
pp. 1405-1429 ◽  
Author(s):  
Van Tan Vu ◽  
Olivier Sename ◽  
Luc Dugard ◽  
Peter Gaspar

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