Performance of Proportional Flow Valve With Pilot Pressure Drop—Spool Opening Compensation

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Jiahai Huang ◽  
Jiangjiao Dai ◽  
Long Quan ◽  
Yuan Lan
Keyword(s):  
Pressure Drop ◽  
Flow Control ◽  
Pressure Sensors ◽  
Control Valve ◽  
Input Voltage ◽  
Analytical Models ◽  
Main Stage ◽  
Flow Control Valve ◽  
Proportional Flow ◽  
Pilot Valve

Flow control valves are extensively used to control the motion of hydraulic actuators in industry. In this paper, a two-stage proportional flow control valve with pilot digital pressure compensator is presented. The proposed valve is composed of two pressure sensors, a proportional pilot valve, a Valvistor poppet valve (main stage), and an electronic controller. The pressure drop across the pilot valve metering orifice is detected by two pressure sensors and fed into the controller which changes the pilot valve input voltage to compensate pressure influence on the outlet flow. The presented valve is investigated theoretically by simplified analytical models as well as numerical methods and also evaluated experimentally. The results show that the proposed scheme is feasible. It has a reasonable static performance and an acceptable dynamic characteristic for low bandwidth disturbances. The flow force on the Valvistor poppet should be estimated and considered in the controller design.

Design and Analysis of a Flow-Control Valve With Controllable Pressure Compensation Capability for Mobile Machinery

2021 ◽  
Author(s):  
Bo Wang ◽  
Yunwei Li ◽  
Long Quan ◽  
Lianpeng Xia
Keyword(s):  
Pressure Drop ◽  
Flow Control ◽  
Pressure Difference ◽  
Control Valve ◽  
Flow Control Valve ◽  
Continuous Control ◽  
Small Flow ◽  
Pressure Compensation ◽  
Force Compensation ◽  
Control Accuracy

Abstract There are the problems in the traditional pressure-compensation flow-control valve, such as low flow control accuracy, small flow control difficulty, and limited flow range. For this, a method of continuous control pressure drop Δprated (i.e. the pressure drop across the main throttling orifice) to control flow-control valve flow is proposed. The precise control of small flow is realized by reducing the pressure drop Δprated and the flow range is amplified by increasing pressure drop Δprated. At the same time, it can also compensate the flow force to improve the flow control accuracy by regulating the pressure drop Δprated. In the research, the flow-control valve with controllable pressure compensation capability (FVCP) was designed firstly and theoretically analyzed. Then the sub-model model of PPRV and the joint simulation model of the FVCP were established and verified through experiments. Finally, the continuous control characteristics of pressure drop Δprated, the flow characteristics, and flow force compensation were studied. The research results demonstrate that, compared with the traditional flow-control valve, the designed FVCP can adjust the compensation pressure difference in the range of 0∼3.4 MPa in real-time. And the flow rate can be altered within the range of 44%∼136% of the rated flow. By adjusting the compensation pressure difference to compensate the flow force, the flow control accuracy of the multi-way valve is improved, and the flow force compensation effect is obvious.

Proportional Flow Control Valve for Construction Vehicle

2019 ◽  
Author(s):  
So-Nam Yun ◽  
Yang-Lae Lee ◽  
Haroon Ahmad Khan ◽  
Chang-Nam Kang ◽  
Young-Bog Ham ◽  
...  
Keyword(s):  
Flow Control ◽  
Control Valve ◽  
Flow Control Valve ◽  
Proportional Flow

Analysis and Modification of the Design of Fluid Power Control System for the Improvement of Product Quality

2013 ◽  
Author(s):  
Tahany W. Sadak ◽  
Taha E. Mkawee
Keyword(s):  
Flow Control ◽  
Flow Rate ◽  
System Performance ◽  
Dynamic Performance ◽  
Control Valve ◽  
Operating Conditions ◽  
Flow Control Valve ◽  
Supply Pressure ◽  
System Designs ◽  
Proportional Flow

This research investigation is focused on providing system performance under different operating conditions, with special focus on variations in the supply pressure. The investigations have been carried out for different system designs. The analysis of the results introduces the effect of system designs on its static and dynamic performance. Also, the investigations provide the effect of variations of system operating conditions and load value. A hydraulic system has been designed with variable velocity, pressure and load. The detailed examination has been carried out on a system that consists of a hydraulic power supply unit, control valves (pressure control valve, flow control valve, throttle valve and directional control valve). We have investigated the effect of adding a flow control valve (FCV) in the chosen circuit and also replacing the FCV with a proportional flow control valve (PFCV). In order to study the effect of this valve on system performance we examine the role of change of operating conditions and loading values on the system performance. Thus the displacement and speed of the piston of the hydraulic cylinder has been experimented under different values of supply pressure, flow rate, and load. We make this investigation to develop the performance evaluation by replacing the (FCV) by proportional flow control valve (PFCV) via position control so that one can achieve the static and dynamic performance of the system more accurate. Apparent improvement in flow rate ranges from 8% to 29.5% and dynamic response from 30 to 64%. The results reveal that this methodology allows one to achieve high quality of the product.

Characteristics Analysis of Proportional Control Valve on Vane Damp

2014 ◽  
Vol 541-542 ◽  
pp. 1266-1270
Author(s):  
Wen Rui Wang ◽  
Yue Lei Yin
Keyword(s):  
Flow Control ◽  
Control Valve ◽  
Flow Control Valve ◽  
Proportional Control ◽  
Damping Characteristics ◽  
Characteristics Analysis ◽  
Execution Unit ◽  
Relationship Of ◽  
The Relationship ◽  
Proportional Flow

The proportional flow control valve is not only one of the key competent of vane damp,but also the execution unit of shock absorber damping force's regulation .The proportional flow control valves self-designed will combine the structural design of proportional control valve and crate CFD model . The thesis analyzes its distribution of flow field by CFD and acquires experimental validation .It analyzes dynamic characteristics and determine the relationship of flow and opening and drive current. The proportional control valve test verifies the correctness, finally. It is basis for analyzing of damping characteristics about vane damp, which can be used other proportional control valve CFD study.

Performance of a flow control valve with pilot switching valve

2017 ◽  
Vol 232 (2) ◽  
pp. 178-194 ◽  
Author(s):  
Xiaoyan Xiong ◽  
Jiahai Huang
Keyword(s):  
Flow Control ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Control Valve ◽  
Duty Ratio ◽  
Main Stage ◽  
Flow Control Valve ◽  
Average Pressure ◽  
Switching Valve ◽  
Outlet Flow

In digital fluid power, fast switching valve is a potential digital hydraulic component because of less throttling loss, reliability, low price, and so on. But its outlet flow is usually small and discontinuous. In this article, a two-stage proportional flow control valve is presented, in which the main stage is a flow amplifying valve, and the pilot stage consists of several switching valves with pulse width modulation control strategy. Peak and hold technique is adopted to improve the dynamic performance of the pilot stage. Benefits of the proposed configuration are continuous outlet flow and large flow capacity. The valve performance is investigated by theoretical analysis, simulation, and test. It is shown that both poppet displacement and outlet flow fluctuate around a stable value because of the discontinuous pilot flow, but the average outlet flow as well as poppet displacement of the main stage can be approximately proportionally regulated by changing pulse width modulation duty ratio. Average outlet flow of the main stage is an amplification of that of pilot stage. Increasing the average pressure drop not only increases outlet flow but also increases the severity of flow pulsations because pressure fluctuation becomes more serious as the average pressure difference increases. In theory, higher carrier frequency leads to smoother outflow; however, tested outflow profile of the proposed valve at 50 Hz is not significantly smoother than that at 30 Hz. This phenomenon may be due to the asynchrony of the four switching valves and the pressure fluctuations during the testing process.

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