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Huayong Yang - One of the best experts on this subject based on the ideXlab platform.

  • realization of direct flow control with load Pressure compensation on a load control valve applied in overrunning load hydraulic systems
    Flow Measurement and Instrumentation, 2017
    Co-Authors: Liang Hu, Huayong Yang, Xin Fu
    Abstract:

    Abstract This paper presents the realization of direct proportional flow control with load Pressure compensation feature on a LCV (load control valve). Proportional flow control performance means the flow through the LCV is proportional to the Pilot Pressure in the control stroke. Proportional flow control decides the overrunning load lowering speed control performance of the whole system. The load Pressure compensation feature means when the load Pressure is too high, the flow of the LCV can be restricted about the maximum rated flow. The load Pressure compensation feature is important to the safety of the system. That is because large flow means undesired fast lowering speed, which will cause accident in applications, especially those large mass overrunning load systems. In this paper, the flow control performance was simulated and the parameter relationship of the orifices was derived, which is the base for the optimizing of the compensation orifice. In addition, load Pressure compensation feature was simulated and the compensation orifice size was optimized. Finally, an LCV built according to above methods was tested on a test rig. Experiment data validates the methods presented and the realization of direct flow control with load Pressure compensation feature gives guidance for the direct flow control performance development of other valves.

  • design of Pilot assisted load control valve for proportional flow control and fast opening performance based on dynamics modeling
    Sensors and Actuators A-physical, 2015
    Co-Authors: Haibo Xie, Jianbin Liu, Huayong Yang
    Abstract:

    Abstract This paper presents a flow control performance design method of Pilot-assisted load control valve (LCV) based on dynamics modeling. Good flow control performance has both static and dynamic aspects for an LCV. In static aspect, proportional flow control is required, which means the static flow through the valve can be proportionally controlled by Pilot Pressure. In dynamic aspect, fast opening performance is required, which means the desired flow can be fast provided but without overshoot when given a step Pilot Pressure. Good flow control performance of an LCV is the key to improve the system performance and to reduce the system complexity. In the method proposed by this paper, a static model of the static flow control performance based on hydraulic half bridge analysis was built to determine the area-displacement features of two key orifices to achieve proportional flow control. In addition, a dynamic model of the spool motions was provided to study the compensation orifice effect on the opening performance of the valve and further to determine the optimized orifice size. An actual LCV was developed according to above method. Tests were carried out both on a mobile crane and a test rig to validate its static and dynamic flow control performance, respectively. The good flow control performance of the valve in the tests indicates that the proposed method can provide theoretical guidance for Pilot-assisted LCV design.

Haibo Xie - One of the best experts on this subject based on the ideXlab platform.

  • design of Pilot assisted load control valve for proportional flow control and fast opening performance based on dynamics modeling
    Sensors and Actuators A-physical, 2015
    Co-Authors: Haibo Xie, Jianbin Liu, Huayong Yang
    Abstract:

    Abstract This paper presents a flow control performance design method of Pilot-assisted load control valve (LCV) based on dynamics modeling. Good flow control performance has both static and dynamic aspects for an LCV. In static aspect, proportional flow control is required, which means the static flow through the valve can be proportionally controlled by Pilot Pressure. In dynamic aspect, fast opening performance is required, which means the desired flow can be fast provided but without overshoot when given a step Pilot Pressure. Good flow control performance of an LCV is the key to improve the system performance and to reduce the system complexity. In the method proposed by this paper, a static model of the static flow control performance based on hydraulic half bridge analysis was built to determine the area-displacement features of two key orifices to achieve proportional flow control. In addition, a dynamic model of the spool motions was provided to study the compensation orifice effect on the opening performance of the valve and further to determine the optimized orifice size. An actual LCV was developed according to above method. Tests were carried out both on a mobile crane and a test rig to validate its static and dynamic flow control performance, respectively. The good flow control performance of the valve in the tests indicates that the proposed method can provide theoretical guidance for Pilot-assisted LCV design.

Greea Aaro - One of the best experts on this subject based on the ideXlab platform.

  • Emulsion Pressure Relief
    ScholarWorks@CWU, 2015
    Co-Authors: Greea Aaro
    Abstract:

    Over time the harsh outdoor environment wears away at asphalt surfaces. Asphalt emulsion is sprayed onto the surface to act as a sacrificial barrier. To pump this asphalt emulsion for spray application, an effective Pressure relief device must be incorporated. High Pressure is needed to achieve the desired spray pattern, but this same Pressure can cause components to fail in the presence of a Pressure spike. Hydraulically driven positive displacement pumps are used to pump the emulsion, so pinched hoses or a clog in the system can result in a severe Pressure spike. Due to the emulsions viscosity and abrasive additives, a direct relief device is not suitable for long term service. A remote activated Pressure relief device is needed to allow adequate spray Pressure and prevent system failure. The device is manufactured with off-the-shelf hydraulic and pneumatic parts bolted to a steel base plate. A Pilot Pressure is taken from the emulsion circuit and feeds a pneumatic cylinder that pulls a linearly actuated hydraulic valve, in turn, diverting the hydraulic flow to the reservoir instead of driving the pump. The pull of the cylinder is balanced by an adjustable spring to allow for different Pressure settings. After installing the Pressure relief device, Pressure was measured at different locations throughout the system. The emulsion Pressure relief device performed as engineered and the Pressure remained between 50 and 90 pounds per square inch

  • Emulsion Pump Pressure Relief
    Central Washington University, 2015
    Co-Authors: Greea Aaro
    Abstract:

    Over time the harsh outdoor environment wears away at asphalt surfaces. Asphalt emulsion is sprayed onto the surface to act as a sacrificial barrier. To pump this asphalt emulsion for spray application an effective Pressure relief device must be incorporated. High Pressure is needed to achieve the desired spray pattern, but this same Pressure can cause components to fail in the presence of a Pressure spike. Hydraulically driven positive displacement pumps are used to pump the emulsion, so a pinched hoses or a clog in the system results in a severe Pressure spike. Due to the emulsions viscosity and abrasive additives a direct relief device is not suitable for long term service. A remote activated Pressure relief device is needed to allow adequate spray Pressure and prevent system failure. The device is manufactured with off the shelf hydraulic and pneumatic parts bolted to a steel base plate. A Pilot Pressure is taken from the emulsion circuit and feeds a pneumatic cylinder that pulls a linearly actuated hydraulic valve, in turn diverting the hydraulic flow to the reservoir instead of driving the pump. The pull of the cylinder is balanced by an adjustable spring to allow for different Pressure settings. After installing the Pressure relief device Pressure was be measured at different locations throughout the system. The emulsion Pressure relief device performed an as engineered and the Pressure remained between 50 and 90 psi.https://digitalcommons.cwu.edu/cwu_met/1009/thumbnail.jp

Jianbin Liu - One of the best experts on this subject based on the ideXlab platform.

  • design of Pilot assisted load control valve for proportional flow control and fast opening performance based on dynamics modeling
    Sensors and Actuators A-physical, 2015
    Co-Authors: Haibo Xie, Jianbin Liu, Huayong Yang
    Abstract:

    Abstract This paper presents a flow control performance design method of Pilot-assisted load control valve (LCV) based on dynamics modeling. Good flow control performance has both static and dynamic aspects for an LCV. In static aspect, proportional flow control is required, which means the static flow through the valve can be proportionally controlled by Pilot Pressure. In dynamic aspect, fast opening performance is required, which means the desired flow can be fast provided but without overshoot when given a step Pilot Pressure. Good flow control performance of an LCV is the key to improve the system performance and to reduce the system complexity. In the method proposed by this paper, a static model of the static flow control performance based on hydraulic half bridge analysis was built to determine the area-displacement features of two key orifices to achieve proportional flow control. In addition, a dynamic model of the spool motions was provided to study the compensation orifice effect on the opening performance of the valve and further to determine the optimized orifice size. An actual LCV was developed according to above method. Tests were carried out both on a mobile crane and a test rig to validate its static and dynamic flow control performance, respectively. The good flow control performance of the valve in the tests indicates that the proposed method can provide theoretical guidance for Pilot-assisted LCV design.

Ming-hwei Perng - One of the best experts on this subject based on the ideXlab platform.

  • Nonlinear Dynamic Model of a Two-Stage Pressure Relief Valve for Designers
    Journal of Dynamic Systems Measurement and Control, 2001
    Co-Authors: Pei-sun Zung, Ming-hwei Perng
    Abstract:

    This paper presents a handy nonlinear dynamic model for the design of a two stage Pilot Pressure relief servo-valve. Previous surveys indicate that the performance of existing control valves has been limited by the lack of an accurate dynamic model. However, most of the existing dynamic models of Pressure relief valves are developed for the selection of a suitable valve for a hydraulic system, and assume model parameters which are not directly controllable during the manufacturing process. As a result, such models are less useful for a manufacturer eager to improve the performance of a Pressure valve. In contrast, model parameters in the present approach have been limited to dimensions measurable from the blue prints of the valve such that a specific design can be evaluated by simulation before actually manufacturing the valve. Moreover, the resultant model shows excellent agreement with experiments in a wide range of operating conditions.