scholarly journals Modeling and Dynamic Characteristics of a Novel High-Pressure and Large-Flow Water Hydraulic Proportional Valve

Machines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 37
Author(s):  
Heng Zhang ◽  
Yaoyao Liao ◽  
Ze Tao ◽  
Zisheng Lian ◽  
Ruihao Zhao

In the field of fully mechanized coal mining equipment, the hydraulic valve used in the hydraulic support is an on/off directional valve. There are many problems caused by the valve such as large pressure shock and discontinuous flow control. Therefore, a novel two-position three-way hydraulic proportional valve suitable for high-pressure and large-flow conditions is proposed to overcome the above problems. The novel valve utilizes a two-stage structure and the displacement follow-up principle is adopted between the pilot stage and the main stage to meet proportional control. In this paper, a simulation model of the novel proportional valve was established after a simplified analysis of the structural principle. Its reliability and the feasibility of the design were verified by the test results under different working conditions. Then, the step response characteristics of the proportional valve under different strokes were predicted and analyzed. Nonlinear characteristics were presented, and the closing time was shorter than the opening time because of the influence of nonlinear flow force. Under different ramp signals, the displacement of the main inlet spool was always approximately equal to the displacement of the pilot stage. Then, the motion relationship between the pilot stage and the main stage was studied, and the influence of the structural parameters on the stability was analyzed.

2020 ◽  
Vol 2020 (14) ◽  
pp. 908-913
Author(s):  
Zhen Zhang ◽  
Liang Liang ◽  
Xudong Wang ◽  
Daihua Wang

2021 ◽  
Vol 67 (5) ◽  
pp. 223-234
Author(s):  
Mingxing Han ◽  
Yinshui Liu ◽  
Yitao Liao ◽  
Shucai Wang

As the key control component of the water hydraulic systems, the water hydraulic proportional valve has a significant influence on the control performance of the systems. Due to the poor viscosity and lubricity of water, the valve spool resistance is large and non-linear. In this study, a novel fast-response water hydraulic proportional valve is presented. The actuator of the valve adopts a voice coil motor (VCM), which has the advantages of fast response, high control precision and small volume. In order to realize the fast control of the valve, a lever amplifier is designed to obtain enough actuation force. A detailed and precise non-linear mathematical model of the valve considering both the valve’s structural parameters and VCM electromagnetic characteristics is developed. A comprehensive performance simulation analysis has been carried out, mainly divided into an electromagnetic simulation, an analysis of the characteristics of the lever magnifier, and a dynamic performance simulation of the valve. The simulation results show that the adjusting time is about 28ms, and the maximum overshoot is about 5 %. The step response rise time is about 15 ms. The test rig of the valve and VCM have been built. The test results of the prototype show that the optimal stroke range of VCM is 4 mm to 15 mm. The maximum overshoot of the valve is around 10 %; the adjusting time is about 30 ms in the opening process and 35 ms in the closing process. The test results prove that the valve has good static and dynamic control performance.


Author(s):  
Mingxing Han ◽  
Yinshui Liu ◽  
Huaijiang Tan ◽  
Defa Wu

The large flow water hydraulic proportional cartridge valve is one of the most important components and also the technical difficulties in the high performance large-tonnage engineering machinery, such as the die casting machine. The structure and principle of the large flow water hydraulic proportional cartridge valve are presented in this paper. The valve utilizes a two-stage structure with the high performance proportional valves as the pilot stage and the cartridge poppet valve as the main stage to overcome the fundamental tradeoff between the flow capacity and dynamic characteristics. A detailed and precise nonlinear mathematical model of the cartridge valve considering both structural parameters and nonlinear factors (compressibility of water, leakage, friction, flow force, etc.) is established. And then MATLAB/Simulink software is employed to build the simulation model and the dynamic simulation is carried out. Compared with the simulation results of the valve with different design parameters, the static and dynamic characteristics of the proportional cartridge throttle valve have been analyzed. The impacts of the parameters on the performance of step-response have been studied. Finally, based on multi-objective optimization method, the optimal parameters of the cartridge valve have been obtained. The simulation results show that the performances have been significantly improved.


2008 ◽  
Vol 07 (01) ◽  
pp. 65-67
Author(s):  
CHANGPING ZOU ◽  
LI DU ◽  
XIANDE HUANG

A new type of six-bar swaying machine was put forward, which is an ingenious combination of plane multi-bar mechanism and high pressure oil cylinder. Preliminary analysis shows that this machine has many advantages, such as the torque produced by its unit weight, its small size, its light deadweight, etc. Thus it can be applied to situations that need swaying mechanism with low rotational speed and great torque. Firstly, the mechanism composition and working principle of the swaying machine were introduced. Secondly, parameterized modeling of the mechanism was carried out by utilizing software ADAMS. Then kinematic analysis and kinetic analysis were completed by using ADAMS. Finally, key dimensions were adjusted according to kinetic analysis. These tasks are believed to be beneficial to the development of the novel transmission.


1989 ◽  
Vol 28 (6) ◽  
pp. 763-765 ◽  
Author(s):  
Peter Neubold ◽  
Beatriz S. P. C. Della Vedova ◽  
Karl Wieghardt ◽  
Bernd Nuber ◽  
Johannes Weiss

2021 ◽  
Author(s):  
Ridwan Hossain ◽  
Rocky Taylor ◽  
Lorenzo Moro

Abstract During ice-structure interactions that are dominated by ice compressive failure, the majority of the ice loads are transmitted through localized contact regions known as high-pressure zones (hpzs). This paper presents a probabilistic modelling framework for dynamic ice-structure interaction based on the mechanics of hpzs. Individual hpzs are modelled as a nonlinear spring-damper system where the stiffness is modelled as a function of nominal strain, with the degree of softening depending on the average strain-rate. Both spalling and crushing failure mechanisms were assessed in the context of periodical sinusoidal response. For spall dominated failure, the model structure showed presence of frequency lock-in in the speed range of 100–125mm/s, beyond which the failure was found to be random in nature with lower amplitude of structural response. The amplitude was also found to be significantly influenced by structural parameters with structural damping having the highest contribution. For pure crushing, an estimated equilibrium layer thickness based on theoretical calculations also showed presence of frequency lock-in. The work highlights the importance of understanding the interplay between these mechanisms, as well as the role of ice conditions and structural parameters on the processes that dominate an interaction.


Author(s):  
Xin Ma ◽  
Zhongpei Ning ◽  
Honggang Chen ◽  
Jinyang Zheng

Ultra-High Pressure Vessel (UHPV) with self-protective Flat Steel Ribbons (FSR) wound and Tooth-Locked Quick-Actuating (TLQA) end closure is a new type of vessel developed in recent years. When the structural parameters of its TLQA and Buttress Thread (BT) end closure are determined using the ordinary engineering design method, Design by Analysis (DBA) shows that the requirement on fatigue life of this unique UHPV could hardly be satisfied. To solve the above problem, an integrated FE modeling method has been proposed in this paper. To investigate the fatigue life of TLQA and BT end closures of a full-scale unique UHPV, a three-dimensional (3-D) Finite Element (FE) solid model and a two-dimensional (2-D) FE axisymmetric model are built in FE software ANSYS, respectively., Nonlinear FE analysis and orthogonal testing are both conducted to obtain the optimum structure strength, in which the peak stress in the TLQA or BT end closure of the unique UHPV is taken as an optimal target. The important parameters, such as root structure of teeth, contact pressure between the pre-stressed collar and the cylinder end, the knuckle radius, the buttress thread profile and the local structure of the cylinder, are optimized. As a result, both the stress distribution at the root of teeth and the axial load carried by each thread are improved. Therefore, the load-carrying capacity of the end closure has been reinforced and the fatigue life of unique UHPV has been extended.


Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6831
Author(s):  
Tianming Li ◽  
Junyu Fan ◽  
Zhuoran Wang ◽  
Hanhan Qi ◽  
Yan Su ◽  
...  

The 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) is a newly energetic material with an excellent performance and low sensitivity and has attracted considerable attention. On the basis of the dispersion-corrected density functional theory (DFT-D), the high-pressure responses of vibrational properties, in conjunction with structural properties, are used to understand its intermolecular interactions and anisotropic properties under hydrostatic and uniaxial compressions. At ambient and pressure conditions, the DFT-D scheme could reasonably describe the structural parameters of LLM-105. The hydrogen bond network, resembling a parallelogram shape, links two adjacent molecules and contributes to the structure stability under hydrostatic compression. The anisotropy of LLM-105 is pronounced, especially for Raman spectra under uniaxial compression. Specifically, the red-shifts of modes are obtained for [100] and [010] compressions, which are caused by the pressure-induced enhance of the strength of the hydrogen bonds. Importantly, coupling modes and discontinuous Raman shifts are observed along [010] and [001] compressions, which are related to the intramolecular vibrational redistribution and possible structural transformations under uniaxial compressions. Overall, the detailed knowledge of the high-pressure responses of LLM-105 is established from the atomistic level. Uniaxial compression responses provide useful insights for realistic shock conditions.


2021 ◽  
Vol 143 (7) ◽  
Author(s):  
He Wang ◽  
Xiaohu Wang ◽  
Jiahai Huang ◽  
Long Quan

Abstract The present research concentrates on the performance improvement of a two-stage proportional valve with internal hydraulic position feedback which is named as the Valvistor valve. In this paper, the performance constraint of this valve is identified and a novel electronic closed-loop control strategy with an integral-separation fuzzy proportional-integral-derivative controller is proposed to improve the valve performance, including the static characteristics and the dynamic characteristics. The results show that in the Valvistor valve, the comparison point and the feedback loop for the internal hydraulic position feedback is only in the main stage, while the input is in the pilot stage. This leads to the poor performance of this valve. The control strategy is very effective and the performance of the Valvistor valve is improved. With the control strategy, the error of the poppet displacement is reduced from 4.9% to 2.1% by adjusting the spool displacement in the pilot stage in real-time and the flow error is reduced from 5.3% to 2.3%. The dead zone of the poppet displacement and the flow is eliminated. The hysteresis is reduced from 5.3% to 2.6% and the linearity is improved. The overshoot is reduced from 0.06 to 0.02 mm and the settling time is reduced from 0.5 to 0.2 s. Moreover, the bandwidth is increased from 8 to 16 Hz.


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