Numerical research on the characteristics of variable annular gap cushioning for high speed hydraulic cylinder

2019 ◽  
Author(s):  
Fangli Lou ◽  
Songlin Nie ◽  
Fanglong Yin ◽  
Guotao Jia ◽  
Anbin Xu ◽  
...  
Keyword(s):  
High Speed ◽  
Hydraulic Cylinder ◽  
Annular Gap ◽  
Numerical Research

scholarly journals Experimental Technique for Dynamic Fragmentation of Liquid-Driving Expanding Ring

2018 ◽  
Vol 183 ◽  
pp. 02034 ◽  
Author(s):  
Jia Zhang ◽  
Yuxuan Zheng ◽  
Fenghua Zhou ◽  
Jun Liu
Keyword(s):  
High Speed ◽  
Fracture Morphology ◽  
Hydraulic Cylinder ◽  
Low Velocity ◽  
Ductile Materials ◽  
Dynamic Fragmentation ◽  
Circumferential Tensile Stress ◽  
Metallic Ring ◽  
Pressure Bar ◽  
Experimental Technology

Expanding ring experiment is an important method for dynamic fragmentation of solid under 1D tensile loading. Based on the split Hokinson pressure bar (SHPB), a liquid-driving experimental technology was developed for conducting expanding ring tests. The loading fixture includes a hydraulic cylinder filled with water, which is pushed by a piston connected to the input bar. As the water is driven, it expands the metallic ring specimen in the radial direction. The approximately incompressible property of the water makes it possible to drive the specimen in very high radial velocity by low velocity movement of piston, according to the large sectional area ratio of the cylinder to specimen. Using liquid-driving expanding ring device, 1060 aluminum rings (ductile materials)/PMMA rings (brittle materials) were fragmented and the fragments were recovered. Impact deformation of free-flying fragments was avoided through the use of “sample soft-capture” technology. The fragmentation process was observable by high speed camera through modifying the driving direction of the water. From the observations of the fracture morphology and the residual internal cracks of the recovered fragments, it is concluded that the fracture of the rings is caused by the circumferential tensile stress.

Numerical research of perspective technical solutions for thermal protection of surfaces flowed by high-speed dispersed flows

2019 ◽  
Author(s):  
Vladislav N. Kovalnogov ◽  
Ruslan V. Fedorov ◽  
Larisa V. Khakhaleva ◽  
Andrei V. Chukalin ◽  
Aleksandr N. Zolotov
Keyword(s):  
High Speed ◽  
Thermal Protection ◽  
Numerical Research ◽  
Technical Solutions ◽  
Dispersed Flows

Modeling and Simulation Research of Hydraulic Cylinder Speed Control System Based on High-Speed On-Off Valve

2012 ◽  
Vol 590 ◽  
pp. 161-164
Author(s):  
Qin He Gao ◽  
Wen Liang Guan ◽  
Hai Zhou Song ◽  
Zhi Yong Yang
Keyword(s):  
Control System ◽  
Hydraulic System ◽  
High Speed ◽  
Speed Control ◽  
Hydraulic Cylinder ◽  
Simulation Research ◽  
Parallel Application ◽  
Proposed Model ◽  
Speed Control System ◽  
Small Flow

Application of high-speed on-off valve in the hydraulic cylinder speed control system was researched in this paper. Series and parallel application schemes between high-speed on-off valve and hydraulic cylinder are proposed. Model of high-speed on-off valve and hydraulic circuit were established to carry out simulation. The speed and acceleration curve of hydraulic cylinder were achieved by the means of simulation with Simulink. The simulation curves show that, two application schemes can both control the speed of hydraulic cylinder effectively. Series application scheme can be only applied to small flow hydraulic system; parallel application scheme has wider application.

The Double Role Piston Pump Based on the Symmetrical Gears and Crank-Link-Slider Mechanism Driven by Servo Motor

2011 ◽  
Vol 121-126 ◽  
pp. 2308-2312
Author(s):  
Ming Di Wang ◽  
Qiang Song ◽  
Kang Min Zhong
Keyword(s):  
High Speed ◽  
Noise Pollution ◽  
Hydraulic Cylinder ◽  
Piston Pump ◽  
Servo Motor ◽  
Straight Line ◽  
Wide Range ◽  
Cylinder Piston ◽  
High Speed Rotation ◽  
New Type

The double role piston pump based on the symmetrical gear and crank-link-slider mechanism driven by servo motor is innovated, its working principle and technical characteristics are introduced. In this new type of piston pump, the hydraulic cylinder piston is drived, and the velocity can be adjusted, but the flow pulse of a single pump is undoubtedly great. So two piston pumps are adopted, whose velocity are controled by NC, then the variable stepless timing in wide range can be achieved. If the velocity in this two pumps |v1|+|v2|=C (C is a constant), the flow curve of two pumps will be coupled into a straight line, in order to achieve constant flow output without the need of complex and inefficient throttle controlling loops, and there has not any power machines and mechanical parts in high-speed rotation ,and the noise pollution is very low. According to the varied circumstance, the high and low pressure conversion can be achieved when the angle velocity in this piston pump is controlled by the instructions. It is also very easy to achieve the dynamic and intelligent control.

scholarly journals INFLUENTIAL PARAMETERS DURING PRESSURE RELIEF EXPOSED IN WORKING CHAMBER OF HYDRAULIC CYLINDER PRESS

2016 ◽  
Vol 22 (2) ◽  
pp. 71-76
Author(s):  
MILUTIN ŽIVKOVIĆ
Keyword(s):  
High Speed ◽  
Hydraulic Cylinder ◽  
Design Parameters ◽  
Embedded Devices ◽  
Pressure Relief ◽  
Performance Requirements ◽  
Hydraulic Impact ◽  
Nominal Size ◽  
Influential Parameters ◽  
Important Design

Relieving volumes, which were under pressure, with all the controls on the distribution and management of oil supply, may lead to the occurrence of the hydraulic impact, which is especially distinct in hydraulic presses. For these reasons, high speed unloading compression volume is the main cause of this phenomenon. This paper provide practical guidance for the design and calculation of important design parameters usually embedded devices - hydraulic command check valves (HCCV) (nominal size, pressure and decompression time) and the possibility of determining performance requirements using, from literature, the expressions and the nomograms.

Flow Boiling Characteristics of R410A in Horizontal Annuli of Enhanced Surface Tubes

2019 ◽  
Author(s):  
Zhi-chuan Sun ◽  
Wei Li ◽  
Xiang Ma ◽  
Yuansheng Lin ◽  
Zhiwu Ke ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Boiling Heat Transfer ◽  
High Speed ◽  
Flow Boiling ◽  
Saturation Temperature ◽  
Outer Tube ◽  
Annular Gap ◽  
Penalty Factor ◽  
Fin Tube

Abstract An experimental study on the flow boiling heat transfer in a horizontal annular passage outside the single tube using R410A. The tested tubes contain a smooth tube, a 1EHT tube (dimpled tube) and a herringbone micro-fin tube with the same outside diameter of 12.70 mm. Tests were carried out at a saturation temperature of 6 °C for a mass flux range of 8∼107 kg/m2s with a fixed inlet quality of 0.1 and three different outlet qualities (0.4, 0.6, 0.8). Changes in vapor quality and annular gap size are found to have a significant impact on boiling heat transfer in the concentric annulus. For tests in the annuli with a 25.4-mm-ID outer tube, the HTC of the herringbone micro-fin tube is highest together with the largest pressure drop. Both the annulus of 1EHT tube and the annulus of herringbone micro-fin tube show a higher boiling HTC at an outlet quality of 0.6. The larger penalty factor is found at an outlet quality of 0.8. For flow boiling in the annuli having different annular gap sizes, it is found that the heat transfer enhancement ratio decreases sharply with the increasing average quality. When the inner diameter of outer tube is 19.0 mm, HTC decreases at first and then rises slowly. The huge bubbles occurred at the low mass fluxes and the scouring effect on the heated annulus walls of high-speed flow may be responsible.

Design of Hydraulic Cylinder Speed Control System Base on High-Speed on-Off Valve

2012 ◽  
Vol 220-223 ◽  
pp. 1661-1664
Author(s):  
Qin He Gao ◽  
Wen Liang Guan ◽  
Hai Zhou Song ◽  
Zhi Yong Yang
Keyword(s):  
Control System ◽  
Hydraulic System ◽  
High Speed ◽  
Speed Control ◽  
Hydraulic Cylinder ◽  
Pulse Control ◽  
Parallel Application ◽  
Speed Control System ◽  
Small Flow ◽  
The Impact

In order to study the Application of high-speed on-off valve in the hydraulic cylinder speed control system, series and parallel application schemes between high-speed on-off valve and hydraulic cylinder are proposed to control the speed of hydraulic cylinder. The duty cycle of pulse control signal was changed according to the displacement of hydraulic cylinder to control the speed of hydraulic cylinder and weak the impact. The simulation curve compared with the experimental results show that, two application schemes can both control the speed of hydraulic cylinder effectively. Series application scheme can be only applied to small flow hydraulic system; parallel application scheme has wider application.

Hydraulic System Design and Simulation of High-Speed Railway Dynamic Test System Excitation Device

2012 ◽  
Vol 271-272 ◽  
pp. 953-957
Author(s):  
Liang Cai Zeng ◽  
Fei Long Zheng ◽  
Yuan Wan ◽  
Qiang Hua Xi
Keyword(s):  
Hydraulic System ◽  
High Speed ◽  
Digital Simulation ◽  
Dynamic Test ◽  
Hydraulic Cylinder ◽  
High Amplitude ◽  
Test System ◽  
Excitation System ◽  
High Speed Railway ◽  
Exciting Frequency

The existing hydraulic excitation mode of valve controlled cylinder or pump controlled motor used in the excitation device of high-speed railway dynamic test system is difficult to meet the requirements of high exciting frequency, high exciting force and high amplitude. To solve these problems, the paper puts forward a bicyclic surface hydraulic cylinder, and designs the corresponding electro-hydraulic servo excitation system. According to the test system parameters，it establishes the mathematical model of the hydraulic system. It uses Matlab/Simulink to carry out theoretical analysis and digital simulation and uses PID Tuner to adjust the PID controller parameters. The simulation results show that the hydraulic excitation system designed meets the performance requirements of the high-speed railway dynamic test system excitation device.

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