USE OF SHAPE MEMORY ALLOY FOR A PILOT STAGE ACTUATOR OF A WATER HYDRAULIC CONTROL VALVE

Driving processes and characteristics are different between the water hydraulic artificial muscle and pneumatic artificial muscle due to the difference of work media employed in muscles. An appropriative hydraulic circuit was designed to control the pressure of the water hydraulic artificial muscle and the performance of this system was analyzed. An AMESim model of the control system was built and the dynamic characteristics are analyzed with various parameters of the hydraulic circuit and various loads by simulation. The results show that the performance of the water hydraulic control valve should agree with the dimension of the water hydraulic artificial muscle. The rated flow rate of the water hydraulic valves can be selected increasingly while the load mass is low. Meanwhile, the overshoot is generated and enlarged along with the increases of the flow rate and load mass. These contribute to the improvements of designs and researches on control systems of water hydraulic artificial muscles.

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Research on the Stability of a System Consisting of a Water Hydraulic Control Valve and Cylinder

BATH/ASME 2016 Symposium on Fluid Power and Motion Control ◽

10.1115/fpmc2016-1738 ◽

2016 ◽

Author(s):

Futoshi Yoshida ◽

Shimpei Miyakawa ◽

Shouichiro Iio

Keyword(s):

Natural Frequencies ◽

Tap Water ◽

Control Valve ◽

Working Fluid ◽

Entire System ◽

Hydraulic Control ◽

Compensation Circuit ◽

Design Guideline ◽

Water Hydraulic ◽

The Stability

Water hydraulic system using tap water as working fluid is a new driving method which provides high speed, high-output control, while providing safety, hygiene, and ecofriendliness. Its applicable markets widely range from food, health, pharmaceuticals, cosmetics, semiconductors, beverages, to energy industries. Applications of the water hydraulic technology differ from those of its oil counterpart in heavy industries. This paper is aimed at analytically considering the stability of systems that use tap water as the working fluid. We studied a comprehensive system, including a water hydraulic control valve, a cylinder, and piping for connecting these components, to determine the transfer function of the entire system that has three elements: a control valve; piping and cylinder; and a compensation circuit. Based on the determined function, we reviewed the relationship among natural frequencies of the system, including the control valve and piping, and examined the effect of the control valve and cylinder on the stability of the entire system according to the Hurwitz stability criterion. This gave us a design guideline about the compensation circuit that stabilizes the system by adjusting the natural frequency of the water hydraulic proportional control valve according to the natural frequencies of the piping and cylinder.

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A Miniature On/Off Valve Concept for High Performance Water Hydraulics

ASME/BATH 2017 Symposium on Fluid Power and Motion Control ◽

10.1115/fpmc2017-4254 ◽

2017 ◽

Author(s):

Miika Paloniitty ◽

Matti Linjama

Keyword(s):

High Performance ◽

Control Valve ◽

Hydraulic Control ◽

Used Oil ◽

Water Hydraulics ◽

Starting Point ◽

Pressure Medium ◽

Water Hydraulic ◽

Valve Control ◽

Hydraulic Valve

Digital hydraulic control valve technology has shown its strengths in providing reliable, leak-tight and high performance valve control regardless of the pressure medium used, oil or water. This is enabled by the intelligent use of robust on/off seat valves. However, the availability of these valves for water hydraulics is limited, especially that of compact valves, which are needed for digital valve systems. Thus, with the aim to create a compact digital water hydraulic valve system, this paper presents the development process of a water hydraulic miniature valve. The starting point for the development is a previously developed miniature valve for oil hydraulics. Experimental results with the new prototype show that good performance can be achieved for the miniature valve even with using stainless steel materials. This enables high-performance digital water hydraulic control.

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Shape memory alloy actuated fluid control valve

Smart Materials Bulletin ◽

10.1016/s1471-3918(01)80157-x ◽

2001 ◽

Vol 2001 (9) ◽

pp. 13 ◽

Cited By ~ 1

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Control Valve ◽

Fluid Control

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Design and Simulation on Multi-Digit Numerical Control Valve in Water Hydraulics

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.422.257 ◽

2011 ◽

Vol 422 ◽

pp. 257-261

Author(s):

Zeng Meng Zhang ◽

Yong Jun Gong

Keyword(s):

Control Valve ◽

Poor Performance ◽

Numerical Control ◽

Hydraulic Control ◽

Control Performance ◽

Poppet Valve ◽

Water Hydraulics ◽

Water Hydraulic ◽

The Stability ◽

And Control

Due to the problems about Lubrication and sealing in water hydraulics, the poor performance, large leakage, extreme requirements of processing, high cost and poor anti-pollution properties exist in water hydraulic servo or proportional valves of spool structure and analogue control. A better seal is provided by the structure of the poppet valve comparing to the spool valve, however, poorer linearity and control accuracy accompanying inevitably. Aiming at improving the control performance of poppet valve, the design of the multi-digit numerical control valve is analyzed in this paper. The novel design using ball seat valves for digital bits is proposed to ensure enough seal ability and lower the cost. The simulation model of the multi-digit numerical control valve is built in AMESim software and the results show high linearity in flow control. However, large overshoot and oscillation encounter during the switching of the digits. Especially the switching process of the high digital bits requires to be regulated to reduce the large overshooting. The adjustment of the spring in the sensitive chamber of the bit valve can decrease the overshoot and improve the stability. These above contribute to the improvement of the control performance of water hydraulic control valves and applications of water hydraulics in the industry.

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