한국정밀공학회 2013 년도 춘계학술대회논문집
Nomenclature:
eq
K
= Equivalent valve conductancesa
K
= valve conductance of sa valvesb
K
= valve conductance of sb valveeq
P
= Equivalent pressureR
= Ratio of area of two side of actuators
P
= Supply Pressurer
P
= Return pressure i.e. tank pressure 1. IntroductionIn recent years, Energy saving by using IMV configuration to control the motion and pressure of hydraulic actuator in the fluid power industry are getting acknowledgeable attention. This is only because of increasing the system efficiency with decreasing the system loss and also wide range of controllability in hydraulic manipulator such as hydraulic excavator and backhoes. In near past many researchers replace convention hydraulic circuit with IMV circuit such as Bu and Yao [1] studied about four way direction control valve, Amir Shenouda [2] developed control algorithm for energy saving by using independently metered four valve assemblies, The major disadvantages are IMV are quite expensive and controlling is getting harder by increasing of the number of IMV. So in proposed configuration we reduce one IMV by using one direction control valve.
2. Mathematical Modeling
During the Power extension mode direction control valve is energized to left position and among there valve Vsb and valve Vab are used. By following mathematical modeling procedure of four valve configuration it can written that .Equivalent valve conductance is
3 2 2 sa ab eq ab sa
K K
K
R K
K
(1.1)And equivalent pressure is
(
) (
)
eq s r a b
P
RP
P
RP
P
(1.2)From equation (1.1) ,(1.2) and considering speed of cylinder we can write that
(
) (
)
b b eq eq s r a bA x
A x
K
P
RP
P
RP
P
(1.3)Details calculation of those two values can be found in reference [2]. The relationship between Keq and Ksa , Kab will be optimized to
minimum valve sensitivity errors and preventing of cavitations of hydraulic actuator as reference [3]. Thus, the relationship is shown as:
3/ 4 3/ 4
sa ab sa ab
K
R
K K
R
K
(1.4)Finally by using equation (1.1) and (1.4) each valve conductance for PE mode can be calculated as:
새로운 IMV 유압회로 개발
Development of new independent metering valve
hydraulic circuit
*윤종일1, #안경관1
아하메드 마쉬룩2, 이지환2
*J. I. Yoon1, #K. K. Ahn([email protected])1 , A. Mashruk2, J. W. Lee2
1울산대학교 기계공학부, 2울산대학교 기계자동차공학과
Key words : Independent metering valve, AMESim, electro-hydraulic valve.
한국정밀공학회 2013 년도 춘계학술대회논문집
3 3/ 4
R
R
K
sa eqK
(1.5)
3 (3/ 4)
R
R
1
K
sb eqK
(1.6)0
abK
(1.7)Similarly we can get mathematical modeling of all five mode of IMV.
3. Simulation Results
In following result we can see that proposed IMV give better result in all energy saving mode
Fig. 1 Energy consumption by both IMV in HSRE,LSRE and LSRR mode respectively
3. Conclusion
This paper presented a new configuration of IMV. The main aim of this paper is to reduce the cost of using IMV concept in automotive industry and make easier to developing the control algorithm for controlling those IMV. And the applicability and performance over Wheatstone bridge configuration of IMV are also checked. It was also shown that by this configuration it is possible to get same number of working mode as previous type of IMV and the performance over Wheatstone bridge configuration is better in all energy saving mode.
후기
본 연구는 21 톤 굴삭기 개발 과제 연구비를 통해 연구되었습니다.
참고문헌
1. Bu, F. and Yao, B., “Integrated Direct/indirect adaptive robust motion control of single –rod hydraulic actuator with time-varying unknown inertia” in Proc. of IEEE/ASME Int Conf on Advance Intelligent Mechatronics, pp 624-629,2001, Italy.
2. Amir Shenouda, “Quasi-Static Hydraulic Control Systems and Energy Savings Potential Using Independent Metering Four-Valve Assembly Configuraton”, Thesis, August 2006
.
3. Keith A. Tabor, “Optimal Velocity Control and Cavitations prevention of a Hydraulic Actuator Using Four Valve Independent Metering” SAE technical paper series paper no: 2005-01-3620.
