This paper presents a systematic method for analyzing and designing the notches on the spool of a flow control valve to influence the area-schedule, i.e., relationship between the spool position and the metering area. The motivation for such a flow control valve comes from a novel hydraulic actuator intended for camless valve actuation in internal combustion engines. The proposed actuator has a unique hydromechanical internal feedback system in which the motion of the flow regulator's spool is directly coupled to the motion of the actuator. Lack of direct control of the spool position necessitates the appropriate modification of the spool design in order to control the variation of the effective area across the valve. The design modifications required to realize the desired area-schedules are first discussed. A systematic procedure which combines computational fluid dynamics (CFD) analysis and geometry based analysis is then developed to characterize the variation of the effective area for various spool designs. It is shown that the mean area available for the fluid flow through the entire notch serves as a better approximation of the metering characteristics when compared to the traditional approach of using the minimum area. The proposed analysis procedure is validated with experimental data from a prototype spool valve. The fast turn around time of the proposed analysis technique is then used to develop an automated procedure to design the 3D features (notches) on the spool required to realize any specified area-schedule.

References

References
1.
Amirante
,
R.
,
Vescovo
,
G. D.
, and
Lippolis
,
A.
,
2006
, “
Flow Forces Analysis of an Open Center Hydraulic Directional Control Valve Sliding Spool
,”
Energy Convers. Manage.
,
47
(
1
), pp.
114
131
.10.1016/j.enconman.2005.03.010
2.
Amirante
,
R.
,
Vescovo
,
G. D.
, and
Lippolis
,
A.
,
2006
, “
Evaluation of the Flow Forces on an Open Centre Directional Control Valve by Means of a Computational Fluid Dynamic Analysis
,”
Energy Convers. Manage.
,
47
(
13–14
), pp.
1748
1760
.10.1016/j.enconman.2005.10.005
3.
Amirante
,
R.
,
Moscatelli
,
P. G.
, and
Catalano
,
L. A.
,
2007
, “
Evaluation of the Flow Forces on a Direct (Single Stage) Proportional Valve by Means of a Computation Fluid Dynamic Analysis
,”
Energy Convers. Manage.
,
48
, pp.
942
953
.10.1016/j.enconman.2006.08.024
4.
Yuan
,
Q.
, and
Li
,
P. Y.
,
2005
, “
Using Steady Flow Force for Unstable Valve Design: Modeling and Experiments
,”
ASME J. Dyn. Syst., Meas. Control
,
127
(
3
), pp.
451
462
.10.1115/1.1997166
5.
Yuan
,
Q.
, and
Li
,
P. Y.
,
2007
, “
Robust Optimal Design of Unstable Valves
,”
IEEE Trans. Control Syst. Technol.
,
15
(
6
), pp.
1065
1074
.10.1109/TCST.2007.908080
6.
Manring
,
N. D.
, and
Zhang
,
S.
,
2012
, “
Pressure Transient Flow Forces for Hydraulic Spool Valves
,”
ASME J. Dyn. Syst., Meas., Control
,
134
(
3
), p.
034501
.10.1115/1.4005506
7.
Pan
,
X. D.
,
Wang
,
G. L.
, and
Zhang
,
L.
,
2008
, “
Simulation Study on Spool Edge's Round Angle Effects on Spool Valve Orifice Discharge Characteristic
,”
Appl. Mech. Mater.
,
10–12
, pp.
918
922
.10.4028/www.scientific.net/AMM.10-12.918
8.
Viall
,
E. N.
, and
Zhang
,
Q.
,
2000
, “
Determining the Discharge Coefficient of a Spool Valve
,”
Proceedings of the 2000 American Control Conference
, pp.
3600
3604
.
9.
Yang
,
R.
,
2003
, “
Hydraulic Spool Valve Metering Notch Characterization Using CFD
,”
Proceedings of the 2003 ASME International Mechanical Engineering Congress
,
10
, pp.
11
17
.
10.
Cao
,
M.
,
Wang
,
K. W.
,
DeVries
,
L.
,
Fujii
,
Y.
,
Tobler
,
W. E.
, and
Pietron
,
G. M.
,
2006
, “
Experimental Characterization and Gray-Box Modeling of Spool-Type Automotive Variable-Force-Solenoid Valves With Circular Flow Ports and Notches
,”
ASME J. Dyn. Syst., Meas. Control
,
128
(
3
), pp.
636
654
.10.1115/1.2232687
11.
Borghi
,
M.
,
Milani
,
M.
, and
Paltrinieri
,
F.
,
2004
, “
The Influence of the Notch Shape and Number on Proportional Directional Control Valve Metering Characteristics
,” SAE Technical Paper Series, Paper No. 2004-01-2619, pp.
1
12
.
12.
Sun
,
Z.
,
2005
, “
Engine Valve Actuator Assembly With Dual Automatic Regulation
,” U.S. Patent No. 6,959,673.
13.
Sun
,
Z.
,
2009
, “
Electrohydraulic Fully Flexible Valve Actuation System With Internal Feedback
,”
ASME J. Dyn. Syst., Meas. Control
,
131
(
024502
), pp.
1
8
.10.1115/1.3072146
14.
Gillella
,
P.
, and
Sun
,
Z.
,
2011
, “
Design, Modeling, and Control of a Camless Valve Actuation System With Internal Feedback
,”
IEEE/ASME Trans. Mechatron.
,
16
(
3
), pp.
527
539
.10.1109/TMECH.2010.2045656
15.
Pan
,
X.
,
Wang
,
G.
, and
Lu
,
Z.
,
2011
, “
Flow Field Simulation and a Flow Model of Servo-Valve Spool Valve Orifice
,”
Energy Convers. Manage.
,
52
(
10
), pp.
3249
3256
.10.1016/j.enconman.2011.05.010
You do not currently have access to this content.