The Dynamic Performance of a Pilot Stage in the Poppet Type Hydraulic Flow Amplifier
2008 (English)In: The 51st NCFP Technical Conference,2008, Proceedings of the 51st NCFP Technical Conference: Omnipress , 2008, 659- p.Conference paper (Refereed)
examines the dynamic properties of the pilot stage in a poppet type
two-stage flow control valve of
the -Valvistor- type. The particular valve studied is a
screw-in Valvistor valve of NG16 size. There are several
benefits to this valve type: it has a high closed loop
bandwidth and the design allows big flow capacities. An
attractive feature of this two-stage valve is that the pilot flow
contributes to the total flow giving higher steady state flow
The dynamic characteristics of the main stage were
discussed in an earlier paper. In this paper the aim is to
study the influence of the pilot stage of the valve. The
bandwidth of this type of valve is often unexpected low.
Due to the high bandwidth of the Valvistor element the
pilot dynamics is often dominating.
In this paper it is shown by measurements the influence
of different parts in the pilot valve that limits its
bandwidth. Flow forces are used in this valve to
compensate the pressure dependency in the flow. It is a
common way of design in so called pressure
compensated valves. It is discussed in the paper how
this flow forces influences the dynamic properties of the
pilot valve. The mentioned flow forces interact together
with the mechanical spring in the pilot valve.
Although the studied valve is just one of many variants
of the Valvistor principle, we will investigate it closely
due to the interest for this valve among other
One important conclusion is that the inductance of the
pilot solenoid is often limiting the bandwidth of the valve
as a whole.
Place, publisher, year, edition, pages
Proceedings of the 51st NCFP Technical Conference: Omnipress , 2008. 659- p.
valvistor, poppet valve, dynamic model
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-42261Local ID: 62134OAI: oai:DiVA.org:liu-42261DiVA: diva2:263117