Proportional Control Valve Required

[Richard111]

I am an electronic engineer with a very limited knowledge of hydraulics. I am looking into the feasibility of an electronically controlled damping valve for use on "off road" competition motorcycles. The main criteria for the valve is to effectively control in real time the damping co-efficient of the suspension system by altering the flow rate (orifice)of the oil within the suspension legs. Control of the valve(s) will be by means of an electronic control unit which will take inputs from various sensors on the machine. In order to to this I require a valve which can operate very quickly, maybe 10 mS to 50mS between full flow and reduced flow states. Ideally the valve should be "analogue" in nature such that I can control the valve for a flow rate anywhere between the prescribed min & max flow rates. An alternative may be to use a number of fixed orifices in parallel which can be operated in an "on-off" fashion to approximate my analogue goal. Could anyone steer me in the right direction regarding a suitable type of valve for development purposes. Of course my secondary requirements of size and power consumption relate more to the production issues which are not my prime concerns at this stage of development.

 

[danhelgerson]

Take a look at this web site. It is for a small proportional flow control that may work well for your application.

http://hydraulics.eaton.com/products/pdfs/V-VLPO-MS001-E.pdf

 

[hydromech]

Good Luck in finding a solution.

Proportional valves vary widely in size and performance. But they all have 1 thing in common...They don't like dirt.

The most basic of proportional valves have a response time of 100ms and a hysteresis of upto 8%.

The top of the range proportional valves or servo performance proportional valves have much better reponse times and are far more accurate. They even have LVDT's connected to the spools to give positional feedback.

If you are lucky you may get 1 lap before the valve stops working.

 

[EdDanzer]

You fail to provide a flow the valve needs to meter. It will require experimentation as most valve manufacture cannot provide a map of the flow and response in relation to time. We build a pilot operated proportional valve in small quantities using a cage from HydraForce, that we drill small metering holes in, make a special spool and spring package. Tuning it was time consuming and required a data collection system to monitor the subtle differences in design. It might be possible to use CFD to reduce the time and number of iterations.

 

[kcj]

Possibly one of the cam timing Caterpillar valves, or Jacobs engine brake valves, or other already developed high pseed PWM valves could be adapted.
-they are already in volume production, designed to operate on somewhat contaminated engine oil, and at high speed pulsing.

kcj