solenoid actuated valves 1

[stanglou]

What is the viability of actuating the intake/exhaust valves of an engine using solenoid valves. If it were possible, it would allow displacement on demand, true VVT, and a mechanical energy loss advantage.

 

[minerk]

I recall seeing something on this some time ago. A guy had developed an engine that operated as you describe, looked rather ingenious. The valve springs were forcing the valves open, and he used solenoids to hold them shut. This had not been practical in the past, but given the advances in onboard computer technology it should be doable. Not sure how the electrical requirements would affect power though.

 

[R1100S]

Its been done. FEV had a few cars driving around 5 or 6 years ago. I takes a lot of power to hold a spring open, and you don't regain any of that energy when the spring closes.

There are also a lot of people working on hydraulic opening of valves, using high speed solenoids to control the hydraulic oil.

 

[stanglou]

what about opening the valve with the solenoid and holding it closed with a spring? anyone have any ideas on where i could get a solenoid that was capable of opening high spring pressures?

 

[GregLocock]

You can buy a cylinder head with controllable valves. Lotus makes them, it is called AVT.

They don't go particularly fast, but they are full authority valves, that is, you can program their instantaneous speed and displacement exactly.

http://www.just-auto.com/proactive/

pdf/Lotus-proActive-issue-4.pdf


Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[stanglou]

when you say that they dont go very fast does that mean that the valves aren't capable of high rpm's, or do you mean that the heads dont flow well?

 

[GregLocock]

Not capable of especially high rpm. I don't know the exact figure, but vaguely remember 4000 rpm for a 500 cc cylinder.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[gmatov]

Stanglou,

Cadillac had the 8-6-4 in 1981, an idea ahead of its time.

Look to this link to see what GM has on the table now.

http://www.popularhotrodding.com/enginemasters/articles/hardcore/0405phr_gmdod/

I don't know if you are theorizing, trying to build, or just curious.

Whichever, just do a search- Cadillac 8-6-4 2400 hits.
Cheers,

George

 

[stanglou]

The new GM bank deactivation still does no t have the adjustability of fully electronic actuated valves, not to mention the mechanical losses still inharent in their design. They claim a 15 percent gain in efficiency, i think with the full solenoid setup we would be getting maybe 20% or more. I think their system will be in all SUV's starting 2006

 

[SomptingGuy]

Note that Ricardo also have fully controllable valve experience. This technology is going to be vital for the 2/4 sight programme:

http://www.rmd.dft.gov.uk/project.asp?intProjectID=11116

 

[rcl41244]

This was done experimentally about 25 yrs ago by Lucas. They had invented a high force, high speed solenoid which they called a Helinoid. So called because of the helical shape of the windings inside I believe. The downside was it had a very short stroke; about .004" as I recall. They built a deomonstration cylinder head incorporating a lever between the valve and Helinoid to increase the stroke at the valve. It was on an ordinary 4 cyl engine and the stated performance was very modest due to limited valve lift. There was a photo of it in Design News descibing this. It required lots of electrical drive, I think it stated 400W/helinoid.

 

[SomptingGuy]

When I used to work for Lucas (CAV, 1986-1990) they were working on something they called a colenoid, which was a fast-acting solenoid for electronic unit injector control. It was helical too (I wound a few myself, by hand). Something tells me they may be one and the same.

(Why/when/where were Lucas dabbling in valve gear though? FIE, electrical systems and brakes were their mainstay when I worked for them.)

 

[Warpspeed]

I would expect the shock loads on the valve and seat would be pretty frightening if unrestrained fast opening and closing were used. It would not be exactly a silent process either.

 

[PJGD]

SomptinGuy,
Who were you working for at Lucas, was it BGB? If you get a copy of SAE Paper 880602, you will find that at the time you were working in west London there were other people at the same site, working on an integrated camless valvetrain and common rail fuel injection system. Very advanced for it's time, but simplified versions of this will appear in the future, I am convinced.

PJGD

 

[SomptingGuy]

PJGD,

I was a sponsored student, doing the rounds of the engineering departments at Acton. At that time Next Big Thing was going to be the EUI, driven off the camshaft. I first saw EUIs when I was working in the engine & pump test department. The names I remember are Robert Bell, George Dryja.

 

[tbuelna]

stanglou:

http://www.sturmanindustries.com/main/hydraulicValveActuation.htm#

 

[metalteacher]

Just curious, could an engine be developed to utilize a diesel fuel rail type system for operating valves? rather than the use of solenoids that draw a lot of electrical power, use hydraulic oil under pressure (pump driven off the crank) and metered out to lift the valves rather than inject fuel? This would eliminate the need for a cam, and reduce electrical power draw from a solenoid actuated system. Has anyone looked into this type of valve operation? a metering plate could be used to vary the timing of the valves by a computer input measuring Mass airflow, info from the O2 sesor etc.
Just seems to me to be a simpler method.

 

[MikeHalloran]

It could work, say for a large engine running at ~300 rpm.

At higher speeds, the valves would need to be fast and allow very high instantaneous flow rates, which would take a pretty high powered solenoid.

The dynamics could also get interesting because the bulk modulus of the hydraulic fluid cannot be ignored above a few Hz.



Mike Halloran
Pembroke Pines, FL, USA

 

[motorsportsdesign]

There is a company developing a system just like you describe with diesel injectors. They presented at AETC a few years ago. I don't remeber the name of the company but I think they were in Colorado.

Jonathan T. Schmidt

http://www.schmidtmotorworks.com

 

[GregLocock]

I used to use a servo controlled hydraulic ram for vibration work. It had half a ton of thrust at low frequency, and 200 Hz frequency response. That is to say, it is a bit bigger than you'd need (but not a lot), and had nowhere near the frequency response that you'd need. 200 Hz implies that it could deliver a pure sinusoid at 12000 rpm, in practice you need a lot more harmonics than the fundamental, I'm not too sure what the number would be?

The hydraulic lines were about 3/8" ID. The powerpack was the size of a fridge.



Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.