Fuel Injector to Paint Ball Cannon 1

[triage]

Am building a science project with my son, and our intent is to use a filled dive tank as source for compressed gas, to make a paint ball cannon. Our hope is to use an automobile direct fuel injector as a solenoid controlled valve that can be purchase at an auto parts store.

I can not locate specs on injectors, can anyone direct me to specs on injectors, for pressure rating, response time, flow rate?

Is there an auto injector which can actuate 3000 psi?

Any help is appreciated

 

[patprimmer]

I doubt it.

Electronic injection injectors normal operate below 100 psi

Regards

eng-tips, by professional engineers for professional engineers
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[triage]

I was thinking of the direct injectors, which inject directly into the cylinder under compression.

Don't these have higher pressure ratings than 100 psi?

Are any direct injectors controlled by solenoid, or are they all driven from a pneumatic distributor?

 

[patprimmer]

They are not so common yet.

I don't know their specs

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[ctmtwilliams]

The potato cannon web guru has your answers along with all of the physics & theroy including solenoids and triggers for combustible and non-combustible gas potato cannons. Go to the link:Spudtech

 

[triage]

Thanks but ctmtwilliams,
Unlike potato guns, I can not pump a chamber and then unleash the contents for a single firing, then repeat.

I am also using a source with 3000 psi and need a valve with electronic control capability so that a controlled packet of compressed gas is delivered, with the ability of rapid fire.

This is why I am looking for an electronically actuated, high duty cycle valve, like a fuel injector.

I am still hoping that someone has a lead on specs and details for injectors of this nature.

 

[waross]

This was the first reponse at yahoo (high pressure solenoid valves)
High Pressure Solenoid Valve - Pneuaire

http://www.pneuaire.com

High pressure solenoid valves up to 3000 Psig for air and liquid prices starting at $56.00, ships within 24 hours, most models available for next day delivery.
yours

 

[triage]

Thanks waross, I was using "injector" in my search.

The products at pneuaire seem to encompass my requirements and I will pursue that path, rather than automotive.

Regards

 

[dgallup]

Most of the gasoline direct injection systems run at 1000 PSI or lower and will run you several hundred dollars per injector. They are designed to fullfill several difficult functions that are of no value to you. The industrial solenoid valves will definately be more cost effective.

 

[ivymike]

why wouldn't you start with a valve mechanism from an off-the-shelf paintball gun?

 

[Majik]

if you brought the pressure down to about 1000psi you could use like a nitrous solenoid.. put probably not in rapid fire.. I don't think a injector would flow enough to get a paint ball any distance either... you should look into that. the direct injectors usually right now while electronically triggered use some sort of hydraulic help. Many direct diesel injectors use a high pressure oil pump that generates 250psi to actuate these injectors. A nitrogen tank would work as well with a small regulator on the front. available at any welding gas supply house

 

[turbocohen]

direct injectors are not what you need, try abs solenoids. they offer much more flow area.

 

[triage]

Great Idea "turbocohen", I had not considered an abs
solenoid.

I am still trying to get pressure and timing specs on
any of the solenoids, either from "waross" pneuaire products or direct injectors, or abs solenoids.

In the design, I need timing for open and closing of the valve, to determine the packet size of the charge.

To make a rapid fire cannon, I am looking to time a packet burst of pressurized gas to power the paintball down the barrel. Too much gas in the packet is a waste and too little reduces the effective velocity.

Paintball valves done work in this application (at least the ones that I have found) because they are mechanical, using springs to set and recoil to reset.

A solenoid valve which can operate with a minimum pulse width of 1-3ms from full open to full close would be optimal. Obviously the apperature size and pressure plays a role in the relationship of TimeOpen vs. Packet Size, however a smaller solenoid valve with fast response is preferred, in that I can use more than one valve in parallel.

Design Engineers for the automotive industry must have some place to access these specs for thier design criteria. I am trying to find this source.

 

[01cobra]

I currently work in an ABS manufacturing plant. We do in fact have several different models of valves. I may be able to obtain some specs on them but I have a feeling they will not work for you. One they are designed to be installed into a custom manifold that we manufacture here. And two they are not designed to flow that kind of volume in that amount of time. The valve speed and response would be there but because they are designed for an automotive hydraulic circuit their intent is not to pass a large volume quickly. A relatively small amount of fluid will actuate the braking system on a vehicle. However we do use air to test these units prior to shipping. I have been searching for 3 years for a reliable electrically operated valve capable of working to pressures of 5k. I havent found them yet. Currently I am using a pneumatic actuated valve. We still have reliability issues with them but it is possible you could get something like that to work. I believe SMC makes the ones we currently use but there are several manufacturers making similar product.

 

[richdubbya]

How about a cam operated poppet valve turned back and forth with solenoids, the ms could be changed with cam profile.

 

[triage]

Actually "01cobra" my application requires very small volumes, in that the packet size to power a paint ball down a barrel is quite small, when you consider that the driving source is 200 times the pressure of atmosphere.

Essentially the fully expanded volume needs to be about 1.2-1.5 times the barrel volume, so the packet size is that volume divided by 200. (quite small)

And "richdubbya" I have considered your suggestion as a backup, although the project would be cool to use a computer program to regulate the packet delivery with a simple timed open and close signal. Using some bits from the parrallel port of a computer into an ampliphier, then driving the solenoid.

Thanks all
Question to "01cobra" can you tell me a year and vehicle type for the abs valve you think is the most responsive so I can buy one and test it?

 

[01cobra]

I dont have the data you are requesting But I can tell you the maximum response time that for a valve in one of our units is 7 miliseconds any slower than that and they are scrap. We currently make several different versions of unit. Each version only seems to last about two years before a new version hits the market. We are now preparing for the newest version which has the ESC (electronic stability control) sorry for rambling there. What I'm trying to say is for one version we actually manufacture the valves. The other version we purchase them from Japan. I can name several make and models but to my knowledge you will not be able to purchase these parts as they are not able to be replaced. They are permenantly staked into their housing. Different vehicles require different size orifices inside the valve. I could probably get you some valves for you to test but you may have a tough time doing anything with it. I believe the cost of an entire ABS hydraulic unit would prevent you from using it. If you are still interested you can email me at mhollon@advics-ohio.com and I will see what I can help you with.

 

[dgallup]

I'm suprised the ABS valves are still so slow. No electronic gasoline fuel injector takes more than 2 ms to open and recent electromagnetic ones are 1.5 ms or less. The piezo ones are much faster. I guess fast response in an ABS situation is not that critical when they only cycle at about 10 Hz.

VW/Audi sells 2 liter 4 cylinder direct injected engines, also MazdaSpeed 2.3 liter and Lexus 3.5 liter V6. All these are brand new on the US market so you may not be able to even buy a replacement injector yet. The outboard motor people have been selling them longer in US. The Yamaha is the highest pressure system but I think it is under 1000 PSI. Mitsubishi was the first in Japan with DI gasoline engines in the Galant but it was never sold here. There have been others in Japan and Europe. Our lower NOx requirements and general indifference to fuel efficiency have kept them out until now.

The diesel common rail electronic injectors will handle the pressure you are looking for (and more) but I don't know what US vehicles use them. Automotive ones may not flow enough for you, however I'm sure if you get something for a class 8 truck it will be up to the job. I hate to think what they cost but maybe you could find a diesel repair shop with one that has some defect unimportant to your application. Electronic drive requirements may be substantial (42V?).

 

[GregLocock]

They are slow because the time constants associated with braking are very slow. The cycle speed on our system is 3 Hz (deliberately), others might be up to 10 Hz. Increasing the response speed of relatively fast components has relatively little effect on the overall bandwidth.



Cheers

Greg Locock

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

 

[turbocohen]

Well, so much for the abs suggestion.. how about a CNG cylinder lockoff valve? They easily operate at 400bar and the volume is way adequate. try contacting GFI and see if their isolation valve works.. tellem turbo cohen sent ya.

http://www.teleflexgfi.com/cng_isolation_valves.php