Theorycrafting an Internal Pilot actuated autococker valve

[devilzcall]

So I'm up late at night with what started out as a morph valve, but because I don't like copying peoples homework i racked my brain for other solutions to the problem.

I have always been fascinated by the concept of pilot valves and the idea of integrating both the pilot and main valve into a single assembly.

So what would i like to see happening here:

• In its resting state, the cup seal shuttle is pressed on by the main pressure inside the left pilot chamber. The leftmost o-ring should allow air to pass through when the firing pin is in its resting position
• On hammer strike the pilot chamber is sealed and then vented as the pin is pushed in
• The pressure difference should now push the shuttle into the pilot chamber and fully open the valve in an instant
• Once the pin resets (probably through a spring inside the pilot chamber, only on the pin, not the shuttle) the pilot chamber is again pressurized and seals the valve

Much like the morph valve this system would work mostly pressure independent, but could achieve high flow rates for very short opening time with high pressure and a lightweight hammer. Alternatively you might be able to actuate the valve pin with a solenoid. Is that how the mq valve works?
There might be some unintended side effects to the pilot chamber vent seal being part of the moving cup seal, but that could be fixed in design.

[BrickHaus]

Its over my head honestly, but seems like it would work in theory, long as that dump chamber held enough volume to make the shot count.

I THINK I see an issue? So from what I can tell can this valve would be dwell independent correct? By the shuttle valve sealing the inlet on shot. You get what you get out of the valve on hammer strike weather you open the valve for 4ms or 4 seconds.

So if this worked, and or took off, how would you adjust a cocker? Just hpr adjustments and go?

[devilzcall]

It's not dwell independent, it still let's air pass from the hpr through the valve as long as it's open. Dwell can be adjusted with the ivg as usual, but without it decreasing when increasing the pressure beyond the sweet spot.

[Jordan]

I think this is how the MQ works. Very cool idea.

[devilzcall]

Here's an update on the project. I figured you could gain a lot of volume by extending the valve in the other direction, slightly shortening the hammer stroke shouldn't be a problem.



In its resting position, the valve shuttle is held forward since its surface area towards the rear valve chamber is greater than towards the front and the pressure is equal. By striking the valve pin, the rear chamber gets vented faster that air can flow in and the valve shuttle gets pushed in by the main pressure. Once the valve pin closes, the rear chamber can pressurise again, pushing the shuttle forward and closing the valve.

Animation

The Valve pin can be extended and driven by Your standard size valve spring and the shuttle shouldn't really need one (but it would be fairly easy to add to the design. The shuttle should open the valve excessively fast, regardless of the striking force.

[flyweightnate]

Very cool ideas!

The second design looks very sensitive to inlet pressure, due to the large, unbalanced area on the front face of the pin. Might be worth addressing that to avoid some pretty serious hammer spring requirements.

I'm gone watch this eagerly. Shame my Illusion uses 3/4" valves, not 11/16".

[zinger565]

Like it a lot! Really cool action.

I agree with flyweightnate about the unbalanced pin, but it shouldn't be too much worse than current valve design.

If I'm understanding the flow, should be able to run fairly low pressure due to high flow rate, correct?

Any other advantage besides that, running a clapper solenoid, and being different?

Side note: if you ever get these machined, I'd definitely buy a few and test.

[imped4now]

Any updates on this?

[tyronejk]

I found this and it does look interesting. I assume no one is currently working on this though, by the looks of it. I think to avoid the reliability/short lube interval problems the Morph valve has, it would be better to use oring face seals here instead of spool valves.

[markdem]

With Dye making the Lazarus valve, theres not much need to create a valve like this unless you wanted something very specific

[tyronejk]

Yeah, you're probably right. After taking this design through a bunch of iterations, you'd probably end up with a Laz valve anyway.

[devilzcall]

I did not know of the Lazarus valve, though from my understanding it’s more or less the same as those zero kick(?) azodin valve kits that extend the valve stem into the front plug to counteract the pressure keeping the valve closed. Really cool system (and probably much more viable than this), but nowhere near my design.

[devilzcall]

So I did a bunch more work on this design a while back and recently picked it back up. I managed to reduce the number of O-rings to 4, by ditching most seals that don't need to hold pressure when the valve is not actuated.
The firing Pin now forms a poppet seal that will hopefully hold air without an o-ring and has been extended to take a standard spring. I also added a return spring for the shuttle component.



Here is also an animation, though fusion has no way to handle springs: https://imgur.com/6dZ4UFX

[tyronejk]

Nice stack up of parts here, avoiding needing any threads or locking assembly. Your purple, red, and yellow part stack held together with just pressure and minimal additional orings is clever.

I think keeping an oring to seal the pin would be more reliable though. Making either the pin or body out of softer plastic would work, but both those parts should be decently stiff to work well.

Also, it looks like you designed in higher flow between the pin and red body than between the pin and yellow shuttle in order to keep the shuttle open when the pin is depressed, but that means the shuttle is probably going to be overdwelled. As an alternative, you could build in a step into the pin to change the relative flow rates, but I'm not sure if that would cause the shuttle to bounce back and forth while the pin is depressed.

It does look like the yellow shuttle has a lot of throw and a lot of volume to vent behind it. I wonder if there are potential efficiency gains there by reducing both of those.

Also, at some point, would you be willing to share dimensioned drawings? I'd love to machine one and see how it works. I could make and send you one in return.

[Trbo323]

I don't understand how you are sealing that center pin. It seems to me that you'll just have air coming straight down the shaft to the hammer at rest

Also, maybe I'm the only one but that animation is a lot harder to follow with the camera also moving.

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[AndrewTheWookiee]

The firing pin has a poppet-face seal at the back of the valve body.

Looking at the overall operation, the current iteration of the valve is basically acting like an MQ with a physical valve at the back instead of a solenoid. Cut the firing pin down until it's just enough to seal the back of the valve body and be opened by the hammer, close up the front of the valve with a bleed hole to feed pressure to remove objects in the airflow path, and it's a mech MQ valve.

*Edit - threw this together as an idea.

[Trbo323]

The firing pin has a poppet-face seal at the back of the valve body.

Looking at the overall operation, the current iteration of the valve is basically acting like an MQ with a physical valve at the back instead of a solenoid. Cut the firing pin down until it's just enough to seal the back of the valve body and be opened by the hammer, close up the front of the valve with a bleed hole to feed pressure to remove objects in the airflow path, and it's a mech MQ valve.

*Edit - threw this together as an idea.

Awesome thanks that really cleared it up for me. I actually have a mq2 so that makes sense.

Is the poppet seal something that can be replaced or will it be specific to the valve?

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[AndrewTheWookiee]

I haven't thought that far, that's one of those "we'll worry about that later" problems. 😄

* Edit - Actually, come to think of it, an internal groove at the back of the body for an o-ring to seal the firing pin might be easiest to implement for sourcing common parts and ease of replacement, as well as ensuring a good consistent seal. Or even simpler a simple undercut at the back of the body and using an o-ring as the face seal itself.

[Trbo323]

As long as it seals up properly that idea would be amazing. One of my biggest fears with the mq2 is if it ever stops sealing, I don't really have a way to fix it easily

Here's another option for the way to do it, this is a vanguard Creed poppet seal. It's a little hard to see because of the way that they took this photo it's not the obvious o ring but to the left of that in between the white poppet head and the steel shaft there is an o-ring that is wedged in there. You can just barely see some black from it if you zoom in

It's a pretty trick little design because you have to unscrew the head from the shaft in order to change the o ring. But the way it's designed I will never lack of a poppet face seal since I can just replace the o-ring

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[AndrewTheWookiee]

I don't mean to hijack the thread or anything, but I added a little o-ring face seal and changed the pin length so the valve pushes the pin and hammer back and resets the pin when it fully opens allowing the valve to close like a normally sprung valve without manually re-cocking the hammer, which should allow it to function in a pump.

I have done no calculations or assessments on this setup so for all I know it could fart like crazy or just not work at all and leave the valve stuck open until the hammer is manually reset either with the 3-way timing or pumped.

[devilzcall]

I like that your shuttle is actually hammering the valve pin back, should definitely help with resetting. I don't think you need cut slots everywhere to allow air to pass through unsealed clearances.