Open Source Solenoid Valve
Electrical controlled valves are necessary in order to remote-control machines from the GVCS. However, the solenoid valves for the power level of interest cost about $300 per double-acting channel. There is thus A strong case for open source solenoid valves, which we could produce for probably 1/5 of that cost.
Requirements
30 gallon per min (~115 l/min) hydraulic flow at 3000 psi (~200 bar) pressure.
How does it usually work
All solenoid valves I saw till now work similar.
http://img.youtube.com/vi/5jspoB6_YuI/default.jpg http://img.youtube.com/vi/eKqfP2F_Pl0/default.jpg
I spool is centered inside of the body with springs. On both sides of the body are electromagnets that can push a shaft that presses the spool towards the other side. Therefore you can realize three different states of operation.
Ideas for simplification
As I see it the most difficult part to produce is the body as there are very complex geometries inside that can only be formed by casting or 3D-printing. For that reason I concentrated on simplifying the geometry of the body.
Possible solutions
The body is a simple metal block with only ordinary drill-holes and threads, easy and cheap to manufacture. The outputs 1 and 2, and 3 and 4 have to be connected width hoses to allow double-acting. Connecting them outside of the block with possibly quite cheap hoses might make the whole thing cheaper than produce the complex forms necessary to work otherwise.
Possible issues
- The form of spool shown above will most probably form turbulences that might be a problem.
- All surfaces have to be very accurately to enable leak tightness.