Need some help understanding a hydraulic diagram for troubleshooting.

I have a smaller Arburg injection molding machine and need some help diagnosing a problem. None of the hydraulics move.

What Ive checked so far...

• Turned on 0.9 motor
• Removed pipe from second pump at 0.11 and there was some flow.
• Re-connected pipe and checked pressure at M0.2 and got ~3000psi. This one is good.
• Removed pipe at 0.10 on primary pipe and got a whole lot of flow!
• Replaced pipe and checked pressure at M0.1 and there was barely enough pressure to read on the gauge.

Now for some questions about the attached diagram....

• The actuator at 0.15 seems to be hydraulically actuated? It seems to be the only one drawn without the coil looking lines.
• The main pump 0.10 i guess is a variable piston pump?
• The dotted line coming from the main pump 0.10, is this to control the pump volume?
• Near the dotted line from the opposite end of the main pump, what is the square with the arrow though it?

If I go under the impression that when I remove the pipe from the main pump, since there is a lot of flow, that the pump is fully stroked because there is no hydraulic feedback to de-stroke the pump. When hooked back up, I get hardly any pressure at the test point. What am I messing here. Keep in mind I only have some general hydraulics knowledge and a lot of assumptions were made. Any thoughts on the issue or maybe I am just misunderstanding how this is supposed to work?

Here is a link to the schematic that can be zoomed in on with good quality. https://drive.google.com/file/d/1N0f...ew?usp=sharing

Regards


Attachment 406634

Hi

Not really up on ISO symbols but valve 0.15 is a proportional solenoid operated pilot assisted (two stage) one. The coil symbol on the far left is the proportional solenoid coil and the little triangle next to it feed through the filter is the pilot flow actuator. You will need to lookup the make and part number of the valve to find out what the solenoid drive is supposed to be. So if the pump output pressure is truly 0 then the valve can't move properly. If you loosen line at 0.03 you should vent the pressure feedback to the pump causing it to go to full stroke. When the pump is running check pressure switch 0.17 state to see if there is excessive flow to tank ( pressure drop across return filter).

John

Thanks John. That bumped things along a little further in the understanding. The 0.15 valve is a Moog D651-346A. Looking at the data sheet it is indeed electronically controlled and I didn't pick this up from the schematic. So, I'll move back to the electrical side and assume for now that the hydraulics are OK. It could be that the controller isn't setup correctly. Having not used one of these machines before there are likely many things i'm missing. Finding a forum that supports these old Arburg's has so far escaped.