SeymourDumore
Diamond
- Joined
- Aug 2, 2005
- Location
- CT
Guys, brainstorm session requested.
I've been getting frequent 130 errors, and today I took the time to investigate.
( all this is on a '06 vintage VF4 with gearbox )
So, after removing the front cover, I've noticed that the drawbar moves down a bit slowly for the first 1/4" or so, then the unclamp solenoid kicks on and it unclamps solidly.
Then, on the return it moves back up solidly until perhaps .250 short from top, and then moves wicked slowly all the way up.
So, after researching for possible tests, here is what I've found:
1: Return spring is NOT broken.
2: Removing the precharge airline ( the one on the right side ) DOES restore the solid clamp/unclamp cycle, obviously without the intermediate stop point ( the function of the precharge )
3: Removing the muffler from the main unclamp solenoid DOES NOT fix the problem.
4: Removing the muffler from the pre-charge solenoid manifold DOES NOT fix the problem. ( sidenote: do not do this unless you are Antman!!! )
5: Precharge regulator makes a "snorting" noise when activating. With finger on regulator it does vibrate as if air has trouble passing by.
So, in an attempt I have removed, disassembled and cleaned the pre-charge regulator. Was careful enough as to not move the stem from it's current setting.
After re-assembly and re-install, the return cycle got noticeably quicker and steadier. Again, did not adjust the pre-charge pressure ( nor checked it at the time but ... )
Now, after about 100 unclamp/clamp cycles I have not had any alarms, but! I did notice that when the tool is fully clamped it sits there for approx 2 seconds before the
carousel shuttle returns to home.
Ergo: I did NOT fix the problem, but I did something.
So, now here is the question for a possible discussion: How does the unclamp/clamp cycle SHOULD work?
In my mind, the idea is this:
1: When UNCLAMP is commanded, the Pre-charge solenoid opens. This air is now routed through a pressure regulator set to about 4-5 PSI, and then this air is
sent to the unclamp piston. With this lower pressure the piston gently moves the drawbar to be in contact with the belleville as to not smack them hard.
2: After a pre-set amount of time the main unclamp solenoid opens. It is routed through a check valve Tee, which now fully extends the drawbar.
At the same time of the main solenoid's opening the pre-charge solenoid turns off. ( question #1 later )
3: When the tool is inserted and RECLAMP is commanded, the main solenoid turns off and drawbar piston is forced back by the belleville washers first to the intermediate position,
then the return spring takes over and pushes the drawbar all the way up and activate the prox switch, signaling that tool is now fully clamped. ( question #2 )
So, question #1: How does the check valve Tee supposed to work? Why is there a muffler on the main solenoid if the check valve not supposed to let air back into it?
Question #2: How does the air in the piston supposed to escape upon clamp? Is it through the check valve back to the main solenoid's muffler, or is it through the precharge
regulator to the precharge solenoid manifold?
I am a bit baffled, mostly because I've noticed that the pressure regulator appears to be connected "backwards", meaning the port with the arrow pointing as OUT is hard piped to the
solenoid manifold.
I've been getting frequent 130 errors, and today I took the time to investigate.
( all this is on a '06 vintage VF4 with gearbox )
So, after removing the front cover, I've noticed that the drawbar moves down a bit slowly for the first 1/4" or so, then the unclamp solenoid kicks on and it unclamps solidly.
Then, on the return it moves back up solidly until perhaps .250 short from top, and then moves wicked slowly all the way up.
So, after researching for possible tests, here is what I've found:
1: Return spring is NOT broken.
2: Removing the precharge airline ( the one on the right side ) DOES restore the solid clamp/unclamp cycle, obviously without the intermediate stop point ( the function of the precharge )
3: Removing the muffler from the main unclamp solenoid DOES NOT fix the problem.
4: Removing the muffler from the pre-charge solenoid manifold DOES NOT fix the problem. ( sidenote: do not do this unless you are Antman!!! )
5: Precharge regulator makes a "snorting" noise when activating. With finger on regulator it does vibrate as if air has trouble passing by.
So, in an attempt I have removed, disassembled and cleaned the pre-charge regulator. Was careful enough as to not move the stem from it's current setting.
After re-assembly and re-install, the return cycle got noticeably quicker and steadier. Again, did not adjust the pre-charge pressure ( nor checked it at the time but ... )
Now, after about 100 unclamp/clamp cycles I have not had any alarms, but! I did notice that when the tool is fully clamped it sits there for approx 2 seconds before the
carousel shuttle returns to home.
Ergo: I did NOT fix the problem, but I did something.
So, now here is the question for a possible discussion: How does the unclamp/clamp cycle SHOULD work?
In my mind, the idea is this:
1: When UNCLAMP is commanded, the Pre-charge solenoid opens. This air is now routed through a pressure regulator set to about 4-5 PSI, and then this air is
sent to the unclamp piston. With this lower pressure the piston gently moves the drawbar to be in contact with the belleville as to not smack them hard.
2: After a pre-set amount of time the main unclamp solenoid opens. It is routed through a check valve Tee, which now fully extends the drawbar.
At the same time of the main solenoid's opening the pre-charge solenoid turns off. ( question #1 later )
3: When the tool is inserted and RECLAMP is commanded, the main solenoid turns off and drawbar piston is forced back by the belleville washers first to the intermediate position,
then the return spring takes over and pushes the drawbar all the way up and activate the prox switch, signaling that tool is now fully clamped. ( question #2 )
So, question #1: How does the check valve Tee supposed to work? Why is there a muffler on the main solenoid if the check valve not supposed to let air back into it?
Question #2: How does the air in the piston supposed to escape upon clamp? Is it through the check valve back to the main solenoid's muffler, or is it through the precharge
regulator to the precharge solenoid manifold?
I am a bit baffled, mostly because I've noticed that the pressure regulator appears to be connected "backwards", meaning the port with the arrow pointing as OUT is hard piped to the
solenoid manifold.