- March 17, 2007 at 10:38 am #19550
I have 3.25" Bore Cylinder mounted vertically, Rod Up, that is lifting a table that weighs approximately 350#
When the 5-way valve that powers the cylinder shifts the tabledoes not raise immediately, in fact there is about a 5 second delay before it starts raising.
When the cylinder is fully extended and the 5-way valve shifts to retract the table it immediately drops about 6" and bounces a few times, then procedes smoothly to the end of stroke.
Can this action be changed to immediate movement on extension and smooth full stroke retraction?November 25, 2020 at 9:53 am #20938
Can you add a Cyl-Check to the app? This would add the hydraulic control necessary to smooth the extend and retract motions.November 25, 2020 at 9:53 am #20939
No ol is alowed in the environment this unit is operating in.November 25, 2020 at 9:54 am #20940
Try using a 5/3 ports open to exhaust valve with an external pilot supply for the solenoid and use a regulator on both exhaust ports to regulate the pressure to both sides of the piston. Also add flow conrtols to the cylinder. With a bit of tweaking that should do it.November 25, 2020 at 9:54 am #20941
I only have a single pilot opearted 5-way at present and need to keep it that way if possible since the control circuit is air also and alredy installed. Would the dual pressure inlets work with a 2 position spring return valve?November 25, 2020 at 9:54 am #20942
I don’t think so as the circuit works by maintaining a pressure on both sides of the piston at the same time.November 25, 2020 at 9:54 am #20943
Have you tried regulating down the pressure holding the table down before energizing your cylinder up? This would reduce the amount of air that has to be exhausted before lifting occurs. This could reduce the 5 second lifting delay. It probably won’t have much effect though if your circuit is causing the restriction. Once the cylinder is up it probably has a lot of air to be exhausted. The inrushing air is giving you your initial motion down at which point the exhausting air is being choked due to the circuit restriction. Have you thought about adding a quick exhaust valve on the cylinder to allow the exhausting air to bypass your circuit? Have you tried reducing this pressure? Have you checked into replumbing your valve for double flow and letting gravity do the work on the return? If redesigning your circuit is an option than this article might help. http://www.machinedesign.com/ASP/viewSelectedArticle.asp?strArticleId=56483&strSite=MDSite&catId=0November 25, 2020 at 9:54 am #20944
The rduced rod end pressure took care of the problem nicely after a litle tweaking22gg. The cylinder operates quickly and smoothly now. THANKS:November 25, 2020 at 9:54 am #20945
You need to resize your valve and tubing, as this is causing your delayed reaction times.
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