ext/ret a cylinder without a DVC
ext/ret a cylinder without a DVC
(OP)
i have to extend and retract a cylinder (and i must be able to control it) with out the use of a DVC this can be done using 1, 2 or 4 componants. i was just wondering if someone could give me an opinion on whether or not the circuit i have come up with will work or if i am on the right track. i am not the best at hydraulics. (*note: a vertical cylinder may be used instead of the horizontal)
thanks
500psi system pressure (the pump has a relief valve already incorperated) goes to both ends of the cylinder (horizontal with no load on it). the blank end will have a T on it also going to a neelde valve which then goes to the tank.
when the needle valve is closed(no flow going though) the pressure will build up on both sides of the cyclinder. because of the area on the blank end, the fluid will be pushed out from the rod end and back to the blank end (causing regeneration). the cylider extends.
when the needle vavle is opened, the fluid on the blank end will travel back to tank and the pressure will build up on the rod end. this should cause the cylinder to retract.
thanks
500psi system pressure (the pump has a relief valve already incorperated) goes to both ends of the cylinder (horizontal with no load on it). the blank end will have a T on it also going to a neelde valve which then goes to the tank.
when the needle valve is closed(no flow going though) the pressure will build up on both sides of the cyclinder. because of the area on the blank end, the fluid will be pushed out from the rod end and back to the blank end (causing regeneration). the cylider extends.
when the needle vavle is opened, the fluid on the blank end will travel back to tank and the pressure will build up on the rod end. this should cause the cylinder to retract.
RE: ext/ret a cylinder without a DVC
When you open the needle valve to tank what will keep pump flow from going to tank?
Bud Trinkel CFPE
HYDRA-PNEU CONSULTING, INC.
fluidpower1 @ hotmail.com
http://www.fluidpower1.us
RE: ext/ret a cylinder without a DVC
RE: ext/ret a cylinder without a DVC
In actual fact, the force required to break the seal contact with the bore of the cylinder will be more than the pressure drop through the valve.
The pump will put all of the oil on the floor!
RE: ext/ret a cylinder without a DVC
Bud Trinkel CFPE
HYDRA-PNEU CONSULTING, INC.
fluidpower1 @ hotmail.com
http://www.fluidpower1.us
RE: ext/ret a cylinder without a DVC
the componants i have are : sequence valve, reducing valve, 2 needle valves, 1 flow control valve and two check valves
RE: ext/ret a cylinder without a DVC
Closing the tee to tank and opening the other tee extends regeneration.
Oprning the tee to tank and closing the other one will power retract the cylinder.
With 4 needle valves you can make it double acting with full force both ways.
Heck of a class assignment. What is the class title.
Bud Trinkel CFPE
HYDRA-PNEU CONSULTING, INC.
fluidpower1 @ hotmail.com
http://www.fluidpower1.us
RE: ext/ret a cylinder without a DVC
you have your own company?
RE: ext/ret a cylinder without a DVC
I teach a lot of the Apprentices at at several local plants. The Mechanics get 128 Hours of Basics and Trouble Shooting while Electrical's only get the 64 Hours of Basics.
Actually I find the electricians pick up on a lot of the theory faster than mechanics.
I am a 73 year young Semi-Retired ex Fluid Power salesman that still does the same thing I did while selling just getting paid by the hour instead of commission. Same customers but I don't have a boss fussing about sales dollars. The company is just a necessary thing to keep it legal.
Bud Trinkel CFPE
HYDRA-PNEU CONSULTING, INC.
fluidpower1 @ hotmail.com
http://www.fluidpower1.us
RE: ext/ret a cylinder without a DVC
sounds like you have a lot of fun doing your part time job. keep it up
one of my class mate actually got my circuit to work....only he has alot more tee's and hoses to create some restiction (roughly 200 psi)
thanks again for your help
amanda
RE: ext/ret a cylinder without a DVC
Pumps don't mke pressure only FLOW
Pressure only happens when there is resistance to flow
Hydraulics & Pneumatics (Fluid Power) defines Normally Closed (NC) as a blocked or no flow situation and Normally Open (NO) as a path for flow or a hole.
As you can see it is exactly reverse of electrical since electrical is defining the Contacts of a Switch. So, when I am discussing Fluid Power with electrical types I use Normally Passing and Normally Non-Passing to keep everyone on the same wave length.
Voltage is the same as Pressure (PSI) in Fluid Power and Current (amps) is equal to Flow (GPM)in Fluid Power.
Bud Trinkel CFPE
HYDRA-PNEU CONSULTING, INC.
fluidpower1 @ hotmail.com
http://www.fluidpower1.us
RE: ext/ret a cylinder without a DVC
we also found another way to may the cylinder ext/ret with only one compnant... a pressure reducing valve. the only problem was, we had to lower our system pressure and do the demo quickly becuase technically we were blowing the seals on the drain. if we disconnected the drain hose the circuit wouldnt work.
RE: ext/ret a cylinder without a DVC
Also with that circuit you could stop the cylinder any place in mid stroke. At least the one I think you used could do that.
Bud Trinkel CFPE
HYDRA-PNEU CONSULTING, INC.
fluidpower1 @ hotmail.com
http://www.fluidpower1.us