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  • Hydraulic Press "speed-up"

    I've got a nice Torin 20Ton press like the one in this link. It has a cylinder connected to the hand pump by a hose, and the pressure relief/return knob is on the pump.
    https://tongrunjacks.en.alibaba.com/...s_TY20005.html
    Works nice for the most part but the movement per stroke is SLOOOOOW. I think the cylinder moves about 1mm per pump so getting the cylinder into contact can take forever unless it it perfectly spaced the work piece. Near as I can tell it isn't air in the lines, just the amount of fluid per stroke from the pump.

    Anybody conjured a way around this flaw? I was thinking of two paths or maybe a combination of both.
    One would be some sort of extra reservoir with a manual valve and pneumatic assistance to quickly move the cylinder, but without much force. I haven't mapped it out yet but the trick may be venting two separate supplies to let the piston return.

    The second would be a big acme screw hanging off the cylinder that could be quickly adjusted to take up the initial space with a travel of 4" or so.

    Thoughts?

  • #2
    I think the easiest answer would be to come up with a piston and cylinder that has more volume but that may impeded the maximum amount of force that each stroke develops.
    Air over hydraulic would be another option. I'm surprised it doesn't have an ACME thread extension ram. If it were me I would look into adding one.

    I'll have to look at my Jet 15 ton to see how much the ram moves per stroke.

    After looking at the picture that the link brought me to I see it uses a Port O Power type pump. That makes it even easier to connect an air over hydraulic foot actuated pump.
    Somewhere I saw a two speed Port O Power hand pump. Cant remember where.

    JL............
    Last edited by JoeLee; 12-20-2021, 04:05 PM.

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    • #3
      Pressurize the oil reservoir with compressed air to rapidly advance the ram.

      -D
      DZER

      Comment


      • #4
        Originally posted by Doozer View Post
        Pressurize the oil reservoir with compressed air to rapidly advance the ram.

        -D
        First off, most reservoirs are vented and use a rubber plug at the filling point. You would have to change all that. I see other problems with this as well. Check ball or valves etc.


        JL.............
        Last edited by JoeLee; 12-20-2021, 04:21 PM.

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        • #5
          The 20 ton cylinders are slow, yes. One of my brakes uses one, another uses a 6 ton, and my press currently uses a 6 ton cylinder. These are all manual pumps, and the retract is much quicker on all of them than the hand cranking is. I would like to have a powered unit, but I think the only way to help the situation is to have a dual action piston. At light loads the bigger piston pumps, and when a certain pressure is reached, the smaller piston takes over. This could be as simple as a piston within a piston, with a defined point where the big piston stalls and the smaller one takes over. I don't know, but I would think there are pumps made to do this. You would get a faster 'pump down', then when the pressure builds the smaller piston takes over. I don't know what is a good point for this transition takes place- possibly 500 psi? Or- and I'm sure this technology is old already- air over. Say 100 psi- that's probably enough to push a ram fairly quickly before a pump takes over.

          This could probably be done while still using a manual pump. I'm trying to think of what a typical hydraulic jack has on it that you could use to enable a system like that. It has the pressure overload valve, and it has the release valve. Between the two I think it's possible to implement a home shop solution to this problem.

          I find myself using the acme threaded part of the ram quite a bit to shorten the distance between the ram and the workpiece before applying hydraulic pressure. I do also use a few different 'heads' with different 'business end' profiles, so I do use the threaded ram to advantage quite a bit. I do try to keep at least several threads engaged at all times so I don't mash the threads. This will be more important on a 20 ton jack than on a 6 ton.
          I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

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          • #6
            One way to get a fast action would be a sealed pressure tank connected to compressed air with a ball valve OR vented to atmosphere using a second ball valve. Then connect bottom of reservoir into line between piston and porta-power with a three way valve.

            You may only view thumbnails in this gallery. This gallery has 1 photos.

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            • #7
              Wouldn't you have pump oil to compress the air to get the jack to lift at load?

              Why doesn't anyone make these like modern floor jacks, with 2 parallel pumps; a fast pump (lo pressure) and slow pump (hi pressure). Best improvement to a floor jack ever.

              Mike

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              • #8
                Originally posted by MikeL46 View Post
                Wouldn't you have pump oil to compress the air to get the jack to lift at load?
                Mike
                No-You’d want the tank maybe half full of oil. The compressed air would push oil into piston but with a little care you wouldn’t get air into the hydraulic line.

                Retracting piston would mean juggling return flow to avoid overflowing one reservoir or the other.

                Two speed pump would be cleaner.
                Last edited by SVS; 12-20-2021, 04:58 PM.

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                • #9
                  My press uses its jack upside down, with a separate tank to keep air out of the jack. I can see using a second tank with air over- perhaps in this case the 'trick' would be in connecting the two tanks through some unique valving. But here's another idea- instead of air, why not a second hand pump? This would have a larger piston to give the faster action, and could be set up to automatically receive overflow from the first tank- 'cause that's where all the fluid is going to end up during retract. Instead of one jack handle there would be two- one for fast actuation, and the other as normal.
                  I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

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                  • #10
                    Originally posted by SVS View Post

                    No-You’d want the tank maybe half full of oil. The compressed air would push oil into piston but with a little care you wouldn’t get air into the hydraulic line.

                    Retracting piston would mean juggling return flow to avoid overflowing one reservoir or the other.

                    Two speed pump would be cleaner.
                    You could use one of these

                    https://www.northerntool.com/shop/to...7&gclsrc=3p.ds

                    Or a two speed pump http://porto-power.com/ProductCatego...cHandPumps/108



                    JL.............

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                    • #11
                      "ACME thread extension ram"
                      Yup. Mine is another home made press with a regular bottle jack. I added a threaded extension which allows me to quickly move the ram down to touch the work piece. Pumping is still slow, but at that point I usually don't care so much and may appreciate the finer control.
                      "A machinist's (WHAP!) best friend (WHAP! WHAP!) is his hammer. (WHAP!)" - Fred Tanner, foreman, Lunenburg Foundry and Engineering machine shop, circa 1979

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                      • #12
                        Air over hydraulic pump, faster then hand operated-

                        https://go.harborfreight.com/coupons.../177357-98318/
                        I just need one more tool,just one!

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                        • #13
                          Originally posted by Doozer View Post
                          Pressurize the oil reservoir with compressed air to rapidly advance the ram.

                          -D
                          This is all well and good until you have to push a 14" long broach through a part 3 times at .05" per stroke (-:

                          For the OP the best method of causing a machine to do what you want is to throw money at it until it obeys, since your business appears to be cycle time sensitive show the press some love and make it run at the speed that you desire.

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                          • #14
                            Find a small hyd pump driven by a electric motor and control valve would fix the issue.

                            Comment


                            • #15
                              Originally posted by JoeLee View Post
                              First off, most reservoirs are vented and use a rubber plug at the filling point. You would have to change all that. I see other problems with this as well. Check ball or valves etc.


                              JL.............
                              Sounds like you could be defeated by a stubborn cork in a wine bottle.

                              -Doozer
                              DZER

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