Advice Needed for Hydraulic Press circuit

Purely from an economic standpoint I think you will be better off to farm out the part to a deep draw specialist. By the time you build a press and fight all the unknowns for an unforseeable period you will have an enormous cost per part involved.

If you really must do it yourself the best way to rapidly extend and retract the ram is air over hydraulic. You must have a tank that can be pressurized with air and a valve to inject and release the air. You could make the valve release the air to atmosphere by using a pressure switch that will trip at the proper point and let the hydraulic take over.

Deep drawing is a very specialized and tricky process. Be sure you study it throughly before attempting it. Even a simple shallow draw is seldom right on first tryout of the tooling. The dies are simple unless they are mulitstage but as with many simple processes every detail must be exactly right. Maybe you already know this but I thought I would toss it in just in case.

Another tip. If you do build a press you might save a lot of money if you can find a shop with a vertical boring mill and has lots of open time on it. Sometimes you can get real bargains. Casting the entire top end in one piece would be a good way to go if you can find such a shop.

Good luck.

Hydraulic design is what I do for a living, so I'll see what we can do. First things first, as with any mechanical exercise, we have to find the load you are working against. After we determine that, we work out the speed issues. There are a lot of ways to skin that cat. I am not so sure I would depend on air over hydraulics to do this though. A lot of potential snakes in that circuit, depending on what part of the country you live in. It is also a maintenance nightmare.

To minimize flow rate issues, you can run a regen circuit, but first you have to look at the load, because you may have to use a decompression circuit to release the energy generated, which is quite common in a press or stamping circuit. The downside to a decompression circuit is it reduces cycle time somewhat, but if you ignore using it, you will pay one heck of a price hydraulically and structurally.

To meet your production requirement, I would be looking at my mold maker to facilitate multiple pieces at one time.That is what keeps Tech Mold, Inc. in business.

Lets look at the structural issues, then we can calc load capacity, then speed. Anything less, and life can get very complicated very quick.

Approximately a 600t press is required for the job. For a blank size of 750 x 500, 75 height is only a shallow draw & not a deep draw. This job can be done on a 600t press with a 200t die cushion. Is this a rectangular draw or an elliptical one? Is the load balanced or offset to one side? What is the tolerance & finish requirements? I can help you if you can send the drawing of the job. Rectangular draw can be tricky.

I do not know, if horizontal boring machines which can macine the press frame is available in your location. Same holds good for other hydraulic components such as pumps, valves, cylinders, fittings etc. If you are new to hydraulic presses, i will advise you not to start with a 600 t press. You are likely to have your hands full with the draw, even without the hassle of repairing a hydraulic press all the time. good luck

Hello,

perhaps I don`t know all the details, but the process required would be considered a draw, not a deep draw. The decision to use a hydraulic process would be correct for a deep draw, depending on the part complexity, rads, and properties. Do you have a picture of a sample part? It is likely that thepart can be manufactured on a conventional press.

The comments of others on the tonnge requirement seems incorrect. I would venture to say the requirement would be much less than 600 Tons, likely within 300 Tons.

With a mechanical press process and the use of a nitrogen cylinder binder system, to assure there is no wrinkeling going into the draw (wrinkles in this fairly thick material would increase the tonnage) should yield you to make 5-10 parts per minute. It seems you have conventional press experience. A draw can be a tricky thing, and an experienced toolmaker / engineer will make all the difference.

If you do decide to go with Hydraulics, assure to use as large a diameter of connectors and hoses as practical, your stroke will be likely 2" and the cycle will be only a couple of seconds per direction.

Need more part info for a better answer, ie rad sizes on final part, bottom rad and draw rad, side wall angle, open or closed draw, etc. A picture would be best.