One of the advantages of using a mechanical press to perform the sheet drawing operation is the speed at which the press can run. It is not uncommon to see these presses running at speeds in excess of 18 strokes per minute. Combining this with a significant draw depth can produce individual cylinder flows rates in excess of 750 gallons per minute.
At these press speeds, the pressure cycle can be as short as .5 seconds. This requires a valve that can open, modulate and fully close in that time; smoothly regulating the rapidly decaying flow. The response time available is so short and the flow rates so high that Oilgear has developed a line of high flow 2-way servo operated, manifold mounted flow control devices along with matching flow control algorithms designed to optimize performance. This "integrated" solution provides very precise, repeatable and reliable tonnage and velocity control in an extremely high dynamic application.
Oilgear's current cushion designs consist of various cylinder and cushion pressure pad arrangements. One of the primary benefits of the intelligent cushion is its ability to accelerate prior to contact. This reduces the impact loading on the part as well as mechanical shocks to the press itself. The system provides for various types of locking features at the bottom of stroke and controlled return rates.