Press with hydraulic overload protection - has discharge valve and pressure measuring devices connected to hydraulic cushion

摘要

The mechanical drive components of the press act on the slide via a pressure pad in the form of a hydraulic overload protection unit, and a compressed-air ram connected between the slide and the press frame counterbalances the weight of the slide and the upper tool mounted on it, the pressure in the ram being adjusted to the necessary level. A discharge valve functioning before air pressure is adjusted, and a pressure measuring device of high sensitivity in a zone including zero bars pressure, are connected to a pressure pad. The valve is controlled by a regulator unit for the air pressure, and the measuring device works in conjunction with valves delivering compressed air to, and discharging it from, the counterbalance ram.