Hegewald & Peschke Meß- und Prüftechnik GmbH has successfully completed the development of its own series of hydraulic power units. Within the series, hydraulic clamping units are offered in a load range from 20kN to 2500kN. The units meet the highest requirements in terms of safety and specimen protection and also impress with their compact design.
Wide range of functions with convenient and simple operation
The devices allow working with different operating modes. In addition to single clamping and retensioning at the pressure threshold, continuous and force-proportional clamping are optionally available. These two optional modes are used for clamping sensitive specimens, for example, in order not to damage the material in the clamping area with the initial clamping pressure. The clamping devices are opened and closed conveniently in jog mode via the manual operation of the testing machine. The unit switches off automatically when the pre-pressure is reached and starts the main pressure automatically at the start of the test.
Maximum safety with compact design
The separation of the electrical components from the hydraulics is an important part of the CE conformity of the units. If required, the clamping pressures of the upper and lower fixtures as well as the system pressure can be continuously monitored via three analogue service manometers, even when the unit is switched off. In addition, a digital display of the upper and lower clamping pressures is mounted in the front area of the unit and it is possible to display the clamping pressures as measuring channels in the test software. The units are integrated into the emergency stop circuit of the testing machine or alternatively used in stand-alone operation. The volume flow of the hydraulic units is adapted to the clamping tool specification via a preset throttle. This allows the opening and closing speeds of the clamping device to be adjusted. A further advantage of the devices, especially for operator safety, is the low noise emission of 64 dB (A) even at maximum power. In order to optimise the space required at the installation site, the hydraulic power packs are available in two different housing types which are adapted to the load levels.
Safe clamping with optimum specimen protection
Optimum clamping of the specimens is ensured by the high-precision start-up of the set pressures. This allows even sensitive samples to be clamped gently. In applications with a temperature chamber, the sample clamping pressure is automatically regulated. When the oil in the fixture is heated, the pressure rises due to thermal expansion. The unit then releases enough oil to maintain the set pressure. In conjunction with the universal testing machine, the hydraulic units also allow an automatic force-hold mode during clamping.