Hydraulics & Pneumatics March 2022

HYDRAULICS 28 HYDRAULICS & PNEUMATICS March 2022 www.hpmag.co.uk With the Carat 840 and the Carat 920, Bühler from Uzwil is further expanding its range of die casting solutions. The company claims they are the most powerful machines of their kind in the world. It is thus responding to the increasing demand from the automotive industry for machines to produce ever larger components. An important part of the new machines are the hydraulic accumulator systems from Roth Hydraulics in Biedenkopf. They enable high component quality and ensure reliable and energy-efficient casting forces for the machine. Automobile manufacturers are breaking new ground in their production. New production processes with high clamping forces are required for the manufacture of large-format and complex aluminium components for car bodies, for example to produce front or rear underbodies for vehicles. The new Carat 840 and Carat 920 die casting machines from Bühler make such production solutions possible. The central component here is an extremely powerful and precise injection unit with uniform clamping force application. To reliably meet this requirement, Bühler decided to use a pressure accumulator system from Roth Hydraulics. It is the drive of the casting unit, which decisively generates the component quality and ensures a permanently reliable performance. Powerful and dynamic casting unit The demands on the accumulator system are many-sided: on the one hand, the new solutions require a larger amount of stored energy and, on the other hand, an extremely fast power development in order to ensure the necessary dynamics of the injection unit. The Carat 920 casting unit, for example, develops 2130 kilonewtons of dynamic casting force and 5340 kilonewtons of solidification pressure. The special challenge here is to enable around 1.5 metres of piston stroke within 100 milliseconds in the second phase of the casting process. The acceleration of the entire system including liquid aluminium is practically from zero. “The Carat 920 can inject more than 200 kilograms of liquid aluminium into a Powerful die casting machine from Bühler with Roth hydraulic accumulator The die casting machine Carat 920 from Bühler is equipped with a hydraulic accumulator system from Roth Hydraulics. (Photo: Bühler AG) Michael Cinelli, product manager die casting at Bühler appreciates the partnership withRoth Hydraulics in the development of new technology solutions. (Photo: Bühler AG)