Reducing pressure transients in hydraulic circuits of die casting machinesto improve the quality of the produced components

Pressure pulses and transients are common problems in hydraulic circuits. T hey create specific problems with component accuracy in hydraulic circuits of die casting machines. In these machines, the molten metal is injected in to dies and a subsequent pressure boost fills all cavity details, improving the component quality. Pressure pulses during this stage result in elastic deformations within the die and cause inaccuracies of components. The pres sure pulses are caused by inertia forces of decelerating hydraulic motors. There is therefore a trend to reduce these forces by reducing the masses (i ncluding masses of hydraulic fluid) involved. Detailed mathematical modelli ng of the circuits in the time domain allows assessment of the magnitude of pulses even in the design stage and therefore the assessment of this aspec t of the design.