Crankshafts for large diesel engines that are used in container ships are usually forged in middle and small series. Because every crankshaft has specific features, their manufacturing and design is a challenge. This is where the forming simulation comes into play.
Wildauer Schmiedewerke GmbH is one of the few companies that is able to manufacture such “calibers.” To use the synergies for the tool concepts and the layout of the manufacturing processes, they cooperate with Schmiedag GmbH. Both companies are independent plants in Holding GmbH group. Because different assemblies are used, they offer a wide range of components. To optimize processes and get the desired results, the use of forming simulation has increased in both companies
Crankshafts have to meet extreme requirements and have to be designed and manufactured to endure the enormous load of the engine during the entire life cycle, because a failure is almost always connected with immense costs and life-threatening situations.
These components are usually forged in two stages. The first stage is for distributing the mass to have sufficient material in the area of the crank arms. Afterwards, the final forging process starts. Multiple blows then create the final shape. Depending on the complexity of the blank component, a forging blank is then designed from which the tool is derived. To check whether the constructed component is realizable by forging, a simulation is run. This makes sure that the blank can be adjusted in time if necessary, before it is presented to the customer for clearance. The goal of the layout is to have the fewest possible defects after forging.
Simufact.forming is used for these processes and the design of a weight-optimized use of the raw material. It is aimed at using a reduced weight for the forging to reduce the flash. This is the goal for all simulation projects at Schmiedag. A weight reduction of 10 – 30% compared to a first draft can be reached with a small simulation effort.
It has been six years since Schmiedag start using Simufact.forming for their simulation test. Since then, the material flow in the die, flash formation and variations of different die and workpiece shapes are analyzed and optimized virtually.
Despite further improvements to the entire manufacturing process of large crankshafts in the future, it can be stated today that the use of forming simulation significantly simplified and accelerated the preliminary layout and the manufacturing process itself and made it more cost-efficient.