“Modern engine hood hinge systems have become very complex products because of the vehicle design, the available building spaces, and pedestrian protection requirements. These demand an enormous amount of strength and stiffness from the material, and are the reasons why steel hinges today are as heavy as 3 kg per vehicle. Addressed to manufacturers of sports cars, premium, and special vehicles, we have developed LightHinge+, the lightest conceivable technical design for an active hood hinge through additive manufacturing and achieved a target weight of 770gr per hinge,” said Dr. Martin Hillebrecht of EDAG.
“For LightHinge+, the voestalpine Additive Manufacturing Center has contributed its expertise in laser technology, metal powder, and laser sintering machine parameters. In this method, a laser melts metal powders at defined locations,” explains voestalpine’s Dr. Eric Klemp. “The component is produced layer by layer. Topology optimization is used to calculate the minimum amount of material required for the hinge to sustain actual loads. The component geometry requires a high proportion of support structures. Thanks to the close cooperation between voestalpine as a construction supplier and EDAG as a developer, we were able to reduce the support structure to a minimum, thus achieving a low cost, low-resource product with little rework. The resulting hinge is ready-for-use after the laser melting process.”
“Simufact is a software specialized for the simulation of metallic production processes. With Simufact Additive, we have contributed to the improved design, protection and warpage optimization of the additively manufactured LightHinge+ hinge. In the additive production process, warping and residual stresses occur in the component due to the concentrated heat input with high heating and cooling rates. A distorted hinge can in turn deviate one to two millimeters from the targeted geometry,” said Dr. Patrick Mehmert.
With Simufact Additive, it is possible to simulate the printing process and the subsequent process steps, and thus predict distortion and stress. On the basis of the simulated warping, the component geometry is negatively deformed so that the shape deviations of the printed hinges to the CAD can be minimized. With Simufact Additive the quality of additive components can be improved significantly. And expensive and time-intensive production tests can be reduced greatly.
“With voestalpine additive manufacturing and simufact engineering, we have found the right partners for the realization of our vision. LightHinge+ dispenses with weight-consuming and complex kinematics and can achieve an additional degree of freedom in the movement kinematics by means of a bionic structure in combination with an additively manufactured breakaway structure. Breakaway structures and ultralight printed kinematics interact with the pyrotechnically triggered components, which lift the active bonnet in the area of the hinge to protect a pedestrian in the event of an impact,” said Hillebrecht.
EDAG’s, voestalpine’s and Simufact’s goal is it to support their customers in the automotive industry with the know-how gathered from the LightHinge+ in the development of new ultralight structures in 3D printing.