A Casting Mould for Rapid Tube Hydroforming Prototyping

Abstract

In recent years, hydroforming has clearly expanded its range of industrial applications due to the growing interest in products which combine high strength with low weight. A current limitation of this technology was its economically justified production volume since the costs of producing tools eliminates the possibility of using hydroforming technology in prototype and single part production. The paper presents a freshly patented solution that allows for single part hydroforming. The new technology combines traditional hydroforming machines with a new approach to tool production. The new rapid die is made quickly and cheaply. The use of materials known from the production of foundry moulds causes the die to deform during hydroforming, but it is a controlled deformation. Thanks to the use of numerical modelling, the deformation of the mould cavity is predicted and taken into account at the design stage. The article presents important issues that need to be considered in the design of this innovative process.

Application of the Numerical Model to Design the Geometry of a Unit Tool in the Innovative RTH Hydroforming Technology

“…On this basis, the width of the cohesion coefficient c and the internal friction angle ϕ which are the critical values for the M-C model, are indicated; c = 0.1-5.0 MPa, and ϕ = 10 • -50 • [14]. The lower values were assigned to the moulding masses, and the upper values were assigned to materials belonging to fragmented centres in the field of geology, i.e., soil and rocks.…”

“…The rapid tube hydroforming (RTH) method, recently patented by the authors [12], makes hydroforming cost-efficient for single-piece production. The new method has thereby complemented the range of hydroforming technology and allowed for its use in the full range of production volumes, as represented in Figure 1 which highlights the new completed classification of hydroforming methods [13,14]. In regular hydroforming processes, as in many other metal forming techniques, the die cavity is designed to force the final product shape.…”