Development of car wishbone using sheet metal tearing process via the theory of inventive problem-solving (TRIZ) method

Abstract

In the automotive industry, sheet metal forming process design is of great importance. The cold forming process in particular is the most widely preferred of these methods. In the production of car parts in complex forms, forming problems such as tearing, wrinkling, back spring and unwanted thinning can appear. Recently, numerical analysis technology and software tools have been widely used in process design and metal forming. Elimination of these problems without the use of analysis programs means the use of the trial and error method, which results in much wasted time and huge costs. In addition to the use of analysis programs, resolving problems without mold process and design knowledge is also problematic. In this study, the theory of inventive problem-solving (TRIZ) approach was utilized to reach an analytical solution. In this methodology, the improving and worsening features were determined and a TRIZ 39 × 39 contradiction matrix was created which led to the solutions. Virtual experiments were carried out on a wishbone mold model designed via the Siemens NX 12 CAD program using the Autoform R7 analysis program. Real environment experiments were then performed, and the problem of tearing during the forming process was eliminated. The measured thickness value of this area, which was formed without tearing, was measured as 2.7 mm in the virtual environment experiments and 2.9 mm in the real environment experiments. In addition, the wishbone was subjected to two-axis (x and z) dynamic testing, with acceptable values reached at 500,000 cycles.