MAPAL – Machining of Unstable Structural Parts

 

Thin-walled parts are used in a wide variety of applications. These components are often manufactured close to the net shape, but nevertheless require a great many machining operations. The particular challenge for these machining processes is that due to their design, these parts are very unstable and susceptible to vibration. That creates special demands upon the design of the process and the tools.

These parts are preferably machined in a single clamping system. In order to meet this demand and to make as many of the surfaces to be machined as accessible to the tools as possible, certain allowances have to be made in the clamping system. As a consequence, the workpiece is not optimally supported and tends to vibrate. Thin webs, voids and interruptions to be machined and widely fluctuating stock removals from the cast blank also call for special tool solutions. For large parts with many machining steps, this would require a huge number of tools. The merging of these steps using combination tools in order to reduce the non-productive times and the number of tool slots is an ideal solution.

Thanks to its vast understanding of the processes for the machining of unstable structural parts, MAPAL is able to offer cost-effective and reliable processes. Three aspects are of particular importance here. Firstly the adjustment of the cutting rate is a factor for reducing or avoiding rising vibration. Both vibration of the tool – which would result in short tool lives and poor machining results – and vibration of the workpiece have to be prevented. The latter would result in a recoiling of the part against the cutting edge and could cause damage to the tool. The second important adjustment in the tool design is the evaluation of the tool body. Vibrations can be reduced here by an appropriate design and choice of material. Furthermore, an intelligent arrangement of the cutting edges in form and position helps to keep the cutting forces low. And finally the machining process itself offers possibilities for reliable machining of parts susceptible to vibration. Reorganization and the choice of alternative sub-processes create a change in the distribution of forces that can increase the process reliability. For example, the use of a circular milling operation instead of a solid drilling operation can help to stabilize the process.

Please contact us for more information on machining of Structural Components.

– This article is an excerpt from Mapal Innovations – Process Solutions