Papers by Keyword: High Precision Machining

Abstract: Narrow tolerances are commonly used to control uncertainty in the production of technicalcomponents. However, narrow tolerances lead to financial expense and limit flexibility. In this paperthe concept of a resilient process chain is presented. This concept covers the product life cycle phases ofproduction and usage. It is enabled by the digitalization in mechanical engineering and offers access tovariable process windows instead of rigid tolerances. First steps of this concept are then applied to the TU Darmstadt active air spring. The active air spring can be used to increase the driving comfort in avehicle or, for instance, to minimize kinetosis during autonomous driving. The focus hereby is toidentify possible production influences on the behaviour of the components usage. For this purpose, theactuator of the active air spring is specifically manufactured with typical uncertainty of high precisionmachining of the bore and characterized experimentally in a test rig. The results show an influenceof the production on the efficiency of the actuator. The measurements are fundamental to establish aresilient process chain on the active air spring.

Abstract: In recent years, with the rapid development of economy in Chinese society, the mechanical manufacturing technology is increasingly maturing and requirements for the product quality and product precision is becoming higher and higher, so the development of mechanical manufacturing technology and high precision machining technology has been widely concerned by the relevant departments. According to the actual development of the modern machinery manufacturing technology and the high precision machining technology, on the basis of the principle of mechanical manufacturing, the characteristics of mechanical manufacturing technology and high precision machining should be analyzed thoroughly, meanwhile, the performance of the mechanical manufacturing process and high precision machining technology should be improved, thus, it can provide more theoretical basis and technical guidance for the development of mechanical manufacturing industry.

Abstract: This paper proposes a new approach to tool path generation in precision machining of parts with sculptured surface. It aims to develop an effective NURBS fitting algorithm suitable for machining sophisticated parts requiring smooth profile on sculptured surface. In order to generate NURBS tool path with fewer control points, a dual-loop fitting technique is proposed in this paper. A general sculptured surface model is used to test the effectiveness of this method. It is shown that the proposed algorithm proved to be robust and effective in generating precise NURBS tool path. This makes the proposed algorithm suitable to convert conventional CNC tool path to more precise NURBS tool path. This approach may be of potential to be widely implemented in the manufacturing industry.

Abstract: A liquid tunable diffractive/refractive hybrid lens which combines the use of high precision diamond turning and soft lithography is developed in this work. This diffractive/refractive hybrid lens comprises a Fresnel lens and a tunable refractive lens automatically aligned during the fabrication process. Multiple PDMS hybrid lens devices can be fabricated from the diamond-turned master mould and AFM results show that the surface quality of the PDMS lenses meets the requirements for optical purposes. The hybrid lens is tested with a green laser (λ = 532nm) and experimental results demonstrate a tunability of more than 20mm.

Abstract: This work proposes a practical approach to generating NURBS tool paths by accurately fitting ideal paths. A two-stage fitting process is included in this approach. Since NURBS paths can make accurate, smooth sculpture surfaces, this approach can promote the use of these paths in the manufacturing industry.