Method of grinding a workpiece having a cylindrical bearing surface and method for determining processing parameters

The present disclosure relates in general to a method of grinding a workpiece by means of a grinding wheel, the workpiece comprising a cylindrical bearing surface, a radially extending sidewall extending outward from the cylindrical bearing surface, and a curved transition portion connecting the cylindrical bearing surface with the sidewall. The present disclosure also relates to a method for determining processing parameters of such a grinding method

On geometry and kinematics of abrasive processes: The theory of aggressiveness

Due to the stochastic nature of the abrasive-tool topography, abrasive processes are difficult to model and quantify. In contrast, their macro geometry and kinematics are usually well defined and straightforwardly controlled on machine tools. To reconcile this seeming contradiction, a novel unifying modelling framework is defined through the theory of aggressiveness. It encompasses the arbitrary geometry and kinematics of a workpiece moving relative to an abrasive surface. The key parameter is the point-aggressiveness, which is a dimensionless scalar quantity based on the vector field of relative velocity and the vector field of abrasive-surface normals. This fundamental process parameter relates directly to typical process outputs such as specific energy, abrasive-tool wear and surface roughness. The theory of aggressiveness is experimentally validated by its application to a diverse array of abrasive processes, including grinding, diamond truing and dressing, where the aggressiveness number is correlated with the aforementioned measured process outputs

Modelling of a continuous veneer drying unit of industrial scale and model-based ANOVA of the energy efficiency

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Method of grinding a workpiece having a cylindrical bearing surface and method for determining processing parameters

A method of grinding a workpiece by means of a grinding wheel is disclosed. The workpiece comprises a cylindrical bearing surface, a radially extending sidewall extending outward from the cylindrical bearing surface, and a curved transition portion connecting the cylindrical bearing surface with the sidewall. During grinding, the feed in an increment is selected so as to achieve a pre-set maximum surface temperature of the workpiece at a point of the grinding wheel resulting in the highest surface temperature of the workpiece. Furthermore, a method for determining processing parameters for such a grinding method is disclosed

Temperature-based method for determination of feed increments in crankshaft grinding

The design of a crankshaft-grinding cycle involves determining the radial infeed and axial infeed in each feed increment. A new method for determination of feed increments is developed to increase productivity while avoiding thermal damage. Analyses of the geometry, kinematics and specific-energy characteristic are made to estimate the feed-dependent distribution of maximum surface temperature along the wheel profile. It is discovered that there are two temperature maxima in the grinding zone when feeding both axially and radially. Therefore, the developed method determines the infeeds such that a predetermined burn threshold is matched in these two critical points. The new technology is validated by measurements of Barkhausen noise and residual stress. A comparison is made between the temperature-based method and the radial-plunge method previously used in production. The comparison indicates that lower cycle times are attainable with less risk of thermal damage. Results for material-removal rate and maximum surface temperature are also presented

High-performance industrial grinding: recent advances and case studies from the automotive engine production

The development of new high-performance industrial grinding technologies for engine production in the automotive industry is presented. The grinding fundamentals are revisited in view of modeling and simulation to examine the effects of process design on grinding temperatures. The advantages associated with utilization of newly developed temperature-controlled grinding processes are explained via the analysis of process-control strategies. Two research-and-development projects from Scania\ub4s engine-production plant are discussed to illustrate industrial challenges and achieved impacts. Two case studies are presented for (1) cam-lobe grinding and (2) crankpin grinding, demonstrating optimized grinding processes for achieving shorter cycle times and higher quality. Both patent-pending technologies are experimentally validated in actual production and are implemented in existing production lines