Research On On-Machine Measuring And Allowance Optimization Technology Of The Integral Impeller

The complicated surfaces parts such as integral impeller is widely used in aerospace, aviation and energy industry. They are generally have the characteristic of high precision, difficult to machining and easy to deformation. How to manufacturing it with higher precise and efficient has been the focus of the research field of digital manufacturing. MeasurementMachining integrated technology makes it possible. The thesis in which the probe error compensation, measurement path optimization and allowance optimization problems are studied.Firstly, the main error source of machine measurement system have been analyzed, used a standard ball to demarcate the effective radius of the probe, and then used the bilinear difference algorithm to establish a mapping relations between the measurement point and standard ball, based on which we realizing point by point compensation of measuring surface. Compared to the setting compensation of commercial software, the way used in this paper has higher precision. I proposed a way which taking into account the step threshold and chord height difference. We can use fewer sampling points fitting the section line with higher precision. According to the detection range of the probe can be achieved, I came up with the concept of the probe feasible cone. Using feasible cone and theoretical model do collision detection to determine the practicable extent of probe. To ensure the smoothness of tool-path and avoid non-linear error caused by the substantially rotation of the rotating shaft, we can use minimum area discrete expression to determine the optimal tool orientation.in order to achieve the adaptive distribution of allowance, I modeled the margin optimization mathematical model, using the K-D tree model to calculate the closest point on the model, then generalized method of multipliers to solve the problem of the allowance optimization.Finally, I do an experiment with Titanium ally integral impeller. The result from show that the method proposed in this thesis can greatly improve the accuracy and quality of integral impeller. Thus, it can be used for controlling the product quality in actual processing, reducing production costs.