Development of a Novel System for Adaptive Machining of Near-Net-Shape Components

Near-net-shape components are popular among the aerospace industry for low material waste and high manufacturing efficiency. However, it is difficult to machine such components into final shapes because the machining allowance is often distributed unevenly and even insufficient. This paper proposed a novel system for adaptive machining near-net-shape components, which integrates units like on-machine measurement based on probe and ultrasonic-sensor, machining allowance constrained localization, tolerance range constrained shape reconstruction, and TCP (tool cutter position) template-based NC programming. Firstly, localization and free form deformation (FFD)-based shape construction are performed within the tolerance ranges of the component, and an even distribution of the machining allowance can be obtained. Next, the quick NC programming that directly manipulates the TCPs by using spatial deformation is introduced. Last, the data transmission between units is illustrated. A case study of the machining titanium turbine blade is performed, which validates the proposed system.

A Study on Interferential Tool Position Correcting Algorithm in Rough Machining of 3d Impeller Variable-axis Plunge Milling

The plunge milling method has remarkably improved the rough machining efficiency of 3D impeller channel. However, in conventional cutter position planning for plunge milling, interference at the end of every cutter position due to sudden increase of radial depth is inevitable, which may seriously compromise the service life of machine tool and cutter, as well as the cutting efficiency at the interferential phase. This study optimized the cutter axis vector for the tool path of conventional rough machining of 3D impeller variable -axis plunge milling to make the angle between the normal vector for workpiece surface at the cutter contact point and the cutter-axis vector of adjacent tool position increase gradually from outlet to inlet at the smallest scale. Based on this, an iterative algorithm for tool center position and safety height for the cutter was provided, thus making the hub allowance of the optimized tool path for plunge milling as small as possible without affecting the subsequent machining on the premise of avoiding the interferential phenomenon. Finally, the correctness of the proposed method was verified by relevant numerical examples.

Solution and Verification of Cutter Position for Machining Split Equal-Base Circle Bevel Gear

The purpose of this study is to achieve machining of a split equal-base circle bevel gear. Based on the equal-base circle bevel gear theory, a cutting coordinate system for the separate piece is developed, and the tooth surface processing path of the separate piece is analysed and planned. According to the working principle of the equal-base circle bevel gear, by analysing the cutter position and posture, the calculation method for the angle between the wheel blank coordinate system and the fixed space coordinate system is derived when machining the separate piece for different spiral angles as well as various concavity and convexity properties. The explicit function expressions for the cutter centre coordinates and axis vectors for machining the separate piece are obtained. Using MATLAB, the tool position model is verified by means of calculation, and the tooth cutting simulation of the separate piece is carried out using VERICUT software. By machining experiment and tooth surface measurement analysis, the feasibility of machining the separate piece and the correctness of the tool position mathematical model are verified.

Research on the Effect of Cutter Position Points Distribution Optimization on Surface Milling Accuracy

The research analyzed the distribution of cutter position point data outputted by software CAM, based on the precision of surface milling. The model of the tool-path is established by using the piece-wise interpolation function, combining with the distribution characteristic of cutter position point. The segmentation optimization of the tool-path is also realized via the limitation and judgment of the string high error of the segmented trajectory and the optimization algorithm is integrated into the post-processing to improve the precision of the surface milling. The experiment results of surface milling show a positive effect of cutter position point optimization on surface milling accuracy.

A Numerical Simulation Study on Machining Performance for Front Face Circular Grooving Using Special Structure Milling Cutters — Part 1: Simulation Method and Examination of Machining Capacity

This paper proposes a simple and convenient numerical simulation approach to examining the characteristics and machining capacity of the manufacture process to machine a front face circular groove on a multi-tasking machine tool by a side milling cutter with special structure. In the first part of the paper, the simulation method is explained and then based on the simulation results, several important problems in applications are discussed such as how to design the cutter profile and determine the cutter position in grooving. Furthermore, an improved process is also developed for correctly machining a groove with specific profile in the required shape.

Method of Tool Path Optimization in Impeller NC Machining Based on Configuration Space Theory

The impeller as the key part of aircraft engine components, and the impeller blade surface is complex, and it is a typical complex difficult machining parts. Five-axis NC machining is the important means to realize sculptured curved surface parts machined with high quality and efficiency. In this paper, in view of the interference problems occurred in the process of impeller five-axis NC machining tool path generating, the configuration space method is proposed to tackle the problem of interference, cutter location point as constraint conditions, the cutter position is described by using two angle parameters, optimization of cutter position, tool path generated without interference, improve the impeller machining quality and production efficiency. Finally, as a case study of a certain type of impeller, it makes arithmetic realization combining with MATLAB.