An integrated framework of tool path planning in 5-axis machining of centrifugal impeller with split blades

Abstract

Centrifugal impeller is a complex part commonly used in aerospace, energy, and air-conditioning industries. Its manufacture involves multi-axis free form machining, a time consuming and error-prone process. Tool path planning is considered a critical issue in the process but still lacking of systematic solutions. This paper proposes a tool path planning framework for 5-axis machining of centrifugal impeller with split blades. It provides several CAM functions that assist the users to generate collision-free cutter motions with smooth tool orientations. First, the machining process is divided into four operations and the planning tasks of each operation are standardized. Second, the hub surfaces are properly decomposed, re-grouped, and re-parameterized to facilitate calculation of quality tool path with reduced cutter retraction and plunging. Finally, geometric algorithms are developed to automatically detect tool collisions and then correct the erroneous tool orientations. An optimization scheme is applied to minimize the total amount of tool posture changes after the correction. An impeller is machined with the NC codes generated from the framework. The result shows the effectiveness of this work in automating the tool path planning in 5-axis machining of highly intricate impeller.

Tool path planning for five-axis U-pass milling of an impeller

“…With the rapid development of industrial technology, demand has increased sharply, and highe Integral impellers are widely used in the aerospace, energy, and power fields. With the rapid development of industrial technology, demand has increased sharply, and higher requirements for the processing cost and efficiency of the product have been put forward [1][2][3]. Approximately 70%-90% of the machining allowance in impeller molding is removed through rough machining.…”

Efficient tool path generation for five-axis machining of a difficult machined centrifugal impeller

“…Through the methodology, rough cutting time was minimized, cutting parameters were optimized, and the productivity of impellers machined by five-axis machining was increased. Chu et al 4 focused on the five-axis machining of centrifugal impeller with split blades and proposed an integrated framework of tool path planning. The machining was divided into four production processes: rough machining, blade semifinish machining, blade finish machining, and hub finish machining.…”

“…The rotary contact method found the optimal tool positions by rotating the tool backward could generate big machined strip width, and the improved rotary contact method is developed to improve and perfect the rotary contact method. Chu et al 4,8 proposed a novel tool path planning for fiveaxis flank milling of ruled surfaces and centrifugal impeller with split blades. It provided several CAM functions in support of different issues in the planning, and the result demonstrated the effectiveness of the novel tool path planning.…”

“…From the above, it can be seen that the study about the five-axis machining of centrifugal impeller has been lasted for many years, and a series of research results are obtained. Despite this, there are so many difficult problems such as machining procedure, 4,5 surface quality, 6,7 and machining efficiency 3,4,8 need to be improved.…”

Optimal process planning for helical bevel gears using Taguchi design of simulated machining experiments

“…Since a different machining strategy is defined for each feature and the part to be machined consists of several equivalent combinations of machining features which interact with each other, process planning is generally a complex problem; thus, some standardisation of machining feature selection is necessary. 1 Typically, well-established or even customised machining strategies may be assigned to different regions of specific part types, 2,3 for example, serial, radial, strip and contour machining when referring to shoe moulds; 4 helical, helical zigzag and longitudinal zigzag in the case of blades 5 and curvature-dependent four-region machining of impeller blades. 6…”