• Journal of Korean Institute of Industrial Engineers
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• v.21 no.2
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• pp.217-237
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• 1995

One of the most distinguished advantages of five-axis machining is that complex free surfaces(such as impeller) can be machined by one setup. Five-axis CNC machine, however, is very expensive so that its usage is restricted to a few large companies. As an economical approach to five-axis machining, this paper presents a method for machining the five-axis free surfaces(using ball-end mill) on a three-axis CNC machine with an index table. The method developed consists of: a) determining the minimum number of part setups and their interference-free and collision-free potential machining area, b) calculating actual machining area for each setup, and c) generating 3-axis cutter path for each part setup. The method has been successfully tested via computer simulations for several complex surfaces including impeller.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.3
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• pp.75-78
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• 2008

Tire molds are manufactured by aluminum casting, direct five-axis machining, and electric discharging machining. Master models made of chemical wood are necessary if aluminum casting is used. They are designed with a three-dimensional computer-aided design system and milled by a five-axis machine. In this paper, a method for generating and machining a tire surface model is proposed and demonstrated. The groove surfaces, which are the main feature of the tire model, are created using a parametric design concept. An automatically programmed tool-like descriptive language is presented to implement the parametric design. Various groove geometries can be created by changing variables. For convenience, groove surfaces and raw cutter location (CL) data are generated in two-dimensional drawing space. The CL data are mapped to the tread surface to obtain five-axis CL data to machine the master model. The proposed method was tested by actual milling using the five-axis control machine. The results demonstrate that the method is useful for manufacturing a tire mold.

• Korean Journal of Computational Design and Engineering
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• v.13 no.5
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• pp.382-390
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• 2008

Five-axis machining has been applied to manufacture of turbine blades, impellers, marine propellers. Nowadays it extends to mold & die machining, where more productivity as well as added value is expected. The five-axis machining can be divided into positional and continuous, according to the variableness of tool orientation during material removal process. The positional five-axis machining is commonly applied to the regional machining on a whole part surface in mold manufacturing industry, where the tool orientation for each region (area) should be determined to be feasible, that is, avoiding any interference such as machine tool collision, etc. Therefore it is required for a CAM programmer to decide a feasible tool orientation in generating tool-paths on a designated area, because it is a very tedious job to obtain such information by utilizing a commercial CAM system. The developed system generates feasibility data on tool orientation and machining region, which facilitates the CAM programmer's decision on a feasible tool orientation.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.1
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• pp.67-84
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• 1995

Five-axis NC machining is advanced machining technology by which highly geometrically complicated parts can be machined accurately with high machinability. In this paper, we investigate the problems of determining the machinability and part setup orientation for a given surface models. We first develop kinematic model of the five-axis machines based on the axis configuration, then develop algorithms for determining the feasibility of machining by one setup(machinability) and the part orientation for the C,A and A,B type configuration. The machinability is determined by computationally efficient procedure for finding the intersection between the feasible area on the sphere and the numerical map called binary spherical map(BSM), and the part setup is chosen such that the rotational range is minimized among the feasible configurations. The developed algorithms are tested by numerical simulations, convincing they can be readily implemented on the CAD/CAM system as an automated process planner giving the efficient machine type and setup for NC machining.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.1
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• pp.123-129
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• 2015

In general, recent critical studies of five-axis machine have tended to center on the question of effective machining to realize complex shape parts. However, the hydrostatic bearing and journal bearing, both of which are involved in the complex process of dividing the processing of internal precision-shape machining, must be optimized. Although the angle head is designed to machine the internal shape as it approaches the inner diameter of the work piece, research on the angle head in five-axis machining has received only minimal attention in domestic industries. In this study, an angle head which is optimized for effective internal shape machining is developed. In pursuit of this purpose, 3D and 2D designs of the angle head for five-axis machining are devised. Reliability is secured through static performance tests and machining accuracy evaluations of the angle head in keeping with the machining accuracy standard of 0.2mm for hydrostatic bearings.

• Korean Journal of Computational Design and Engineering
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• v.9 no.1
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• pp.35-43
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• 2004

It is well known that the five-axis machining has advantages of tool accessibility and machined surface quality when compared with conventional three-axis machining. Traditional researches on the five-axis tool-path generation have addressed interferences such as cutter gouging, collision, machine kinematics and optimization of a CL(cutter location) or a cutter position. In the paper it is presented that optimal CL data for a face-milling cutter moving on a tool-path are obtained by incorporating TSS(tool swept surface) model. The TSS model from current CL position to the next CL position is constructed based on machine kinematics as well as cutter geometry, with which the deviation from the design surface can be computed. Then the next CC(cutter-contact) point should be adjusted such that the deviation conforms to given machining tolerance value. The proposed algorithm was implemented and applied to a marine propeller machining, which proved effective from a quantitative point of view. In addition, the algorithm using the TSS can also be applied to avoid cutter convex interferences in general three-axis NC machining.

• Journal of Computational Design and Engineering
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• v.2 no.4
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• pp.197-205
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• 2015

Bladed disk (BLISK) is a vital part in jet engines with a complicated shape which is exclusively machined on a five-axis machine and requires high accuracy of machining. Poor quality of tool orientation (e.g., false tool positioning and unsmooth tool orientation transition) during the five-axis machining may cause collision and machine vibration, which will debase the machining quality and in the worst case sabotage the BLISK. This paper presents a reference plane based algorithm to generate a set of smoothly aligned tool orientations along a tool path. The proposed method guarantees that no collision would occur anywhere along the tool path, and the overall smoothness is globally optimized. A preliminary simulation verification of the proposed algorithm is conducted on a BLISK model and the tool orientation generated is found to be stable, smooth, and well-formed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.9
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• pp.924-933
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• 2007

An impeller is a important part of turbo-machinery. It has a set of twisted surfaces because it consists of many blades. Five-axis machining is required to produce a impeller because of interference between tool and workpiece. It can obtain good surface integrity and high productivity. This paper proposes finish cutting method for machining impeller with 5-axis machining center and optimization of cutting condition by response surface method. Firstly, cutting methods are selected by consideration of operation characteristics. Secondly, response factors are determined as cutting time and cutting error for prediction of productivity. Experiments are projected by central composite design with axis point. Thirdly, regression linear models are estimated as single surface in the leading edge and as dual surface in the hub surface cutting. Finally, cutting conditions are optimized.

• Journal of Computational Design and Engineering
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• v.2 no.4
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• pp.268-275
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• 2015

Blisk is an essential component in aero engines. To maintain good aero-dynamic performance, one critical machining requirement for blades on blisk is that the generated five-axis tool path should be boundary-conformed. For a blade discretely modeled as a point cloud or mesh, most existing popular tool path generation methods are unable to meet this requirement. To address this issue, a novel five-axis tool path generation method for a discretized blade on blisk is presented in this paper. An idea called Linear Morphing Cone (LMC) is first proposed, which sets the boundary of the blade as the constraint. Based on this LMC, a CC curve generation and expansion method is then proposed with the specified machining accuracy upheld. Using the proposed tool path generation method, experiments on discretized blades are carried out, whose results show that the generated tool paths are both uniform and boundary-conformed.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.7 s.196
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• pp.60-68
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• 2007

This paper presents an efficient 5-axis roughing method for centrifugal impeller. The efficient roughing is minimization of cutting time through minimizing tool tilting and rotating motions. To minimized cutting time, machining area is divided into sub-cutting regions using control points on hub curves and shroud curves of blade used to design and analyze centrifugal impeller. For sub-cutting regions, diameters of cutting tools are determined as big as possible. Then, tool paths are generated with the tilting axis and rotating axis of 5-axis machine limited and fixed, which can give more efficient machining speed and machining stability than the conventional methods. Experimental results show that the proposed method is more efficient than the conventional methods to mill with the only one cutting tool without dividing area and the previous methods to mill with simultaneous 5-axis processing with dividing area.