Papers by Keyword: Tool Path

Abstract: This study involved planning different tool paths for an axisymmetric cup to explore the forming characteristics of the single point incremental forming (SPIF) process. In addition, this study developed a gradient theory to compute the inclined angle between the tangential and horizontal directions of the cup formed using single point incremental forming. The sheet thickness distribution of the cup was also calculated. To verify the theory, circle arc cups were formed by CNC machining using different tool paths. It was found that the cup formed using the spiral evolutional snail-line tool path produced a better surface than that formed using the equal height evolutional tool path. The sheet thicknesses of circle arc cups obtained by the experiment and using the cosine law were compared. A larger deviation was noted in the initial portion of the cup, whereas a smaller deviation was found in the other portion. This study also adopted a dual-conical cup to investigate the relationship between thickness and the initial inclined angle at the initial portion. It was found that a larger initial inclined angle led to good coincidence between the experimental and theoretical sheet thicknesses.

Abstract: The use of freeform (sculptured) surfaces in the product design process is accelerating at an exponential rate driven by functional as well as esthetics demands. CAD/CAM software is a must in their design are relatively well-covered, issues still remain when it comes to the actual manufacture of freeform surfaces. The major issues are related to the chosen feed rate, toolpaths and step over that would assure the required surface quality, the minimization of the total machining time, etc. This research presents an experimental study to define the effects of machining’s parameters (including: feed rate; toolpath and step over) for CNC 3-axis ball end milling process. The result shows a model for cutting is formulated and incorporated into the parameters of machining that is compatible with all CAD/CAM systems. This result can be used to choose parameters of optimum including federate, toolpath and step over when machining of other freeform surfaces. Keywords: Freeform surface; tool path; ball end milling

Abstract: This paper investigates different machining toolpath strategies on machining efficiency and accuracy in the micro milling of linear and circular micro geometric features. Although micro milling includes many characteristics of the conventional machining process, detrimental size effect in downscaling of the process can lead to excessive tool wear and machining instability, which would, in turn, affects the geometrical accuracy and surface roughness. Most of the research in micro milling reported in literature focused on optimising specific machining parameters, such as feed rate and depth of cut, to achieve lower cutting force, better surface roughness, and higher material removal rate. However, there was little attention given to the suitability and effect of machining tool path strategies. In this research, a tool path optimisation method with respect to surface roughness and dimensional accuracy is proposed and tested experimentally. Various toolpath strategies, including lace(0°), lace(45°), lace(90°), concentric and waveform in producing linear and circular micro geometric features were compared and analysed. Experimental results show that the most common used strategies lace(0°) and concentric reported in the literature have provided the least satisfactory machining performance, while waveform toolpath provides the best balance of machining performance for both linear and circular geometries. Hence, at process planning stage it is critical to assign a suitable machining toolpath strategy to geometries accordingly. The paper concludes that an optimal choice of machining strategies in process planning is as important as balancing machining parameters to achieve desired machining performance.

Abstract: Taking the CY4105 crankshaft mould as the research target, this paper introduced the CNC machining method based on CAD/CAM technique. At first, structure of the mould was introduced. Then, machining method was introduced, including blank setting method, cutting tool selection, machining method selection and technological parameters setting method. After that, generation method of the mould machining programs was introduced, including tool path and G codes generation. At last, the mould was machined by a vertical machining center, and the results show that the machining accuracy is high.

Abstract: Cutting temperature generated during high speed machining operations has been recognized as major factors influence tool performance and workpiece geometry. This paper aims to model the cutting temperature and to investigate cutting temperature behaviours when contour-in tool path strategy applied in high speed end milling process. The experiments were carried out on CNC vertical machining center by involving PVD coated carbide inserts. Cutting speed, feed rate and depth of cut were set to vary. Results obtained indicate that cutting temperature is high in the initial stage of milling and at the corners region or turning points region. Portion of radial width of cut with workpiece in combination with the abrupt change of the milling path direction occur particularly in acute internal corners of a pocket leads to rise of cutting temperature.

Abstract: In NC milling tool path reflects all the processing process, the tool path is reasonable or not, related to the workpiece processing quality and production efficiency, through several parts of the typical contour shape analysis, determination method of NC machining tool path, determined by the combination of NC milling tool path, to reduce the surface roughness of the workpiece, improve workpiece processing quality objective.

Abstract: Point cloud has been used as representation model for tool path planning. However, for point cloud machining, there are few tool path generation strategies but iso-planar method. In this paper, a method of generating tool paths from point cloud for three-axis machining is presented. A simple base surface, such as plane or cylindrical surface, etc., is first created according to the shape of the point cloud. On this base surface, the guide curves of tool path are rapidly designed, and then are projected onto the point cloud surface to generate the final tool path by using the least squared projection method. Finally, this method is tested on a sample surface to demonstrate its validity.

Abstract: The cloud computing can allocate computer resources according to customers different demand dynamic status, which has improved the calculation efficiency, and saved the cost of hardware. This paper establishes the 3D mathematical model of data programming tool radius compensation system, and gets the tool radius compensation control equation according to the interpolation function. It designs the tool radius compensation discrimination system with the combination of UG software. In order to verify the validity and reliability of the system, the paper takes the processing process of leaf as an example to design the tool radius compensation algorithm, and the compensation deviation has been made numerical simulation, which has obtained error compensation curve and tool radius compensation parameter table. It can obtain reasonable tool compensation cutter and cycle according to the input of tool parameters, which provides technical support for the research of numerical control (NC) machining technology.

Abstract: This Paper Designs the Intelligent Automatic Processing System of Precision Complex Work pieces by using the computer scanning technology and PLC control technology, and the use of computer scanning can capture the physical map, and then according to the physical map to divide into finite element grid, we can get the mechanical processing node path. The intelligent machine drive system is designed, and the system equip with MD32207 signal driver, 220V single-phase AC, power supply and using the pulse and direction signals common anode connection terminal, Finally, the system is applied to the computer college students' ideological and political education public opinion monitoring system, and the Meta search and intelligent information event extraction idea are also put forward, to provide the technical reference for the college students’ internet ideological and political online education.

Abstract: In order to solve the problem of poor steam turbine blade processing efficiency, and on the basis of analyzing the turbine blade surface and the existing processing methods, a model of circular cutter turbine blade machining is built. By comparing the tool paths of horizontal and vertical section envelope machining, choosing quasi-vertical cross section envelope machining method and utilizing the original datum and NURBS surface matching mathematic methods, this paper provides an algorithm of residual height calculating, and based on this, the tool path can be planned. Datum show that, the tool path of circular cutter machining blades is much longer than the tool path of ball-end cutter envelop milling machining blades, and the machining efficiency is also highly enhanced.