共查询到20条相似文献,搜索用时 15 毫秒
1.
Planning of tool orientation for five-axis cavity machining 总被引:2,自引:2,他引:0
PhD. Robert Gian Masters student T.W. Lin Prof. Alan C. Lin 《The International Journal of Advanced Manufacturing Technology》2003,22(1-2):150-160
This study examines the feasibility of using open regions and vector fields to determine the appropriate tool orientation in five-axis NC machining of cavity regions with undercut areas. The first step involves slicing the to-be-machined surface into thin layers and then comparing those layers to find the position of the undercut; that is, the position of open region. Two-staged checking is proposed to determine the tool orientation that prevents collision. The two stages are initial tool orientation and collision inspection. An initial tool orientation is obtained by assessing the angle of the vectors determined by data points of contours of the open region and cutter contact (CC) points. If a collision is found in the initial orientation, then the tool orientation must be revised until no obstacles are generated from the collision. 相似文献
2.
Chen-Wei Shan Ding-Hua Zhang Wei-Wei Liu Jun-Xue Ren Xiao-Jun Lin 《The International Journal of Advanced Manufacturing Technology》2009,43(5-6):563-572
This paper aims at developing a novel spiral machining technique for four- or five-axis milling of blades. The main contributions are twofold. First, detailed algorithms are presented to model the blade surface with the idea that it can be separated into four patches, i.e., the pressure surface, the suction surface, the leading edge surface, and the trailing edge surface. The G1 continuity across the boundary of each patch is considered. Second, based on the four patches modeled, the key routine of a new spiral machining method is further addressed in detail. It is carried out by machining the pressure and suction surfaces actually whereas passing by the leading and trailing edges in air cut. Experimental results show that the proposed methods can improve the machining quality and avoid overcut near the leading and trailing edges. 相似文献
3.
Armando Roman S. Bedi F. Ismail 《The International Journal of Advanced Manufacturing Technology》2006,29(5):524-531
Despite the inbuilt advantages offered by five-axis machining, the manufacturing industry has not widely adopted this technology
due to the high cost of machines and insufficient support from CAD/CAM systems. Companies are used to three-axis machining
and their shop floors are not yet ready for five-axis machining in terms of training and programming. The objective of this
research is to develop and implement a machining technique that uses the simplicity of three-axis tool positioning and the
flexibility of five-axis tool orientation, to machine sculptured surfaces. This technique,
-axis, divides a sculptured surface into patches and then machines each patch using a fixed tool orientation. This paper presents
the surface partitioning scheme and the method of selecting an optimum number of sub-divisions along with actual machining
experiments. For the example surface utilized in this study, the proposed hybrid method led to shorter machining time compared
to traditional three-axis machining and comparable to simultaneous five-axis machining . 相似文献
4.
Armando Roman S. Bedi F. Ismail 《The International Journal of Advanced Manufacturing Technology》2006,29(5-6):524-531
Despite the inbuilt advantages offered by five-axis machining, the manufacturing industry has not widely adopted this technology due to the high cost of machines and insufficient support from CAD/CAM systems. Companies are used to three-axis machining and their shop floors are not yet ready for five-axis machining in terms of training and programming. The objective of this research is to develop and implement a machining technique that uses the simplicity of three-axis tool positioning and the flexibility of five-axis tool orientation, to machine sculptured surfaces. This technique, 3½½-axis, divides a sculptured surface into patches and then machines each patch using a fixed tool orientation. This paper presents the surface partitioning scheme and the method of selecting an optimum number of sub-divisions along with actual machining experiments. For the example surface utilized in this study, the proposed hybrid method led to shorter machining time compared to traditional three-axis machining and comparable to simultaneous five-axis machining. 相似文献
5.
Zhenpeng Mi Chun-Ming Yuan Xiaohui Ma Li-Yong Shen 《The International Journal of Advanced Manufacturing Technology》2017,88(5-8):1243-1255
Collision avoidance is a fundamental problem in five-axis tool path planning. A two-step frame is widely used in tool path generation, that is, to determine C-spaces and then to design collision free pathes in the C-spaces. We present a feasible C-space computation algorithm for triangular mesh models based on collision-cone computation and stereographic projection. Then we sample points in the free area at each CC point and generate a tool orientation using the graph-based method. We also introduce a difference graph to find a smoother tool orientation. Experimental results show that the accelerations and velocities of the rotation axes are much smoother than those given by Plakhotnik and Lauwers (Int J Adv Manuf Technol 74:307–318, 2014). 相似文献
6.
Closed-loop machining cell for turbine blades 总被引:1,自引:1,他引:0
Reuven Katz Vijay Srivatsan Lalit Patil 《The International Journal of Advanced Manufacturing Technology》2011,55(9-12):869-881
This paper presents an innovative concept of a closed-loop machining cell for turbine blade finishing that integrates a robotic surface finishing device with an electro-optical, non-contact precision measuring system. We propose that a synergistic combination of these leading edge technologies allows us to close the loop between finishing and inspection. Instead of part measurement being a mere off-line verification operation, it can direct the robot to do the necessary work and provide feedback to achieve higher finishing precision. In this paper, we describe the challenges in closing the loop seamlessly and our approach to resolve them. We present the overall architecture in which the part is measured using a multiple cooperative sensor system, and the robot is directed until the desired finish is obtained. We present details on the use of multi-sensor inspection and corresponding integration of the various components (hardware and software). We validate by application to turbine blades that are used commercially. Utilizing the suggested concept, turbine blade manufacturers will benefit by realizing greatly increased product throughput and reduced cost. The potential for generating scrap is reduced, and two separate, time-consuming operations will be consolidated into a single setup. It will also reduce hardware, footprint, maintenance, and energy costs by their sharing of common components. This concept can be extended to similar closed-loop manufacturing cells with minor modifications. 相似文献
7.
A design method is proposed for automated processes used in the manufacture of gas-turbine blades. As an example, the manufacture of stator blades for a gas turbine is considered. A multifunctional numerically controlled grinding machine is used in the example. 相似文献
8.
Graph-based optimization of five-axis machine tool movements by varying tool orientation 总被引:1,自引:0,他引:1
Denys Plakhotnik Bert Lauwers 《The International Journal of Advanced Manufacturing Technology》2014,74(1-4):307-318
There is a relatively vast class of tool path optimization methods that minimize cost functions depending on a whole tool path. In these methods, cost functions are usually limited to convex function because the used optimization approaches cannot either handle nonsmooth functions or perform with an acceptable computational time. This paper describes a developed optimization method that finds a sequence of tool orientations that can minimize various cost functions including displacement of machine rotary axes. Every posture, tool feasible orientation can be represented in discrete fashion as nodes of a directed graph in which the edge weights denote an objective. Shortest paths are sought iteratively by applying Dijkstra’s algorithms and narrowing intervals of feasible tool orientations around the previous solution. The developed algorithm is a derivative-free optimization method working in a linear time. 相似文献
9.
虚拟物理数控加工仿真主要研究加工过程中切削力、切削热、机床运动误差、加工系统颤振以及负载变化引起加工结果变化的预测问题,目前已成为虚拟制造最具魅力的地方。通过在VERICUT下的电吹风外壳模盖的虚拟数控加工刀具轨迹优化研究,为复杂曲面零件的加工生产提供了有效参考。 相似文献
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11.
An optimization method of the machining parameters in high-speed machining of stainless steel using coated carbide tool for best surface finish 总被引:1,自引:1,他引:0
Ahmad Hamdan Ahmed A. D. Sarhan Mohd Hamdi 《The International Journal of Advanced Manufacturing Technology》2012,58(1-4):81-91
High-speed machining (HSM) has emerged as a key technology in rapid tooling and manufacturing applications. Compared with traditional machining, the cutting speed, feed rate has been great progress, and the cutting mechanism is not the same. HSM with coated carbide cutting tools used in high-speed, high temperature situations and cutting more efficient and provided a lower surface roughness. However, the demand for high quality focuses extensive attention to the analysis and prediction of surface roughness and cutting force as the level of surface roughness and the cutting force partially determine the quality of the cutting process. This paper presents an optimization method of the machining parameters in high-speed machining of stainless steel using coated carbide tool to achieve minimum cutting forces and better surface roughness. Taguchi optimization method is the most effective method to optimize the machining parameters, in which a response variable can be identified. The standard orthogonal array of L9 (34) was employed in this research work and the results were analyzed for the optimization process using signal to noise (S/N) ratio response analysis and Pareto analysis of variance (ANOVA) to identify the most significant parameters affecting the cutting forces and surface roughness. For such application, several machining parameters are considered to be significantly affecting cutting forces and surface roughness. These parameters include the lubrication modes, feed rate, cutting speed, and depth of cut. Finally, conformation tests were carried out to investigate the improvement of the optimization. The result showed a reduction of 25.5% in the cutting forces and 41.3% improvement on the surface roughness performance. 相似文献
12.
Julien Chaves-Jacob Gérard Poulachon Emmanuel Duc 《The International Journal of Advanced Manufacturing Technology》2012,58(5-8):573-583
This paper deals with the machining of impeller blades by defining a numerical method to optimize the finishing strategy. This method is based on the evaluation of new multi-physical functional indicators, which express the geometric and economical performances of a toolpath. Geometric indicators are defined to ensure functional requirements: aerodynamic, mechanical, and machining-related. Using these indicators, the viable impeller blade finishing strategies are compared, considering their geometric performances and production cost. The production cost is represented by machining time, which is accurately computed to limit blade and tool deflections, in order to reduce and control the geometric errors caused by these deflections. Machining time is directly linked to the feed rate, which is coupled to radial cutting forces. Thus, the finishing strategy is optimized by considering simultaneously a complete set of impeller machining problems: geometric errors and deflections. The method presented to optimize the blade finishing strategy is then applied to an industrial impeller used in a pump. 相似文献
13.
Jinting Xu Yuwen Sun Xiangkui Zhang 《The International Journal of Advanced Manufacturing Technology》2013,67(9-12):2489-2500
Almost 80 % of the milling operations to produce mechanical parts are produced by NC pocket milling, especially in aerospace and automobile industry. At present, for 2.5D pocket machining, direction-parallel and contour-parallel machining strategies have gained nearly universal acceptance. However, in such tool path, abrupt change of path direction, frequent acceleration and deceleration, and sharp velocity discontinuous are found to significantly limit the machining efficiency of pockets. To address these problems, this paper introduces a method for generating a spiral tool path that maintains a steady-state cutting process by as smoothly as possible curvature evolution of the tool path for pocket machining. First, the machined region of a layer of a pocket is mapped onto a circular domain by means of mesh mapping, which reduces the task of tool path generation from the geometrically complex pocket region to a topologically simple disk. On this disk, a guide spiral is constructed according to a mathematical function constrained by the calculated path interval map. Using the mapping from the pocket to the disk as a guide, the guide spiral is inversely mapped into the interior of the pocket and then a smooth low-curvature spiral path is derived. The generated tool paths are guaranteed to not inherit any corners in the subsequent interior tool paths and allows cutting of the pocket without tool retractions during the cutting operations. Finally, the proposed method is implemented and tested on several typical sample pockets to demonstrate its validity and significance. 相似文献
14.
Wei Li Beizhi Li Jianguo Yang 《The International Journal of Advanced Manufacturing Technology》2017,91(9-12):3135-3143
The influences of tool setting errors on skiving accuracy are discussed in this paper. Firstly, a method for the calculation of error-free cutting edge of skiving cutter is proposed. Based on the theories of cutter enveloping gear, the gear profile deviations, which are affected by the tool position and orientation errors in skiving, are analyzed. Results show that the profile deviations are insensitive to this kind of setting error of the cutter. Then, the effects of tool eccentricity error on skiving accuracy are analyzed. Results show that the waves on the tooth flanks, which are caused by the tool eccentricity error, have obvious influences on the helix deviations and the profile deviations of the workpiece. The waves on the tooth flanks are periodic ones and can be obviously affected by the number of teeth of the cutter. 相似文献
15.
Yingchun Liang Wanqun Chen Qingshun Bai Yazhou Sun Guoda Chen Qiang Zhang Yang Sun 《The International Journal of Advanced Manufacturing Technology》2013,69(1-4):237-244
This paper presents the design and dynamic optimization of an ultraprecision diamond flycutting machine tool for producing flat half-meter-scale optics. A novel tool holder is designed, which can achieve micron-level axial feeding and tool angle accurate adjustment, and new technology is also used to allow alignment of the spindle axis to the horizontal-slide travel. The design and characteristic analyses of this machine tool are presented, including the static, modal, harmonic, and rotor dynamic analysis for predicting its static and dynamic performance. A prototype is built based on the analysis and FE model considering the joint parameters. The machining test shows that this machine tool can successfully produce 415?×?415-mm surfaces on aluminum and crystalline optics, with 1.3-μm flatness and 2.4-nm rms roughness. Moreover, the differences of design concepts are discussed between the ultraprecision machine tool for optical parts machining and the conventional machine tool. 相似文献
16.
转轮叶片是水轮机能量转换的关键部件,也是最难加工的零件,目前多轴联动数控加工是解决该类大型雕塑曲面零件最有效的加工方法。多轴联动数控加工编程则是实现其高精度和高效率加工的最重要环节。本文介绍混流式水轮机叶片五轴联动数控加工大型雕塑曲面编程中涉及到转轮叶片三维造型、刀位轨迹计算、切削仿真、机床运动碰撞仿真、后置变换等关键技术。通过对这些技术的链接和研究,开发实现了大型叶片的多轴联动加工。 相似文献
17.
Yan LV Congbo LI Jixiang HE Wei LI Xinyu LI Juan LI 《Frontiers of Mechanical Engineering》2022,17(3):38
The machining unit of hobbing machine tool accounts for a large portion of the energy consumption during the operating phase. The optimization design is a practical means of energy saving and can reduce energy consumption essentially. However, this issue has rarely been discussed in depth in previous research. A comprehensive function of energy consumption of the machining unit is built to address this problem. Surrogate models are established by using effective fitting methods. An integrated optimization model for reducing tool displacement and energy consumption is developed on the basis of the energy consumption function and surrogate models, and the parameters of the motor and structure are considered simultaneously. Results show that the energy consumption and tool displacement of the machining unit are reduced, indicating that energy saving is achieved and the machining accuracy is guaranteed. The influence of optimization variables on the objectives is analyzed to inform the design. 相似文献
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20.
Jui-Jen Chuang Daniel C. H. Yang 《The International Journal of Advanced Manufacturing Technology》2007,34(7-8):714-723
In this paper, a method for generating boundary-conformed pocketing toolpaths is developed. Based on the 2D Laplace parameterization
of pocket contours and the redistribution of the original Laplace isoparametrics, continuous toolpaths are generated. These
generated toolpaths have neither thin walls nor leftover tool marks. Detailed algorithms are formulated in steps. The method
can be applied to general pockets either with or without islands. Some examples are provided to demonstrate the applicability
of this method. In most cases, the method can successfully generate satisfactory toolpaths for arbitrary shaped pockets. However,
according to the shape of the pockets and the distribution of the islands, when using this method, over machining may occur
in some narrow or bottlenecked areas. Further investigation on how to alleviate this problem is needed. We believe that this
method provides an alternative choice for pocket machining. 相似文献