Optimization of Planar Honing Process for Surface Finish of Machine Tool Sliding Guideways

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Kory Chang ◽  
Masakazu Soshi
Keyword(s):  
Machine Tools ◽  
Cubic Boron Nitride ◽  
Three Dimensional ◽  
Numerical Control ◽  
Machining Process ◽  
Cnc Machine Tools ◽  
Cnc Machine ◽  
Manufacturing Method ◽  
Traditional Manufacturing ◽  
Sliding Guideways

Sliding guideways are often used as the foundation for linear motion in computer numerical control (CNC) machine tools due to their high damping capabilities especially for heavy duty machining applications. However, the traditional manufacturing process with grinding is time-consuming, and the product’s sliding performance has not been optimized nor clearly understood. In order to increase productivity, a machining center based manufacturing method with cubic boron nitride (CBN) milling tools was introduced and tested by researchers. While greatly reducing manufacturing time and cost, a rougher milled surface, in comparison to traditional grinding, is a possible concern for the performance as well as the life of sliding guideways. In this study, a novel planar honing process was proposed as a postprocess of CBN milling to create a finish surface on hardened cast iron sliding guideways used for CNC machine tools. A design of experiment (DOE) was conducted to statistically understand significant factors in the machining process and their relationship with surface topography. Effective planar honing conditions were discovered and analyzed with three-dimensional (3D) and two-dimensional surface parameters.

scholarly journals Evaluating Safety Systems for Machine Tools with Computer Numerical Control using Analytic Hierarchy Process

Safety ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 14 ◽  
Author(s):  
Sever-Gabriel Racz ◽  
Radu-Eugen Breaz ◽  
Lucian-Ionel Cioca
Keyword(s):  
Analytic Hierarchy Process ◽  
Machine Tools ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Machining Process ◽  
Cnc Machine Tools ◽  
Cnc Machine ◽  
Analytic Hierarchy ◽  
Safety Systems ◽  
Hierarchy Process

Computer numerical control (CNC) machine tools are complex production systems with fully automatic machine parts. Nowadays, high feed rates and machining speeds are used during the machining process. Human operators are still needed to set-up the machine, load/unload workpieces and parts, load the machining code, and supervise the machining process. The operators work in an environment where automated high-speed motions occur, and consequently, CNC machine tools have to be equipped with safety systems. The approach presented in this paper was to evaluate the main safety systems of CNC machine tools based upon the analytic hierarchy process (AHP). The analyzed systems were divided into six main categories and compared pairwise using five criteria proposed by the authors. The approach and the obtained results significantly relied upon the situation found at the industrial company used as a benchmark for the research. The analysis reveals that, among considered safety devices, manually operated controls are the most efficient ones. Finally, a sensitivity analysis was conducted to test the stability of the AHP solution.

scholarly journals Study of Machining of Gears with Regular and Modified Outline Using CNC Machine Tools

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2913
Author(s):  
Rafał Gołębski ◽  
Piotr Boral
Keyword(s):  
Machine Tools ◽  
Coordinate Measuring Machine ◽  
Optical Microscope ◽  
Numerical Control ◽  
Cnc Machine Tools ◽  
Cnc Milling ◽  
Cnc Machine ◽  
Cylindrical Gears ◽  
Measuring Machine ◽  
Five Axis

Classic methods of machining cylindrical gears, such as hobbing or circumferential chiseling, require the use of expensive special machine tools and dedicated tools, which makes production unprofitable, especially in small and medium series. Today, special attention is paid to the technology of making gears using universal CNC (computer numerical control) machine tools with standard cheap tools. On the basis of the presented mathematical model, a software was developed to generate a code that controls a machine tool for machining cylindrical gears with straight and modified tooth line using the multipass method. Made of steel 16MnCr5, gear wheels with a straight tooth line and with a longitudinally modified convex-convex tooth line were machined on a five-axis CNC milling machine DMG MORI CMX50U, using solid carbide milling cutters (cylindrical and ball end) for processing. The manufactured gears were inspected on a ZEISS coordinate measuring machine, using the software Gear Pro Involute. The conformity of the outline, the tooth line, and the gear pitch were assessed. The side surfaces of the teeth after machining according to the planned strategy were also assessed; the tests were carried out using the optical microscope Alicona Infinite Focus G5 and the contact profilographometer Taylor Hobson, Talysurf 120. The presented method is able to provide a very good quality of machined gears in relation to competing methods. The great advantage of this method is the use of a tool that is not geometrically related to the shape of the machined gear profile, which allows the production of cylindrical gears with a tooth and profile line other than the standard.

An Analytical C3 Continuous Local Corner Smoothing Algorithm for Four-Axis Computer Numerical Control Machine Tools

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Qin Hu ◽  
Youping Chen ◽  
Jixiang Yang ◽  
Dailin Zhang
Keyword(s):  
Machine Tools ◽  
Numerical Control ◽  
Cnc Machine Tools ◽  
Smoothing Algorithm ◽  
Linear Motion ◽  
Tool Orientation ◽  
Cnc Machine ◽  
B Splines ◽  
Rotary Axes ◽  
Tip Position

Linear motion commands of multi-axis computer numerical control (CNC) machine tools need to be smoothed at the transition corners, because the velocity discontinuities at corners can result in fluctuations on machine tool motions and lead to poor surface quality. However, no research has been reported on local corner smoothing algorithm for four-axis CNC machine tools with two rotary axes by considering their special kinematic characteristics. To this end, this paper proposes an analytical C3 continuous local corner smoothing algorithm for four-axis CNC machines with two rotary axes. After coordinates transformation, the tool tip positions and tool orientations are smoothed by locally inserting specially designed three-dimensional (3D) quintic B-splines and one-dimensional (1D) quintic B-splines into the corners between linear motion segments, respectively. The smoothing algorithm guarantees C3 continuity of the tool tip position and C3 continuous synchronization of the tool orientation related to the tool tip position, through analytically evaluating control points of the inserted microsplines. The maximum error tolerances of the tool tip position and tool orientation are mathematically constrained. Experiments on an in-house developed four-axis machine verify the efficacy of the proposed algorithm, where maximal errors caused by the local corner smoothing algorithm are constrained, the synchronization of the tool orientation and the tool tip position are achieved, and the proposed C3 continuous corner smoothing algorithm has lower jerk and jounce but higher tracking and contour accuracy than C2 continuous algorithm.

Application of Tree Graph Method for Reducing the Total Time of Tool Changing in Milling and Boring Machine Tools

2013 ◽  
Vol 371 ◽  
pp. 431-435 ◽  
Author(s):  
Claudiu Obreja ◽  
Gheorghe Stan ◽  
Lucian Adrian Mihaila ◽  
Marius Pascu
Keyword(s):  
Machine Tools ◽  
Design Method ◽  
Machining Process ◽  
Cnc Machine Tools ◽  
Tree Graph ◽  
Cnc Machine ◽  
High Productivity ◽  
Automatic Tool Changer ◽  
Automatic Tool ◽  
Set Up

With a view of increasing the productivity on CNC machine tools one of the main solution is to reduce, as much as possible, the auxiliary time consumed with the set-up and replacement of the tools and work pieces engaged in the machining process. Reducing the total time of the tool changing process by the automatic tool changer system can be also achieved through minimizing the number of movements needed for the actual exchange of the tool, from the tool magazine to the machine spindle (the optimization of the tool changing sequences). This paper presents a new design method based on the tree-graph theory. We consider an existing automatic tool changing system, mounted on the milling and boring machining centre, and by applying the new method we obtain all the possible configurations to minimize the tool changing sequence of the automatic tool changer system. By making use of the method proposed we obtain the tool changing sequences with minimum necessary movements needed to exchange the tool. Reconfiguring an existing machine tool provided with an automatic tool changer system by making use of the proposed method leads to obtaining the smallest changing time and thus high productivity.

scholarly journals On the Application of Impeller in Multi Axis CNC Machine Tools

2021 ◽  
Vol 2066 (1) ◽  
pp. 012113
Author(s):  
Weiwen Ye
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Complex Surface ◽  
Machining Process ◽  
Cnc Machine Tools ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Surface Processing ◽  
The Third ◽  
Machining Characteristics

Abstract Multi axis CNC machine tool has good linkage processing effect. Through the application of integral impeller in CNC machine tools, to improve the adaptability of CNC machine tools to complex surface processing parts, to improve the accuracy of multi axis CNC machine tools. The first part of this paper introduces the integral impeller and its machining characteristics; the second part introduces the basic NC machining process of integral impeller; the third part discusses the application of impeller in multi axis CNC machine tools from the creation of guide track, the simulation of integral impeller, software processing and generation. The purpose is to provide some reference for the processing and production of integral impeller.

Maintenance Strategy Optimization for Computer Numerical Control Machine Tools

2015 ◽  
Vol 809-810 ◽  
pp. 1504-1509 ◽  
Author(s):  
Ana Lacramioara Ungureanu ◽  
Gheorghe Stan ◽  
Paul Alin Butunoi
Keyword(s):  
Machine Tools ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Condition Based Maintenance ◽  
Financial Impact ◽  
Cnc Machine Tools ◽  
Cnc Machine ◽  
Maintenance Strategies ◽  
Time Period ◽  
A Company

In this paper are proposed two new approaches to maintenance strategies for Computer Numerical Control (CNC) machine tools. The analysis is done for different families of CNC machine tools from S.C. Elmet Bacau, a company specialized in aviation. In maintenance actions applied to CNC machine tools is very important to know the evolution of defects and critical state of electrical and mechanical components. The results of this analysis concludes that maintenance actions can be judged by the developing time period diagram, between failure appearance and interruptions in operation. It is also analyzed the financial impact, revealed from known maintenance strategies adopted on CNC machine tools, resulting in a positive approach of condition based maintenance.

scholarly journals Research on Deterministic Figuring of Ultra-Precision Shaft Parts Based on Analysis and Control of Figuring Ability

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2458
Author(s):  
Zizhou Sun ◽  
Yifan Dai ◽  
Hao Hu ◽  
Guipeng Tie ◽  
Chaoliang Guan ◽  
...  
Keyword(s):  
Machine Tools ◽  
Measured Data ◽  
Numerical Control ◽  
Cnc Machine Tools ◽  
Machining Efficiency ◽  
Air Bearing ◽  
Cnc Machine ◽  
Ultra Precision ◽  
Precision Machine Tools ◽  
And Control

The application of ultra-precision shaft parts is widely used, such as the spindle core of the air bearing spindle in ultra-precision machine tools. The precision of the spindle core is extremely high, and it is very difficult to obtain directly by traditional Computer Numerical Control (CNC) machine tools but is mostly obtained by manual grinding, whose machining efficiency is greatly limited. Based on the deterministic figuring theory, this paper focuses on the ultra-precision roundness, optimizing the filtering parameters of the measurement error data and studying the generation mechanism of the removal function morphology; the shape of the removal function is adjusted by combining the analysis of the figuring ability and positioning error. Finally, the optimized removal function is used on an experimental steel shaft, the average roundness convergence ratio is 72% higher than that of the original removal function, and the roundness reaches a 0.1 μm level. The result shows that a reasonable filtering of measured data and the removal function adjusted for the surface feature can improve the efficiency and precision of deterministic figuring on shaft parts.

Mathematical Approach for Geometric Error Modeling of Three Axis CNC Vertical Milling Machine

2016 ◽  
Vol 842 ◽  
pp. 303-310 ◽  
Author(s):  
Widyanti Kwintarini ◽  
Agung Wibowo ◽  
Yatna Yuwana Martawirya
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Machining Process ◽  
Cnc Machine Tools ◽  
Milling Machine ◽  
Cnc Machine ◽  
Geometrical Errors ◽  
Vertical Milling ◽  
Vertical Milling Machine ◽  
Accuracy And Repeatability

The aim of this paper overviews about to find out the errors that come from three axis CNC vertical milling machine. The errors come from, the CNC milling machine can be modelled into mathematical models and later on these error models will be used to analyse the errors in the measured data. Many errors from CNC machine tools have given significant effects toward the accuracy and repeatability of manufacturing process. There are two error sources come from CNC machine tools such as tool deflection and thermal distortions of machine tool structure. These errors later on will contribute to result in the geometrical deviations of moving axis in CNC vertical milling machine. Geometrical deviations of moving axis such as linear positioning errors, roll, pitch and yaw can be designated as volumetric errors in three axis machine tool. Geometrical deviations of moving axises happen at every axis in three axis CNC vertical milling machine. Geometrical deviations of moving axises in linear and angular movement has the amount of errors up to twenty one errors. Moreover, this geometrical errors play the major role in the total amount of errors and for that particular reason extra attention towards the geometrical deviation errors will be needed along machining process. Each of geometrical error of three axes vertical machining center is modeled using a homogeneous transformation matrix (HTM). The developed mathematical model is used to calculate geometrical errors at each axis and to predict the resultant error vector at the interface of machine tool and workpiece for error compensation.

scholarly journals A Low-Cost Vision-Based Monitoring of Computer Numerical Control (CNC) Machine Tools for Small and Medium-Sized Enterprises (SMEs)

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4506 ◽  
Author(s):  
Hyungjung Kim ◽  
Woo-Kyun Jung ◽  
In-Gyu Choi ◽  
Sung-Hoon Ahn
Keyword(s):  
Open Source ◽  
Machine Tools ◽  
Low Cost ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Smart Factory ◽  
Cnc Machine Tools ◽  
Shop Floor ◽  
Cnc Milling ◽  
Cnc Machine

In the new era of manufacturing with the Fourth Industrial Revolution, the smart factory is getting much attention as a solution for the factory of the future. Despite challenges in small and medium-sized enterprises (SMEs), such as short-term strategies and labor-intensive with limited resources, they have to improve productivity and stay competitive by adopting smart factory technologies. This study presents a novel monitoring approach for SMEs, KEM (keep an eye on your machine), and using a low-cost vision, such as a webcam and open-source technologies. Mainly, this idea focuses on collecting and processing operational data using cheaper and easy-to-use components. A prototype was tested with the typical 3-axis computer numerical control (CNC) milling machine. From the evaluation, availability of using a low-cost webcam and open-source technologies for monitoring of machine tools was confirmed. The results revealed that the proposed system is easy to integrate and can be conveniently applied to legacy machine tools on the shop floor without a significant change of equipment and cost barrier, which is less than $500 USD. These benefits could lead to a change of monitoring operations to reduce time in operation, energy consumption, and environmental impact for the sustainable production of SMEs.

Applied Research on Reliability Evaluation of CNC Machine Tools Based on D-S Evidence Theory

2013 ◽  
Vol 446-447 ◽  
pp. 645-649
Author(s):  
Jie Yu ◽  
Wu Sheng Tang ◽  
Ting Ting Wang ◽  
Qiao Chan Li ◽  
Zhan Guo Li
Keyword(s):  
Machine Tools ◽  
Evidence Theory ◽  
Reliability Evaluation ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Cnc Machine Tools ◽  
Production Cycle ◽  
Scientific Policy ◽  
Cnc Machine ◽  
Control Machine

Reliability is most important to the CNC machine tools and reliability estimation is a very important part of the reliability which has magnificence to allocate resources and put forward scientific policy. Reliability evaluation of computer numerical control machine tools can use all sorts of effective information to decrease the size of test samples and save the development costs and shorten the production cycle. The paper put forward to use D-S evidence theory and the information of experts system to decrease the uncertainty of the reliability evaluation of computer numerical control machine tools. The results show that the method can effectively decrease the uncertainty of the reliability evaluation of computer numerical control machine tools.

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