A Note on the Early Failure Period for CNC Machining Tools

2012 ◽  
Vol 605-607 ◽  
pp. 734-738
Author(s):  
Zhi Cheng Jia ◽  
Zhao Jun Yang
Keyword(s):  
Cnc Machining ◽  
Distribution Model ◽  
Early Failure ◽  
Reliability Level ◽  
Failure Data ◽  
Tracing Test ◽  
Automatic Tool Changer ◽  
Main Fault ◽  
Automatic Tool ◽  
Fault Mode

Through the plentiful authentic early failure data collected by field tracing test of 30 CNC machining tools with ATC (Automatic Tool Changer), we searched for the rules and distribution of early failure of the CNC machining tools. Main fault mode and facts which usually make a great possible impact on the reliability of these products are identified based on an analysis of these early failure data. The distribution model of early failure is found by analyzing and processing these data with the method of regression analysis and hypothesis testing as well as Bayesian forecasting of early fault phenomena. Suggestions how to enhance reliability level of these products are proposed.

Early Failure Mode Effect and Criticality Analysis for CNC Machining Tools

2013 ◽  
Vol 303-306 ◽  
pp. 1653-1656 ◽  
Author(s):  
Zhi Cheng Jia ◽  
Zhao Jun Yang ◽  
Gui Xiang Shen
Keyword(s):  
Cnc Machining ◽  
Weak Links ◽  
Early Failure ◽  
Failure Data ◽  
Mode Effect ◽  
Automatic Tool Changer ◽  
Main Fault ◽  
Automatic Tool ◽  
Fault Mode ◽  
Criticality Analysis

According to the plentiful early failure data collected on the spots of 30 CNC machining tools with ATC (Automatic Tool Changer), FMECA method is used to analyze the main fault mode and facts which usually make a great possible impact on the reliability of these products during early failure period.We find out the fault positions and the ratios of the fault modes and fault causes. We further analyze the fault modes and fault causes which frequently arise in the subsystems and parts. Through the analyses of FMECA, we learn the weak links of CNC machining tools and provide bases for removing the products faults. Suggestions how to enhance reliability level of these products are proposed.

Reliability Analysis for CNC Machining Tools during Early Failure Period

2014 ◽  
Vol 988 ◽  
pp. 663-667
Author(s):  
Wei Chen ◽  
Bo Jiang ◽  
Zhi Cheng Jia
Keyword(s):  
Reliability Analysis ◽  
Cnc Machining ◽  
Weak Links ◽  
Early Failure ◽  
Reliability Level ◽  
Failure Data ◽  
Main Fault ◽  
Fault Mode

According to the plentiful early failure data collected on the spots of 50 CNC machining tools , FMECA method is used to analyze the main fault mode and facts which usually make a great possible impact on the reliability of these products during early failure period.We find out the fault positions and the ratios of the fault modes and fault causes. We further analyze the fault modes and fault causes which frequently arise in the subsystems and parts. Through the analyses of FMECA, we learn the weak links of CNC machining tools and provide bases for removing the products faults. Suggestions how to enhance reliability level of these products are proposed.

Track-based analysis for profile generation on globoidal cam in automatic tool changer of CNC machining center

2019 ◽  
Vol 39 (2) ◽  
pp. 369-379 ◽  
Author(s):  
Kuldeep Verma ◽  
R.M. Belokar ◽  
Vinod Kumar Verma ◽  
Klimis Ntalianis
Keyword(s):  
Practical Implication ◽  
Cnc Machining ◽  
Numerical Control ◽  
Practical Implementation ◽  
Cnc Machines ◽  
Content Type ◽  
Automatic Tool Changer ◽  
Cam Profile ◽  
Measuring Machine ◽  
Automatic Tool

PurposeThis paper aims to propose an elementary approach towards the measurement of a globoidal cam profile used in an automatic tool changer (ATC) of computer numerical control (CNC) machines.Design/methodology/approachA simple and unique online method has been designed for the profile metrology of the cam. This simple methodology will replace the traditional methodology of profile metrology of cam by coordinate measuring machine (CMM). A globoidal cam with an indexable turret and roller follower (rotating in an enclosed track) has been evaluated in our analysis. This analysis plays a significant role in the performance determination of the cam as well as the ATC of CNC machines.FindingsA novel model has been designed and implemented to investigate the profile of a globoidal cam. The proposed methodology becomes an enhancement over the old methodology, i.e. measurement through CMM. Theoretical analysis and practical implementation prove the significance of the method.Originality/valueAn enhanced methodology to effectively measure the globoidal cam profile has been proposed. The practical implication of the proposed methodology remains for the CNC machine tool and ATC manufacturers. Finally, analytical explorations have been carried out to prove the validity of the proposal.

Reliability Analysis and Improvement of ATCs of CNC Lathes

2010 ◽  
Vol 37-38 ◽  
pp. 939-943 ◽  
Author(s):  
Yi Qiang Wang ◽  
Xiao Jun Wang ◽  
Shun Ming Hua
Keyword(s):  
Failure Analysis ◽  
Block Diagram ◽  
Numerical Control ◽  
Coding System ◽  
Failure Data ◽  
Cnc Lathe ◽  
Automatic Tool Changer ◽  
Automatic Tool ◽  
Set Up ◽  
Field Failure

An automatic tool changer (ATC) is one of the most important subsystems of a computerized numerical control (CNC) lathe. The field failure analysis is very important to improve the reliability of the ATC. The structure and mechanism of an ATC is briefly introduced. Its brief reliability block diagram is set up. With this understanding, through the collection of the field failure data, a coding system to code failure data is devised and a failure analysis database of CNC lathes is accrued. The failure mode and cause are analyzed to indicate the weak subsystem of the ATC. Some suggestions on improving the reliability have been proposed.

Fault Detection System and Reliability Analysis for Chain-Type Tool Magazine

2012 ◽  
Vol 542-543 ◽  
pp. 941-944
Author(s):  
Ye Hu ◽  
Zhao Jun Yang ◽  
Xiao Ming Zeng ◽  
Peng Fei Song ◽  
Yu Peng Ma ◽  
...  
Keyword(s):  
Fault Detection ◽  
Reliability Analysis ◽  
Large Scale ◽  
Detection System ◽  
Tool Magazine ◽  
Failure Data ◽  
Automatic Tool Changer ◽  
Automatic Tool ◽  
A Chain ◽  
Chain Type

By analyzing the structure features and tool changing process of a large-scale national Automatic Tool Changer (ATC) with a chain-type tool magazine, a chain-type tool magazine reliability test bench is designed with a new fault detection system, where a new failure data collecting method is applied for taking failure data statistics and reliability analysis. This set of fault detecting and reliability analyzing system not only provides a way for ATC to predict system faults, but also creates good conditions for further ATC reliability research.

Reliability Evaluation of Chain-Type Tool Magazine and ATC

2012 ◽  
Vol 271-272 ◽  
pp. 461-465 ◽  
Author(s):  
Xiao Hong Lu ◽  
Peng Zhuo Han ◽  
Wen Yi Wu
Keyword(s):  
Reliability Evaluation ◽  
Evaluation Index ◽  
Tool Magazine ◽  
Failure Data ◽  
Machining Center ◽  
Automatic Tool Changer ◽  
The Mean ◽  
Automatic Tool ◽  
Mean Time ◽  
Chain Type

As the tool magazine and automatic tool changer (ATC) are the important function units to reserve and change tools for the machining center, the tool-changing rate affects their reliability life which directly influences the performance level of the machining center. However, the reliability of the tool magazine and ATC has not yet got a reasonable evaluation index. Directing at the features of the tool magazine and ATC system, the mean tool change numbers between failures evaluation index is proposed, which is used to calculate the mean time to repair and estimate the collected failure data of the chain-type tool magazine and ATC. It can be seen that the tool magazine with continuous tool-changing adopts the mean tool change numbers between failures as the reliability evaluation index.

Optimization of Distribution Model for CNC Lathes Early Failures

2009 ◽  
Vol 407-408 ◽  
pp. 107-111
Author(s):  
Dian Sheng Chen ◽  
Tian Shan Lv
Keyword(s):  
Weibull Distribution ◽  
Exponential Distribution ◽  
Estimation Method ◽  
Likelihood Estimation ◽  
Distribution Model ◽  
Early Failure ◽  
Index Method ◽  
Failure Data ◽  
Failure Distribution ◽  
Early Failures

To eliminate early failures of CNC lathes, it is necessary to study the early failure distribution to establish accurate early failure distribution model of CNC lathes. During the modeling process, the same group of failure data obeys Weibull distribution, exponential distribution, super-exponential distribution and gamma distribution at the same time. To optimize the failure distribution model, this paper used “relevant index” method by comparing the distribution function curve fitting and determined that this group of failure data fitted Weibull distribution using maximum likelihood estimation method with its shape parameter k 0.8706 and scale parameter b142.6991.

Reliability Evaluation of Circular Tool Magazine and Automatic Tool Changer

2012 ◽  
Vol 630 ◽  
pp. 245-248 ◽  
Author(s):  
Xiao Hong Lu ◽  
Peng Zhuo Han ◽  
Wen Yi Wu ◽  
Wei Jie
Keyword(s):  
Reliability Evaluation ◽  
Cnc Machine Tools ◽  
Cnc Machine ◽  
Mean Time Between Failures ◽  
Tool Magazine ◽  
Failure Data ◽  
Automatic Tool Changer ◽  
Automatic Tool ◽  
Availability Index ◽  
Mean Time

Tool magazine and automatic tool changer is important parts to fulfill the machining center tool reserve and automatic changing of the spindle tool. The reliability of them directly affects the performance of the host. But recently there are no researches on the reliability evaluation methods, so considering this situation, the reliability evaluation researches on CNC machine tools and their main parts at home and abroad are analyzed and concluded. Combining the collected failure data of the circular tool magazine and automatic tool changer, use MTBF (Mean Time between Failures), MTTR (Mean Time To Repair) and the inherent availability index to realize the reliability evaluation of the circular tool magazine and automatic tool changer. Thus put forward a method to study the reliability evaluation of circular tool magazine and automatic tool changer.

A Methodology for the Configuration Synthesis of Machining Centers With Automatic Tool Changer

1996 ◽  
Author(s):  
Hong-Sen Yan ◽  
Fu-Chen Chen
Keyword(s):  
Design Methodology ◽  
Systematic Approach ◽  
Coordinate Systems ◽  
Linear Type ◽  
Open Type ◽  
Tool Magazine ◽  
Automatic Tool Changer ◽  
Configuration Synthesis ◽  
Automatic Tool ◽  
Motion Characteristics

Abstract The purpose of this paper is to present a design methodology for the configuration synthesis of machining centers with automatic tool changer to meet the required topology and motion characteristics. According to the concept of coordinate systems, graph theory, generalization, specialization, and motion synthesis, this design methodology is proposed and computerized, and the machining centers with automatic tool changer up to eight links are synthesized. As the result, for the machining centers with drum type tool magazine, the numbers of configurations of machining centers with 6, 7, and 8 links are 2, 13, and 20, respectively. And, for the machining centers with linear type tool magazine, the numbers of configurations of machining centers with 5, 6, 7, and 8 links are 1, 5, 20, and 60, respectively. Furthermore, this work provides a systematic approach for synthesizing spatial open-type mechanisms with topology and motion requirements.

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