E-tracking: towards an intelligent wire-edm manufacturing system 18.06.2014 EPHJ FOF 2014 R. Perez, O. Dixmerias, Ch. Chapatte GF Machining Solutions
Outline Introduction EDM technology Latest innovations in Electroerosion Machining: a smart machine The Fofdation project E-tracking system for wire-edm: a smart environment Conclusions and perspectives 2 EPHJ FOF 2014
Electric Discharge Machining: What is it? No mechanical contact between the tool and the workpiece A controlled discharge is produced in the gap filled by a dielectric liquid The discharge melts and evaporates the workpiece material: In die-sinking EDM the electrode shape is printed in the workpiece In wire-edm a profile is cut along a pre-determined path 3 EPHJ FOF 2014
Advances in micro-wire-edm Micro wire EDM machines Taper angles 3 / 80mm Wire diameter range 0.07 0.33 mm 0.02 0.05 mm (option) Automatic wire changer: Twin-wire = 2 x 8kg of wire spools Grain of salt 60 µm Wire diameter used in W-EDM down to 20 µm Hair section 4 EPHJ FOF 2014
Advances in Wire-EDM Dedicated EDM machines: Using integrated axis Taper angles >30 degrees Wire diameter range 0.07 0.33 mm 5 EPHJ FOF 2014
Advances FORM in micro-die 1000 sinking-edm Designed for maximal Accuracy and Micro Applications Traverse paths X, Y, Z 220 x 160 x 250 mm Work piece dimensions 550 x 330 mm Electrode weight 5 kg Work piece weight 35 kg Generator ISPG 40A SF Module standard Ra 0.05 µm iq technology standard for graphite and copper 6 EPHJ FOF 2014
Integrated Vision Units In process measurement Repeatability less than 1µm Accuracy ±1.5 µm 0.5 mm Application: Machining of teeth of endoscopic pliers Material: Stainless steel External diameter : 0.5mm Wire diameter: 50 microns 7 EPHJ FOF 2014
Advances in Nano generator Roughness technology Neg. Impuls Length. 60 ns Impuls peal 2 Amp Discharge frequency 8 MHz Ra = 49 nm Rz = 460 nm 8 EPHJ FOF 2014
Quality in surface finishes 2.5 1.58 1.26 0.5 0.32 0.2 0.03 mm Ra Programmable surface finish for meeting moulding, aerospace and medical applications as well as manufacturing demands May eliminate the need for subsequent polishing Real-time monitoring and recording of quality process indicators: Historical analysis Data Acquisition 9 EPHJ FOF 2014
Quality in surface integrity Ti-6Al-4V After roughing, recast layer < 6 µm Ti-6Al-4V After 4 finishing cuts, recast layer is not visible Programming the right spark energy = respect of surface integrity Use of MHz range pulsed discharges eliminates recast layers and prevents unexpected fatigue failure of machined parts. Courtesy of Birmingham University 10 EPHJ FOF 2014
Micro-applicationsof application Micro EDM Main sectors Medical instruments, implants, High precision mould Watch making Microelectronics Micro drilling LED applications. Micro applications Micro connectors Micro stamping dies Micro assembly Injection moulding 11 EPHJ FOF 2014
Micro-slits Wire / Sinker Erosion Application Die for punching tool Electrodes Pin arrays Direct structuring Advantages Low tool costs Transfer: 2D to 3D Economic efficiency by replication Flexibility and autonomy 12 EPHJ FOF 2014
Lead frame Fine Cutting Technical Parameters Workpiece Carbide Workpiece height 5 mm Thread CCA Thread Ø 0.10 mm Ra 0.1 mm Sharp edge tol. +/-1 mm 0.20mm Main criteria Profiles with the sharpest possible edges and best degree of roughness 13 EPHJ FOF 2014
EDM intelligence: The smart machine Ref Pilot Expert Defect level min TECHNO. Tables A j Pilot & Execution Software q c Pos q dot Motor and mechanics ms / t q rot t e, t o, q lin ms Generator Process Control ms Ū Gap (mm) ms V w mm 3 /s q mat 14 EPHJ FOF 2014
Process Control Innovations Ref Defect level Pilot Expert min TECHNO. Tables A j Pilot & Execution q c Pos q dot Motor and mechanics ms / t q rot t e, t o, q lin ms Generator ms Ū Gap (mm) ms V w mm 3 /s q mat 15 EPHJ FOF 2014
Process control Innovations Ref Defect level Pilot Expert min TECHNO. Tables A j Pilot & Execution q c Pos q dot Motor and mechanics t e, t o, Automatic calculation of part height in wire EDM : adjustment of machining power q lin ms Automatic adjustment of wire straigthness ms / t q rot Generator Process Control ms ms Ū V w mm 3 /s Gap (mm) q mat 16 EPHJ FOF 2014
FOFDATION: Intelligence beyond the machine Today, Tomorrow, powered by FOFdation Top-down approach, disparate and incompatibles IT islands, lack of interoperability, point solution Holistic & bi-directional approach, end-to-end digitization, convergent and science-based process, interoperable IT modules, plug-and-produce IT environment, lifecycle management, sustainability monitoring, all integrated! 17 EPHJ FOF 2014
I-Innovations at various levels Smart (open) Machine Controller (SMC) to implement intelligent (What-to-Make process) & adaptive (closed loop with in-situ verification process) machining towards «first part correct» Smart Manufacturing Optimizer (SMO) based on unique machine-tool signature (characterization) to optimize and simulate its kinematic and dynamic performance behaviour Smart Manufacturing Execution System (SMES): help the manufacturing industry pragmatically implement the sustainability objectives by extending the scope of (existing) MES to achieve Energy Efficiency and Sustainability Goals Smart Enterprise Content Management (SEMC) towards the «production-to-enterprise» asset integration and overall sustainability management 18 EPHJ FOF 2014
Impacts Strategic impacts for the manufacturing sector Reduce machine idle times Reduce average machine cycle times Increase machine availability Improve the manufacturing performance (complexity) and quality (precision) Reduce consumables and waste Increase the competivity advantage of European manufacturers in the global market Special Focus on supporting SMEs to embrace the knowledge and digital era Driving (triple) bottom-line with integrated planning Contribution to relevant standards European synergy & International cooperation Adaptive & open Controller SMC Smart & Green Factory Product/Process Optimization SMO Manufacturing Execution System SMES PLM ERP Innovation/Knowledge Sustainability Productivity 19 EPHJ FOF 2014
Application to EDM : etracking concept & architecture Concept One platform unique to be installed: Connected to the machine: execution activities Placed in the office: supervision and management activities Functionalities to cover: Activities Before, during, and after machining Architecture Workshop supervision level (SMES) Mode management Data Base Track & Trace level (SMO) Mode execution esupervision esupervision m/c 1 m/c 2 20 EPHJ FOF 2014
A higher level intelligence concept: SMO Optimised path for complex parts with Step-NC inteface Definition of «reference» (defects, energy consumption), Simulation Detect if a part is correct or not and where are located the problems. Optimisation Part signature Reference Compare ClassCad 3D CAD model Step-NC model Simulation Machining Histograms, Energy cons. Part #1 DataBase (History & Traceability) Check if part is correct Detect where problems occur Identify critical factors in part design Assess energy consumption 21 EPHJ FOF 2014
MIP Wire-EDM SMC/SMO architecture STEP-NC 22 EPHJ FOF 2014
Going higher: the Smart Manufacturing Execution System Workshop supervision level Mode management Define the standard for production Supervision of on going production reporting Before machining During machining After machining Apply standard Reaction according: - Alarms - Stops of machining - Materials consumption - Energy consumption Track & Trace level Mode execution -23- EPHJ FOF 2014
Before machining: management level Configuration of machine cell Machining reference: criteria and expected real time reaction (alarm stop) Maintenance reference: criteria and expected real time reaction (alarm stop) Checklist: Procedure for setup Before machining -24- EPHJ FOF 2014
During machining: management level General supervision of activities Basic status of the entire machine park Detailed supervision Similar than in front of machine During machining -25- EPHJ FOF 2014
During machining: execution level During machining Error machining detection Result: Alarm or stop According reference machining file -26- EPHJ FOF 2014
During machining: execution level During machining Risk maintenance detection Result: Alarm or stop According reference maintenance file -27- EPHJ FOF 2014
After machining: management level Report analysis: Results: Decision for a maintenance task Decision for a specific control on the part Final record for traceability Statistical production analysis After machining 28 EPHJ FOF 2014
SMO detail - Part preparation Selection of process signals to monitor per each power setting. Reference wire length Reference machining time Power setting Selection process signals -29- EPHJ FOF 2014
Definition of references Definition of process signal references based on previous machining. The reference is based on selection of a previous machining and tolerances Find previous machining List of previous machining for selection Profile of process signal of selected machining according to position on path (with tolerance) Definition of tolerance to apply on reference + actions when tolerances exceeded -30- EPHJ FOF 2014
Machining monitoring Selected process signals are followed up in real time during machining according to cutting path. Actions are executed (email, user message, machine suspension) when tolerances exceeded. Graphic follow up of process signals according to position on cutting path Graphic follow up of machining position on 2D viewer -31- EPHJ FOF 2014
Part machining report Machining report : display machining data + in / out of tolerance Process signal in tolerance Process signal out of tolerance Machining time out of tolerance Detail of report on process signal 32 EPHJ FOF 2014
View detail of process signal Display process signal data on path with position in / out tolerance on cutting path Graphic display (2D viewer) of cutting path where process signal is in /out of tolerance. Profile of process signal according to cutting path 33 EPHJ FOF 2014
View detail of process signal 3D visualiser with out-of-tolerance representation 34 EPHJ FOF 2014
Available Monitoring signals Overall strategy level Protection activation Strategy level on frequency Strategy level on pulse frequenc y Servo control parameter Cutting speed Protection pause Activation of protection pause Generator information can be recorded at two levels: strategy and CNC (position and speed) 35 EPHJ FOF 2014
Available Monitoring signals 120 bleu:tbreel[us], rouge:freq[khz], magenta:sympa[%], cyan:conta[%], jaune:impat[%], noir:td[us] 100 Fichier stop 80 60 Abnormal increase of short circuits 40 20 0 0 2 4 6 8 10 12 14 16 temps[s] At a second level it is possible to retrieve detailed process information on the pulse type distribution, which can be used afterwards to elaborate a part quality identification and discrimination system. Next step: closing the loop... 36 EPHJ FOF 2014
Conclusions EDM technology is an advanced technology with adaptive process control: a Smart Machine Advanced strategies and adaptive control for improved precision and accuracy Integrated Vision Units for on-machine control An new smart environment has been defined by the FOFDATION project for wire-edm technology: e-tracking A smart machine optimiser (SMO) able to follow up and record critical process indicators, with respect to a quality reference, and take action in case of need A smart manufacturing execution system (SMES) able to define manufacturing conditions and supervision a machining cell, at operational and sustainability levels The framework for developing an intelligent machine both at process and interaction levels is defined and offers outstanding possibilities for improving manufacturing performances by using the full potential of current digital capabilities. 37 EPHJ FOF 2014