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Project tailor welding blanks crack analysis & cm

  1. Post Graduate Professional Development Program in Energy Management and Climate Action (Nov 2020 – July 2021) Project Report Name Harsh Vardhan Email Date 18.11.2021 Contact No. 9667214130
  2. Zero Rejection due to TWB Crack TWB PROJECT : RESOURCE CONSERVATION Elimination of TWB Crack in Door Panels THEME VASTUPAL Team Members SAURABH DATA COLLECTION & TARGET No of Rejected Parts ROADMAP ❖ Methodology Fixation ❖ Grasping the Facts ❖ Process Stabilization ❖ Visual standardization 5th Step Sustain 1st Step 2nd Step 4th Step System Build up Analysis Initiation 3rd Step Implem. Theme Selection & Target Setting Situation Analysis & RCA Establishing Standards C/M implement ation Sustain the Process ❖ Target Setting ❖ C/M Trial & Imp. ❖ Result Check 1 Actual Target 0.0 TWB Crack (Jan’21 – Jun’21) 0.1% 102 19 51 14 11 6 2 0 Weight of 1 Part : 6.5 kg Weight of 102 Parts : 663 Kg Eliminate the Wastage of Steel to 0 by Controlling Rejection HARSH VARDHAN (Team Leader)
  3. UNDERSTANDING OF STEEL BLANK: WHAT IS STEEL BLANK…??? Unfinished Piece of Steel that has been Stamped out from a Steel Coil which is of different Sizes as per Part Specification ( thickness 0.5 mm to 2 mm) HOW IT IS PROCESSED…??? Steel Coils Processing on Blanking Line with Dies Steel Blanks WHAT IS TWB…??? TAILOR WELDED BLANKS (TWB) are made from individual sheets of steel of same or different Grade, Thickness, Strength and Coating which are joined together by LASER WELDING. 3D View 3D LASER WELDING 0.65mm 1.2mm Side View 側面図 LASER WELDED OR TWB BLANK 2 TWB Welding TWB TWB Blanks made of two sheets of different thickness & steel blanks production know-how done.
  4. 3 UNDERSTANDING OF TWB PART PRODUCTION: Bolster Upper Die Lower Die Lower Die Pressure Pad Bolster Part Scrap Chute Part Part Production Process Flow at Press… TWB Part 1.2 mm 0.65 mm TWB Blanks Draw Trim Bend Process Understanding of TWB Part Production done by using TWB Blanks. Draw Trim Bend Input Output Process
  5. 4 REDUCTION OF THE WEIGHT ✓ Optimization of material use – reduction of material use and less scrap ✓ Right steel grade and material thickness where needed – tailor made solution for the part design and weight savings WHY TWB…??? The Right Steel Grade is in the Right Place, in the Right Thickness for each part to reduce weight and to improve strength & safety of the vehicle. ADVANTAGES OF TAILORED BLANKS TWB PARTS APPLICATION & ADVANTAGE INCREASED TECHNICAL PERFORMANCES ✓ Higher stiffness ✓ Better energy absorption ✓ Better crash behavior SIMPLIFICATION OF THE PROD. PROCESS ✓ Reduction of the number of parts ✓ Reduction in the stamping and assembly tools ✓ Shorter manufacturing process Data Analysis & Process Flow study done. SUPPLYING BLANKS BLANKS RECIEVING & STORING AT PLANT-TKR PRODUCING PARTS AS PER PRODUCTION PLAN PARTS QUALITY CHECK PARTS STORAGE CHECKING OF PARTS AT Q – GATE PACKING OF PARTS FOR DELIVERY PARTS DELIVERY AT PLANT PROCESS WORK FLOW : PRESS
  6. ➢ High Rejection Rate ➢ Poor Quality of Parts ➢ Line Loss ➢ Rechecking of Parts increasing ➢ Repair Man-hour loss ➢ Leakage Problem in Car ➢ Major cost in Door Replacement ➢ Impact on CBU Quality & Customer Satisfaction CBU Part setting/Cutter clearance Trim condition found OK Blank setting Found ok Blank touching on gauges/ No blank shifting DOOR PNL TWB AREA CRACK No burr/ Trim condition Draw Die (OP-10) Bending block profile/movement Part found ok No deform/No cam jam Trim Die (OP-20) Bend Die (OP-30) FACTOR CONTROL ITEM ACTUAL STATUS CONTROL STD PROBLEM TWB condition TWB Defects may occur No TWB Defects allowed Raw Material TREE STRUCTURE ANALYSIS FOR CRACK GENERATIONー During detailed study, suspected Issue found in Raw Material Quality as No method to check TWB Blanks at HCIL so need to take action at Supplier End. Cushion Pressure Found ok Should be as Specific Part Std Die height of every Part Found ok Should be as per Specific Part Std. Draw Die Bead Found Ok No scratches/No Chrome Peel off in Bead Area TWB CRACK ANALYSIS & ITS IMPACT : TWB 6 Edge Crack Speaker Fitment Issue Moulding Fitment Issue IMPACT OF TWB CRACK Input R/M Process Output Part ❑ Draw ❑ Trim ❑ Bend ❑ Part Found Crack near TWB ❑ R/M material condition ok Concern
  8. SITUATION ANALYSIS FOR DEFECT GENERATION DEFECTS IN TWB WELDING LASER AT NEW POSITION 430 310 290 130 98 92 90 80 70 0 100 200 300 400 500 Laser Beam Co- ordinate Found not ok Lens Condition Dirt Found No Dirt allowed on Lens Should be at matching Point of Both Sheet( X:0, Y:0) Input Material Focal Length of Lens Found ok Should be as per Std. 3mm Burr & Trim Line Condition Burr & Trim Line not found ok Burr: 10% of sheet thickness Trim Line: No damage allowed Atmospheric Parameter Found not ok as per Std. Laser Speed Found as per std. 6.0 - 6.5 m/min Temp: 20C – 30C Humidity: 40-70% Laser Power O/P Found not ok O/P should be as per Std ( 2 – 3kW) TWB Process 8 Fumes collecting on Lens affects power O/P & defects starts to occur FACTOR CONTROL ITEM ACTUAL STATUS CONTROL STD TREE STRUCTURE ANALYSIS FOR TWB DEFCETS Types of Defects No of Parts Undercut Bead Width Mismatch TWB REJECTION ANALYSIS AT RPSC TWB PROCESS UNDERSTANDING FOR DEFECT GERNERATION TWB WELDING Ok TWB Welding Manual Cleaning of Lens leads LASER to Deflect in Y Direction leads to defect generation TWB WELDING LASER AT OLD POSITION Welding with Defects LASER CO-ORDINATES Laser Deflects in Y Direction due to manual cleaning Concern ok
  9. WELDING DIRECTION GANTRY Y-AXIS X-AXIS Y-AXIS THIN SHEET THIN SHEET THICK SHEET THICK SHEET OFFSET (+VE) (-VE) (+VE) (+VE) (-VE) (-VE) Y Co-ordinate fixed after trial Setting of Y –Axis & Defects Range Stand. COUNTERMEASURE-1 9 Y Axis offset value & Range for Defects fixed to eliminate TWB Defects 500 Sample checked to freeze Parameter after lens cleaning TWB Welding Process Top 3 Defects Range Observed Laser Parameter Observed 1. Y –Axis Offset : 0.19 – 0.28 mm 2. Laser Power O/P: 2.5 – 2.9 kW 3. Laser Speed: 6 – 6.5m/min Range Standard set for all three major defects 1. Mismatch: 0.3 – 0.6 mm 2. Bead Width : 0.4 – 1.2 mm 3. Under Cut: 0 – 0.05 mm PARAMETER FIXED AFTER TRIAL & VALIDATION Process Name LASER WELDING Part Number Machine Number TWB Part Name MaterialDescription :- Description Part Dimensions Material Traciability at Machine St. Edge(H. Th.) 0.08/0.05 BLANK 1 1.15X1100X330 Burr Lev.(H. Th.) 0.03 BLANK 2 0.63X1310X1030 St. Edge(L. Th) 0.05 BLANK 3 Burr Lev.(L. Th.) 0.03 Process Parameter:- Parameter level Sample Size Parameter Sample-1 Sample-2 Sample-3 Sample-4 Station No.-1 Offset(Y) 0.10 0.13 0.16 0.19 Power(kW) 2.5 176 91 96 101 2.6 177 92 97 102 2.7 178 93 98 103 2.8 179 94 99 104 2.9 180 95 100 105 Station No.-2 Offset(Y) 0.10 0.13 0.16 0.19 Power(kW) 2.5 171 136 141 146 2.6 172 137 142 147 2.7 173 138 143 148 2.8 174 139 144 149 2.9 175 140 145 150 0.22 0.25 0.28 0.31 106 111 116 121 107 112 117 122 108 113 118 123 109 114 119 124 110 115 120 125 151 156 161 166 152 157 162 167 153 158 163 168 154 159 164 169 155 160 165 170 Test Name Power Sample-1 Sample-2 Sample-3 Sample-4 Erichsion test Station No.-1 2.5 O O O O 2.6 X O O O 2.7 X O O O 2.8 X O O O 2.9 X O O O Station No.-2 2.5 O O O O 2.6 O O O O 2.7 O O O O 2.8 O O O O 2.9 X O O O Tensile Test Station No.-1 2.5 O O O O 2.6 O O O O 2.7 O O O O 2.8 O O O O 2.9 O O O O 2.5 O O O O 2.6 O O O O 2.7 O O O O 2.8 O O O O 2.9 O O O O Bead Value(UPPER) Station No.-1 2.5 O O O O 2.6 O O O O 2.7 O O O O 2.8 O O O O 2.9 O O O O Bead Value(LOWER) Station No.-1 2.5 O O O O 2.6 X O O O 2.7 X O O O 2.8 X O O O 2.9 X O O O X X X X O X X X O X X X O O X X O O O X X O O O O O O O X O O O O O O O O O O O O O O X O O O X O O X X O X X X X X X X
  10. 10 COUNTERMEASURE-2 Control of Temp & Humidity to eliminate TWB Defects If temp is more than std then working of Laser Welding components will not be proper and abnormalities found during welding. No method to monitor Temp & Humidity while welding Poka-Yoke done by deploying Alarm to monitor for any change Eliminate TWB Defects in case of Sheet Damage Laser welding done if any Sheet Damage/Edge Blunt/Gap is there between both sheets leads to poor Welding Impacts Working Components PLC Program changed that if camera detects such problem then automatically Laser welding will stop & reject the blanks Poka-Yoke done to stop welding & reject blanks in case of Sheet Damage & Temp, Humidity Problem Std: Temp: 19C – 21C, Humidity: 50 – 70% Humidity Temp. Poor Welding If temp & humidity goes more than std then it gives signal & alarms the operator & action taken accordingly while TWB Welding Sheet Damage Welding with defects due to sheet damage Poka-Yoke done by stopping welding as soon as camera Detects The sheet damage Sheet Damage Sheet Damage
  11. 11 METHODOLOGY BEFORE & AFTER COUNTERMEASURE Methodology to check TWB Blanks Before Countermeasure Methodology to check TWB Blanks After Countermeasure Blank Loading on TWB machine Process the TWB Blanks in Machine Monitor the Parameter( Laser Speed, Power O/P) in check sheet Check TWB Quality Manually 100 % Visual & Record the parameter in check sheet Blank Loading on TWB machine Check Parameter for both stations Do lens cleaning & set Y offset value as defined after 1500 to 2000 Parts Monitor temp, Humidity & take action accordingly Fill the change mgmt. sheet in case of any change point Monitor the Parameter( Laser Speed, Power O/P) in check sheet Machine will automatically Reject the TWB Defected Blanks Visually, chances of inspection miss 1 2 2 Auto Rejection of Defected TWB Blanks Methodology changed after taking C/M to eliminate TWB Defect generation 1 Change Mgmt Sheet Parameter Recording
  12. RESULTS & STANDARDIZATION. ➢ Zero Rejection ➢ Zero Handwork ➢ Team work improved ➢ Confidence level improved ➢ Problem solving skills improved ➢ Part Quality Improved ➢ Felt joy of working ➢ Piling OPS Updated ➢ OPL made for better understanding at Q- Gate & Online ➢ Quality OPS updated ➢ Process Validation done ➢ Process Parameter recorded in Lot check sheet ➢ Training given to all concerned on line Month-wise number of TWB parts of all models 102 Before After Zero No of Parts Crack No of Parts Total Parts Produced Crack 203203 Zero RESULTS INTANGIBLE BENEFITS STANDARDIZATION TWB Inspection Report QA Lot Check Sheet 12 Before 0.65 Tonnes Scarp in 6 months --> 1.3 Tonnes scrap annually. After 1.3 Tonnes Metal Saving Annually Annual Electricity Saving : Power Consumed to Produce 1.3 Tonnes of Steel = 9.8 Mwh (7.5 Mwh/ tonne * Source Data : Ministry of Power) 9.8 Mwh Annually --> 9800 units of Power of Nation Conserved. Monetary Benefits : 1 Piece Cost - Rs. 1150/- Net Saving = 1150 x 102 = Rs. 117300/- Emissions per unit Electricity Generation = 0.9 kg Avg. (Source : Ministry of Power) 9800 Units ≈ 8820 Kg of Emissions --> 8.8 Tonnes of Emissions Reduced