JOHN DEERE FOUNDRY WATERLOO

Transcription

1 JOHN DEERE FOUNDRY WATERLOO Simulation: John Deere s Communication & Profitability Tool

2 John Deere s Casting Center of Excellence Outside Casting Suppliers Outside Designers Casting Center of Excellence John Deere Designers John Deere Foundry Waterloo 2

3 John Deere s Casting Center of Excellence Communicate between designers and foundry personnel inside John Deere. Communicate between designers and foundry personnel of John Deere and outside suppliers. Achieve Lowest Costs of castings purchased/made by John Deere. Achieve Highest Quality of castings purchased/made by John Deere. Assure Delivery of castings purchased/made by John Deere. Implement Improvement Proposals for castings purchased/made by John Deere. 3

4 Cost Avoidance vs. Cost Improvement Cost avoidance is escaping the dollars associated with a project before the geometry hits the lockedin phase. Cost improvement is reducing costs by revisiting a project once tooling has been built and castings are being produced. Cost avoidance is the preferred method! Cost improvement involves the absorption of costs related to production of castings such as scrap, x- ray, additional castings made to replace scrap, machining costs, etc. 4

5 Role of Casting Process Simulation Enable Communication as Designers can see and understand the castability of a design in cooperation with foundry personnel. Achieve Lowest Costs by moving the trial and error process into the virtual world and determine the cost of different design and process options. Achieve Highest Quality by unlocking the entire casting process and visualize it. Assure Delivery by minimizing real world trial and error (and surprises) making castings right the first time. Enable Implementation of Improvement Proposals as new cutting edge designs and processes can be tried out in a low cost environment. 5

6 The N313462/N Continuous Improvement Project

7 Natural Simulation A natural simulation is running casting geometry in a correct size sand mold without risers or gating. This allows the foundry personnel to gather information such as feed modulus, hotspots, and the solidification pattern. 7

8 Solidification Simulation A solidification simulation is running the casting geometry with feeders. This allows the operator to gather information on porosity tendency, feeding, and solidification pattern. The next step is to develop the complete gating system and run a full filling and solidification simulation. 8

9 A full simulation will allow the MAGMASOFT user to review the filling for temperature, velocities, and possible mold erosion. It will determine the solidification pattern with the full gating system. The temperature results will help in adjusting the gating system to prevent cold iron defects. The velocity results will allow the gating system to be modified to reduce/eliminate any slag defects due to excess turbulence. The mold erosion results will allow for reduction of sand defects due to sand being carried into the mold cavities. Full Simulation 9

10 Current Gating 10

11 Costs Related to the Knee Castings for Des Moines Teton Program

12 Costs Incurred Jan. 1, Aug. 31, 2010 Shrink scrap N $28, Shrink scrap N $43, % X-ray costs for both $4, Machining charge-backs $3, TOTAL COSTS FOR SHRINK $80, Currently costs expected for the year exceed $120,000.00! Remember, this does not reflect the loss of production, the costs associated with pouring replacement castings, the additional cleaning, and the additional handling charges. 12

13 Example of Scrap from X-Ray 5 out of 18 scrap = 28% The range of shrink level from casting to casting is the problem with having consistent wall thickness 13

14 Root Cause Analysis What is the problem? The Teton Program knees continue to produce approximately $10,000 per month in shrink scrap, x-ray, and machining charge-back costs. Why did it happen? The length of the casting made solidification and porosity extremely unpredictable. What specifically should be done to correct it? Using lessons learned, it was determined that if a casting wall is tapered from thin to thick that the solidification pattern is predictable and risers may be placed that will feed the casting as expected. 14

15 Revised Geometry and Schedule to Production

16 Revised Geometry Consistent Wall Thickness Current Geometry Tapered Walls The taper is very subtle and hard to see here but the solidification pattern shows how effective it is Revised Geometry 16

17 Schedule for Permanent Design Change Scrap data collected and reviewed with root cause analysis Decision made to follow up with Design Engineers on a possible continuous improvement project Casting models created for MAGMASOFT simulations Simulation work completed and presented to Design Engineers and Continuous Improvement Engineers Request for quotes sent out for prototype and production tooling Tooling costs of $22,000 for prototype and production tooling determined to be recovered in approximately 2.2 months CI project approved for analysis work to be performed Models released to Design Engineers for finite element (FE) analysis FE analysis reviewed and approved Prototype core boxes produced and prototype castings poured Prototype castings sent for bench and field testing Prototype castings approved for production Production core box sent out for revisions Castings released into production Timeline of approximately 6 months 17

18 Outcome of the N313462/N Continuous Improvement Project

19 Outcome of CI Project Reduction of internal scrap, external scrap, x-ray, and machining charge-back costs for approximately $120,000 annual savings Increased mold utilization through reduction in unnecessary molds ran to replace scrap Savings of $3.74 per mold and increased mold yield through the removal of (2) V-83 exothermic sleeves Design Engineers considering cost avoidance instead of cost improvement in the future The Design Engineers modeling in wall tapers on new program castings such as the Aspen project knees early in the concept phase due to lessons learned Mutual respect for our MAGMASOFT simulation tool and its power 19

20 New Aspen Project Knees All of the new knees are tapered internally and the simulations look excellent. 20

21 The R282335/R Continuous Improvement Project

22 R282335/R Axle Extensions Original Geometry Casting Weight = 459 lbs EAU = 1200 each part number 22

23 Original Cope and Drag Pattern Cope 23 Drag

24 Original Gating Geometry Mold Weight = 1675 lbs 24

25 Filling Process 25

26 Tracer Particles 26

27 Solidification Process 27

28 Hotspots Issues seen included hotspots remaining in the castings 28

29 Thermal Modulus The feed modulus of the feeders is 20% greater than the casting and is still unable to adequately supply the castings with material 29

30 Porosity Porosity tendency in the flange is up to 5%. In a casting this size this may produce level 3-4 shrink with suck-down on the flange surface. 30

31 Porosity Opposite from the large flange side shows up to 5% porosity tendency and by the brake groove up to 10% porosity tendency. If the porosity by the brake groove migrates, it will open up in machining and result in a scrap casting. 31

32 Porosity Feeding results were used to correlate the porosity results. 32

33 Summary of Issues and Next Steps Low Mold Yield of 58% - Target is 65! 10.3% Scrap for sand, slag, porosity, and suck down at the flange transition costing $1,527.53/week or $79, annually! Geometry Change deemed necessary after reviewing MAGMASOFT results. New Geometry Developed by Foundry Engineering using MAGMASOFT results. Approval Given after FE analysis. 33

34 New Geometry Changes were made that removed 26.4 lbs per casting or 6% of the total weight. Current cast weight = lbs 34

35 New Gating Geometry Mold Weight = 1349 lbs A savings of 326 lbs per mold 35

36 Filling Process 36

37 Tracer Particles 37

38 Solidification Process 38

39 Hotspots Hot spots are now contained entirely in the feeders. 39

40 Thermal Modulus The feed modulus of the feeders is <20% but the reduction of weight in the flange and repositioning of the feeders allows for complete feeding of the castings with no porosity evident. 40

41 Porosity No porosity evident in the castings. 41

42 Summary Sand/Slag Defects Greatly Reduced through bottom filling vs. top filling. Weight Reduced by modifying the thick continuous flange to individual bolt bosses. Stress Load Reduced by spreading it out over a larger area with single bosses. Porosity and Suck down Reduced/Eliminated by reducing Modulus (thinner flange) and increased surface area (better heat extraction). Two-Fold Use of Simulation: Develop New Geometry. Cost Justification for management to make changes 42

43 Savings 26.4lbs Weight Reduction per Casting (5.8%) - $6,331.00/year savings in material costs Scrap Reduced from 10.3% to 1.4% - $66,936.48/year savings Mold Yield Increased from 58% to 64% - $66,000.00/year savings Weight Savings of 1,200 molds/year 200 tons more capacity on a line that ran at 100%! 43

44 Savings and Cost Avoidance Casting ran for one year with high scrap and low yield! New Design Total 1 st Year Savings:$139, Pattern Mod. + Engineering: - $120, Cost Net Savings 1 st Year: $ 19, Potential Cost Avoidance if Simulation and New Design would have been used right away: Year 0 : $139, Year 1 : $139, Avoided Pattern Mod. + Eng.: $120, Total: $399, Cost Avoidance is better than Cost Savings or Cost Improvement! 44

45 Casting Process Simulation is Integral Tool of Cost Avoidance Enables Communication as Designers can see and understand the castability of a design in cooperation with foundry personnel. Achieves Lowest Costs by moving the trial and error process into the virtual world and determine the cost of different design and process options. Achieves Highest Quality by unlocking the entire casting process and visualize it. Assures Delivery by minimizing real world trial and error (and surprises) making castings right the first time. Enables Implementation of Improvement Proposals as new cutting edge designs and processes can be tried out in a low cost environment. 45

46 Questions?