《DFMA面向制造与装配的设计》英文版 第11-12部分(98页)

  • 《DFMA面向制造与装配的设计》英文版 第11-12部分(98页)

    在产品设计阶段,充分考虑来自于产品制造和装配的要求,使得机械工程师设计的产品具有很好的可制造性和可装配性,从根本上避免在产品开发后期出现的制造和装配质量问题。

    本附件包含以下内容:

    Product Design for Manufacture and Assembly(Third Edition)

    11. Design for Powder Metal Processing.............. 461

    11.1 Introduction............ 461

    11.2 Main Stages in the Powder Metallurgy Process..................... 462

    11.2.1 Mixing........463

    11.2.2 Compaction.......................463

    11.2.3 Sintering.....464

    11.3 Secondary Manufacturing Stages............464

    11.3.1 Repressing and Resintering........464

    11.3.2 Sizing and Coining..........464

    11.3.3 Infiltration.........................464

    11.3.4 Impregnation....................465

    11.3.5 Resin Impregnation.........465

    11.3.6 Heat Treatment.................466

    11.3.7 Machining.........................466

    11.3.8 Tumbling and Deburring............466

    11.3.9 Plating and Other Surface Treatments........................466

    11.3.10 Steam Treating..................466

    11.3.11 Assembly Processes.........466

    11.4 Compaction Characteristics of Powders.............. 467

    11.4.1 Powder Compaction Mechanics..............468

    11.4.2 Compression Characteristics of Metal Powders........ 470

    11.4.3 Powder Compression Ratio......... 473

    11.5 Tooling for Powder Compaction.............. 473

    11.5.1 Compaction Dies.............. 474

    11.5.2 Punches for Compaction.............. 475

    11.5.3 Core Rods for Through Holes..... 475

    11.5.4 Die Accessories................. 476

    11.6 Presses for Powder Compaction.............. 476

    11.6.1 Factors in Choosing the Appropriate Press............... 476

    11.6.1.1 Punch Motions............... 476

    11.6.1.2 Load Required...............477

    11.6.1.3 Fill Height..........477

    11.6.1.4 Ejection Stroke............... 478

    11.6.1.5 Maximum Die Diameter............................... 478

    11.6.2 Presses for Coining, Sizing, and Repressing............. 478

    11.7 Form of Powder Metal Parts........ 479

    11.7.1 Profile Complexity...........480

    11.8 Sintering Equipment Characteristics...... 481

    11.8.1 Sintering Equipment....... 481

    11.8.1.1 Continuous-Flow Furnaces...........................482

    11.8.1.2 Batch Furnaces...............484

    11.9 Materials for Powder Metal Processing...............484

    11.10 Contributions to Basic Powder Metallurgy Manufacturing Costs.....................486

    11.10.1 Material Costs...................486

    11.10.2 Compacting Costs............ 492

    11.10.2.1 Press Selection............. 492

    11.10.2.2 Setup Cost....... 494

    11.10.3 Compaction Tooling Costs........... 495

    11.10.3.1 Initial Tooling Costs... 495

    11.10.3.2 Tool Material Costs.... 495

    11.10.3.3 Tool Manufacturing Costs......................... 497

    11.10.3.4 Dies.................. 497

    11.10.3.5 Punches.......... 498

    11.10.3.6 Core Rods.......500

    11.10.3.7 Total Tool Manufacturing Costs............... 501

    11.10.4 Tool Accessory Costs....... 501

    11.10.5 Tool Replacement Costs...............502

    11.10.6 Validation of the Tool Cost-Estimating Procedure...503

    11.10.7 Sintering Costs.................503

    11.10.7.1 Continuous-Flow Furnaces.......................504

    11.10.7.2 Batch Furnaces............505

    11.10.8 Repressing, Coining, and Sizing.................................506

    11.11 Modifications for Infiltrated Materials...506

    11.11.1 Material Costs...................506

    11.11.2 Compaction Costs............507

    11.11.3 Sintering Costs.................507

    11.12 Impregnation, Heat Treatment, Tumbling, Steam Treatment,and Other Surface Treatments....507

    11.12.1 Processing Costs..............507

    11.12.2 Additional Material Costs...........507

    11.12.2.1 Self-Lubricating Bearing Materials...........508

    11.12.2.2 Materials Impregnated with Oil or Polymer.........................508

    11.13 Some Design Guidelines for Powder Metal Parts..................509

    11.14 Powder Injection Molding........... 510

    11.14.1 Feedstock Preparation and Pelletization.................... 511

    11.14.2 Molding...... 512

    11.14.3 Debinding......................... 512

    11.14.4 Sintering..... 514

    11.14.5 Secondary Operations..... 515

    11.14.6 Feedstock Characteristics............ 515

    11.14.7 Material Costs................... 519

    11.14.8 Mold Cavity Geometry... 521

    11.14.9 Molding Costs.................. 521

    References.......................... 525

    12. Design for Sand Casting....................... 527

    12.1 Introduction............ 527

    12.2 Sand Casting Alloys..................... 528

    12.3 Basic Characteristics and Mold Preparation........................... 529

    12.3.1 Sand Preparation.............. 529

    12.3.2 Gating System................... 529

    12.3.3 Mold Risers and Chills...530

    12.3.4 Pattern Types.................... 531

    12.3.5 Sand Compaction Methods......... 532

    12.4 Sand Cores..............533

    12.5 Melting and Pouring of Metal.....533

    12.6 Cleaning of Castings....................534

    12.7 Cost Estimating......535

    12.7.1 Metal Cost.........................535

    12.7.2 Sand Costs.........................538

    12.7.3 Tooling Costs.................... 539

    12.7.4 Processing Costs..............542

    12.8 Design Rules for Sand Castings...............545

    12.8.1 Avoid Sharp Angles and Multiple-Section Joints.....545

    12.8.2 Design Sections of Uniform Thickness......................546

    12.8.3 Proportion Inner Wall Thickness................................547

    12.8.4 Consider Metal Shrinkage in the Design...................547

    12.8.5 Use a Simple Parting Line...........547

    12.8.6 Define Appropriate Machining Allowances..............548

    12.8.7 Use Economical Tolerances.........548

    12.9 Example Calculations...................549

    References..........................556

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  • 科研开发
  • 2020-01-02
  • 电子电气;材料分析;机械设备与装置;特种设备;机动车;医疗器械;计量与测量