《三大汽车公司冲压工艺分析报告.pdf》由会员分享,可在线阅读,更多相关《三大汽车公司冲压工艺分析报告.pdf(58页珍藏版)》请在三一文库上搜索。
1、Automotive Sheet Steel Stamping Process Variation An analysis of stamping process capability and implications for design, die tryout and process control. Auto/Steel Partnership Automotive Sheet Steel Stamping Process Variation: An Analysis of Stamping Process Capability and Implications for Design,
2、Die Tryout and Process Control Auto/Steel Partnership Program Body Systems Analysis Project Team 2000 Town Center - Suite 320 Southfield, MI 48075-1123 2000 Auto/Steel Partnership AK Steel Corporation Bethlehem Steel Corporation DaimlerChrysler Corporation Dofasco Inc. Ford Motor Company General Mot
3、ors Corporation Ispat Inland Inc. LTV Steel Company National Steel Corporation Rouge Steel Company Stelco Inc. U. S. Steel Group, a Unit of USX Corporation WCI Steel, Inc. Weirton Steel Corporation This publication is for general information only. The material contained herein should not be used wit
4、hout first securing competent advice with respect to its suitability for any given application. This publication is not intended as a representation or warranty on the part of The Auto/Steel Partnership or any other person named herein that the information is suitable for any general or particular u
5、se, or free from infringement of any patent or patents. Anyone making use of the information assumes all liability arising from such use. This publication is intended for use by Auto/Steel Partnership members only. For more information or additional copies of this publication, please contact the Aut
6、o/Steel Partnership, 2000 Town Center, Suite 320, Southfield, MI 48075-1123 or phone: 248-945-7777, fax: 248-356-8511, web site: www.a-sp.org Copyright 2000 Auto/Steel Partnership. All Rights Reserved. ii Table of Contents Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7、. . . . . . . . . . . . . . . . . vi Executive Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.0Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1Motivation for Researc
8、h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2Study Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.0Stamping Variation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9、 . . . . . . . . . . . 7 2.1Components of Variation Explained. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.2Calculating Components of Variation Using ANOVA . . . . . . . . . . . . . . . . . . . . . 9 2.3Description of the Sources of Stamping Variation . . . . . . . . . . . .
10、. . . . . . . . . . . 13 3.0Analysis of Stamping Variation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.1Mean Conformance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.1.1Benchmark Comparison - Body Side Outer
11、 and Inner Panels. . . . . 14 3.1.2Mean Bias and Part Tolerances . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.1.3Benchmark Comparison - Tryout versus Production . . . . . . . . . . . . . 18 3.1.4Mean Bias Stability over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
12、8 3.1.5Impact of Shipping on Mean Bias . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3.2Stamping Process Variation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3.2.1Benchmark Comparison - Part-to-Part Variation . . . . . . . . . . . . . . . . 21 3.2.2Vari
13、ation Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 3.2.3Impact of Shipping on Variation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3.2.4Components of Variation: Part-to-Part, Run-to-Run, and Begin-End of Run . . . . . . . . . . . . . . . . .
14、. . . . . . . . . . . . . . . . . . 25 3.2.5Steel Properties and Press Setup Control and Stamping Variation . . 27 3.2.6Effect of Mean Shifts on Statistical Process Control Techniques . . . . 29 4.0Tolerance Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15、 . . . . . . 34 4.1Tolerances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 4.2Cpand Cpk(Ppand Ppk). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 4.3Recommended Tolerances for Sheet Metal . . . . . . .
16、 . . . . . . . . . . . . . . . . . . . . . 35 4.4Part Tolerances and Functional Build . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 5.0Conclusions and Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Appendix A - Part Sketches by
17、 Company . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 iii iv List of Figures Figure 1.Body Side Components Chosen for Company C . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Figure 2.Components of Variation . . . . . . . . . . . . . . . . . . . . .
18、 . . . . . . . . . . . . . . . . . . . . . . . . 7 Figure 3.Potential Sources of Stamping Variation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Figure 4.Total Variation Partitioned into Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Figure 5.Body
19、 Side Outer for Company A: 12 Measurement Locations. . . . . . . . . . . . . . . . . 12 Figure 6.Histogram of Mean Values across 5 Parts for Company C . . . . . . . . . . . . . . . . . . . . 15 Figure 7.Mean Conformance: Rigid vs. Non-Rigid Panels . . . . . . . . . . . . . . . . . . . . . . . . . .
20、. 15 Figure 8.Mean Conformance: Two-Piece Body Side Panel vs. One-Piece. . . . . . . . . . . . . . . 16 Figure 9.Correlation of Mean at Part Approval vs. Production . . . . . . . . . . . . . . . . . . . . . . . . . 19 Figure 10.Effect of Stamping Mean Shift on Body Side Assembly. . . . . . . . . . .
21、 . . . . . . . . . . . 20 Figure 11.Average Variation (Standard Deviation) by Type of Part . . . . . . . . . . . . . . . . . . . . . . 23 Figure 12.Part-to-Part Variation: Home Line Tryout Approval vs. Production, by Dimension. . . 24 Figure 13.Components of Variation for Body Side Panel at Company
22、C and Company D . . . . . 26 Figure 14.Relationship between Press Tonnage and Mean Shift Variation (mean shift) . . . . . 29 Figure 15.X-Bar/Range Chart vs. Individuals/ Moving Range Charts . . . . . . . . . . . . . . . . . . . . 32 Figure 16.Illustration of Cpand Cpkcalculations for three scenarios
23、. . . . . . . . . . . . . . . . . . . . 35 Figure 17.Part Sketches at Company A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Figure 18.Part Sketches at Company B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Figure 19
24、.Part Sketches at Company C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Figure 20.Part Sketches at Company D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Figure 21.Part Sketches at Company E . . . . . . . . . . . .
25、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Figure 22.Part Sketches at Company F . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Figure 23.Part Sketches at Company G . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
26、. . . . 44 v List of Tables Table 1.Participating Automotive Manufacturers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Table 2.Components Studied at Each Automotive Manufacturer . . . . . . . . . . . . . . . . . . . . . . 5 Table 3.Formulae for Calculating Components of Var
27、iation . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Table 4.36-Data Samples for a Stamping Dimension. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Table 5.SPSS Output Calculations for Mean Squared Errors (all factors) . . . . . . . . . . . . . . . . 11 Table 6.SPSS Output C
28、alculations for Mean Squared Errors without Begin-End Factor . . . . . 11 Table 7.Summary of Components of Variation Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Table 8.Variance Summary for twelve Body Side Dimensions . . . . . . . . . . . . . . . . . . . . . . . . 12 Table 9
29、.Mean Conformance by Company . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table 10.Mean Bias by Type of Part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Table 11.Mean Conformance and Tolerances . . . . . . . . . . . .
30、 . . . . . . . . . . . . . . . . . . . . . . . . . 18 Table 12.Summary of Mean bias: Tryout vs. Production - Case Study Parts . . . . . . . . . . . . . . 18 Table 13.Comparisons of the Change in Mean Bias from Tryout to Home Line . . . . . . . . . . . . 19 Table 14.Change in Mean from Home Line to L
31、ong-term Production. . . . . . . . . . . . . . . . . . . 20 Table 15.Summary of Panels Measured Before and After Shipping . . . . . . . . . . . . . . . . . . . . . 21 Table 16.Part-to-Part Variation for the Body Side Outer Panels . . . . . . . . . . . . . . . . . . . . . . . . 22 Table 17.Effect of
32、Dimension Location on Variation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Table 18.Part-to-Part Variation: Home Line Approval vs. Production, by Company . . . . . . . . . 24 Table 19.Summary of Remeasured Data Before and After Shipping via truck . . . . . . . . . . . . . 2
33、5 Table 20.Summary of Part-to-Part and Total Variation for the Body Side Outers. . . . . . . . . . . 25 Table 21.Sources of Variation by Part for Company A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Table 22.Sources of Variation by Part for Company C . . . . . . . . . . . . . .
34、 . . . . . . . . . . . . . . . . . 27 Table 23.Summary of Product and Process Variation Compliance. . . . . . . . . . . . . . . . . . . . . 28 Table 24.Summary of Mean Shift Variation across Companies . . . . . . . . . . . . . . . . . . . . . . . . 30 Table 25.Process Control Data . . . . . . . . .
35、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Table 26.Effect of Stamping Mean Shifts on Assembly Variation . . . . . . . . . . . . . . . . . . . . . . . 33 Table 27.General Recommended Tolerances for Stamped Parts Based upon Process Capability . . . . . . . . . .
36、. . . . . . . . . . . . . . . . . . 36 Preface This report is one of a series published by the Auto/Steel Partnership Body Systems Analysis Project Team on stamping and assembly variation, body measurement systems and process valida- tion. These reports provide a summary of the proj- ect research an
37、d are not intended to be all inclu- sive of the research effort. Numerous seminars and workshops have been given to individual automotive manufacturers throughout the project to aid in implementation and provide direct techni- cal support. Proprietary observations and imple- mentation details are om
38、itted from the reports. Thisautomotivebodydevelopmentreport, “Stamping Process Variation: An Analysis of Stamping Process Capability and Implications for Design, Die Tryout and Process Control,“ updates ongoing research activities by the Body Systems Analysis Team and the Manufacturing Systems staff
39、 at The University of Michigans Office for the Study of Automotive Transportation. An over-riding goal of this research is to develop new paradigms that will drive automotive body-in- white development and production towards a total optimized processing system. Previous reports described fundamental
40、 research investigating simultaneous development systems for designing, tooling and assembling bodies, and flexible body assembly. Since the inception of this research pro- gram, considerable emphasis has been focused on benchmarking key world class body develop- ment and production processes. These
41、 bench- marks created foundation elements upon which further advances could be researched and devel- oped. This report summarizes recommendations for moving toward a new “functional build“ paradigm by tightly integrating the many individual activities ranging from body design and engineering through
42、 process and tooling engineering. Revised stamping die tryout and buyoff processes receive special emphasis, as does the launch of stamping and assembly tools. The researchers are indebted to several global automotive manufacturers for their on-going dedi- cation and participation in this research.
43、They include DaimlerChrysler Corporation, Ford Motor Company, General Motors Corporation, Nissan, NUMMI (Toyota), Opel and Renault. Each con- ducted experiments under production conditions involving hundreds of hours of effort and often requiring the commitment of many production workers and enginee
44、ring personnel. Although it may be impractical to mention each one of these people individually, we do offer our sincere appre- ciation. These reports represent a culmination of several years of effort by the Body Systems Analysis Project Team. Team membership, which has evolved over the course of t
45、his project, includes: J. Aube, General Motors Corporation H. Bell, General Motors Corporation C. Butche, General Motors Corporation G. Crisp, DaimlerChrysler Corporation T. Diewald, Auto/Steel Partnership K. Goff, Jr., Ford Motor Company T. Gonzales, National Steel Corporation R. Haan, General Moto
46、rs Corporation S. Johnson, DaimlerChrysler Corporation F. Keith, Ford Motor Company T. Mancewicz, General Motors Corporation J. Naysmith, Ronart Industries J. Noel, Auto/Steel Partnership P. Peterson, USX R. Pierson, General Motors Corporation R. Rekolt, DaimlerChrysler Corporation M. Rumel, Auto/St
47、eel Partnership M. Schmidt, Atlas Tool and Die TheUniversityofMichiganTransportation ResearchInstituteconductedmuchofthe research and wrote the final reports. The principal research team from the Manufacturing Systems Group was: Patrick Hammett, Ph.D. (734-936-1121/pham- mettumich.edu) Jay Baron, Ph
48、.D. (734-764- 4704/jaybaronumich.edu) Donald Smith, Associate Director (734-764-5262) vi Executive Summary The Auto/Steel Partnership (A/SP) is an innovative internationalassociationthatincludes DaimlerChrysler, Ford, General Motors and eleven North American sheet steel producers. The Partnership wa
49、s formed in 1987 to leverage the resources of the automotive and steel industries to pursue research projects leading to excellence in the application of sheet steels in the design and manufacture of vehicles. The Partnership has established project teams that examine issues related to steel properties including strength, dent resistance, surface texture and coating weights, as well as manufacturing methods including stamping, welding and design improvements. Automotive manufacturers face the challenge of identifying when a process is capable of produc- ing dimensionally acceptable stam
链接地址:https://www.31doc.com/p-3697934.html