Designing Capable and Reliable Products Episode 2 Part 8 pdf

Sheet J Sheet metalworking processes (cont'd) Appendix IV 325 Sheet K Machining processes 326 Appendix IV Sheet L Machining processes (cont'd) Appendix IV 327 Sheet M Powder metallurgy processes 328 Appendix IV Sheet N Plastic moulding processes See material key and notes. Appendix IV 329 Sheet P Elastomer and composite moulding processes 330 Appendix IV Sheet Q Non-traditional machining processes These processes are not strictly dimensional dependent. Appendix IV 331 Sheet R Non-traditional machining processes (cont'd) 332 Appendix IV Appendix V Sample case studies used in validation Component name Cylinder housing Calculation of q m Drawing number CH1878-1018 m p  1:3  1:5  1:95 g p  1 Â1:1  1  1 Â1 Â1  1:1 Adjusted tolerance  Design tolerance m p  g p  Æ0:05 1:95  1:1 Æ0:023 t p  1:4  1  1:4 s p  1  1  1 q m  t p  s p  1:4  1  1:4 Material Alloy steel Manufacturing process Turning/boring Characteristic description Internal core length Characteristic dimension 122.09 (mm) Design tolerance Æ0.05 (mm) Surface roughness 0.6 (mm Ra) Process capability index C pk  1:79 Process capability index C p  2:1 Manufacturing variability risk q m  1:4 Component name Cover support leg Calculation of q m Drawing number N/A m p  1:7  1:5  2:55 g p  1  1  1  1:7 Â1 Â1:1  1:87 Adjusted tolerance  Design tolerance m p  g p  Æ0:2 2:55  1:87 Æ0:042 t p  9 Â1  9 s p  1  1  1 q m  t p  s p  9  1  9 Material 0.6 mm spring steel Manufacturing process Sheet metal bending Characteristic description Top face to bottom lip Characteristic dimension 43.6 (mm) Design tolerance Æ0.2 (mm) Surface roughness ± (mm Ra) Process capability index C pk  0 Process capability index C p  0 Manufacturing variability risk q m  9 Component name End cap Calculation of q m Drawing number N/A m p  1  1  1 g p  1  1:1  1  1 Â1:1 Â1  1:21 Adjusted tolerance  Design tolerance m p  g p  Æ0:2 1  1:21 Æ0:165 t p  1:3 Â1  1:3 s p  1  1  1 q m  t p  s p  1:3  1  1:3 Material Phenolic Manufacturing process Injection moulding Characteristic description Clip length Characteristic dimension 55.0 (mm) Design tolerance Æ0.2 (mm) Surface roughness ± (mm Ra) Process capability index C pk  2:18 Process capability index C p  2:67 Manufacturing variability risk q m  1:3 334 Appendix V [...]... Calculation of qm Drawing number FQ2 186 mp ˆ 1  1 :2 ˆ 1 :2 Material 0.9 mm mild steel gp ˆ 1  1  1:7  1  1  1 :2 ˆ 2: 04 Manufacturing process Sheet metal bending Characteristic description Leg clearance Characteristic dimension 2. 95 (mm) Design tolerance Æ0 .25 (mm) Surface roughness ± (mm Ra) Adjusted tolerance ˆ ˆ Design tolerance mp  gp Æ0 :25 ˆ Æ0:1 02 1 :2  2: 04 tp ˆ 9  1 ˆ 9 sp ˆ 1  1 ˆ 1... 18 (mm) Design tolerance Æ0 .2 (mm) Surface roughness ± (mm Ra) Adjusted tolerance ˆ ˆ Design tolerance mp  gp Æ0 :2 ˆ Æ0:0 78 2: 55  1 tp ˆ 1:3  1 ˆ 1:3 sp ˆ 1  1 ˆ 1 qm ˆ tp  sp ˆ 1:3  1 ˆ 1:3 Process capability index Cpk ˆ 2: 24 Manufacturing variability risk qm ˆ 1:3 Process capability index Cp ˆ 2: 64 Component name Lamp holder bracket Calculation of qm Drawing number FQ2 186 mp ˆ 1  1 :2 ˆ 1 :2. .. 341 3 42 Appendix V Component name Lamp holder bracket Calculation of qm Drawing number FQ2 186 mp ˆ 1  1 :2 ˆ 1 :2 Material 0.9 mm mild steel gp ˆ 1  1  1:7  1  1  1 :2 ˆ 2: 04 Manufacturing process Sheet metal bending Characteristic description Top width Characteristic dimension 50.75 (mm) Design tolerance Æ0 .25 (mm) Surface roughness ± (mm Ra) Adjusted tolerance ˆ ˆ Design tolerance mp  gp Æ0 :25 ˆ... dimension 42. 05 (mm) Design tolerance Æ0.5 (mm) Surface roughness ± (mm Ra) Adjusted tolerance ˆ ˆ Design tolerance mp  gp Æ0:5 ˆ Æ0: 321 1 :2  1:3 tp ˆ 4  1 ˆ 4 sp ˆ 1  1 ˆ 1 qm ˆ tp  sp ˆ 4  1 ˆ 4 Process capability index Cpk ˆ 0 : 28 Process capability index Cp ˆ 0: 42 Manufacturing variability risk qm ˆ 4 339 340 Appendix V Component name Plunger housing Calculation of qm Drawing number CH 187 8-1 021 mp... of qm Drawing number FF476 mp ˆ 1  1 :2 ˆ 1 :2 Material 0.9 mm mild steel gp ˆ 1  1  1  1  1  1 :2 ˆ 1 :2 Manufacturing process Sheet metal bending Characteristic description Bottom leg length Characteristic dimension 8. 4 (mm) Design tolerance Æ0 .25 (mm) Surface roughness ± (mm Ra) Adjusted tolerance ˆ ˆ Design tolerance mp  gp Æ0 :25 ˆ Æ0:174 1 :2  1 :2 tp ˆ 6  1 ˆ 6 sp ˆ 1  1 ˆ 1 qm ˆ tp  sp... (mm Ra) Adjusted tolerance ˆ ˆ Design tolerance mp  gp Æ0:076 ˆ Æ0: 024 1:7  1 :87 tp ˆ 1 :25  1:1 ˆ 1:4 sp ˆ 1  1 ˆ 1 qm ˆ tp  sp ˆ 1:4  1 ˆ 1:4 Process capability index Cpk ˆ 1 :88 Process capability index Cp ˆ 2: 15 Manufacturing variability risk qm ˆ 1:4 337 3 38 Appendix V Component name Bush Calculation of qm Drawing number ERC 421 5 mp ˆ 1  1:7 ˆ 1:7 Material Bronze gp ˆ 1  1:1  1  1  1  1... Design tolerance mp  gp Æ0 :2 ˆ Æ0:097 1  2: 06 tp ˆ 1:1  1 ˆ 1:1 sp ˆ 1  1 ˆ 1 qm ˆ tp  sp ˆ 1:1  1 ˆ 1:1 Process capability index Cpk ˆ 3 :88 Process capability index Cp ˆ 4: 48 Manufacturing variability risk qm ˆ 1:1 335 336 Appendix V Component name Channel Calculation of qm Drawing number FF476 mp ˆ 1  1 :2 ˆ 1 :2 Material 0.55 mm mild steel gp ˆ 1  1  1  1:7  1  1:1 ˆ 1 :87 Manufacturing process... Æ0.05 (mm) Surface roughness 1.6 (mm Ra) Adjusted tolerance ˆ ˆ Design tolerance mp  gp Æ0:05 ˆ Æ0:045 1  1:1 tp ˆ 1: 02  1 ˆ 1: 02 sp ˆ 1  1 ˆ 1 qm ˆ tp  sp ˆ 1: 02  1 ˆ 1: 02 Process capability index Cpk ˆ 2: 99 Manufacturing variability risk qm ˆ 1: 02 Process capability index Cp ˆ 3 :22 Component name Channel Calculation of qm Drawing number FF476 mp ˆ 1  1:4 ˆ 1:4 Material 0.55 mm mild steel gp ˆ... roughness ± (mm Ra) Adjusted tolerance ˆ ˆ Design tolerance mp  gp Æ0:5 ˆ Æ0 :22 3 1 :2  1 :87 tp ˆ 9  1 ˆ 9 sp ˆ 1  1 ˆ 1 q m ˆ t p  sp ˆ 9  1 ˆ 9 Process capability index Cpk ˆ 0 Manufacturing variability risk qm ˆ 9 Process capability index Cp ˆ 0 Component name Cylinder housing Calculation of qm Drawing number CH 187 8-10 18 mp ˆ 1:3  1:5 ˆ 1:95 Material Alloy steel gp ˆ 1  1:1  1  1  1  1 ˆ... Spherical diameter Characteristic dimension 116.64 (mm) Design tolerance Æ0. 025 (mm) Surface roughness ± (mm Ra) Adjusted tolerance ˆ ˆ Design tolerance mp  gp Æ0: 025 ˆ Æ0:013 1:7  1:1 tp ˆ 1:7  1:1 ˆ 1 :87 sp ˆ 1  1 ˆ 1 qm ˆ tp  sp ˆ 1 :87  1 ˆ 1 :87 Process capability index Cpk ˆ 1 :2 Manufacturing variability risk qm ˆ 1 :87 Process capability index Cp ˆ 1:33 Component name Plenum Calculation of . Calculation of q m Drawing number FQ2 186 m p  1  1 :2  1 :2 g p  1 Â1  1:7  1 Â1 Â1 :2  2: 04 Adjusted tolerance  Design tolerance m p  g p  Æ0 :25 1 :2  2: 04 Æ0:1 02 t p  9  1  9 s p  1  1. Calculation of q m Drawing number FQ2 186 m p  1  1 :2  1 :2 g p  1  1  1:7  1 Â1 Â1 :2  2: 04 Adjusted tolerance  Design tolerance m p  g p  Æ0 :25 1 :2  2: 04 Æ0:1 02 t p  9 Â1  9 s p  1  1. q m Drawing number FF476 m p  1  1 :2  1 :2 g p  1  1  1  1:7 Â1 Â1:1  1 :87 Adjusted tolerance  Design tolerance m p  g p  Æ0:5 1 :2  1 :87 Æ0 :22 3 t p  9 Â1  9 s p  1  1  1 q m 