제4장 검사 및 품질인증 II Topic: 품질관리 Q: 대량생산되는 부품의 품질은 어떻게 관리하는가?
Coordinate Measuring Machine FIGURE 4.18 (a) A coordinate measuring machine with part being measured; (b) a touch signal probe measuring the geometry of a gear; (c) examples of laser probes. Source: Courtesy Mitutoyo America Corp.
Dimensional Tolerance FIGURE 4.19 (a) Basic size, deviation, and tolerance on a shaft, according to the ISO system. (b)-(d) Various methods of assigning tolerances on a shaft. Source: L.E. Doyle.
Tolerances by Process FIGURE 4.20 Tolerances and surface roughness obtained in various manufacturing processes. These tolerances apply to a 25-mm (1-in.) workpiece dimension. Source: After J.A. Schey.
Topic: 통계적 품질관리 검사과정 산술평균 분산 소재검사: 소재특성, 치수, 표면상태 부품검사: 부품사양 조립검사: 조립여부 성능검사: 제품기능 산술평균 분산 범위 표준편차
Topic: 통계적 공정관리-관리도 관리한계(3s법의 경우) 상한관리한계(UCL) 하한관리한계(LCL)
관리도 예(1): 선삭부품 공정변수 변화: 공구마멸로 관리한계를 벗어난 후, 공구교환 (b) 공정변수 부적절 (c) 재료 물성 변화: 관리한계를 벗어난 경우
관리도 예(2) M/D 1 2 3 4 5 6 7 8 9 10 평균 표준편차 6/1 87.7 86.7 83.2 78.0 86.0 84.9 89.1 90.3 82.4 77.0 84.5 4.4 84.1 93.2 89.4 91.0 87.6 76.8 82.5 86.3 90.0 86.4 4.9 6/2 85.7 67.8 73.0 81.3 89.9 90.9 85.6 83.8 7.8 79.2 87.1 86.1 89.5 84.4 88.7 84.6 93.3 3.9 6/3 89.6 93.1 85.8 95.7 85.9 88.0 90.5 87.5 77.6 87.2 75.2 86.5 88.3 85.2 5.3 6/4 84.8 88.9 81.8 91.4 92.8 4.1 90.7 76.0 88.6 93.9 88.8 81.4 5.5 6/5 95.1 86.9 82.2 87.4 91.7 93.6 3.8 92.6 87.8 89.7 94.5 89.8 90.2 92.2 92.1 91.1 2.1 87.0 4.6
관리도의 양상 n = 5 n = 10 n = 50