tailieunhanh - Geometric Dimensioning and Tolerancing for Mechanical Design Part 7

Tham khảo tài liệu 'geometric dimensioning and tolerancing for mechanical design part 7', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Position General Position General 107 Figure 7-4 Inspecting the hole pattern controlled to a datum feature of size at RFS. datum feature such as a chuck vise or adjustable mandrel is used to position the part. In Fig. 7-4 the outside diameter datum B is specified at RFS. The pattern of features is inspected by placing the outside diameter in a chucking device and the hole pattern over a set of virtual condition pins. If the part can be set inside this gage and all the feature sizes are within size tolerance the pattern is acceptable. Maximum Material Condition The only difference between the tolerances in and is the MMC modifier specified after the numerical tolerance in the feature control frame. Downloaded from Digital Engineering Library @ McGraw-Hill Copyright 2006 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Position General 108 Chapter Seven Figure 7-5 Location of a size feature with a position tolerance at MMC. When the MMC symbol circle M is specified to modify the tolerance of a size feature in a feature control frame the following two requirements apply 1. The specified tolerance applies at the MMC of the feature. The MMC of a size feature is the largest shaft and the smallest hole. The MMC modifier circle M is not to be confused with the MMC of a size feature. 2. As the size of the feature departs from MMC toward LMC a bonus tolerance is achieved in the exact amount of such departure. Bonus tolerance equals the difference between the actual feature size and the MMC of the feature. The bonus tolerance is added to the geometric tolerance specified in the Downloaded from Digital Engineering Library @ McGraw-Hill Copyright 2006 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Position General Position General 109 feature control frame. MMC is the .