上海交通大学：《现代机械工程图学》教学资源_教学课件_Lec04_GD&T1

GEOMETRIC DIMENSIONING TOLERANCING (GD T) ME 250:Design Manufacturing I School of Mechanical Engineering Shanghai Jiao Tong University 1

Shanghai Jiao Tong University 1 GEOMETRIC DIMENSIONING & TOLERANCING (GD & T) ME 250: Design & Manufacturing I School of Mechanical Engineering

GD &T Outline Dimensioning Principles ■Standards ■Tolerancing Definitions Datums Form Controls Shanghai Jiao Tong University 2

Shanghai Jiao Tong University 2 GD & T Outline n Dimensioning n Principles n Standards n Tolerancing n Definitions n Datums n Form Controls

Working Drawing Three orthographic views Auxiliary views,section views Dimensions Special lines/symbols/notations ■Tolerances ■Title block Bill of materials ■Other notes/labels Shanghai Jiao Tong University 3

Shanghai Jiao Tong University 3 Working Drawing n Three orthographic views n Auxiliary views, section views n Dimensions n Special lines/symbols/notations n Tolerances n Title block n Bill of materials n Other notes/labels

Working Drawing M■TaI⊙7c1412 总智9 1E7261 030 D置 4x' 6-J0 NOTE B 30TH ENDS 01t9.994t0.096 0-/ Oc .005 HAX TAPER ON DIA 86T4N5 A▣ 18-99 D因 -1E226I0,64HA×FE7E0 =249.7540.25- DETAIL B BOTH ENDS SCALE NONE 15ME经 J品容 NOTE A CARSURIZED DEPTH MUST BE SUFFICIENT TO OBTAIN HARDENED CASE DEPTH SPECIFIED.ALL SURFACES MUST BE HARDENED TO REV 3CN-72 MIN.RARDENED DEPTH 1.2-2.3 TO REW C49.AFTER 260.MIN TEHPER FOR 2 HOURS MIN.HARONESS CORE RKW C20 IN.9y4·C CARBU聘121 NB OPTIONAL 4E NOTE D.INSIDE DIA MAY BE HONED AFTER HEAT TREAT.MAX MATL THAT 缺AYBE典EMOVED-Q.D30 N RADIU5 155 NOTE C.APPS SUPPLIER S0的EUT5 CHE KOL8E8 DLZENFABR】K GHBH ATERIAL16制nCF5$T九 R2,0时0.9 ☒ DETAIL A OPTIONAL CHAMFE片 5LE,5+1 受 Shanghai Jiao Tong University 4

Shanghai Jiao Tong University 4 Working Drawing

Dimensioning Dimension is used to specify the object size and its location. Specify the exact theoretically values for the size,orientation and location of features. Shanghai Jiao Tong University 5

Shanghai Jiao Tong University 5 Dimensioning Dimension is used to specify the object size and its location. Specify the exact theoretically values for the size,orientation and location of features

Principles ■ Show every necessary dimension. Never repeat a dimension. Locate dimensions that are linked to one another with respect to the same datum. If possible,avoid crossing two dimension lines. Arrange a series of dimensions in a continuous line. Place longer dimensions outside shorter ones so that extension lines will not cross dimension lines. Place dimensioning information outside the orthographic views if possible. Leaders note dimensions and information. Fillet are dimensioned with leaders or by an appropriate note. Shanghai Jiao Tong University 6

Shanghai Jiao Tong University 6 Principles n Show every necessary dimension. n Never repeat a dimension. n Locate dimensions that are linked to one another with respect to the same datum. n If possible, avoid crossing two dimension lines. n Arrange a series of dimensions in a continuous line. n Place longer dimensions outside shorter ones so that extension lines will not cross dimension lines. n Place dimensioning information outside the orthographic views if possible. n Leaders note dimensions and information. n Fillet are dimensioned with leaders or by an appropriate note

Principles 618 71- 50 40 色30 00So 55 10 160 43129 481.29 Shanghai Jiao Tong University 7

Shanghai Jiao Tong University 7 Principles

Standards Extension Lines Dimension Lines Dimension 582 Shanghai Jiao Tong University 8

Shanghai Jiao Tong University 8 Standards n Extension Lines n Dimension Lines n Dimension

Threads Threads are specified by giving the nominal diameter and threads per inch. ANSI:%-13UNC;%-13UNF ■Metric:M8x1.25 Shanghai Jiao Tong University 9

Shanghai Jiao Tong University 9 Threads n Threads are specified by giving the nominal diameter and threads per inch. n ANSI: ½-13UNC; ½-13UNF n Metric: M8x1.25

Schematic Symbols EXTERNAL SECTION EXTERNAL THREADS ELEVATION SECTION INTERNAL THREADS Shanghai Jiao Tong University 10

Shanghai Jiao Tong University 10 Schematic Symbols