3-4-公差原则教案.pptVIP

4.形状公差（ t ）与尺寸公差（ T ）的关系：The relationships between geometrical tolerances and size tolerances 最大实体状态时：形状公差tmin=0 When in maximum material condition:Form tolerances tmin=0 最小实体状态时：形状公差 tmax=T When in least material condition:condition:Form tolerances tmax=T φ30h7 E 中心轴线 Central axis 垂直度 Verticality * 小结：Summary: 尺寸公差Th Ts与形状公差 t Size tolerances Th Ts and form tolerances t 尺寸公差具有双重职能：控制尺寸公差和形状公差 Size tolerances contain dual functions:Controling size tolerances and form tolerances. dmin Dmax dmax Dmin * 5.最大实体要求应用举例（一） Application examples of maximum material requirements(1) 该轴应满足下列要求：This shaft should satisfy the following requirements: 实际尺寸：φ9.985 ～ φ10 Actual size: 边界：实际轮廓不超出最大实体实效边界 Boundary:Actual cam doesn’t overstepping maximum material virtual boundary. dMV=dM+t1=10+0.005 =10.005mm 即体外作用尺寸：External mating size dfe≤10.005 A ? 10h7 A ? 0.005 M * 合格条件：Acceptance condition: 轴：dfe ≤ dMV ＝ dmax+t1=10.005 Shaft 9.985 ≤ da ≤ 10 尺寸公差：Ts=0.015 Size tolerance: 形状公差：Form tolerance: When: 当：dM=dmax=10 t=t1=0.005 When: 当：dL=dmin=9.985 t=t1+t2=t1+Ts=0.005+0.015=0.02 直线度 Straightness da ?9.985 ? 10（dM） ? 10.005(dMV) 0.005 0.02 -0.3 动态公差图 Dynamic tolerance chart * 1.尺寸公差Th Ts与形位公差t的关系：The relationships between size tolerances Th Ts and geometrical tolerances t. 当 Da = Dmin da = dmax ： 允许形位公差 t=tmin=t1 Allow geometrical tolerances 当 Da = Dmax da = dmin ： 允许形位公差 t=tmax=t1+Th〔Ts〕 Allow geometrical tolerances 小结：Summary: 2.合格性判定：Qualification determinations: 对于孔：Dfe ≥ DMV ＝ Dmin-t1 Dmin≤ Da ≤ Dmax For hole 对于轴：dfe ≤ dMV ＝ dmax+t1 dmin≤ da ≤ dmax For shaft * THE END * 4.3 公差原则 Tolerance principles GB/T4249-1996 * 基本内容：Basic contents: 公差原则 1.Tolerance principles 有关术语及定义 2.Related terms and definitions 相关原则 3.Related principles 难点内容： Aporia contents: 相关原则的应用 The applications of r