The difference in their sizes is the applied cylindrical tolerance limits. The cylindricity tolerance zone is the volume enclosed by the radial separation between these two concentric cylinders. These cylinders run along the entire length of the curved surface, one on the inside and the other on the outside, creating a perfect cylindrical boundary around the part’s entire surface. The cylindricity tolerance zone is represented by two concentric cylinders. Purple is the surface of the cylinder and has to fit into the zone. Cylindricity Tolerance Zone Green represents the tolerance zone. If even one of the discs deviates too much in size or roundness compared to the others or it shifts to one side more than allowed, the whole stack would fail to adhere to the tolerance limits. The cylindricity control, besides checking the circularity of each disc, also checks that the discs are stacked straight. We can explain the working of the cylindricity callout by means of a disc stack. The size and alignment of each disc is taken into account The cylindricity callout specifies how close the cylindrical dimensions of an actual part need to be to an ideal cylinder. Even if the pin is perfectly round (good circularity), a small deviation from desired straightness (bend along the length) will prevent it from passing through the hole. Take the example of a pin that needs to pass through a hole with tight diametral tolerance. This is especially true for parts that fit into long, tight bores where the circularity, straightness, and taper of the cylindrical part must be within tight specifications. Many cylindrical parts that fit into a tight assembly must be “cylindrical enough” for a good fit. The cylindricity control is a GD&T tolerance from the form control group and guarantees a part’s cylindric shape by determining the two key aspects of roundness and axis straightness. VII Important Points to Remember What Is Cylindricity?
0 kommentar(er)
