tailieunhanh - Application of geometrical tolerances

In the chapter, examples are given of the application of tolerances to each of the characteristics on engineering drawings by providing a typical specification for the product and the appropriate note which must be added to the drawing. | Chapter 21 Application of geometrical tolerances In this chapter examples are given of the application of tolerances to each of the characteristics on engineering drawings by providing a typical specification for the product and the appropriate note which must be added to the drawing. In every example the tolerance values given are only typical figures the product designer would normally be responsible for the selection of tolerance values for individual cases. Straightness A straight line is the shortest distance between two points. A straightness tolerance controls 1. the straightness of a line on a surface 2. the straightness of a line in a single plane 3. the straightness of an axis. Case 1 Product requirement The specified line shown on the surface must lie between two parallel straight lines apart. Drawing instruction In the application shown at left column tolerances are given controlling the straightness of two lines at right angles to one another. In the left-hand view the straightness control is and in the right-hand view . As in the previous example the position of the graduation marks would be required to be detailed on a plan view. Case 2 Product requirement The axis of the whole part must lie in a boxed zone of X over its length. Drawing instruction As indicated the straightness of the axis is controlled by the dimensions of the box and could be applied to a long-rectangular key. A typical application for this type of tolerance could be a graduation line on an engraved scale. Manual of Engineering Drawing Copyright 2009 Elsevier Ltd. All rights of reproduction in any form reserved. 169 170J Manual of Engineering Drawing Case 3 Product requirement The surface must be contained between two parallel planes apart. Drawing instruction A7 I The axis of the whole part must lie within the cylindrical-tolerance zone of . Drawing instruction Case 4 Product requirement The geometrical tolerance may be .

• Cơ khí - Chế tạo máy
• Application of geometrical tolerances
• Profile tolerance of a surface
• Circular run out
• Total run out
• Profile tolerance of a line
• Characteristics on engineering drawings