Bushing: When designing dies, bushings are generally needed where quick-change drill sleeves are used.
Casing usually plays a protective role for different purposes. The drill sleeve is used to guide the drill bit, so the hardness of the drill sleeve is very high, usually not lower than HRC55.
The technical requirements between the working surface of the positioning element and the connecting surface of the machine tool are the factors that affect the installation error, while the connecting surface of the drilling fixture and the machine tool is the bottom surface A of the fixture body, so the technical requirements of the workpiece surface of the positioning element and the bottom surface of the fixture body should be marked, such as the verticality between the end surface of the bushing and the bottom surface A of the fixture body is 0.02 mm The technical requirements between the working surface of the positioning element and the position of the tool are the factors that affect the adjustment error. For drilling fixture, the position of the drill sleeve axis is the position of the hole machining tool, so the necessary technical requirements should be marked between the drill sleeve axis and the working face of the positioning element. For example, the perpendicularity between the axis of the drill sleeve and the bottom surface A of the clamp body is 0.02mm, the dimensional accuracy of the distance between the axis of the drill sleeve and the end surface of the positioning sleeve is 25 0.015 mm, the dimensional tolerance of the inner diameter of the drill sleeve is 20F7, and the matching accuracy of the drill sleeve and the bushing and the drilling template is φ26f 7/M6, φ32h 7/n6, etc. The adjustment error of drilling fixture is also called guide error.
The structural dimensions of drill sleeve and bushing conform to the relevant parts of national standards GB 2265- 199 1 and GB 2263- 199 1.
The main mating dimensions are: the mating dimension of bushing and drilling template is φ75, and the mating dimension of drilling sleeve and bushing is φ62.