1. Shape tolerance: including straightness, flatness, roundness, cylindricity, line profile and surface profile, etc. These tolerances are used to describe the shape characteristics of parts and ensure that they meet the design requirements.
2. Direction tolerance: including parallelism, verticality and inclination. These tolerances are used to describe the directional characteristics of parts relative to the reference axis and ensure that they meet the design requirements.
3. Position tolerance: including coaxiality, symmetry and position. These tolerances are used to describe the position characteristics of parts relative to the datum and ensure that they meet the design requirements.
4. Runout tolerance: including circular runout and full runout. These tolerances are used to describe the runout of parts during rotation to ensure that they meet the design requirements.
Geometric tolerance application scenario:
1. Mechanical manufacturing: In mechanical manufacturing, the form and position tolerance is used to determine the allowable deviation range of the size and shape of parts. By using the form and position tolerance, the parts can be guaranteed to have good interchangeability and reliability during assembly. For example, in machine tool manufacturing, form and position tolerances are used to control the parallelism, verticality and roundness of parts.
2. Engineering design: In engineering design, form and position tolerance is used to determine the clearance and fit between assembled parts. Using the form and position tolerance, the gap between assembled parts can be ensured not to be too large or too small, and the assembly difficulty or looseness can be avoided. For example, in the design of automobile engine, the clearance between piston and cylinder liner is controlled by geometric tolerance to ensure the stability and sealing of piston movement in cylinder.
3. Assembly process: In the assembly process, the order and method of the assembly process are determined by the form and position tolerance. The use of form and position tolerance can ensure the smooth progress of each link in the assembly process. For example, in spacecraft assembly, geometric tolerances are used to determine the assembly sequence and method of each component to ensure the integrity and reliability of spacecraft structure and function.
4. Electronic equipment manufacturing: In electronic equipment manufacturing, the position and spacing of components on the circuit board are controlled by form and position tolerances to ensure the reliability and stability of electronic equipment.
5. Manufacture of medical devices: In the manufacture of medical devices, geometric tolerances are used to control the size, shape and position of medical devices to ensure the safety and effectiveness of medical devices.
6. Aerospace field: In the aerospace field, the size and shape of aircraft and spacecraft parts are controlled by form and position tolerance to ensure the performance and safety of aircraft and spacecraft.