Patent RU-2745990-C1 (RU)
Inventor: Chigrik Nadezhda Nikolaevna
IPC: F16S5/00
Filed: 2020-06-30
Granted: 2021-04-05
Abstract: FIELD: mechanical engineering. 
     SUBSTANCE: invention relates to mechanical engineering and namely to measuring equipment. The invention can be used to measure and control parts including those in the tested batches when batching and selecting parts by sorting them into an equal number of size groups with subsequent assembly according to the same-name size groups. The method includes an initial reduction in the tolerances of the actual dimensions with respect to the no-pass limit by twice the probabilistic limit value of the size output (c) for each tolerance limit for incorrectly accepted defective parts with known accuracy of the technological process or by the value of the permissible measurement error (δ chg ) with unknown accuracy of the technological process to exclude the displacement of the grouping center   of tolerances of actual dimensions. When batching and selecting parts by sorting them into an equal number of size groups followed by assembly according to the same size groups excluding displacement of the grouping centers   of tolerances of intermediate and extreme size groups in relation to the middle of the tolerance of actual dimensions Ес(IТ), the tolerances of actual dimensions are divided into an equal number of size groups and completing and selecting parts by sorting them into an equal number of size groups with subsequent assembly according to the same size groups of an equal number of parts of one size group is carried out in such a way so that the largest group gaps and tightness decrease with a decrease in real gaps and tightness in matching joints by narrowing the tolerances of the actual dimensions to the shape tolerance of real surfaces TCEd=Т s d(2Δ s d), TCED=Т s D(2Δ s D) in diametrical terms because the deviations of the shape of the real surface (ECE) limited by the size tolerance are counted from the base surface of the shape and, depending on the type of surface, are estimated by complex and elementary parameters of the geometric accuracy of the shape, reducing the tolerances of the actual dimensions to the shape tolerance of real surfaces, which limits the shape deviations in diametrical terms to the area in space or on a plane, inside which there are points of a real surface or a profile set according to a two-contact scheme by a universal instrument measuring shape errors of real surfaces with a limited tolerance of the size Td, TD in a symmetric relation to the average diameter   by random scattering of its actual dimensions or shape tolerance TCEd=Т s d(2Δ s d), TCED=Т s D(2Δ s D) symmetrically from the middle radius   by the probability distribution of deviations of its shape, provided that the straight line r=a⋅x+b is located along the shortest distance relative to at least one of the enveloping lines of the family of radii of the real profile {r 1 ,r 2 ,…r n } of the cylindrical part. 
     EFFECT: method makes it possible to ensure that an equal number of parts of the same size group are supplied to the assembly within the same size groups in the tested batches of parts during the assembly and selection by sorting them into an equal number of size groups, for example, when assembling parts such as cylinder liners, pistons, piston pins, a bearing bush located in the upper head of the connecting rods, the main and connecting rod journals of the crankshaft and their liners, the cylinders of the hydraulic vacuum amplifier and the control valve and their pistons, the front axle beam and the kingpin of the pivot pin, the main brake cylinder and its piston, the sleeve of the steering gear housing and the steering bipod shaft , cross studs, bearing bushings of satellites and differential box cups, rolling elements when installed in rolling bearings. 
     1 cl, 5 dwg