In the case when grinding of the ends cannot be carried out, the following changes are allowed in the above plan of operations: in operation 1 before cutting off each ring, its outer end is gripped with the purity of the surface VV6, after which the ring is cut off with a height of 0.10-0.15 mm ; Operation 2 is not performed; The test of metal for hardness is carried out at a processed end; Instead of grinding (operations 7), the ends of the ring are sawed and stuck and stuck with the required height and cleanliness of the surface processing, on which, when checking on the paint on the step-by-step plate, the stains of the paint should be distributed evenly with a density of A-5 spots per 1 cm2.
The accuracy of the processing of the rings, the cleanliness of the surface and the testing of them after processing for warping, the fit and elasticity must correspond to the above instructions.
The piston finger is replaced with fractures, cracks, deep corrosion, which cannot be removed with an emery cloth. In addition, a smooth finger should be replaced if its ovality exceeds 0.001 d +0.05 mm (where D is the diameter of the finger). The step (stopping) finger with such an ovality of the working part (mating with the bearing of the upper head of the connecting rod) should not be allowed to further work, but it can be repaired by polishing the working part under conditions, which: it does not have fractures, cracks or corrosion; After grinding, the diameter of the working part of it will be no less than the diameter of the thinner end entering the hole in the piston; The hardness of the polished surface will be not lower than HRC – 55; In the conjugation of the ends of the finger (TRAPF) with the piston beans will be ensured by landing.
When the finger is weakened in the piston beavers, so that the gap formed exceeds 1.5 expansion, which is possible during planting, and in the absence of other defects, which are the basis for replacing the finger, it can be repaired by chrome ends or their grinding 3-4 mm according to with the diameter and collapse of their electric welding, followed by grinding and grinding to ensure the required landing.
