How to measure the fit clearance between piston and cylinder wall by tension method?

Excessive clearance between piston and cylinder wall will lead to direct consequences, such as lower mechanical efficiency, lower output power and poor machine operation. If it is not handled in time, it may lead to combustion or failure of lubricating oil. If the lubricating oil fails or is too little to be found in time, the cylinder wall will eventually be pulled due to poor lubrication, resulting in dry grinding of friction pairs and cylinder pulling! Cylinder pulling is mainly caused by poor lubrication! After the repair size of the cylinder is determined, the piston of the same level can be selected (gasoline engine has 6 repair sizes and diesel engine has 8 repair sizes), and the difference of each size is 0. 25 mm, increasing step by step. At present, the cylinder is generally ground according to the selected piston, that is, the outer diameter of the selected piston skirt is measured first, and then the impact cutting amount is calculated according to the actual size of the piston and cylinder. The method is as follows. T it cutting amount = maximum diameter of piston skirt-minimum diameter of cylinder+fit clearance between piston skirt and cylinder wall-cylinder grinding allowance.