Several adjustment methods of valve clearance of tractor engine

The so-called valve clearance refers to the clearance between the end of the valve rod and the rocker arm when the tractor engine valve is closed. Its function is to leave room for the valve mechanism to expand when heated. When the engine is working, the valve clearance is required to meet the technical requirements. If the valve clearance is too small, when the parts expand when heated, the valve will not close tightly, the cylinder pressure will be poor, the engine power will be reduced, and the contact surface of the running-in valve will be burned out due to the impact of high temperature gas. If the valve clearance is too large, it is suggested that the valve opening should be reduced and the valve opening duration should be shortened, resulting in insufficient intake and unclean exhaust, which will lead to the decline of engine power. In addition, due to the knocking between the valve stem and the rocker arm, it is easy to damage the parts and shorten the service life of the parts. In work, the valve clearance will change due to the wear of parts, the disassembly and assembly of cylinder basin or the retightening of cylinder head nut and the loosening of valve adjusting screw. Therefore, the valve clearance must be checked and adjusted regularly. The inspection and adjustment of valve insertion should generally be carried out in the cold state, and the valve clearance is most convenient to adjust only when the compression stroke is at the top dead center. For a four-stroke engine, the specific adjustment process is different due to the different number of cylinders and working sequence, but the following two methods are generally adopted. First, the cylinder-by-cylinder adjustment method is suitable for engines with relatively few cylinders (I) and two-cylinder four-stroke engines. The working sequence table of a two-cylinder four-stroke engine is 1: the working process of a four-cylinder four-stroke engine is generally: L-2-O- 1 ... (This article * * * counts 1 page) How to obtain this article >>