ИССЛЕДОВАНИЕ ПАРАМЕТРОВ РАБОТЫ ГАЗОРАСПРЕДЕЛИТЕЛЬНОГО МЕХАНИЗМА ПРИ ВИБРОАКУСТИЧЕСКОМ КОНТРОЛЕ В РЕЖИМЕ ТЕСТОВОГО ДИАГНОСТИРОВАНИЯ

Abstract

Statistical analysis of ICE system faults shows a considerable growth of gas distribution mechanism failures: on average 7-12 %.This is explained by complicacy of gas distribution elements and occurrence of numerous new elements ( hydraulic pushers, hydraulic tensioners, automatic correcting mechanism of gas distribution phases, multivalve systems). However, in practice improvement of the gas distribution mechanism conspicuously surpasses development of new veracious techniques and methods of technical condition control. Development of new techniques and methods of technical condition control over the gas distribution mechanism enables solving of the important task to increase the engine operational resource. The most informative and veracious diagnostic method is vibroacoustic one, which makes it possible to evaluate technical condition of gas distribution mechanism at any stage. In order to diagnose the gas distribution mechanism with consideration of minimum interference and maximum information content, we chose the equipment which includes USB-Avtoscope III (Postolovsky oscillograph), a laptop with data analysis software, a pressure sensor for pressure control in the cylinder and an accelerometer. For prevention of linear expansion of metals , diagnostics was made on the engine with the temperature ranging from +80 to +90° C (measurements which are taken by a measuring probe within this temperature range are identical). The maximum expansion of metal was fixed at 1100 min-1 in 14 sec., at 1300 min-1 - 13 sec., at 1500 min-1 - 10,2 sec. Change of valve expansion clearance from 0,35 mm to 0,7 mm reduces the valve opening phase by 2×15°30′ (i.e. results in considerable delay of valve opening by 15°30′ and acceleration of its closure by 15°30′).