Дослідження стійкості дискових ножів при розрізуванні еластомерів

Abstract

Приведено конструкцію пристрою до заточувального верстата для заточування дискових ножів, ножових блоків для розрізування еластомерів конвеєрних стрічок заданих розмірів. У результаті експериментальних досліджень встановлено межу працездатності ножів у часовому просторі й режими різання та заточування ножів.

The construction of device of the grinding machine for sharpening unit disk blades for cutting elastomers conveyer belts of given size was shown. Industry of Germany exports rubber-cotton conveyer belt in roll of 0,9…2 m width and 50 m length to Ukraine. Special devices with the knives units and possibility of change their location due to the required belt width are used for cutting rolls into strips of the given width. Special devices for simultaneous grinding of two cutting blades was designed and produced with U-type bracket with the possibility of a circular rotation around the vertical axis. Knives unit which was designed as two parallel driven shafts with possibility of cranking circular and axial movement on a special support was installed inside of it. Cutting edges of circular blades are connected with grinding wire cup circles. As a result of experimental research the limit of performance of cutting elements in time space and cutting conditions during sharpening was found. The main problem in the design of cutting disc blades and selection of cutting regimes is their greasing by rubber sticking and fuming, and as a result – pollution of the environment. So, primarily task was to solve the problem with two contradictions: maximum performance of cutting process with the limited cutting speed, and elimination of tools heating to the melting point of the cord material. Limited cutting speed was determined experimentally. As a result of experimental researches rational cutting speed by circular knives within V=0,15-0,25 m/s was found. Diameter of disc blades due to conditions of the drive shaft strength, thickness of the conveyer belt, normal work conditions and other design parameters was selected. It was found that the outer diameter of blades is within 130-150 mm. Sharpening angle was selected experimentally and it is α = 12º, 19º, 25º and 30º. Due to result, of experiments and from the joint of view of stability and normal operation conditions it is recommended to take it within α = 16-22º. Criterion wearing allowance of disk blades was selected as 0,20 mm diameter, which is recommended and confirmed by our researches.