不同工况下采煤机截齿截割阻力实验研究

摘要

针对采煤机在不同工况下的截齿截割阻力的变化特性及斜切进刀工况下事故频发的状况,该文设计了由贴应变片插入式测量截齿和无线信号采集模块等组成的截齿截割阻力在线实验方案.将该方案用于MG400/930-WD型采煤机,在某大型采掘装备研究中心进行截割实验,得到了不同工况下采煤机截割阻力的变化曲线.分析实验结果可知,各截齿截割阻力在斜切进刀和正常工况下均为"间歇周期"变化,在单个周期内截割阻力先增大后减小,且增大和减少过程中呈波动变化;截割阻力在斜切进刀工况下先增大后减小,正常工况下较为稳定;在斜切进刀工况下,各截齿最大截割阻力数值及其出现的位置均不同,越晚参与截割的截齿出现最大截割阻力的位置越靠后,数值也越小,最大相差0.4 kN;斜切进刀工况下各截齿开始参与截割时,采煤机位置差异较大,最早与最晚位置相差约11.0 m;斜切进刀工况下的最大截割阻力达到6 kN,约为正常工况下的6倍.该文实验方案可为采煤机斜切进刀工况下事故频发原因分析和截割部设计提供实验依据.%Aiming at properties of the cutting resistance under different conditions of shearers and frequent accidents under the oblique cutting feed condition,the on line experimental program consisting of the strain gauge plug-in measuring cutting teeth and the wireless strain acquisition module is designed.The program is applied to the type MG400/930-WD shearer under different conditions in a large mining equipment research center and the experimental curves of cutting resistance are obtained.Analysis of the experimental curves show that the cutting resistance is in intermittently periodical change and fluctuates in every period under both the oblique cutting feed condition and the normal condition.Within a single period,the cutting resistance first increases and then decreases and fluctuates.Under the oblique cutting feed condition,the cutting resistance firstly increases and then decreases,and it is relatively stable at the normal condition.Under the oblique cutting feed condition,the maximum cutting resistance of every tooth has different values and positions.The later the cutting of shearers starts,the later the position of the maximum cutting resistance occurs,the smaller the value is,and the biggest difference of the maximum cutting resistance reaches 0.4 kN.Under the oblique cutting feed condition,every tooth has different starting positions and the maximum difference of starting positions is 11.0 m;the maximum cutting resistance is 6 kN,six times of that at the normal condition.All the results show that the experimental scheme is feasible,it can provide experimental data for the reason analysis of accidents under the oblique cutting feed condition and the designing of the cutting tooth and the shearer cutting unit.