放顶煤支架铰接千斤顶对提高铰接梁支护能力的应用研究
Research on the application of hinged cylinder in top caving powered support to improve supporting capacity of hinged canopy
-
摘要: 为提高四柱支撑掩护式液压支架铰接式顶梁的支护能力, 同时改变对铰接式顶梁支护能力不足的传统认知, 建立了四柱支撑掩护式液压支架杆系模型, 根据液压支架内加载条件求解液压支架承载能力区, 得到液压支架可承受的最大载荷数值及其在顶梁上的具体作用位置, 给出了铰接梁支护力和铰接千斤顶缸径2种求解方法。重点介绍了铰接梁支护力和铰接千斤顶缸径简化求解方法, 根据外部载荷在顶梁上作用位置的不同, 依据泰勒公式将作用在顶梁上的外部载荷简化为二次多项式、三角形、梯形和矩形等不同分布形式, 结合铰接式结构的顶梁和铰接梁上方载荷连续分布条件, 基于力的合成原理求解出铰接梁上外部载荷大小及其作用位置。在此基础上, 根据静力平衡条件推导出铰接千斤顶所需合理缸径, 给出了具体求解公式。分析了相同工作阻力条件下铰接式顶梁和整体式顶梁前端支顶力大小, 得出了缸径较大的铰接千斤顶可显著提高铰接梁支护能力, 设计合理的铰接梁式顶梁液压支架支护能力要高于同等条件的整体式顶梁液压支架的支护能力, 解决了现有铰接梁支护能力不足的难题。以山能正通煤业公司放顶煤开采为主要应用背景, 建立ZF20000/26/48四柱支撑掩护式液压支架铰接式顶梁载荷连续分布模型, 按照顶梁上方载荷连续性分布条件, 基于力的合成和分解原理, 得到铰接式顶梁外部载荷的大小及其作用位置, 并根据静力平衡条件推导出铰接千斤顶理论缸径。工程实践表明, 改进后的铰接式顶梁结构合理, 前端支护力大, 支护效果明显, 在多个工作面得到推广应用, 未出现前端支护力不足带来的端面顶板冒落和煤层片帮等问题, 满足了工作面支护需要, 验证了理论的正确性。Abstract: To improve the supporting capability of the hinged canopy of the four-leg shield powered support and to address the common perception of inadequate support provided by these canopies, a rod system model for the four-leg shield powered support was developed. This model was employed to determine the bearing capacity zone of the powered support based on the loading conditions. It yields the maximum load that the powered support can withstand and identifies its specific action location on the canopy. Two methods of the hinged canopy support force method and the hinged cylinder diameter methodfor solving this problem are presented. The simplified resolution method transforms the external load acting on the canopy into various distribution forms, including quadratic polynomial, triangular, trapezoidal and rectangular shapes, depending on the position of the external load, as described by Taylor's formula. By integrating the hinged structure of the canopy with the assumption of continuous load distribution above it, the magnitude and point of action of the external load on the hinged canopy are determined using the principle of force synthesis. This analysis allows for the derivation of the required diameter for the hinged cylinder based on static equilibrium conditions and specific formulas for solving the problem are provided. The support forces at the front end of the hinged canopy is compared with those of the overall top canopy under identical working resistance conditions. The findings indicate that a larger diameter hinged cylinder significantly enhances the support capacity of the hinged canopy, establishing that the support capacity of a well-designed hinged canopy-powered support surpasses that of an equivalent overall canopy-powered support under the same conditions. Using the mining practices of Shandong Energy Zhengtong Coal Industry Company's four-leg shield-powered support as the primary application context, a continuous load distribution model for the hinged canopy of the ZF20000/26/48 four-leg shield-powered support was established. Based on the continuous load distribution conditions above the canopy, the size and location of the external load on the hinged canopy were determined using the principles of force synthesis and decomposition. Furthermore, the theoretical diameter of the hinged cylinder was derived from static equilibrium conditions. Engineering practice demonstrates that the improved hinged canopy structure is rational, exhibiting significant front-end support force and pronounced support effects. It has been widely applied in various mining faces without encountering issues such as insufficient front-end support force leading to roof collapse or coal layer spalling, thereby validating the accuracy of the theory and effectively meeting the support needs of the mining face.
下载: