某型叉车门架中横梁力学性能与结构优化研究

Investigation of mechanical properties and structure optimization of the middle beam in fork lifter mast frame

针对某型叉车起升机构中横梁弯角频繁出现的断裂现象进行了理论与数值分析,并对失效部位进行了试验检测。通过比较发现,数值分析与试验测试结果一致,即安全系数偏低,接近于1.0。然后,进一步数值分析了中横梁的基本尺寸参数(厚度b、高度h、弯角半径R)对横梁强度性能的影响。结果表明:厚度b是影响强度的最主要因素;弯角半径R对强度有较大影响;而高度h对结构强度影响较小。基于此,对中横梁结构尺寸进行了优化,最优化结构的应力大幅降至125MPa,较现有结构降低了约91MPa,安全系数显著提升至1.7左右,而结构质量基本不变,较好地解决了这类叉车门架横梁的失效问题,对类似的工程机械的设计研究和生产使用具有指导和借鉴意义。

Theoretical and numerical analysis of the frequently emerging fracture on corners of the fork lifter mast is investigated. Test is also carried out by electrometric method. Results obtained by the electrometric method coincide with the finite element results and it is revealed that the safety factor is less than 1.0. Furthermore, the strength of middle beam by changing three dimensions in beams(b, h, R) is analyzed, which shows that the thickness of the beam b is the most important factor affecting the strength and the bending radius of the beam R also has a relative pronounced impact on strength. According to the analysis, the beam size has been optimized and the stress is reduced to 125 MPa greatly, while the safety factor increases to 1.7 and its weight remains almost unchanged. The fracture problems on corners of the fork lifter mast are solved and some guidance and references are provided to the similar mechanical engineering designs.