摩擦缓冲器服役状态下的阻抗特性数值模拟

Numerical Simulation on Resistance Characteristics of Friction Draft Gears in Service Conditions

为了评估MT-2型缓冲器的服役性能,根据大修规程和实际运用经验,建立考虑侧楔块磨耗和弹簧断裂的缓冲器退化模型,分析服役状态对阻抗特性的影响规律;以车辆冲击条件下的缓冲器性能指标极限为边界条件,对侧楔块磨耗安全限度和弹簧断裂风险等级进行界定。结果表明:侧楔块主摩擦面呈凹型磨耗状态会引起阻抗特性显著退化,当其分布在中央1/2区域时,磨耗的安全限度为0.5 mm,远小于现有大修限度1 mm;主弹簧外簧呈断裂接触状态也会引起阻抗特性显著退化,此时最大阻抗力和半行程容量指标均已超出限值,缓冲器处于迫切的风险状态。因此,建议缓冲器侧楔块大修限度应结合具体磨耗形状和位置综合考虑,且在非大修期间应对缓冲器外簧状态进行重点管控。

To evaluate the performance of the MT-2 friction draft gear in service,based on the overhaul regulations and practical application experience,a degenerate draft gear model considering side wedge wear and spring fracture was developed to analyze the influence of service state on resistance characteristics.Then,with the limit of draft gear performance index under vehicle impact condition as the boundary condition,the safety limit of side wedge wear and the risk level of spring fracture were defined.The results show that the concave wear in the main friction surface of the side wedge will cause significant degradation in the resistance characteristics.In the case of the distribution of the concave wear in the central 1/2 area of the main friction surface,the safety wear limit was 0.5 mm,far less than the existing overhaul limit of 1 mm.The external main spring in a broken but contact state will also cause significant degradation in the resistance characteristics.Under this condition,the maximum resistance force and the half stroke capacity have exceeded the limit values,leaving the draft gear in an urgent risk state.Therefore,it is suggested that the overhaul limit of the draft gear side wedge should be comprehensively considered in combination with the specific wear shape and position,and the status of the external main spring should be mainly monitored and controlled during the non-overhaul period.