• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2019, Vol. 55 ›› Issue (20): 222-230.doi: 10.3901/JME.2019.20.222

• 交叉与前沿 • 上一篇    

充液阀系对液力缓速器制动转矩起效的迟滞影响

魏巍1, 邝男男2, 孔令兴1, 张晓东3, 闫清东1   

  1. 1. 北京理工大学车辆传动国家重点实验室 北京 100081;
    2. 中国汽车技术研究中心有限公司 天津 300300;
    3. 北奔重型汽车集团有限公司 包头 014025
  • 收稿日期:2018-09-04 修回日期:2019-06-24 发布日期:2020-01-07
  • 作者简介:魏巍,男,1978年出生,博士,副教授。主要研究方向为车辆传动与液力传动、流体传动与控制等。E-mail:weiweibit@bit.edu.cn
  • 基金资助:
    国家自然科学基金(51475041)、国家部委创新计划(237099000000170009)和车辆传动国家级重点实验室基金(614221304040517)资助项目。

Brake Hysteresis Effect of Charging Valves in Hydrodynamic Retarder

WEI Wei1, KUANG Nannan2, KONG Lingxing1, ZHANG Xiaodong3, YAN Qingdong1   

  1. 1. National Key Lab of Vehicular Transmission, Beijing Institute of Technology, Beijing 100081;
    2. China Automotive Technology & Research Center Co., Ltd., Tianjin 300300;
    3. Beiben Trucks Group Co., Ltd., Baotou 014025
  • Received:2018-09-04 Revised:2019-06-24 Published:2020-01-07

摘要: 迅速起效是重型车辆对液力缓速辅助制动系统的核心需求之一,但目前对液力缓速器工作腔内从气相到液相间瞬态制动起效过程的预测方法难以考虑充液阀系流动状态的影响,导致制动转矩起效时间的预测与测试存在较大偏差。为获取阀系对充液过程影响规律以准确预测制动起效时间,分别构建有无考虑充放液阀系流动的两种全流道液力缓速器计算模型,以全气相流场作为充液瞬态数值模拟初始条件,以流体进出充放液阀流速作为仿真边界条件,对比研究两种模型在制动过程中内流场参数分布特征,以及对应缓速制动转矩的瞬态变化趋势,并进行试验验证。结果表明,充液阀系对瞬态制动转矩起效具有明显的迟滞效应,未考虑阀系模型的瞬态制动特性计算结果与试验存在明显偏差,尤其对起效时间的预测过于理想化,而实测给定工况下最大时间迟滞可达4 s;考虑充放液阀系流动的液力-液压集成流动模型的预测精度较高,起效时间偏差不足0.8 s。利用所提出的预测方法能够为液力缓速器制动控制策略设计和整车制动系统设计提供理论依据。

关键词: 液力缓速器, 起效时间, 迟滞效应, 计算流体力学

Abstract: Baking rapidly is one of the core requirements of heavy duty vehicles with hydrodynamic retarder auxiliary braking system, but it is difficult to consider the influence of the flow state in valve system in the transient braking process of the hydrodynamic retarder in which working medium changes from the gas phase to the liquid phase, which leads to the large deviation of the initialization time by simulation compared with test data. In order to obtain the influence of the valve system on the fluid filling process so as to accurately predict braking initialization time, hydraulic and hydrodynamic integrated flow system computational models with and without control valves are built. The full gas phase flow field in the hydrodynamic retarder is taken as the initial condition for the transient numerical simulation of the fluid filling, and the flow velocity of charging valve discharging valve are tanken as boundary conditions, and the transient trend of braking torque and the distribution characteristics of flow field parameters in the integrated flow system in the process of filling and braking of two models are simulated and verified by experiment. The results show that the charging valve had obvious effect on the brake torque hysteresis effect, and there are obvious deviations if valves are not considered, and especially the prediction of the initialization time is too idealistic and up to 4 s hysteresis, while he computational model of hydraulic and hydrodynamic integrated flow system with charging and discharging valves system isproved to be more accurate and the initialization time deviation is reduced to 0.8 s.The prediction method in this paper can provide theoretical basis for the design of dynamic braking control strategy and the design of vehicle braking system with hydrodynamic retarder.

Key words: hydrodynamic retarder, initialization time, hysteresis effect, computational fluid dynamics

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