一种新型空气停放制动系统

New Type of Air Parking Braking System

目的:为解决现有轨道交通车辆用弹簧停放制动装置存在停放制动力大小不稳定、停放制动力随弹簧疲劳而衰减、机械结构复杂等问题,设计了一种新型空气停放制动系统。方法:介绍了弹簧停放制动系统的结构组成及功能原理,分析了其系统特性;介绍了空气停放制动系统结构组成及功能原理;分析了新型空气停放系统的特性。结果及结论:所提新型空气停放制动系统能够改变行车制动缸的工作模式,将制动缸的输出力转变为停放制动力。当向停放缸充入压缩空气时,停放缸内部弹簧被压缩,使停放缸与拉杆保持分离,同时非自锁螺纹也保持在解锁状态,此时制动缸具备行车制动和行车制动缓解功能。当停放缸内无压缩空气时,停放缸与拉杆保持压紧,同时非自锁螺纹被单向锁死,此时停放缸将制动缸锁定在最大行程处无法退回,实现停放制动作用。在行车制动控制模块和停放制动控制模块之间安装双向阀,双向阀的出口与制动缸连通,停放制动控制模块的另一出口与停放缸连通。在施加停放制动时,充入制动缸内的压缩空气由停放制动控制模块提供。该系统可实现全列车所有空气停放复合制动装置的停放制动力大小一致,也可根据需要灵活调节单个停放制动力的大小,还可保持停放制动力的长期稳定,避免了现有系统存在的弹簧停放力与空气制动力同时叠加作用的风险。

Objective:To address the issues of unstable parking braking force,fatigue-induced attenuation of parking braking force,and the complex mechanical structure in the spring parking braking devices for existing rail transit vehicle,a new type of air parking braking system is designed.Method:The structural composition and functional principles of the spring parking braking system are introduced.The above composition and principles of air parking braking system are also presented,along with an analysis of its system characteristics.The characteristics of new air parking system are analyzed.Result&Conclusion:The proposed new air parking braking system could change the operating mode of the service brake cylinder,transform the output force of the brake cylinder into the parking braking force.When compressed air is introduced into the parking cylinder,the internal spring of it is compressed,keeping the parking cylinder separated from the pull rod.At the same time,the non-self-locking thread remains in unlocked state.In this state,the brake cylinder performs service braking and service braking release.When there is no compressed air in the parking cylinder,the parking cylinder is tightened against the pull rod,and the non-self-locking thread is unidirectionally locked.In this condition,the parking cylinder locks the brake cylinder at the maximum stroke,preventing it from retracting and achieving the parking braking function.A two-way valve is installed between the service braking control module and the parking braking control module,with one outlet of the two-way valve connected to the brake cylinder,and another outlet of the parking braking control module connected to the parking cylinder.When applying parking braking,compressed air supplied by the parking braking control module is introduced into the brake cylinder.This system ensures consistent parking braking force for all air parking compound braking devices in the entire train,and allows flexible adjustment of individual parking braking force as needed.It also maintains long-term stability of the parking braking force and eliminates the risk of simultaneous superimposition of spring parking force and air braking force in the existing system.