Research On The Characteristics Of Large Mining Hoister Constant Deceleration Braking Electro-hydraulic Control System

The coal mine safety production not only relates to the development of the national economy,but also directly relates to the life security of coal mine workers.Therefore,ensuring the safety production of coal mine is very important to national and social development.In our country,the vast majority of coal mine are underground mine,the miners,equipment and mineral are all transported by hoist.According to the investigation,the coal mine accidents caused by the hoists fault is the secondary coal mine accidents compared with the top failure and gas accidents.So the safe operation of the hoists is very important to ensure the coal mine safety production.Due to the wire rope flexibility,emergency braking will cause.With the coal mine enlargement,the hoisting height,speed and load of hoists will increase more and more,so the hoist shocking and vibration becomes more and more vigorous,which will cause the wire rope to slip and mechanical construction of the main shaft device to damage,even cause major accident of wire rope breakage.Currently,the shock and vibration caused by emergency braking is relieved by constant deceleration braking system.Therefore,the research on the characteristics of large mining hoister constant deceleration braking electro-hydraulic control system is very significant to the coal mine safety production.In this paper,the braking principle of mine hoist is firstly analyzed,then the mathematic model of steel wire rope is established,and the constant deceleration braking characteristics are co-simulated and analyzed by SimulationX software.The characteristics of three way proportional pressure reducing valve are studied,and the three way proportional pressure reducing valve replaces the electro-hydraulic directional valve in constant deceleration braking system to improve the reliability of constant deceleration braking system.The main contents of this paper will be divided into the following parts:In the first chapter,the background and significance of the research is demonstrated,and according to the reference literatures and the existing research results the research status of constant deceleration braking system and three way proportional pressure reducing valve are introduced,and the modeling principle of steel wire rope is summed up.In the second chapter,the constitutes and classification of the mining hoist are demonstrated,the mathematical model of the braking system is established,the factors affecting braking performance are identified,and the braking process of hoist during rising and falling is analyzed.In the third chapter,the principle of constant deceleration braking electro-hydraulic control system is introduced,the parameter identification of electro-hydraulic proportional directional valve is established,and the simulation model of mine hoist constant deceleration braking system is established.In the fourth chapter,the modeling principle of steel wire rope is analyzed,the accuracy of wire rope model in SimulationX software is analyzed.And the co-simulation model of hoist is built by SimulationX.Then the integral separation PID control algorithm is adopted to improve the performance of the constant deceleration braking system.In the chapter five,the mathematical model of the direct three way proportional pressure reducing valve is established,and the simulation model of valve is set up in simulation software SimulationX.The influence of the valve pre-opening on the valve performance is analyzed.And the spool velocity feedback and the pressure closed loop is introduced to improve the performance of the pressure reducing valve.Finally,the characteristics of the constant deceleration braking system with three way proportional pressure reducing valve are analyzed.In the chapter six,the research work on the characteristics of the constant deceleration braking electro-hydraulic control system of mine hoist is summarized,and the lack of the research work and the further research work are put forward.The results show that the flexibility of the wire rope is the important reason for the hoist speed fluctuation.The characteristics of three way proportional pressure reducing valve and the reliability of the constant deceleration braking system can be improved by adopting pressure closed-loop.And the integral separation PID control algorithm can improve the performance of the constant deceleration braking system in a certain condition.