Research On Some Key Technologies Of Wet Spraying Trolley

With the rapid development of the economy,concrete construction projects such as tunnels have continued to increase,promoting the development of wet spraying trolley.In order to reduce the transit time of the trolley and to improve the rebound rate of the concrete,higher requirements are placed on the existing trolleys.In this thesis,the wet spraying trolley walking system,the optimal matching relationship between the concrete pumping volume and the amount of accelerator,and the selection of the air pressure of the air compressor are mainly analyzed,which provides a theoretical basis for the optimization of the wet spraying trolley.According to the requirements of transitional driving conditions of wet spraying trolley,the different power transmission modes of vehicles chassis are analyzed and compared.Finally,the hybrid hydraulic transmission combined with the rear gearbox is adopted as the chassis power transmission method.The maximum required traction force,tire adhesion and maximum steering resistance torque for the most complex walking conditions of the trolley are obtained by mechanics analysis of the walking mechanism and wheel steering.The closed hydraulic system consisting of variable displacement pump and variable displacement motor and the full hydraulic steering system using load sensing technology are analyzed.The main hydraulic components are selected and calculated.The mathematical model of variable displacement pump,variable motor and full hydraulics steering system are established by mathematical expressions,and the internal characteristics and dynamic characteristics of the components are analyzed in the mathematical level.The walking mechanism and the steering hydraulic system are simulated by AMEsim software and relevant performance curves are obtained,provides reference for the design of the actual hydraulic system.The function between the concrete pumping volume and the accelerating agent addition amount are deduced,and the key factors affecting the mixing ratio are obtained.The quantitative relationship between each other is established from the mathematics aspect,the function of air pressure and air volume of the air compressor are obtained by analyzing the optimal shotcreting velocity of the concrete.The pressure field and velocity field distribution cloud diagram of the compressed air in the pipe are simulated by FLUENT software.It is concluded that Air Pressure change is greater of the compressed air in the pipe and smaller in the wind speed change,which provides a theoretical basis for the selection of air compressor.