Research On Performance Test Of Hydraulic Disc Brake Pump

As one of the core components of automobiles and motorcycles,the brake system has a direct impact on whether the vehicle can be safely driven on the road.With the increasing awareness of driving safety,the vehicle industry pays more and more attention to the braking performance of motor vehicles.Hydraulic disc brake is commonly used on motorcycle.In order to avoid the defective brake coming into the market,it is critical to effectively and accurately test the performance and quality of brake.This thesis analyzes domestic and overseas situation of brake system detection technology and releasing of gas theory,and combines the project“Brake Performance Online Detection”with a brake manufacturer to develop a set of motorcycle brake performance testing platform,the platform detects the piston idle stroke of brake cylinder on-line.Firstly,the ideal gas related equations are used to describe the gas in the sealed chamber,the mass flow characteristic equation is established.Based on the above equations,a process is analyzed,in which the gas inside the seal of the brake pump is released through the bypass hole.A mathematical model is established for simulation.Simulation of this model shows that gas as the test medium instead of hydraulic oil is feasible.Secondly,a gas-releasing model is established,that the gas is released by the bypass hole during the movement of the piston in the brake pump body,the releasing process is numerically simulated using the dynamic grid technology.The results show that when the gas in the sealed chamber is released through the bypass hole,the pressure and temperature fields in the brake pump are evenly distributed.The gas state at the bypass hole is an isentropic adiabatic process during the charging.The pressure and temperature at the monitoring point inside the brake pump is monitored,the analysis shows that theoretical model calculations and numerical simulations are of a good consistency.Finally,according to the national automotive industry standard QC/T654-2005Motorcycle and Mopeds Brake Bench Experimental Method,build a brake pump performance testing platform,the platform includes mechanical design part and computer monitoring and control part,it adopts a stepping motor to complete the driving of the manual manipulative force.The displacement and pressure sensors realize the collection of piston~'s displacement and pressure in the brake pump body.The platform uses the industrial control computer as the carrier and the VC++as the development tool,with self-exploited sample card and test control program,human-computer interaction interface is developed,which realized products~'automatic detection and graphical display.Filter the test data collected during the product testing process,use a piecewise polynomial curve fitting to obtain the Piston idle stroke.By comparing the result with the actual value and the national automobile industry standard requirement,the manufacturer could evaluate effectively products~'brake performance.According to the test data,determine the exact position of the bypass hole on the pump body.This thesis adopts the research methods of theoretical estimation,numerical simulation and test detection to design a complete set of brake pump performance testing solutions.This research content provides an important guarantee for the actual performance testing of products and the technical development of the manufacturing enterprise.