The Performance Analysis And Experimental Study For The Brake System Of The Wheel Loader

The wheel loader is one kind of significant technical equipment in the 2015 long-termplan which it is the foundation industry and the infrastructure construction serving for ourcountry, it is widely used in the field of the foundation industry and infrastructure construction,and some other field to promote the development.The wheel loader can be used for shovelattire, transporting, unloading, smooth bulk material;digging mildly,and also can be used forwheelring the earth,rock or hard soil,lifting heavy objects, loading and unloading work and soon,if replaced the corresponding installment. Therefore, The wheel loader play an importantroal on speeding up the engineering construction, reducing the labor intensity, inhancing theproject quality, reducing the cost of the project.The driving braking system is an important constituention on the wheel loader. Theperformance quality of braking system directly related to the security and the stability when itworks, so people put a lot of attention on the research of this system.When the wheel loaderworks the reciprocal motion frequency decide the brake frequency,thus the rationality design ofthe overall constructure and the constitution of the braking system decide the quality of thissystem, and affects directly the efficiency of the entire machine,and also relates directly thesafety of people and property, At present, the wheel loader market in our country, the centertonnage (2 ~ 6t) the wheeled wheel loader is variety,and approximately occupies 80% of themarket, therefore in this article we take the most representative one ZL50 wheel loader as theobject to research, and do some experiment on its driving braking system to find out somefactors which can effect the performance of the braking system,in order to improve or redesignthe wheel loader braking system in the future.This article is divided into five chapters altogether.Chapter1:mainly elaborated the development condition of the wheeled wheel loader andits the braking system in the domestic and foreign development condition, and brieflyintroduced the composition of the wheel loader braking system, at the same time elaborated thepurpose and content of this article.Chapter2:analyzed the ability of the braking system on the wheel loader by mechanics.At First,we start the research from the moment of the touch of the tire and the road surface,thenemphatically analyzed the relations between graund braking force and the ground coefficient ofadhesion,or the force of the brake.And then got the conclusion that the ground braking forcewas decided first by the braking force of the brake,and at the same time was restricted by theground wherence condition. Second,we start from the redistribute of the bridge Holland whilethe wheel loader is braking,emphatically analyzed effeconcy of braking force,then conclusionof how to distribut the bridge Holland rationally. Third , analyzed the factor which influencethe stopping distance from a derived formula. And then we know the acceleration onlyrestricted by the fluid pressure of the cylinder of the brake,little influenced by the otherinfluence factor while the the initial velocity has a big influence on the stopping distance ,but itdo not distance the hugs braking separately ,its only increace the time of the braking ,expeiallythe time after the hug of the back wheel,which us the maily reason that increace the stoppingdistance,Chapter3:analyzed the characteristic and the principle of the constitution of the brakingsystem . At first introduced how the braking system system had run,then made the mechanicsmodeling and the dynamic analysis separately to the brake, the supercharger, the brake control,the gas tank and so on,in order to find out how the braking system parts influence the brakingability.Mainly has :the pressure of the brake cylinder is strong non-linear ,It maily displayswhen the pressure change the speed of the pressure has a sudden change;displays a kind ofsluggish response characteristic. The supercharger have the tremendous influence to the brakelag response of the braking systems.This is because the dynamic character of the superchargeris mainly display for the gas characteristic. This chapter also analyzed the friction heatgenerated at the time of the braking,established the heat source model and the energydistributeon modle.Through the analysis we got a conclusion,when it comes to the brake whichregarding the metal and the organic material,the temperature of the friction surface influencethe friction stability,therefore we should enhance the calorific capacity and the thermal stabilityof the brake,all of the thermal conductivity,helpful to make the brake work steadily.Chapter4:by contrasting to the experimental curve,it confirmed us the accuracy of thefront theory.Moreover,through the experiment,the hydraulic brake pipeline influence thedynamic characteristic of the braking system especially the brake hose.The reason was,it madethe equivalent bulk modulu of the pipeline liquid slightly,thus the time of the pressure whicnshould be established in the pipeline would be longer.Chapter5:provided the conclusion of the full text.By analyzing,experimenting and researching the driving braking system on the ZL50wheel loader, we knew some factors which can effect the braking quality, and we can improveor redesign this system properly.This arcticle once mentioned of using the supercharger whichratio is different in order to make brake pressure of the rear axle smaller than the front,to makethe braking force draw close to the time when it hugs together.Fit out the gear box which canseparate the axle,to let the axles have respective weight of adheres.Does not make the frontaxle hugs while the rear hugs happening,thus enable the braking force of the entire machinedraw close to the braking force they hug together.As the time is urgent and running short of thetest installation,the above experiment is not accomplished,therefore hope in the later researchwill obtain the further confirmation.