Research On Service Brake System Of LG953 Wheel Loader

The wheel loader is one kind of significant technical equipment in the 2015 long-term plan which it is the foundation industry and the infrastructure construction serving for our country, 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 shovel attire,transporting, unloading, smooth bulk material;digging mildly,and also can be used for wheelring the earth,rock or hard soil,lifting heavy objects, loading and unloading work and so on,if replaced the corresponding installment. Therefore, The wheel loader play an important roal on speeding up the engineering construction, reducing the labor intensity, inhancing the project quality, reducing the cost of the project.The service brake system is an important constituention on the wheel loader. The performance quality of braking system directly related to the security and the stability when it works, so people put a lot of attention on the research of this system.When the wheel loader works the reciprocal motion frequency decide the brake frequency,thus the rationality design of the overall constructure and the constitution of the braking system decide the quality of this system, and affects directly the efficiency of the entire machine,and also relates directly the safety of people and property.At present, the wheel loader market in our country, the center tonnage (2～6t) the wheeled wheel loader is variety,and approximately occupies 80% of the market, therefore in this article we take the most representative one LG953 wheel loader as the object to research, and do some experiment on its driving braking system to find out some factors which can effect the performance of the braking system,in order to improve or redesign the 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 and its the braking system in the domestic and foreign development condition, and briefly introduced the composition of the wheel loader braking system, at the same time elaborated the purpose and content of this article. Chapter2:analyzed the ability of the braking system on the wheel loader bymechanics. At First,we start the research from the moment of the touch of the tire and the road surface,then emphatically analyzed the relations between graund braking force and the ground coefficient of adhesion,or the force of the brake.And then got the conclusion that the ground braking force was decided first by the braking force of the brake,and at the same time was restricted by the ground wherence condition. Second,we start from the redistribute of the bridge Holland while the wheel loader is braking,emphatically analyzed effeconcy of braking force,then conclusion of how to distribut the bridge Holland rationally. Third , analyzed the factor which influence the stopping distance from a derived formula. And then we know the acceleration only restricted by the fluid pressure of the cylinder of the brake,little influenced by the other influence factor while the the initial velocity has a big influence on the stopping distance ,but it do not distance the hugs braking separately ,its only increace the time of the braking ,expeially the time after the hug of the back wheel,which us the maily reason that increace the stopping distance.Chapter3:analyzed the characteristic and the principle of the constitution of the braking system . At first introduced how the braking system system had run,then made the mechanics modeling 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 braking ability.The supercharger have the tremendous influence to the brake lag response of the braking systems.This is because the dynamic character of the supercharger is mainly display for the gas characteristic. This chapter also analyzed the friction heat generated at the time of the braking,established the heat source model and the energy distributeon modle.Through the analysis we got a conclusion,when it comes to the brake which regarding the metal and the organic material,the temperature of the friction surface influence the friction stability,therefore we should enhance the calorific capacity and the thermal stability of 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 the front theory.Moreover,through the experiment,the hydraulic brake pipeline influence the dynamic characteristic of the braking system especially the brake hose.The reason was,it made the equivalent bulk modulu of the pipeline liquid slightly,thus the time of the pressure whicn should be established in the pipeline would be longer.Chapter5:provided the conclusion of the full text. This arcticle once mentioned of using the supercharger which ratio is different in order to make brake pressure of the rear axle smaller than the front,to make the braking force draw close to the time when it hugs together.As the time is urgent and running short of the test installation,the above experiment is not accomplished,therefore hope in the later research will obtain the further confirmation.