Study On The Loading System Of Truck's Braking Performance Testing Bench

With the development of the our country socialism modernization construction, and the international important games and activities to be hold in our country, in these construction items, the vehicle transportation has already been the important mission as the main transportation means.Nowdays ,under the concept of people-oriented, the safe working and the safe conveyance is the first important event of the people concerns.And the safety of vehicle transportation also is relate to our construction and the safety of people's life.So the two tests of the truck in a year are very important, and the test of brake system is a very important item to assess total function of the vehicle.Although the vehicle brake system test is as the point of the examination, according to currently local examination condition, there are a lot of shortcomeings and limit.It is without loading that vehicle is requested while examineing.It's result just stands for the function of the vehicle without loading, don't reflect the really function of vehicle with full loading. There are so many traffic accidents every year, some of them are because the brake system of the vehicle can't provid the enough brake force on full loading.So, it is important to test the function of the loading truck.In the national standards GB 7258-2004《Safety specifications for power driven vehicles operating on road》, it is requested to test the function of the loading vehicle.There is the different brake function between the unloading truck and the loading truck, because of the influence of the loading.These influences include the change of working condition between brake bottom plate and brake drum, and the change of the pressure in braking line.It's also indicate that it is important to test the function of the loading truck.So, the paper's purpose is to design an automatic system to detect the brake function on loading of the unloading truck.On this condition, my paper develops an automatic loading system according to the brake condition tester for the purpose that we can detect the brake function on loading.This paper involves the following aspects:1. The introduction of detection condition of vehicle.The paper analyzes systematically the shortcomeings in detection syetem of vehicle in the domestic, and clarifies it important to detect the brake function on loading of the unloading truck.2. The difference of the brake system function is theoretically analyzed in the loading and unloading truck.The paper mainly clarifies the influence of the partes of the brake system while the truck is full of loading and describes the changes of all standards (including the braking distance\the braking force\ the braking deceleration\the braking time…).The paper clarifies that the way is feasible that detect the brake system function on loading of the unloading truck by analyzing the National standards GB 7258-2004《Safety specifications for power driven vehicles operating on road》.The project is done by analyzing the advantages of the detection on the road and the detection on the tester.3. The design of the automatic loading system's hardware.The condition are showed up that some problems will come up while the truck on the automatic loading system.The project is done to solve the coming problems.The power of the automatic loading system– the hadraulic system––is designed, including the plan to load and the parts'design of the hadraulic system.After that, the circuit is work out for the function of the automatic loading system.4. The design of the signal processor &software system. The plan for the system of acquiring data is done,and the model of the sensor is picked up to suit for the weight tester.Some parts are picked up for aquiring the data of the sensor and the switch. Windows XP is the system platform, and Visual C++ 6.0 is the programming language. Some switch signal, like electric switch and displacement switch, is gathered by IPC5375 card and SJKGLB-3 interface board. The industry computer gathers the data by RS 232 port. Application software mainly completes detection process controlling, data gathering, data analyzing and making the result of detection. The program of the automatic loading system is worked out to be absorbed by the automatic detection system.5. Test and validation.After testing, the detection result is fit to the theory. The automatic detection system can detect the brake function on loading of the unloading truck on the brake tester.The automatic detection system also give an evaluation whether the brake function is enough or not,when the truck is driven with full loading.After the paper is finished and adopted, it is safer than before that the truck is driven on the road.It is also become another safety belt for the driver.