The Development Of Scale Dynamomenter And The Research Of Test Method

Friction material is one of the most important parts in the car's brake system,it effects the car's maneuverability, reliability and comfortability directly. Frictionmaterial also effects the car's safety. Swindle test and bench test are typical testingmethod in the friction and wear test of friction material, the contratest between theswindle test and the bench test is an important topic in the test of friction material.Current swindle test is made in the brake operation of continuous rub, whichdoesn't consider the real driving condition and the designated car parameter, andthe simulating rule of the swindle test is different with the bench test. Those havean effect on the contratest report. So current swindle test and bench test don't havethe comparability.The article summarizes the development and composition of friction material,the testing method and testing machine, the theory of friction and wear and thebraking theory. The article brings forward a new idea to develop a new typeswindle tester and formulates the corresponding test operating rule. The machineis different from the current tester, such as the constant speed tester, chase tester,and so on. It is a dynamometer of contractible proportion. Because it is adynamomenter, it can simulate the real operating condition. The design principleof contractible proportion dynamometer is to make the friction work on the unitarea and the line speed at the friction radius coordinate with the dynamometer ofJF122B. The brake's structure of scale dynamometer is designed according to thecontractible proportion of thermal capacity. The speed of revolution is controlledby the DC velocity control system. The change of brake's temperature is measuredby the thermocouple. The brake pressure and brake moment are measured by thepressure sensor and feed back to the computer. The testing program is work outaccording to the test criterion of SAE J2681. The criterion is more newer in thebench test.At the similar test environment with the prototype dynamometer, we carryout the scale dynamometer test. By the test data compare of pressure correlation,speed correlation, recovery, fade and high temperature performance with theprototype, we research the pertinence between the swindle test and bench test.And consider to replace the prototype dynamometer with the scale dynamometertotally or partly.