Study On Middle-duty Diesel Engine Brake Technology Based On Variable Valve

Along with our country road conditions are improving and the continuousdevelopment of automobile technology, Vehicle can make the power higher andhigher, the speed is faster and faster, and the load increasing rapidly. For the pursuit offuel economy, it asks for engine’s lower friction work, final led to a decline in theability of Vehicle to slow down. Make sure the good driving braking performance, toensure the safety of Vehicle driving. According to the requirements of national lawsand regulations, certain types of vehicle must impose auxiliary braking device toensure the safe operation of the vehicle. This paper through the study of thecomparison of several kinds of auxiliary brake system, come to a conclusion that theengine brake system is small size, light quality, simple and compact structure, italmost did not affect on the layout of vehicle transmission system, and it works highefficiency, Stable and controllable because it brakes the vehicle directly, it hasbecome the mainstream of vehicle auxiliary braking system development direction.This paper main innovation points and research work is as follows:1、The Variable Valve engine brake technology is a kind of bleeder braketechnology, its innovation is it can dynamic adjust the opening of the exhaust valvereal-time according to the engine speed, and it can make the ideal braking effect underthe engine’s every speed.2、Design research and development process，was subdivided into concept designstage、layout design stage、detailed design stage，bringing in advanced design ideasuch as lean design、CAE auxiliary research and analysis、FEMA and so on.We canidentify the problem early in the research and development, and take measures toprevent the problem occurred.3、Performance research and development process，according to early researchdirection，using the advanced testing equipment，optimization of the actual optimalengine braking power，testing and evaluation the braking condition cylinder pressure，noise level，fuel injector nozzle temperature. 4、Reliability of the research and development process，through500hours ofreliability test，study the wear and fatigue of the exhaust butterfly valve，enginebrake，valve timing mechanism system, exposure to unexpected failure mode andtake corrective actions.5、The vehicle matching research and development process，experimental studyvehicle matching with the car factory，testing vehicle auxiliary braking performancelevels after install the engine with variable valve engine brake.