The Design Method Of The Internal Combustion Engine Tribology Design - Application Of The Model Of Intelligent Design Knowledge And Expand Research

The study of engine tribological design methods aims at reducing mechanical loss , improving efficiency, reducing fuel loss, preventing severe wear and prolong machine lifetime, which is based on well developed lubrication analysis and calculation of several important tribopairs: piston rings-cylinder ,piston-cylinder, bearings and valve system. This dissertation major in using intelligent design methods to present design support for engine designer based on tribological knowledge from lubrication calculation, experts and experiments. The most important question in engine tribological intelligent design system is its ability to make design decision based on field knowledge. In this thesis, we research the engine tribological intelligent design system in three layers based on its intelligent design abilities, which are simulating design ability, associating design ability and evolutionary design ability. Accordingly three knowledge models are presented and studied, which are symbol model, artificial-neutral-net model and gene model. Our main creative work includes the following parts: 1 The three main knowledge models of intelligent design are proposed . The three models and their technologies are studied and then used as design methods of engine tribological design. 2 In order to build the engine tribological intelligent design system ,a new knowledge representation method is presented to integrate knowledge representation ,knowledge acquisition , reasoning and researching ,basing on object-oriented technology. A engine tribological intelligent CAD system is developed and can finish some fine-defined tribological design problems. 3 Because of implicit character of tribology knowledge and the shortage of conflict decision knowledge ,a tribology knowledge acquisition model is presented and m ~frttI*& carried Out basing on artificial-neutral-net technology, which is used to acquire redesign rules in low-loss design of engine piston rings to enhance the associating design ability. 4 In order to fIilflhl the parallel design decision ,a new hybrid evolutionary design method embedded with expert knowledge is discussed. The gene model of mechanical design is built, accordingly the evaluation method, restriction question, knowledge acquisition and application question are ail resolved successfully. Several new operators in evolutionary design are realized. This new method is successfully used to make parallel design decision in enwne bearing system, piston system and valve system. The evolutionary results are analyzed. 5 The design syntheses of complicated machine, just as engine ,is vety difficulty. A new hierarchical co-evolutionary model for design syntheses of complicated machine is built. Accordingly a new co-evolutionary algorithms and a new communication system are presented and realized. The new model and method are used to 搊ptimize?the engine basic parameters and local parameters to make the syntheses decision. The improved design projects based on 4105 diesel engine are put forward and discussed.