本文選題：可變壓縮比　切入點：VCR技術(shù)　出處：《武漢理工大學(xué)》2011年碩士論文

【摘要】：VCR (Variable Compression Ratio,可變壓縮比)技術(shù)能夠有效改善發(fā)動機的低負(fù)荷性能。本文針對一種VCR活塞技術(shù)方案,利用動力學(xué)仿真軟件ADAMS及有限元分析軟件ANSYS聯(lián)合建立了VCR活塞的三維動力學(xué)仿真模型,確定了VCR活塞模型的邊界條件。VCR活塞靜態(tài)模擬試驗和VCR活塞動態(tài)響應(yīng)模擬試驗對比驗證了VCR活塞的動力學(xué)仿真模型,完成了多方案的VCR活塞的動力學(xué)仿真計算分析,仿真計算結(jié)果驗證了所研究的VCR技術(shù)方案的可行性。 在VCR活塞的動力學(xué)仿真過程中,基于ADAMS模擬了機構(gòu)各部件之間剛體受力位移,利用有限元軟件ANSYS建立了碟形彈簧的3D柔性體模型,模擬碟形彈簧與鋼球的接觸,并考慮了接觸點變化對剛度的影響。VCR活塞仿真模型采用ADAMS耦合ANSYS求解,能夠更為真實的反映VCR活塞機構(gòu)的實際工作狀況。提出了一種新的建模方法,能夠在ADAMS和ANSYS耦合求解中處理軸對稱問題。 根據(jù)VCR活塞機構(gòu)中各零部件的實際裝配關(guān)系和空間位置,在ADAMS中定義了整體結(jié)構(gòu)的約束和各零部件之間接觸關(guān)系。接觸參數(shù)根據(jù)材料性質(zhì)、接觸狀態(tài)設(shè)置,為了驗證VCR活塞仿真模型的正確性,根據(jù)靜態(tài)模擬試驗和動態(tài)模擬試驗的試驗條件建立了對應(yīng)的力學(xué)邊界條件,為了仿真VCR機構(gòu)在發(fā)動機中的工作狀況,建立了發(fā)動機的力學(xué)邊界條件。 靜態(tài)模擬試驗采用液壓式萬能試驗機對各種結(jié)構(gòu)方案的實際VCR機構(gòu)和彈性元件施加靜力載荷,動態(tài)模擬試驗利用MTS試驗機對實際VCR機構(gòu)施加動態(tài)模擬載荷。試驗數(shù)據(jù)與仿真結(jié)果的比較驗證了模型可行性。 采用所建立的VCR活塞的動力學(xué)仿真模型對135型非增壓柴油機進(jìn)行了多方案VCR活塞動力學(xué)仿真計算分析,作用在活塞頂?shù)母變?nèi)氣體力由發(fā)動機性能仿真提供,分析了轉(zhuǎn)速、負(fù)荷、運動件質(zhì)量和結(jié)構(gòu)參數(shù)對VCR機構(gòu)力學(xué)性能和動態(tài)響應(yīng)的影響。仿真計算表明,所提出設(shè)計的VCR技術(shù)方案具有較好的動態(tài)響應(yīng),能夠?qū)崿F(xiàn)預(yù)期的設(shè)計要求。
[Abstract]:VCR variable Compression Ratio (variable compression ratio) technology can effectively improve the low load performance of engine.In this paper, the three-dimensional dynamic simulation model of VCR piston is established by using ADAMS and ANSYS, a kind of VCR piston technology scheme, which is based on the dynamic simulation software ADAMS and the finite element analysis software ANSYS.The boundary conditions of the VCR piston model are determined. The dynamic simulation model of the VCR piston is verified by comparing the static simulation test of the VCR piston model with the dynamic response simulation test of the VCR piston model, and the dynamic simulation analysis of the VCR piston with multiple schemes is completed.The simulation results verify the feasibility of the proposed VCR technology.In the process of dynamic simulation of VCR piston, the displacement of rigid body is simulated based on ADAMS. The 3D flexible body model of disc spring is established by using finite element software ANSYS, and the contact between disc spring and steel ball is simulated.Considering the influence of contact point change on stiffness, the simulation model of VCR piston is solved by ADAMS coupling ANSYS, which can reflect the actual working condition of VCR piston mechanism more realistically.A new modeling method is proposed, which can deal with the axisymmetric problem in the ADAMS and ANSYS coupling solution.According to the actual assembly relation and space position of the parts in the VCR piston mechanism, the constraint of the whole structure and the contact relation between the parts are defined in ADAMS.In order to verify the correctness of VCR piston simulation model, according to the test conditions of static simulation test and dynamic simulation test, the corresponding mechanical boundary conditions are established.In order to simulate the working condition of VCR mechanism in engine, the mechanical boundary condition of engine is established.The static simulation test uses the hydraulic universal testing machine to exert static load on the actual VCR mechanism and elastic elements of various structural schemes, and the dynamic simulation test uses the MTS testing machine to exert the dynamic simulation load on the actual VCR mechanism.The comparison between experimental data and simulation results verifies the feasibility of the model.The dynamic simulation model of the VCR piston is used to simulate and analyze the dynamics of the 135 type non-turbocharged diesel engine with VCR piston. The gas force acting on the top of the piston is provided by the engine performance simulation. The speed and load of the engine are analyzed.Effects of mass and structure parameters of moving parts on mechanical properties and dynamic response of VCR mechanism.The simulation results show that the proposed VCR technical scheme has good dynamic response and can meet the expected design requirements.
【學(xué)位授予單位】：武漢理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2011
【分類號】：TK403;TH113

【引證文獻(xiàn)】

相關(guān)期刊論文 前1條

1 潘晴川;董健;張智杰;劉紅雷;陳克朋;;車用汽油發(fā)動機的VCC活塞技術(shù)可行性論證[J];內(nèi)燃機;2013年02期

相關(guān)碩士學(xué)位論文 前2條

1 周越;可變?nèi)紵野l(fā)動機性能仿真研究[D];武漢理工大學(xué);2012年

2 歐陽林;可變?nèi)紵一钊膭恿W(xué)特性研究[D];武漢理工大學(xué);2012年

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本文編號：1704283