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economy 2nd 1st 3rd step 1.5th I. I. －134－ 22D-VTCAY KSweN 7102 2 2D-V TCA KYS 210 2l ao GStepped Egg-bowl shape HP: FGT step マツダ技報 Far Previous step Performance Function / control factor HP-EGR Piezo Injector Distance to ideal Close Diesel engine step Breakthrough technology Inter Cooler 2 Stage Turbocharger DOC DPF *「 i-ART®」is a registered trademark of DENSO CORPORATION ルクの拡大を図った（Fig. 4）。最大空気量の増量と燃料噴射率の向上による燃焼期間短縮により，SKYACTIV-D燃焼コンセプトの特徴である最高燃焼圧力13.5MPaの低実現した。 Engine Engine Type Displacement Compression ratio Fuel Injection System Max. Injection Pressure Combustion Bowl Shape 2 Stage Turbocharger EGR System After-treatment System Max.Torque/rpm Max.Power/rpm Emissions 3.1 出力／トルク性能 新型では更なる商品性改善のため，最大出力，最大トPmax燃焼を踏襲しつつ，更なる高出力・高トルク化を2017 New SKYACTIV-D 2.2 ← ← 14.4 ← G4P-i (Piezo w/ i-ART® *) ← Stepped Egg-Bowl Shape HP: FGT LP: Turbocharger with variable turbine geometry ← ← 450 Nm / 2000 rpm 140 kW / 4500 rpm JPN H30 (WLTC) Control factors Compression ratio Specific heat ratio Combustion Low CR 14 High boost period Combustion timing Heat transfer to wall Pressure diff. Btw IN.&Ex. Mechanical friction Fuel Compression ratio Shortened combustion period Reduction of heat transfer to wall Reduction of mechanical friction Reduction of pressure difference between Int. & Exh. Max. power Max. torque Driving performance Transient acceleration response Emissions NV Fig. 1 Vision for Evolution of Diesel Engine Fig. 2 Upgrading Technologies Fig. 3 Engine System Low CR 14.4 High-response injector Stepped Egg–bowl shape High-efficiency 2 stage TC Coolant control valve Low friction machineries Compression ratio up Multiple sprays in proximity High-response injector Reduction of squish flow in combustion Oil pump chain system with dual tensioner Low-friction piston ring chamber improvement Rapid warming up Mechanism Coolant control valve Boosting efficiency 2-stage TC improvement & widened range Optimization of under transient Fine mixture LP: Turbocharger with variable turbine geometry High-precision Air / EGR volume DE boost control Rapid multiple combustion Table 1 Specifications 2012 SKYACTIV-D 2.2 In-Line 4 2188 cm3 14.0 Common Rail System G3P (Piezo) 200 MPa Conventional Egg-Bowl Shape HP: FGT LP: FGT HP-EGR DOC + DPF 420 Nm / 2000 rpm 129 kW / 4500 rpm JPN H21 Fig. 4 Engine Performance 3. 性能パフォーマンス No.34（2017）