Tribology Analysis Technology Supports Engine Fuel …

1 203 36 1 3 4 Engine Performance Development Dept. Powertrain Technology Development Dept. 2015 Tribology Analysis Technology Supports Engine Fuel Economy 1 2 3 Toru Kurisu Shohei Kimura Hirohisa Shirai 4 Naonori Kanchika SKYACTIV NV CAE

2 Summary Reduction in the friction loss of Internal Combustion Engine (ICE) is a key for fuel efficiency. In the SKYACTIV Technology development, this was one of the seven control factors established for the improvement in fuel efficiency, which was addressed with a high target. To reduce the machine friction loss, recognizing the lubrication status at various driving conditions, and controlling oil films without ruining NVH performance, reliability of lubricant consumption and others is important.

3 For that purpose, Mazda has been promoting the application of CAE to Tribology areas. Clarifications of lubrication mecha-nisms and optimization of lubrication status are performed by various Analysis softwares such as high function applications on the markets and internaly-made simulation programs based on fluid lubricant theory and elastohydrodynamic lubrication theory. This paper introduces various tlyporogy Analysis technologies of engin and how to use them for the reduction in fuel cunsumption of the SKYACTIV Engine .

4 1. 20 2020 Fig. 1 3 204 2015 7 Fig.

5 2 SKYACTIV-G SKYACTIV-D SKYACTIV 2. Table 1 EHL Elasto-Hydrodynamic Lubrication Fig.

6 3 LIF Laser Induced Fluorescence (1) (2) 3 a) Visualization Engine b) Visualization System c) Visualized Oil Film Fig. 2 Ideal Vision of 7 Control Factors Lower CRcurrentMillercycleFrictionreductionCom res ionratioSpecificheat ratioCombustion periodPressure IN. & transferto wallDistance to ideal FarCloseSKYACTIV-GSKYACTIV-DAdiabaticMec hanicalloadreductionOptimum injectiontimingGasoline engineDiesel engineFINALH igher CRFrictionreductionAdiabaticIdealcurrent HCCILean burnFig.

7 3 Visualization of Piston Skirt Oil Film Provided by Tottori University Table 1 Relation of Engine Sliding Bearings and Its Tribological Problems PartsPortionFriction LossSeizureWearStrengthLOCBBI mpact NoisePistonPiston Skirt BearingSSMMMNSP iston Ring BearingSMMNSSSP iston Ring GrooveNNMMMMNP iston Pin BearingWMSMNNMC rankCrankpin Journal BearingMSSMNNMC rank Main Journal BearingMMMMNNSV alvetrainCam vs. TappetSMSMNNSC amshaft BearingWWWMNNWVVL vs. CamNMSMNNNCamDriveTiming ChainWWSSNNSO thersBalancer Shaft BearingNWWWNNSI njector NeedleNSSNNNMI njector Pump BearingNSSNNNWR elationship S Strong M Medium W Weak N NothingFig.

8 1 Status of ICE Efficiency 205 2015 1 Fig. 4 Fig. 5 2 Fig.

9 6 SKYACTIV-G , SKYACTIV-D Fig. 7 MOFT Minimum Oil Film Thickness (3) Fig. 6 Comparison of Second Land Pressure Fig.

10 4 Optimization of Piston Skirt Profile Fig. 5 Improvement of Piston Skirt Profile a) Before Optimization b) After Optimization c) Friction Calculation Result Before Optimization After Optimization 206 2015 Fig. 8 1 EHL 20 EHL Fig.