Engine Mount Force Prediction for Strength Design during Rapid Start

Transcription

1 1 Engine Mount Force Prediction for Strength Design during Rapid Start Honda R&D Co.,Ltd. Automobile R&D Center Yasufumi Jo Date:9/Oct/214

2 Contents 2 Background Overview of the models -Engine model and clutch model -Engine mount model -Full-vehicle model Simulation, verification and results Consideration of the engine mount force mechanism Conclusion

3 Contents 3 Background Overview of the models -Engine model and clutch model -Engine mount model -Full-vehicle model Simulation, verification and results Consideration of the engine mount force mechanism Conclusion

4 Background 4 Strength design of engine mount requires... full vehicle CAE Force prediction in an early phase of design Force due to driving torque during rapid start Accurate prediction of maximum force This project Engine mount force due to driving torque Suspension force due to road input Rapid start Rough road Curb

5 Contents 5 Background Overview of the models -Engine model and clutch model -Engine mount model -Full-vehicle model Simulation, verification and results Consideration of the engine mount force mechanism Conclusion

6 Clutch clamping force [N] Engine torque [Nm] Engine model and clutch model 6 Clutch T = 2μ F R Engine Throttle position 1% 9% 8% 7% 6% 5% 4% 3% 2% 1% 5% Engine speed [rpm] Clutch engagement time T :Torque μ :Clutch friction coefficient F :Clutch clamping force R :Clutch effective diameter Time [s]

7 Force[N] Engine mount model 7 Engine mount Transmission mount Vehicle front High load curve Torque rod Engine mount force main direction Power plant rotational displacement Engine side mount Displacement [mm] Bush spring characteristic

8 Full-vehicle model 8 Rapid start of MT vehicle

9 Engine side mount force reduction rate[%] Reduction rate [%] Influence of coordinate and bush spring 9 Changed parameters of engine side mount 5mm front 5mm back Vertical coordinate has a large influence on engine side mount force 3 Coordinate 5mm left 5mm right 2 5mm up 5mm down 1 Bush spring mm up Bush spring 2. 5 mm front 5 mm right

10 Contents 1 Background Overview of the models -Engine model and clutch model -Engine mount model -Full-vehicle model Simulation, verification and results Consideration of the engine mount force mechanism Conclusion

11 Torque [Nm] Wheel torque comparison 11 Sufficient prediction accuracy for maximum peak value Time history waveform also matched closely Peak Measurement Simulation Engine mount force Wheel torque Time [s]

12 Force [N] Force [N] Force [N] Engine mount force comparison 12 Transmission mount Measurement With-stopper model Without-stopper model Peak With-stopper model has sufficient prediction accuracy Time [s] Measurement With-stopper model Without-stopper model Peak Torque rod Time [s] Engine side mount Measurement With-stopper model Without-stopper model Peak Time [s]

13 Torque [Nm] Torque [Nm] Wheel torque comparison for another vehicle 13 This vehicle has higher torque engine Peak Measurement Simulation Engine mount force Wheel torque Time [s] [s]

14 Force [N] [N] Force [N] [N] Force [N] [N] Engine mount force comparison for another vehicle 14 Measurement Simulation Peak Sufficient prediction accuracy Time [s] [s] (a)lower torque rod Engine mount force Measurement Simulation Peak Measurement Simulation Peak Wheel torque Time [s] [s] (b)upper torque rod Time [s] [s] (c)transmission mount

15 Contents 15 Background Overview of the models -Engine model and clutch model -Engine mount model -Full-vehicle model Simulation, verification and results Consideration of the engine mount force mechanism Conclusion

16 Wheel torque component of engine mount force 16 Engine mount force Wheel torque component F T Inertia force component F I Wheel torque component F T : Wheel torque T Engine mount span L Engine mount Body Power plant F T L F T T

17 Inertia force component of engine mount force 17 Engine mount force Wheel torque component F T Inertia force component F I Power plant Inertia force Inertia moment I angular acceleration α component F : I Engine mount span L Engine mount Body Power plant F I L α F I I

18 Force [N] Torque [Nm] Influence of power plant angular acceleration Power plant Inertia force Inertia moment I angular acceleration α component F : I Engine mount span L Engine mount force decreases with smaller power plant angular acceleration α 18 Engine mount force α:large α:middle α:small Wheel torque Time time [s]

19 Force [N] Torque [Nm] Influence of engine mount span Power plant Inertia force Inertia moment I angular acceleration α component F : I Engine mount span L 19 Engine mount force decreases with larger engine mount span L Engine mount force L:Small L:Middle L:Large Wheel ホイールトルク torque Time [s]

20 Conclusion 2 (1)SIMPACK full-vehicle model was confirmed to have adequate accuracy to predict wheel torque peak value and engine mount force peak value during rapid starts (2)Wheel torque, power plant angular acceleration, and engine mount span were found to have influence on engine mount force (3)Engine mount force is decreased by either: decreasing of power plant angular acceleration or increasing of engine mount span

21 Acknowledgment many thanks to... Steven Mulski (SIMPACK AG) for building the first SIMPACK model for rapid start maneuver in 24 SIMPACK AG and SIMPACK Japan K.K. for extension of the model and technical support