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Investigation on the Dynamic Behaviour of a Torque Transmission Chain for an Innovative Hybrid Power Unit Architecture

Università degli Studi di Modena-Valerio Mangeruga, Matteo Giacopini, Saverio Barbieri, Michele Russo
  • Technical Paper
  • 2020-37-0013
To be published on 2020-06-23 by SAE International in United States
In this contribution, the mechanical torque transmission between the Elecrtic Motor (EM) and the Internal Combustion Engine (ICE) of a P0 architecture hybrid power unit is analysed. In particular, the system is made up of a brand new, single-cylinder 480cc engine developed on the basis of the Ducati "959 Superquadro" V90 2-cylinders engine. The thermal engine is assisted by a custom electric motor (30 kW), powered by a Li-Ion battery pack. The Ducati "959 Superquadro" engine is chosen because of its high power-to-weight ratio, and for taking advantage of its V90 2-cylinders layout. In fact, the vertical engine head is removed and it is replaced by the electric motor directly engaged to the crankshaft using the original valvetrain transmission chain, thus achieving a very compact package. This solution could be suitable for many V-type engines and aims to obtain a small hybrid power unit for possible motorcycle/small vehicle applications. The original timing chain object of this study is a silent chain, which is commonly employed as a transmission component in hybrid power unit because it…
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A Modular Gasoline Engine Family for Hybrid Powertrains: Balancing Cost and Efficiency Optimization

AVL LIST GmbH-Wolfgang Schoeffmann, Michael Howlett, Alois Fuerhapter, Paul Kapus, Christoph Sams, Helfried Sorger
  • Technical Paper
  • 2020-01-0839
To be published on 2020-04-14 by SAE International in United States
The electrification of the powertrain is a prerequisite to meet future fuel consumption limits, while the internal combustion engine (ICE) will remain a key element of most production volume relevant powertrain concepts. High volume applications will be covered by electrified powertrains. The range will include parallel hybrids, 48V- or High voltage Mild- or Full hybrids, up to Serial hybrids. In the first configurations the ICE is the main propulsion, requiring the whole engine speed and load range including the transient operation. At serial hybrid applications the vehicle is generally electrically driven, the ICE provides power to drive the generator, either exclusively or supporting a battery charging concept. As the ICE is not mechanically coupled to the drive train, a reduction of the operating range and thus a partial simplification of the ICE is achievable. The paper shows the advances on a modular powertrain technology approach with different combinations of ICE, electrification and transmission variants, based on an engine family architecture with common parts, machining and assembly concepts, as well as the feasibility to integrate different…
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Effect of a Cylinder Deactivation Actuator with Electro-Mechanical Switching System on Fuel Economy of an Automotive Engine

Motonic Corporation-Dong Hyeong Lee, Wan Jae Jeon, Yong Seok Hong, Jong Wung Park
University of Ulsan-Dojoong Kim
  • Technical Paper
  • 2020-01-1408
To be published on 2020-04-14 by SAE International in United States
This paper introduces a two-step CDA mechanism equipped with an electro-mechanical switching system, which can be applied to OHC valve trains with end pivot rocker arms, and can operate two valves simultaneously with a single cam. The electro-mechanical switching system is driven by a dedicated solenoid, so the latching and unlatching processes are not affected by the temperature and pressure of the engine oil. Therefore, not only the dynamic stability can be secured at the time of mode switching but also the operation delay time can be kept short enough. To verify the effect of the CDA system on the fuel economy, a four-cylinder 2.0L gasoline engine with the intake port injection was selected and tested on an engine dynamometer. The effect of the present apparatus was evaluated by measuring the fuel economy of the engine in the two test modes: Federal Test Procedure-75 (FTP-75) and Worldwide Harmonized Light Vehicles Test Procedure (WLTP). The optimal operating conditions were established which minimize the engine vibration, friction loss and the adverse effects on fuel efficiency. According to…
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Dynamic Strength Co-Simulation for Valve Train Mechanism Design Virtual Validation

Maruti Suzuki India, Ltd.-Ved Prakash Choudhary, Bhupinder Singh, Sanjay Poonia, Jaspreet Singh
  • Technical Paper
  • 2020-01-0949
To be published on 2020-04-14 by SAE International in United States
As the automotive market is very dynamic and vehicle manufactures try to reduce the vehicle development cycle time, more focus is being given to CAE simulation technologies to reduce the design cycle time and number of physical tests. CAE engineers are continuously working on improving the accuracy of CAE simulation, such as using flexible body dynamic simulation in place of linear static analysis. Strength calculation under dynamic condition is more accurate as compared to static condition as it gives more clear understanding of stress variation with motion, contacts and mass inertia.Failure has been observed in new development of valve train pivot screw under test conditions. As per linear static analysis, design was judged OK. Normal linear static analysis is a two stage process. In first stage loads are calculated by hand or peak loads are taken from multibody dynamics (MBD) rigid body analysis. In second stage, stress calculation is carried out for peak load in quasi-static condition using finite element analysis (FEA). To investigate the reason of failure and prediction of stress in new proto…
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Diagnostic Evaluation of Exhaust Gas Recirculation (EGR) System on Gasoline Electric Hybrid Vehicle

Ford Motor Company-Sumanth Reddy Dadam, Robert Jentz, Tyler lenzen, Herbert Meissner
  • Technical Paper
  • 2020-01-0902
To be published on 2020-04-14 by SAE International in United States
Diagnosing the Exhaust Gas Recirculation (EGR) Valve remains one of the most challenging problems in emissions control systems diagnostics. California Air Resources Board (CARB) has started imposing specific requirements on automotive companies since 2011 that required the integration of on-board diagnostics (OBD) monitor for the detection and reporting of this type of control malfunction. In this paper, some methodologies of EGR valve system monitoring are investigated and a novel approach is proposed that shows reliable detection capability compared to the other methods. The proposed method requires certain conditions during deceleration fuel shutoff events to intrusively reactivate the EGR system and determine the obstructed valve condition. The method was evaluated on a 2.5L iVCT engine in an experimental Ford Escape Full Hybrid Electric vehicle. Vehicle results are shown and discussed.
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Impact of Miller Cycle Strategies on Combustion Characteristics, Emissions and Efficiency in Heavy-Duty Diesel Engines

University of Michigan-Erick Garcia, Vassilis Triantopoulos, Andre Boehman
Volvo Trucks North America-Maxwell Taylor, Jian Li
  • Technical Paper
  • 2020-01-1127
To be published on 2020-04-14 by SAE International in United States
This study experimentally investigates the impact of Miller cycle strategies on the combustion process, emissions, and thermal efficiency in heavy-duty diesel engines. The experiments were conducted at constant engine speed, load, and engine-out NOx (1160 rev/min, 1.76 MPa net IMEP, 4.5 g/kWh) on a single cylinder research engine equipped with a fully-flexible hydraulic valve train system. Early Intake Valve Closing (EIVC) and Late Intake Valve Closing (LIVC) timing strategies were compared to a conventional intake valve profile. While the decrease in effective compression ratio associated with the use of Miller valve profiles was symmetric around bottom dead center, the decrease in volumetric efficiency (VE) was not. EIVC profiles were more effective at reducing VE than LIVC profiles. Despite this difference, EIVC and LIVC profiles with comparable VE decrease resulted in similar changes in combustion and emissions characteristics. Miller cycle operation at constant intake pressure resulted in lower peak cylinder pressures, higher exhaust temperatures and lower EGR requirements compared to the baseline case, albeit with a significant fuel consumption penalty. Increasing intake manifold pressure to match…
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Landing Gear Fatigue Spectrum Development For Part 25 Aircraft

A-5B Gears, Struts and Couplings Committee
  • Aerospace Standard
  • AIR5914
  • Current
Published 2020-02-28 by SAE International in United States
This SAE Aerospace Information Report (AIR) provides guidelines for the development of landing gear fatigue spectra for the purpose of designing and certification testing of Part 25 landing gear. Many of the recommendations herein are generalizations based on data obtained from a wide range of landing gears. The aircraft manufacturer or the landing gear supplier is encouraged to use data more specific to their particular undercarriage whenever possible.
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High Efficiency by Miller Valve Timing and Stoichiometric Combustion for a Naturally Aspirated Single Cylinder Gas Engine

Karlsruhe University of Applied Sciences-Jörn Judith, Denis Neher, Maurice Kettner
SenerTec Kraft-Wärme-Energiesysteme GmbH-Danny Schwarz, Markus Klaissle
  • Technical Paper
  • 2019-32-0588
Published 2020-01-24 by Society of Automotive Engineers of Japan in Japan
Small-scale cogeneration units (Pel < 50 kW) frequently use lean mixture and late ignition timing to comply with current NOx emission limits. Future tightened NOx limits might still be met by means of increased dilution, though both indicated and brake efficiency drop due to further retarded combustion phasing and reduced brake power. As an alternative, when changing the combustion process from lean burn to stoichiometric, a three-way-catalyst allows for a significant reduction of NOx emissions. Combustion timing can be advanced, resulting in enhanced heat release and thus increased engine efficiency.Based on this approach, this work presents the development of a stoichiometric combustion process for a small naturally aspirated single cylinder gas engine (Pel = 5.5 kW) originally operated with lean mixture. To ensure low NOx emissions, a three-way-catalyst is used. In order to achieve high engine efficiency, measures implemented include Miller valve timing, optimized intake system, reduced engine speed and increased compression ratio. In the first step, a detailed 1D engine cycle simulation model was used to investigate the efficiency benefit of Miller valve timing…
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Dynamic implicit analysis of valve train with cylinder head assembly

CAE, Product Development, Royal Enfield-Prasanth Venkatesan, T Sreenivasulu, S Karthik, Rod Giles
  • Technical Paper
  • 2019-32-0584
Published 2020-01-24 by Society of Automotive Engineers of Japan in Japan
Transient dynamic behaviour of the valve train system at constant engine speed is simulated with an implicit time integration method. The Interference fit between the valve guide, valve seat to cylinder head and preload between cam housing to cylinder head has been modelled as initial loads in the valve train. The cylinder head and cam housing have been modelled to consider the mounting stiffness on dynamics of the valve train. The temperature from steady-state CFD simulation has been mapped to the valve train, cylinder head and cam housing assembly. The expansion of the whole system has been considered, due to an increase in temperature. The cam has been rotated at specified engine speed for 360 degrees. The change in valve to guide clearance, Contact Pressure and Contact Status between valve to seat for both hot and cold condition has been compared and plotted from the simulation. Valve guide & valve seat distortion have been plotted to compare the cold and hot effects. The stress from the simulation has been used to predict the fatigue life…
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Engine Valve Train Dynamic Analysis using 1-D Simulation Approach

Tafe Motors and Tractors Limited-Ajay Nain, Devendra Nene
  • Technical Paper
  • 2019-28-2422
Published 2019-11-21 by SAE International in United States
In order to reduce engine development timing and cost, a numerical calculation used to evaluate valve train systems. This paper discusses the work done on kinematic and dynamic analysis of Valve Train (VT) system of a diesel engine by using 1-D Ricardo Valdyn software. The goal is to meet optimum intake, exhaust valve timing requirement, maximize, valve open area and 30% over-speed requirement. Valve train model is prepared and inputs like mass and stiffness are estimated from 3-D model and finite element analysis, respectively. Simulation model is used for predicting valve bounce speed, valve displacement, cam-follower contact stress and strain in the rocker arm. Initially, Kinematic analysis is carried out to study the change in valve motion characteristics such as cam contour radius, tappet contact eccentricity etc. Further to this, dynamic analysis is carried out to assess forces and stresses on valve train components. Effect of cam tappet contact stresses, buckling load on push rod, spring surge, ratio of spring force to inertia force, valve seating velocity at increased speed condition etc. are discussed in…
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