Browse Topic: Timing chains

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Development of Design and Engineering Recommendations for In-Vehicle Alphanumeric MessagesJ2831_202007 (Current)7/29/2020
This Information Report provides recommendations for alphanumeric messages that are supplied to the vehicle by external (e.g., RDS, satellite radio) or internal (e.g., infotainment system) sources while the vehicle is in-motion. Information/design recommendations contained in this report apply to OEM (embedded) and aftermarket systems. Ergonomic issues with regard to display characteristics (e.g., viewing angle, brightness, contrast, font design, etc.) should review ISO 15008.
Driver Vehicle Interface (DVI) Committee
Brake Power Availability Led Optimisation of P0 versus P2 48V Hybrid Powertrain Architectures2020-01-04394/14/2020
Through improving the 48V hybrid vehicle archetype, governmental emission targets could be more easily met without incurring the high costs associated with increasing levels of electrification. The braking energy recovery function of hybrid vehicles is recognised as an effective solution to reduce emissions and fuel consumption in the short to medium term. The aim of this study was to evaluate methods to maximise the braking energy recovery capability of the 48V hybrid electric vehicle over pre-selected drive cycles using appropriately sized electrified components. The strategy adopted was based upon optimising the battery chemistry type via specific power capability, so that overall brake power is equal to the maximum battery charging power in a typical medium-sized passenger car under typical driving. This will maximise the regenerative braking energy whilst providing a larger torque assistance for a lower battery capacity. Dynamic simulation models were developed using GT-DRIVE software, emulating a mid-sized car with a 48V battery, and different turbocharged gasoline engines with motor-generator unit positions along a drivetrain. The 1.3 kWh battery pack was developed using a 14 Ah Lithium Iron Phosphate cell arranged in a 14 series 2 parallel configuration. A fuel economy comparison was produced using the FTP, WLTP, and HEFET drive cycles. When the motor-generator unit was attached via a synchronous belt, a 10-17% fuel saving was achieved in the WLTP drive cycle. Comparatively, when placing the electric machine after the clutch in a “P2” position, a 17-21% fuel saving was attained. The energy loss analysis of both P2 and P0 configurations revealed up to 7% overall reduction in total energy losses for the P2 setup. This was despite an increase in the motor-generator unit and battery losses due to the extended use of both in the electric-only mode capability with the P2 layout.
Alnamasi, Khaled, Terry, Simon, La Rocca, Antonino, Cairns, Alasdair
The Isochoric Engine2020-01-07964/14/2020
For the gasoline engine, the isochoric process is the ideal limit of the ideal processes. During the project, a combustion engine with real isochoric boundary conditions is built. A “resting time” of the piston for several degrees crank angle in the top dead center (TDC) can be realized with a special crank drive. This crank drive consists of two crankshafts with different strokes, which are combined. The two crankshafts rotate with a ratio of two to one in opposite directions. The total stroke corresponds to the amount of the first crankshaft, so it is possible to investigate different strokes of the second crankshaft in the same crankcase. Different “resting times” can be achieved by different strokes of the second crankshaft. A specific combination of both crankshafts make a stroke possible which corresponds to that of a conventional combustion engine. In addition to the standard cylinder pressure sensor, a quick surface temperature probe is also used as supplementary measurement technology. The influence of isochoric combustion is studied with constant air mass and constant lambda at three different strokes of the small crankshaft.
Burger, Benjamin, Bargende, Michael
Optimum Positioning of FIP Drive System for Type-II BSVI Engine Based on Coupled 1D “Valve-Train - Chain Drive Dynamic Analysis2020-01-10204/14/2020
The automotive industry is gearing up to meet the accelerated emission compliance changes posed by the government. This transition to eco-friendly system would also necessitate an automotive engineer to retain the engine packaging as compact and simple as possible. The packaging layout considered should not be at the expense of deteriorating engine performance. The work started with concept level layout development, with the aim of having simplified system with minimum number of components. The engine on which the work was carried out was 4cylinder 3Liter with OHC configuration A number of layouts were developed which included gear type, belt drive and integrated shaft arrangement for driving FIP. Each of these concepts were brainstormed with its advantages and disadvantages, based on which two concepts were initially proposed for driving FIP system (i) Front Driven FIP (ii) Rear Driven FIP. The difference between the two layouts was that in the latter case the FIP system was directly driven through exhaust camshaft with gear type arrangement. For the above two proposed layouts, dynamic evaluation was done up-to max intermittent speed of engine by modeling complete valve-train system along with chain drive in AVL Excite timing drive. The Excite timing drive model dynamic results showed that with the rear layout FIP system, the valve-train along with chain drive system was getting heavily loaded demanding more robust design leading to an unintentional increase in system mass. For further visualization of the two layouts, engine level testing was done by developing proto parts for both the concepts and the conclusive results were found to be in-line with the simulation results.
Kaundabalaraman, Kaarthic, Rathi, Hemantkumar, Bisht, Jasvir Singh
Performance Engine Building Recommended PracticesJ2379_201910 (Current)10/3/2019
This SAE Recommended Practice applies to the function of building reciprocating spark-ignition engines which are used in conjunction with standard and high-performance ancillary components in applications intended to achieve a minimum of 1 hp/in3. This document does not apply to rebuilt engines which may only be partially repaired with little or no machining, nor does it apply to second-hand or used engines.
Motor Vehicle Council
SAE 17.6 Cubic Inch Spark Plug Rating EngineJ2203_201906 (Current)6/11/2019
This SAE Standard defines the standard engine to be used in determining spark plug preignition ratings. The engine is known as the SAE 17.6 Cubic Inch Spark Plug Rating Engine.
Ignition Standards Committee
Noise Problem Resolution and Sound Quality Improvement of Valve Timing Belt in 4 Cylinders PFI Gasoline Engine2019-01-07834/2/2019
IC Engine Timing belt is a major noise prone area and it takes time during development to achieve acceptable NVH characteristics. In an existing engine under series production noise problem observed due to excitation of timing belt span by crank timing sprocket tooth. From vehicle perspective noise was heard in vehicle cabin at around idling RPM and a second peak observed around twice the initial RPM. This paper includes a methodology for use of computer based analytical simulation methods to predict timing belt dynamic behavior and NVH characteristics. Along with development of computer based multi body dynamic model for timing belt, validation of simulation model with actual testing was done and after correlation of testing and simulated results countermeasure were finalized based on iterations in multi body simulation model. Multi body dynamics model of timing drive indicated resonance in one belt span when belt transverse vibration amplitude was converted from time domain to frequency domain using FFT. In an existing engine layout change to modify belt span length was not feasible to avoid resonance, other alternatives like reduction of belt natural frequency (by increasing belt mass density, tension reduction etc.) were explored using parametric simulation model. Final solution to avoid belt resonance in engine working RPM range was proposed as reduction of belt natural frequency by modifying the belt tension. Above proposal was checked on engine bench and anechoic vehicle test showed noise reduction of 5 and 11 dB at first and second harmonic respectively due to avoidance of resonance in engine working RPM range. Multi body dynamic simulation model helped to drastically reducing the number of testing trials/combination used to resolve the NVH issue of timing belt.
Poonia, Sanjay, Singh, Amandeep, Singh, Jaspreet, Sharma, Shailender, Kumar, Narinder
Dynamic Modeling of CNC Drive Systems: Comparison of Two Models2019-01-08034/2/2019
Accurate positioning and precision of CNC machines are directly affected by performance of their mechanical drive system and control unit (CNC feeddrive system). This is more important in contouring operations where axes motion is synchronized by interpolators and errors are accumulative. This research work is focused on study of dynamics of the feeddrive unit. In this regard, a detailed dynamic model is developed in state-space format that is used to study its response properties. A parametric study of the system is carried out by studying shifts in eigenvalue loci when a parameter is changed. The results are used in further simplifying this model to a reduced order system which is simpler in structure and more appropriate for control applications. A comparison is made between these models and the merits of each individual model are presented.
Mehrabi, Mostafa
Single-Axis Motion Control Systems: Multi-Sourced vs. Single-SourcedTBMG-3307810/1/2018
In today’s fast-paced industrial settings, speed and efficiency are key. Reducing time spent on sourcing, installing, and testing motion control systems can play a big role in cost containment and design cycle efficiency. Machine designers face a variety of challenges and ever-changing requirements. They customize and configure their designs to address global markets as well as customer-specific applications. Also, industry trends are moving to smart products, connectivity, total cost of ownership, efficiency, flexibility, and complete, integrated motion control systems. These factors change how components are researched, designed, purchased, tested, and implemented to optimize system performance.
The Dual Phase Twin Synchronous Belt Drive2017-01-17736/5/2017
The dual phase twin synchronous drive has been developed for belt noise reduction. Two identical synchronous belts are arranged parallel side by side with one tooth staggered against other by the half pitch offset. The noise cancellation effect is achieved as one belt tooth engagement coincides with the other belt tooth dis-engagement. A center flange is used as a divider to prevent the belts contacting each other along the axial direction during their entrance and exit of the sprocket. An overall 20 [dBA] noise reduction has been achieved with the dual phase twin belt drive compared to an equal width single belt counterpart. The vibration amplitude of the hub load is also reduced which is directly correlated to the structural borne noise. Comparing to the related dual phase helical tooth belt, the dual phase twin belt is superior in torque carrying capability; and is on par with noise mitigation. The dual phase twin belt has been demonstrated with the automotive transfer case application by four wheel drive SUV, where a conventional metal chain, or Morse Chain, is commonly used. Besides the apparent mass saving, replacing the metal chain with a belt also benefits the environment, as the normally essential chemical lubrication is completely eliminated.
Yuan, Jing
Thermal Protection of Rear Mounted Engine and Its Components Using a Ventilation Fan with Unique Monitoring and Fault Diagnosis Technique2017-01-06203/28/2017
The engine compartment of passenger car application contains various source which radiates the produced heat and raises the temperature level of the compartment. The rise in compartment temperature increases the body temperature of individual component. The rise in body temperature of critical components can endanger the durability or functionality of the specific component or a system in which it operates. The aim of this paper is to strategize thermal protection of the rear mounted engine and its components of a vehicle having radiator and cooling fan mounted in front. An additional ventilation fan with speed sensor is fitted alongside rear mounted engine and a unique monitoring technique framed in the EMS ECU to protect critical components like HT cables, alternators, ECUs, wiring harness etc. from thermal damage. The EMS continuously monitors the engine speed, vehicle speed and the PWM signal of ventilation fan to ensure the intended operation of the ventilation fan. With the implementation of additional ventilation fan it is observed that maximum engine compartment temperature does not exceed safe operating temperature limit when the vehicle is driven in all road load condition (including highway, city & gradient drive conditions) and in all vehicle operating conditions. Excessive operation at higher compartment temperature unnecessarily causes individual component durability & performance to deteriorate at considerably faster rate. Thus, method of the present disclosure ensures that every component in engine compartment is operating in safe operating limits. In-case any failure occurs in the ventilation fan, newly developed EMS diagnosis strategy identify fault and indicates the problem to the driver through telltale. EMS also restricts the vehicle speed to safely maneuver vehicle to the nearest service center for repair.
Parmar, Chandrakant, Tyagarajan, Sethuramalingam, Tiwari, Sashikant, Thonge, Ravindra, Paul, S Arun
Physically Motivated Model for Efficient Dynamic Simulation of Chain Tensioners with Labyrinth Seals2017-01-10733/28/2017
The object of this study is a new chain tensioner with two labyrinth seals. For the simulation of chain tensioners within the framework of multi-body dynamics, a physically orientated model to describe the fluid dynamics of the labyrinth seals is derived. The easiest way to describe labyrinth seals is to use maps obtained from measurements. As this is very time-consuming, methods of 1D and 2D fluid-mechanics are used in this work to model the labyrinth seals. The seals are characterized by physically motivated parameters e.g. coefficients of resistance or friction. As these parameters can be derived from geometric data, a very good forecast feasibility without experimental investigations is provided. For high accuracy simulations model parameters can be refined by experimental data. As many and highly complex parameters have to be identified, this refinement is very time-consuming and requires lots of experiments. Therefore, a third approach for modeling a labyrinth sealing is derived. Using dimensional analysis the labyrinth can be described by a non-dimensional equation. Only a few coefficients have to be determined by measurements. Hence, the effort for parameter identification as well as the number of necessary experiments is significantly reduced. All three approaches are validated with experimental data. Next, a dynamic model of a complete chain tensioner including labyrinth seals was built up. A comparison between simulation and measured data of the flow characteristics as well as of the dynamic behavior is presented to prove accuracy, benefits and practicability of the presented approach. Furthermore, the influence of fluid inertia in the hydraulic lines is analyzed.
Huber, Robert, Clauberg, Jan
Gear Whine Noise Due to Deformation- A Case Study2017-01-11223/28/2017
Vehicle noise has reduced over the years due to the customer demand for quieter vehicles. As the background noises such as combustion noise, pumping noise, etc. have reduced, mechanical noises such as gear noise have become prominent and a major cause of customer complaints. Engine timing gear train uses gears for transferring torque to cam and accessory gears. As engines have become quieter by efforts to reduce the combustion noise, as well as, by moving away from mechanical fuel pumps to common rail fuel pumps, the gear train noise has come under increased scrutiny. Gear whine could be a result of multiple factors. Gear profile distortion is one of the factors. Gear torque variation also has a significant effect on gear whine. Operation of the accessory drives such as hydraulic pumps under variable loads and speeds, is one of the major challenges for resolving a gear whine issue in the engine gear train. ISO 10064 provides guidance on the distortion due to temperature effects, but there is not much published literature about gear whine due to distortion. The work attempts to fill that gap by describing a gear whine problem due to profile distortion and load change and its resolution by changing the gear design.
Joshi, Yashodhan V.
Advanced Lubrication - Enabling and Protecting Turbocharged, Direct Injection Gasoline Engines for Optimum Efficiency2016-01-227510/17/2016
There has been a global technology convergence by engine manufacturers as they strive to meet or exceed the ever-increasing fuel economy mandates that are intended to mitigate the trend in global warming associated with CO2 emissions. While turbocharging and direct-injection gasoline technologies are not new, when combined they create the opportunity for substantial increase in power output at lower engine speeds. Higher output at lower engine speeds is inherently more efficient, and this leads engine designers in the direction of overall smaller engines. Lubricants optimized for older engines may not have the expected level of durability with more operating time being spent at higher specific output levels. Additionally, a phenomenon that is called low-speed pre-ignition has become more prevalent with these engines. While more pre-ignition may be expected with highly-boosted engines, an especially destructive version of this has been found to be related to some of the essential compounds that comprise the lubricant additive package. Newly introduced OEM specifications have been designed to anticipate the needs of these downsized, down-speeded, turbocharged direct injection engines. New areas of protection include: low speed pre-ignition, enhanced protection against turbocharger deposits, and timing chain wear. Since lubricants must still protect and enable many other items associated with durability like sludge, piston deposits, wear, and resistance to oxidation, we discuss a holistic formulation strategy that ensures a maximum level of engine protection and oil durability to enable the highest degree of fuel economy.
Yang, Kongsheng, Fletcher, Kristin A., Styer, Jeremy P., Lam, William Y., Guinther, Gregory H.
Simplified Machine Design Approach for Optimal Servomotor ControlTBMG-248936/1/2016
An often asked question from industrial machine builders or integrators is how they can effectively design or implement the conversion of a machine with servo technology to meet performance expectations. This is a specialized task filled with layers of complexity that can prove difficult to execute, even when the scope of work is fully understood.
Design Methodology and Development of an Economical 3D Printer2016-01-03254/5/2016
Additive manufacturing has experienced rapid growth over a span of 25 years. Additive manufacturing involves the development of a three-dimensional (3D) object by stacking layer upon layer. Conventional machining techniques involve the removal of material. However, this technique differentiates itself from other techniques by means of addition of the material. The integration of CAD with additive manufacturing has offered the ability to create complex structures. Despite its clear benefits, additive manufacturing suffers from a high initial investment. An average cost of an entry level commercial 3D printer is 600$. A low-cost 3D printer has been designed and built for experimental investigation within a budget of 300$. The paramount process of 3D printing involves a combination of interpreting data from CAD files and controlling the motors using this data. The various design considerations while developing the 3D printer have been discussed. The 3D printer developed, provides the user with a build volume of 140*280*100 mm3. This is comparable to an entry level commercial 3D printer. The fabricated printer frame serves to absorb the vibrations and ensures optimum quality prints. The choice of motors to provide the necessary torque, the dependence of layer height on lead screw pitch and belt selection is crucial. The components involved in the construction of 3D printer will be presented and accompanied by brief commentary on the underlying principle of each component. The necessary steps involved in the calibration of the 3D printer are presented before the readers. Through this study, an insight is provided into the basic problems involved while 3D printing and their solutions.
Javed, Farhan, Javed, Salman
Towards the Direct Evaluation of Turbine Isentropic Efficiency in Turbocharger Testing2016-01-10334/5/2016
Turbocharging is playing today a fundamental role not only to improve automotive engine performance, but also to reduce fuel consumption and exhaust emissions for both Spark Ignition and diesel engines. Dedicated experimental investigations on turbochargers are therefore necessary in order to get a better understanding of its performance. The availability of experimental information on realistic turbine steady flow performance is an essential requirement to optimize engine-turbocharger matching calculations developed in simulation models. This aspect is more noticeable as regards turbine efficiency, since its swallowing capacity can be accurately evaluated through the measurement of mass flow rate, inlet temperature and pressure ratio across the machine. Actually, in the case of a turbocharger turbine, isentropic efficiency directly evaluated starting from measurement of thermodynamic parameters at the inlet and outlet sections can give significant errors. This inaccuracy is mainly related to the difficulty of a correct evaluation of the turbine outlet temperature due to the flow field and temperature distribution at the exit of the machine. In the paper a preliminary experimental analysis on the direct evaluation of turbine isentropic efficiency is reported. In particular, a specific “hand-made” three holes probe was adopted to measure flow field distribution and thermodynamic quantities downstream the turbine.
Marelli, Silvia, Marmorato, Giulio, Capobianco, Massimo, Boulanger, Jean-Maxime
Study of Optimization of Reciprocating Parts for General-Purpose Engine with Aluminum-Alloy Connecting Rods2015-32-080511/17/2015
The connecting rods employed in most of general-purpose engines with a power from 1.5 kW to 10 kW are manufactured from aluminum alloy in order to increase productivity and reduce weight, and therefore display lower material strength than steel connecting rods. In terms of operating conditions, general-purpose engines are frequently operated under high load while being held at a comparatively low engine speed, necessitating strength and durability in relation to combustion pressure. Realizing a balance between the rigidity of each part is an important factor in reconciling the achievement of weight reduction in the reciprocating parts while also keeping strength. The research discussed in this paper developed a structure optimization system to examine shape parameters for reciprocating parts targeting 4 kW class engines, and studied shapes that would balance the reduction of weight with the keeping of strength. These realizes design shapes of 4 kW class engines in which the stress generated on each part is equivalent to or lower than the stress generated on the mass-production shape, while reducing the mass of reciprocating parts by approximately 6% (compared to the initial shape). Investigation using reciprocating shapes of general-purpose engines with different power showed that shapes of reciprocating parts with the smallest weight had the same dimension pattern as discussed above irrespective of the cylinder bore size.
Okubo, Masami, Suzuki, Masato
Evaluation of Drain Life and Filtration of Engine Oil for New Gen-ICV's Operating in Extreme Conditions2015-01-28769/29/2015
In tropical conditions, twelve numbers of ten ton intermediate commercial vehicles run at regular interval from zero to 60000 kilometer. Vehicle field run data were composed and analyzed with intended duty cycle for engine oil drain life estimation. The intermediate commercial vehicle trucks with sump capacity 0.083- 0.104 liter/HP and SAE 15W40 viscosity of oil meeting API CH-4, API CI-4+ from group-I and group-II base stocks are considered. The engine wear is more a function of silica concentration, load factor and age than the API category of the oil. Oil drain interval is found to be proportional to the sump volume for the same stress on the oil. Iron concentration and kinematic viscosity decide to be useful oil life with respect to the limits fixed by the engine manufacturer. In tropical conditions, field trials are carried out on 10 ton payload vehicles at higher temperature, humidity, dust levels and payload factor. API CI-4+ oil provide higher level of protection against soot related viscosity increase and viscosity loss due to shear. Kinematic viscosity @100 degree Celsius is within the limiting range of 11.5 to 18.5 centistoke. Total base number of a minimum of 9 and Max 11.5 is sufficient for BS-III and BS-IV fuel without affecting the oil drain interval. Wear elements like ferrous; copper; chromium; lead; aluminum and silicon Dirt (external) are also within limits. The analysis shows that the CI-4+ oils are best suited for the subject engines. The fresh new oil filter and oil filter run on reliability vehicle has been tested on filter test rig and comparative data have been analyzed. Also the effect of organic sludge; such as unburned fuel, soot, fuel deposits; solvents; and inorganic contamination; like dirt, dust, core sand and wear metal contamination on the filtration of engine oil have been investigated. Pressure drop across the filter and dust holding capacity were measured with respect to oil flow rate and analyzed.
Patil, Shankar, Mahesh, P, Sadagopan, Krishnan, Gokhul, Senniappan Arunachalam
Choosing the Right Drive TechnologyTBMG-229319/1/2015
Although there are a number of variations of drive technologies for motion applications, there are a few that are used for the majority of systems being built today. These most common drives do take a bit of understanding before applying.
The New Toyota 1.2-Liter ESTEC Turbocharged Direct Injection Gasoline Engine2015-01-12684/14/2015
Toyota Motor Corporation is developing a series of engines belonging to its ESTEC (Economy with Superior Thermal Efficient Combustion) development concept. This paper describes the development of 8NR-FTS after the subsequent launch of the 2.0-liter DI Turbocharged 8AR-FTS. 8NR-FTS is a 1.2-liter inline 4-cylinder spark ignition downsized turbocharged direct injection (DI) gasoline engine. By following the same basic concepts as 8AR-FTS engine [1], the 8NR-FTS incorporates various fuel efficient technologies such as a cylinder head with an integrated exhaust manifold, the Atkinson cycle using the center-spooled variable valve timing with mid-position lock system (VVT-iW), and intensified in-cylinder turbulence to achieve high-speed combustion. Instead of the D-4ST (Direct injection 4-stroke gasoline engine Superior version with Turbo) system that incorporates port and direct injection, this engine adopts the D-4T (Direct injection 4-stroke gasoline engine with Turbo) system that performs only DI in each cylinder. In combination with a single-scroll turbocharger, high torque is achieved from low engine speeds by cooperative control with the VVT system. This engine also adopts a stop and start control strategy that achieves speedy and shock-free re-start performance by starting the engine with stratified injection in the first compressed cylinder. The engine can be mated with either a 6-speed manual transmission (6MT) or continuously variable transmission (CVT). Especially with CVT, turbocharger lag duration is reduced by shifting control, and both fun-to-drive dynamic performance and excellent fuel economy are capable by switching two driving mode; “normal” or “sport”.
Shinagawa, Tomohiro, Kudo, Masahito, Matsubara, Wataru, Kawai, Takashi
Demands on Future Timing drives - Chain and Belt in Competition2015-01-12754/14/2015
When designing a new internal combustion engine, the choice of technology for the timing drive system is one of the key decisions that determines the overall characteristics of the engine with far reaching implications on the remaining architecture and overall packaging of the engine. For Passenger car engines there are two mainstream technologies: toothed belts and chains. Each of these offers several sub-variants, such as dry vs. wet belt, or toothed vs. roller chain. This paper examines the differences between these technologies in relation to the key engine attributes including package, cost, weight, durability, NVH and frictional losses. A quantitative evaluation is made where possible, based on data collected from recent engine development programs, backed up by literature study and data from the component supply industry. These differences are reviewed in the light of current and expected future engine development trends in order to give a basis for the engine designer to choose the appropriate technology for coming years.
Schoeffmann, Wolfgang Johann, Truffinet, Caroline, Howlett, Michael, Ausserhofer, Norbert, Zurk, Andreas
Development of Indigenous Methodology for Design and Dynamic Analysis of Engine Valve Train System with Timing Chain Drive for High Speed Applications2015-26-00221/14/2015
In the pursuit of design and development of efficient, reliable and durable system and components for modern engines, there is a need to understand complications involved in building mathematical models for simulation. Valve train and timing drive systems are having higher rankings for addressing these attributes. Hence, a new comprehensive multi body dynamics model is built and equations are solved by state-variable approach. Model developed is validated and in order to probe into details of Hydraulic Lash Adjuster (HLA) behavior and coupled analysis of timing chain drive systems for valve train system, simulation is carried out to freeze design options. Engine timing drives used in engines are one of the most critical systems. Timing chains are preferred widely in modern high speed engines as compared to timing belts and gear drives. In spite of advantages of chain drive systems, their complex dynamic behavior is not well researched. The major objective of the current work is to design & develop timing chain drive and valve train system for a high speed three cylinder diesel engine and investigate about its durability. In this research work, dynamic model of type-2 valve train with HLA and chain drive with hydraulically operated tensioners is built in GT valve train software. The final goal is to optimize the valve train and timing system performance by simulation. The results related to timing chain analysis are expressed in terms of parameters such as contact forces, normal forces between different components and link tension etc. The effectiveness of this model calibration technique was confirmed through comparison of unit dynamic characteristics in an excitation test and a calibrated simulation. The proposed simulation process is validated experimentally and has shown considerable reduction in development time with improved robustness.
Mulik, Rakesh, Ramdasi, Sushil S
Approach to the Main Transmission Phenomena for Timing Chain Drive Systems2014-36-076611/4/2014
More and more, the automotive vehicle consumers tend to opt for internal combustion engines which use chain in their timing system, since the chain drive system presents high durability, avoiding the usual maintenance common to the belt timing system. The necessity of developing parts which increase the fuel consumption efficiency and minimize noise and vibration leads to the study and comprehension of some physical phenomena such as “polygonal action” and the ability of predicting the fluctuation of angular velocity of the sprockets used for timing the crankshaft and camshaft. The study of mathematic models in parallel to the physical test guides the development of the present work.
Chagas, Clodoaldo Borges, de Freitas, Thiago Caetano, Pederiva, Robson
Evaluation and Comparative Study of ValveTrain Layouts with Different Rocker Ratio2014-01-287710/13/2014
The Valve Train system is an integral part of any engine and the impact of its design is very crucial, particularly in high speed engines. Maintaining the required valve timing throught the engine operating speed and longer component life are the two important parameters which drive current valvetrain designs. An engine ValveTrain system designed for a valve lift of 7mm is to be modified for an increased valve lift of 8mm. A study was conducted to understand which design parameters are to be changed /modified to make this possible. For this study, the valvetrain of an air-cooled motorcycle engine is taken up. The valvetrain arrangement was an Over Head Camshaft (OHC) design with a Roller-Follower. A 1D commercially available numerical code was used to simulate the kinematics and dynamics of the system. The effect of the addition of stiffer springs to the base valvetrain layout to counter the decrease in its dynamic stability because of the larger cam (which was provided to produce the required 8mm valvelift) is studied. Also the outcome of increasing the Rocker Arm Ratio (RAR) and how it alters the dynamic behavior of the valve train was understood. RAR is the ratio of the length of the valve side of the rocker arm to the pivot and the length of the follower-roller to the rocker pivot. Increasing the RAR is an effective way of increasing the valvelift of the engine (hence it's breathing capacity) with the same cam profile. Also because of the increased RAR, undesirable valve dynamic phenomenon such as valve float would occur later in the rpm range, hence aiding in the dynamic stability of high speed engine valvetrain. But by increasing the RAR, the forces and Hertz stress generated at the cam/follower interface will also increase. In this paper Valvetrain layouts with three different rocker ratios i.e. 1.2, 1.5 and 1.8 were studied. Also two spring designs were evaluated on these rocker designs. How the change of RAR and the spring stiffness affects the valve dynamic phenomenon like valve bounce, valve float and how it alters the valve train forces and stresses were understood. From this study an optimized rocker ratio with suitable spring design is suggested for the considered engine.
John, Ajay Paul, Agarwal, Vikas Kumar
Strobing to Mitigate Vibration for Display LegibilityTBMG-200197/1/2014
This method mitigates the motion blur introduced when a display, and/or the operator reading it, is undergoing vibration (e.g. during the launch phase of spaceflight). If both the operator and the display are undergoing vibration, their respective impulses need not be in phase. This mitigation occurs when the display is illuminated at a strobing rate that corresponds with the frequency of the vibration. This can be done either by strobing the ambient illumination in the environment (e.g., if the operator is reading a reflective surface display), or by strobing the display itself (e.g., strobing the LED backlighting of an electronic display).
Augmenting Light Weighting Horizon in Automotive2014-28-00234/28/2014
Better ride and comfort, enhanced safety, reliability and durability, lower running cost as well as cost of ownership continue to be challenges for automotive OEMs. Higher fuel efficiency is considered as USP not only for lower running cost but also is hygiene factor from sustainability point of view. This has necessitated the need for Augmenting Light weighting horizon in automotive OEMs. Augmenting this leads to invention of innovative materials and processes for emerging cost competitive market. This paper focuses on technology efforts towards augmenting light weighting Horizon in Automotive. Light weighting concepts being explored by OEMs with the help of automotive component manufacturers from Powertrain - Engines & Transmission, Chassis and Suspension are discussed. The Innovative concepts and case studies covered include Hollow Crankshaft and Camshafts, PM gears, composite / bimetallic brake drum, steering knuckle & leaf spring, hollow Anti Roll Bar (ARB) & Front Axle Beams (FAB), high strength polymers for fuel tank etc.
Raghvendra, G, Shende, Deodatta, Pathak, Udayan
Vibroacoustic Method of IC Engine Diagnostics2014-01-02824/1/2014
The article provides the rationale for, and describes a new internal combustion engine (ICE) diagnosing method, which involves obtaining a signal within the audio frequency range and its examination together with engine performance through the use of algorithms of high resolution time-and-frequency analysis and techniques involving partial signal reconstruction in the phase space. Examples of how the method may be applied to reveal defects and faults of various units and systems are also described in the article. The paper shows that the method may also be used for other assemblies and units of cars (apart from engines) to analyze patterns for periodic wave structures.
Beresnev, Alex, Beresnev, Max
Rapid Design and Development of Noise Radiating Engine Components2014-01-16814/1/2014
This paper describes the rapid design and development of thin walled powertrain components which act as external cover for engine subsystem assemblies. Computer Aided Engineering plays a major role in reducing the overall product development lead time. An approach by using ‘Simulation Driven Design and Development’ helps the developers to bring the necessary confidence about the components' required functionality during the design stage itself. During the design stage, typical inputs available for the development of these components are the broad dimensions obtained from the packaging considerations. The designer is required to develop the concepts targeting least noise radiation from component surfaces due to various excitations. Based on cost considerations, the designer can even opt for plastic materials instead of steel. The current paper considers two major noise radiation members namely valve cover and timing gear cover for rapid product development. A conventional modal analysis followed by harmonic response studies provides the basis for the iterations towards designing these members. The modal analysis, harmonic response studies and noise radiation efficiency calculations are performed by using a commercial FEA program. It is observed that the suggested Simulation Driven Design and Development approach has reduced the development time from 2 months to 3 weeks for the design finalization.
Shanmugam, Manivasagam, Kharatmal, Raghavendra, Satpute, Shirish
SAE 17.6 Cubic Inch Spark Plug Rating EngineJ2203_201402 (Historical)2/26/2014
This SAE Standard defines the standard engine to be used in determining spark plug preignition ratings. The engine is known as the SAE 17.6 Cubic Inch Spark Plug Rating Engine.
Ignition Standards Committee
Upgrading a 2V 1Litre / Cylinder Diesel Engine for Euro 5 Compliance2013-01-277811/27/2013
An older generation 2V 6 cylinder diesel engine operating with max specific power of 20kW/l and 11.0MPa peak firing pressure was upgraded for higher peak firing pressure capability, higher specific power output and adaptation of a common rail fuel injection system. Key basic dimensions of the major components were retained to enable continued usage of existing fixed transfer line machining facility. The 2V /cyl configuration was retained. Thermodynamic simulations, Finite Element analysis of head, block gasket structure, connecting rod and main bearing walls were carried out. Analysis of the crankshaft torsional vibration system and bearings were performed. The bolting system and tightening methods were reviewed and modified. Theoretical calculations on coolant flow and lub oil flow requirements were done. Physical experiments were done to study the gasket sealing behavior, bore distortion. A common rail system from Bosch was adapted and a Selective Catalytic Reduction method was adopted for reduction of NOx emissions. Performance and emission development was done with a 2V inclined injector with various TC, nozzle combination using a 1600bar common rail system. The engine was upgraded to 29kW/lt specific power operating at 14.0MPa. The result of the development proved it is feasible to meet Euro 5 emission norms with a 2V configuration and with incremental changes the life of an older platform Euro 2 engine was extended upto Euro 5.
Mahesh, P., Umashankar, N.
Design and Development of Cylinder Block for High Power Density Diesel Engine using CAE/CFD Tools for a Tractor Engine with Integrated Approach2013-01-275311/27/2013
Engine Block, being the most vital component requires serving various functions all together. Design of block for higher power densities and BMEP levels, needs a complete change in the design strategy compared to the existing design approach. Also, balancing other factors like engine cooling efficiency, blow by targets, weight, and manufacturing cost becomes a huge challenge upfront in designing an engine block. Design of block is carried out within several design, assembly and manufacturing constraints such as to maintain a specific cylinder centre distance, Block NVH, Better cooling jacket, controlled bore deformation and incorporation of various accessories viz. CRDI System, Fuel Filter, Oil Filters, Fuel Injection System, steering pump, Air Compressor etc. This paper portrays the complete perspective and design methodology used during design process. Integration of classical methods, and FE analysis is presented. FE analysis is mainly carried out for understanding bore deformation, stress flow path and cylinder head gasket pressure distribution. CFD analysis helped in optimizing the cooling jackets for a better thermal efficiency. Tools like DFMEA, DFMA etc are used along with value engineering concepts to make an efficient and cost effective product development process. Simulation results are elaborated to show the effectiveness of an integrated approach used in this development program. The simulation tools have helped us in selecting the right parameters for the design and ensure the rightness at the first development.
Dharan R, Bharani, Goud, Raghu Ram, manoharan, Rajkamal, Dhiman, Vikas
Innovative Product and Project for Timing Chain Drive System with Increase in Transmission Efficiency2013-36-012210/7/2013
A proper way to innovate consists in identify some kind of customer dissatisfaction and within this observation the companies ought to develop products which will be acceptable by the market. Only in this way, companies will be able to stand out in front of their competitors and the innovative companies can create new needs and valuable knowledge. More and more, the automotive vehicle consumers tend to opt internal combustion engines which use chain drive in their timing system, since the chain drive system presents high durability, avoiding the usual maintenance common to the belt timing system. The necessity of developing parts which increase the efficiency and minimize the fuel consumption, noise and vibration in the timing chain drive system lead the study and comprehension of some physical phenomena. It is inherent to the chain drive system the fluctuation of the angular velocity between shafts, this feature is known as “polygonal action”. In the present work the fluctuation of the angular rotations between camshafts and crankshafts are treated by the geometry of the transmission. Initially, the chain drive is modeled as being a four bar linkage, following by a more complex way, which uses theory of instant center of zero velocity and acceleration to understand the role of each chain link and the chain guide profile. The chain guides have presented fundamental importance to increase the efficiency of the chain transmissions, consequently, a better understanding about its profile and others phenomena such wear and manufacture process allowed the developing an innovative chain guide which is adaptable and can find market demand.
Chagas, Clodoaldo Borges, Freitas, Thiago Caetano, Falleiros, Murilo Fregonesi, Silva, André Fernandes, Gonçalves, Gustavo José Corrêa
Piston Cleanliness via Fuel Additive Technology2013-24-01019/8/2013
This work compared the piston deposit ratings in an engine when it was run on gasoline with a high concentration of deposit control additive (DCA) versus gasoline with a low concentration of additive. The additives came from different sources and contained detergents with different functional groups. The engine was a Ford V-8 PFI engine, which is used in ASTM D6593, the Sequence VG test. The experimental procedure followed the ASTM protocol, except for the fuel, which was treated with additives. Deposit ratings were better, at 95% confidence, in the tests using a high concentration of additive versus the tests using a low concentration.
Mengwasser, John H., Macias, James, Nelson, Edward
Development of New V6 3.5L Gasoline Engine for ACURA RLX2013-01-17284/8/2013
Honda has developed a new next-generation 3.5 L V6 gasoline engine using our latest Earth Dreams Technology. The overall design objective for the engine was to reduce CO₂ emissions and provide driving exhilaration. The Earth Dreams Technology concept is to increase fuel economy while reducing emissions. To achieve this and provide an exhilarating driving experience, 3-stage Variable Valve Timing and Lift Electronic Control (VTEC) was combined with the Variable Cylinder Management (VCM) system. This valve train technology in conjunction with Direct Injection (DI), resulted in dramatic improvements in output (a 3.3% increase) and combined mode fuel economy (20% reduction). Helping to achieve Midsize Luxury Sedan level NV, a new mount system was developed to reduce engine vibrations during three-cylinder-mode operation. In this paper, we will explain the 3-stage VTEC with VCM + DI system, friction reducing technology, and the structure and benefit of the new engine mount system.
Suzuki, Nobuo, Hayashi, Yasutaka, Odell, Marc, Esaki, Tatsuhito, Sato, Atsushi, Ishiki, Kazuya, Watanabe, Satoshi
Premature Flame Initiation in a Turbocharged DISI Engine - Numerical and Experimental Investigations2013-01-02524/8/2013
This paper presents the results of experimental and numerical investigations on pre-ignition in a series-production turbocharged DISI engine. Previous studies led to the conclusion that pre-ignition can be triggered by auto-ignition of oil droplets generated in the combustion chamber. Analysis of more recent experiments shows that a modification of the engine operation parameters that promotes spray/lubricant interaction also increases pre-ignition frequency, while modifications that enhance the speed of chemical reactions (thereby favoring auto-ignition) have little or no influence. The experimental and numerical findings can be explained if we assume the existence of a substance (originating from lubricant/fuel interaction) that displays extremely short ignition delay times.
Palaveev, Stefan, Magar, Max, Kubach, Heiko, Schiessl, Robert, Spicher, Ulrich, Maas, Ulrich
On the Design of High Power Low Frequency Harvesters for Car Engine2013-01-10424/8/2013
Vibration energy harvesters are considered as green and sustainable power supply for wireless sensor networks (WSN) used in different vehicle applications. Kinetic energy from ambient vibration is typically converted into electrical energy using electromagnetic, piezoelectric or electrostatic transducers. In comparison with other harvesters, electromagnetic transducers enable design of high power (few mill watts) low frequency (tens of Hz) harvesters. Electromagnetic harvesters can be considered as a power source for wireless sensor networks used for vehicle electronic devices. This paper demonstrates theoretically and experimentally the design procedures of electromagnetic harvesters of mechanical vibrations emitted from car engine. The research in this paper is concerned with the modeling, designing, and testing of the vibration energy electromagnetic harvesters that should be mounted on car engine. A prototype of electromagnetic energy harvester based is developed and its application in harvesting of car engines vibration is validated using a 4-cylinder in-line reciprocating engine model. The electromagnetic harvester used in this study is a single degree of freedom spring-mass system consisting of elastic cantilever with three magnets at its free tip. The analysis and investigation demonstrate that car engine harvester must be tuned to 2nd order engine speed to harvest power at either 1st or 2nd order engine speeds which allow the continuous power generation during city and highway driving.
Sherif, Hany, Eltaib, Mohamed, Alsuwaiyan, Abdullah
Dynamic Characteristic Calibration of a Hydraulic Lash Adjuster Model Using Unit Excitation Test2013-01-17314/8/2013
In order to simulate the valve behavior of an engine that uses a hydraulic lash adjuster (HLA), it is necessary to accurately reproduce the dynamic characteristics of the HLA in the model. Formerly, the model used values from drawings and values based on past experiences, and did not reflect actual driving conditions such as oil properties, leaked oil quantity, or oil aeration rate. We therefore developed a technique to reproduce HLA unit dynamic characteristics in a high-accuracy simulation. This representation was made possible using a unit excitation test to quantify the HLA unit dynamic characteristics in four categories: HLA stiffness, load response delay of the plunger, sinking displacement after relaxation, and lissajous curve of load vs. displacement. The effectiveness of this model calibration technique was confirmed through comparison of unit dynamic characteristics in a unit excitation test and a calibrated simulation.
Sano, Yuki, Yanagisawa, Nagao, Sakaguchi, Motoyasu, Yoshii, Kenta
Improvement of Comfort Aspects for High Efficiency Diesel Engines2013-26-01191/9/2013
Besides an excellent driving performance and power output the reduction of CO2 emission is one of the main driver for the increasing distribution of modern diesel engines. Downsizing/downspeeding, friction reduction, new combustion processes and light weight engine architecture describe additional improvement potentials. Nevertheless, these development trends have a significant influence on the noise and vibration behavior of diesel engines. Therefore measures are also necessary to compensate these acoustic disadvantages. Within this publication the most important and efficient countermeasures are described and assessed. Combustion is still one of the dominant noise sources of a modern diesel engine. Diesel knocking is annoying and the combustion noise level is typically higher than for gasoline engines. In the midterm, cylinder pressure based control of pilot combustion and injection characteristic will become a promising approach as an extension of conventional, already established closed-loop combustion control algorithms to improve this situation. First investigations at FEV have demonstrated that a closed-loop control of the rate of heat release through multiple injections is able to reduce both, emissions and combustion noise. However, further measures are necessary to improve the overall NVH behavior of diesel engines. An optimized base engine architecture is essential in this context. On one hand, conceptual measures have to be introduced; on the other hand, a detailed layout of each component is necessary.
Steffens, Christoph, Korfer, Thomas, Hanses, Georg, Rosplesch, Adrian, Kremer, Florian, Schaub, Joschka
Analysis of the Friction Losses in an Internal Combustion Engine2012-36-030310/2/2012
This work presents the results of the study of the forces involved in the rubbing friction between the moving parts of the Otto cycle internal combustion engine. In order to study the friction force, a Honda GX 35 engine was modified and a load cell was attached to its chassis. The friction forces among the internal parts of the engine were transferred to the engine chassis, and, by means of a support, to the load cell. Those forces were measured in several situations of the engine, making possible to identify the amount of friction related to each component. The total measured friction power was equal to 112W, representing about 10% of the developed power of the engine. The results obtained by the tests showed the contribution of each individual part of the engine on the friction losses. By the results, it was possible to propose modifications to reduce the total internal friction of the engine, in order to increase its efficiency. After the measurements of the friction force related to different components of the engine, new measurements were carried out in order to analyze the influence of the geometry of the pistons on the friction. During the tests, they were employed pistons with different geometries in relation to the original one. When a modified piston was employed, a reduction of up to 24% could be obtained on the values of friction when compared to those ones produced by original crankshaft - rod - piston assembly. Most of the friction energy is dissipated as heat through the coolant and lubricant. This heat is removed from the system by the water and oil radiators, so the friction losses also have great influence in the cooling system design.
Da Silveira, Marilia Amaral, Gertz, Luiz Carlos, Cervieri, Andre, Rodrigues, Antonio Flavio Aires, Senger, Marcio
Development of a Low Friction Chain Drive System for Gasoline Engines2012-01-17529/10/2012
With fuel costs continuing to rise, and with regulations seeking to lower overall fuel emissions, improved fuel economy has become indispensible for today's gasoline engine designer. Reducing engine friction is an effective means of improving fuel economy and specific engine components have been developed towards this objective. Chain drive system components are no exception to this trend. In an attempt to decrease friction loss in the timing chain system and thereby improving fuel economy, the following three topics were studied: 1) defining sources of friction loss; 2) investigating the effect(s) of each loss factor using friction simulation; and, 3) evaluating methods to minimize friction losses. Chain system friction loss can occur when the chain slides on the Arm & Guide face. Friction loss can also occur between the chain link and pin joint, and during chain engagement with the sprocket. The low friction chain drive system under development is designed for future 2.4L 4-cylinder gasoline engine production.
Baek, Hong-Kil, Kang, HoYoung
Improvements in Fuel Efficiency through Improvements in Cord Reinforcements for Timing Belts2012-01-17509/10/2012
The overhead camshaft engine efficiency can be improved by control of the rotation and phase of the cam shaft rotation. The aim of this paper is to show the improvements that have been made to the cam shaft rotation through the improvements in the timing belt, and in particular the reinforcing cords within the timing belt. The current state of the art of timing belt reinforcement is presented, and an independent study of the fuel efficiency of a modern timing belt compared to the efficiency of a fully optimised gasoline engine with a timing chain. This considers the power losses due to friction as the timing belt (or chain) transmits power from crank to cam, the power losses expressed as vibrations and noise, the variations in speed of cam rotation for different designs of timing belt, and also consistency of cam rotation through the life of the timing belt (or chain). The improvements have been quantified from engine studies of engine efficiency, engine dynamics, engine friction measurements, accelerometer studies for NVH behaviour and from these the benefits in fuel economy and CO2 emissions were quantified. Novel systems that use a timing belt running within the engine immersed in oil are discussed. These have been adopted on two engines to date, with significant interest and development projects under way. Of concern to the motorist are not only fuel efficiency but also the cost and frequency of changing a timing belt. The historical mechanisms will be discussed of the changes in timing belts that control the belt durability. The improvements in reinforcing cord design and performance that contribute to life-of-engine belts will be presented, together with cord and belt developments that increase the durability and reliability of the timing belt even further.
Stevens, Chris A., Hayes, Craig H.
Automotive Synchronous Belt DrivesJ1313_201208 (Current)8/14/2012
The following information applies to automotive camshaft drives, distributor drives, or other underhood drives that may require synchronization. For other power transmission drives requiring synchronization, refer to Specifications for Drives using Synchronous Belts (MXL, XL, L, H, XH and XXH belt sections) (IP 24/1978), published jointly by the Rubber Manufacturers Association (RMA), the Mechanical Power Transmission Association (MPTA), and the Rubber Association of Canada (RAC).
Belt Drive (Automotive) Systems Committee
SI (Metric) Synchronous Belts and PulleysJ1278_201207 (Current)7/5/2012
Synchronous belt drives consist of a toothed belt which mates with grooved pulleys to provide a precise speed ratio between the driver and driven pulleys. This SAE Standard covers the synchronous belt and pulley sections currently in use in automotive applications such as camshaft, distributor, and other underhood drives that may require synchronization. It also provides for future sections to be added as usage develops.
Belt Drive (Automotive) Systems Committee
Development of a Hydraulic Variable Valve Timing Control System with an Optimum Angular Position Locking Mechanism2012-01-04164/16/2012
This paper describes a newly developed hydraulic variable valve timing control (VTC) system, targeting the internal combustion gasoline engine, with an optimum angular position locking mechanism to reduce tailpipe emissions (TPE). In general, emission control catalysts are used as one measure to reduce TPE. However, there is the issue that catalysts cannot remove pollutants before reaching its light-off temperature at cold engine start. To address this issue, we have been using a method of increasing the valve overlap period between intake valve opening (IVO) and exhaust valve closing (EVC) by operating a VTC system at engine start. This brings engine-out emissions (EOE) back to the combustion chamber to be burned, thereby reducing EOE levels. However, this method requires about 3 seconds for the sufficient hydraulic pressure to start VTC operations. Additionally, the air-to-fuel ratio at engine start is calibrated to a rich condition to maintain combustion stability, which also increases EOE. The amount of EOE at this time accounts for a substantial portion of the total emissions in an emission test. Therefore, we have developed a new VTC system that adds a function for locking the initial phase at an optimum angular position within the control range before the engine starts. This paper explains the operating principle of the new VTC system with an optimum angular position locking mechanism and the EOE reduction obtained by increasing valve overlap and other resultant effects.
Miura, Takahiro, Aoyama, Shunichi, Onogawa, Kaoru, Fujia, Takaya, Murata, Tetsuro, Ariga, Kenji, shiozawa, Ken, Adachi, Kazunari, Kobayashi, Masaki
Study on Reduction of Timing Chain Friction Using Multi-Body Dynamics2012-01-04124/16/2012
A method for reducing friction loss in the engine timing chain was investigated using multi-body dynamics simulation. The method known as the link-by-link model was employed in the simulation to enable representation of the behavior of each single link of the chain and its friction due to contact. In order to predict the friction under actual engine operating conditions, a model that takes camshaft torque fluctuation and crankshaft rotational speed fluctuation into account was created. This simulation was used to verify the detailed distribution of friction in each part of the chain system as well as the changes of friction in the time domain. As a result, it was found that the sliding friction in the chain tensioner guide and chain guide was larger than in other locations. Based on this result, a method of reducing friction entirely by measures in mechanisms and structures without relying on low-friction materials was investigated. Simulation was used to verify the predicted effects of these measures, with the result that reducing the moment of inertia of the camshaft and reducing the initial load on the chain tensioner were confirmed to reduce friction loss.
Sakaguchi, Motoyasu, Yamada, Shinji, Seki, Masao, Koiwa, Yojiro, Yamauchi, Takahiro, Wakabayashi, Tomohiro
Modeling and Analysis of Powertrain NVH2012-01-08884/16/2012
Current modeling techniques of the powertrain noise, vibration and harshness (NVH) involve fully meshed structural components and rely, in general, on predefined excitation loads to evaluate linear transfer or structural attenuation functions. While effective for comparative assessment of various designs, these methods neglect the complex dynamic interactions between the powertrain structure and crankshaft, piston, valve train, timing drive, and accessory drive systems. This paper presents an overview of modeling methods of low and high frequency powertrain NVH with focus on dynamic interaction among structural components. A coupled and fully flexible multi-body dynamics model using AVL/Excite is presented. The model includes the cranktrain, crankcase, cylinder head, covers, oil pan, mounts, and transmission housing represented as finite element meshes. The main bearings are represented using elasto-hydrodynamic joints to account for the effect of oil film stiffness and damping as well as bearing clearance. The structural components are reduced using component mode synthesis and used to determine dynamic loads at various engine speeds and loading conditions. The main excitation sources relevant for both low and high frequency NVH and the influence of cylinder pressure, bottom end design, and crankshaft stiffness are discussed. An overview of piston related noise and modeling techniques to identify the causes and mechanisms leading to excessive impact noise in a floating piston pin design are presented.
Beloiu, Dumitru M.
A Method to Calculate the Natural Frequency of the Timing Belt Drive2011-28-014010/6/2011
A method to calculate the Natural frequency of the Timing belt drive is developed and validated. Timing belt drives are widely used in the automotive engines for valve actuation drives where accurate motion and force transmission is utmost necessary. Natural frequency is an important parameter to understand the vibration behavior of a system. Previous studies have found the Natural frequency and frequency response of the timing belt with experimental method and with FEA/ MBD software. In this study attempt has been made to develop a tool which will require basic material properties to calculate the natural frequency. Complete timing belt drive system is divided into set of standard components/elements. The belt tooth is divided in four layers and stiffness calculation is based on apparent modulus of elasticity derived from form factor. For belt pulley tooth analogy with cantilever beam is used. The model can be used for trapezoidal shaped timing belt as well as for other forms of the tooth. The belt drive level mathematical model is developed by calculating the equivalent system properties from the individual element properties. In order to reduce computational efforts a MATLAB based tool is developed. The validation is done by comparing the mathematical model with the experimental data. The predicted value from the mathematical model and experimental values are in close agreement.
Kulkarni, Chaitanya, Aher, V. S.
System Automated for the Lifting Curves Camshaft2011-36-007310/4/2011
In internal combustion engines, gas exchange in the combustion chamber through the intake and exhaust are directly related to engine efficiency. The mechanical element responsible for handling and synchronization of the valves during cycles of intake, compression, combustion and exhaust, in Otto cycle engines and diesel cycle is the camshaft. Soon to know the characteristics of lift, duration, crossing, and the characteristics of velocity and acceleration of the valve assembly is very important to assess the performance of internal combustion engines. However, the engine manufacturers do not provide such features accurately, in order to avoid being easily modified or acquired by other manufacturers. And subtle changes between camshafts fitted the same engine family may promote different torque characteristics and power consumption as well as without, however, characterize a new engine. So that the lifting of curves camshafts is currently done manually, through a process and time-consuming labors, which, besides being inefficient and is prone to failure. The camshaft is positioned to be measured between two points, and this is mounted an encoder scale. A linear sensor is mounted on the lobe of the command to be lifted and the reading is taken linear displacement associated with the reading of the angular spin of the command, in order to get an admission to the curve and a curve for the leakage. Therefore generating an automated madder and fast curves of camshafts in the study, with appropriate precision.
Pereira, Thiago Antonio, Fontana, Filipe, Vandresen, Marcelo, Cardoso, Pedro Oliveira, Pereira, Milton, Campos, Bruno Abdias
Development of a Timing Chain Drive Model for a High Speed Gasoline Engine2011-01-04014/12/2011
Engine efficiency and optimization are key aspects for automotive manufacturers. Lamborghini has particularly focus attention for reduction of time to market building up a synergic approach for new component's development using simulation, Know-how experiences, engine engineering expertise and experimental validation. In particular to reach the best results in the shortest time it is used, in the preliminary stage of development, a massive support of simulation analysis. In the Lamborghini approach analysis and simulation has become key aspects during concept and development of timing drives. This type of activity is used to support the development of better chain timing drives focusing on improving durability, lower friction, less noise and reduced cost in less time than conventional trial and processes. Even during the concept design phase it is useful to use a mathematical model to calculate dynamic forces and motions of a chain drive. These models are used to assess in detail the choice of drive layout, to check that component load limits are not exceeded and to make a first choice of the tensioner settings. Later, when the first prototype engines are available, measurements of timing drive sprocket motion, tensioner motion and tensioner force are typically taken. At this stage the model can be correlated to the measured data and then the correlated model can then be used to explore the potential for improvements to the timing drive during later phases of engine development. This paper describes the correlation of a mathematical model of a complex timing chain drive for a Lamborghini V12 gasoline engine to measurements made on a prototype engine. The depth of model required and the choice of stiffness and damping values needed to give excellent agreement between calculations and measured data are discussed.
Calabretta, Michele, Cacciatore, Diego, Carden, Phil, Plail, Jonathan
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