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Technical Paper

Development of Programmed-Fuel Injection for Two-Stroke Cycle Racer Engine

1991-11-01
911224
An electronically controlled fuel injection system for controlling the air/fuel (A/F) ratio has been looked forward as a means for improving drivability, output characteristics, and fuel consumption of two-stroke cycle motorcycle racer engines. However, actual installation of such a system on a high output two-stroke cycle engine (which utilizes exhaust gas pressure pulsation effects) has been considered difficult for the following reasons. Fluctuation in the delivery ratio (L) during firing and misfiring becomes great due to effects from the exhaust pipe. Applying the control method used for conventional four-stroke cycle engines (by which the delivery ratio (L) is measured) would necessitate a large and heavy system. The authors have eliminated such problems by developing an electronically controlled fuel injection system, the PGM-FI (Programmed-Fuel Injection) system, which employs basic intake air flow data according to engine speed (NE) and throttle opening (θTH).
Technical Paper

Improvement of Fuel Economy in a Four Stroke Spark Ignition Engine for a Small Motorcycle

1985-11-11
852238
For the purpose of reducing the fuel consumption of a motorcycle with a small-displacement, four-stroke spark-ignition engine, a compact combustion chamber was tried and the weight of the moving parts of the engine was reduced. As a result, the gas mileage under 30 km/h cruising condition was increased to 110 km/l with an improvement of 50% over a conventional motorcycle.
Technical Paper

Management System for Continuously Variable Valve Lift Gasoline Engine

2007-04-16
2007-01-1200
A continuously variable valve lift gasoline engine can improve fuel consumption by reducing pumping loss and increase maximum torque by optimizing valve lift and cam phase according to engine speed. In this research, a new control system to simultaneously ensure good driveability and low emissions was developed for this low fuel consumption, high power engine. New suction air management through a master-slave control made it possible to achieve low fuel consumption and good driveability. To regulate the idle speed, a new controller featuring a two-degree-of-freedom sliding-mode algorithm with cooperative control was designed. This controller can improve the stability of idle speed and achieve the idle operation with a lower engine speed. To reduce emissions during cold start condition, an ignition timing control was developed that combine I-P control with a sliding mode control algorithm.
Technical Paper

Effects of Fuel Volatility on Combustion Characteristics of PCCI Diesel Engine

2007-07-23
2007-01-1862
In PCCI diesel engine, the fuel is injected much earlier than the injection timing of conventional diesel engines. Exhaust-emission improvements are attained by the lean-premixed combustion. It is expected that fuel properties influence mixture formation and combustion characteristics. In this research, experiments were carried out using a single-cylinder PCCI diesel engine operating on pure fuels with different volatilities. The injection timing and overall equivalence ratio of the premixed spray were varied. The results showed that the maximum heat release rate was smaller for lower-volatility fuel while ISFC was maintained smaller. So the combustion of a lower-volatility fuel would moderately make progress.
Technical Paper

Development Project of a Multi-cylinder DISI Hydrogen ICE System for Heavy Duty Vehicles

2010-10-25
2010-01-2175
The planned development of a hydrogen ICE system for trucks is one of the technological candidates for air pollution reduction and global warming prevention for the large-sized (heavy-duty) trucks supporting Japanese freightage. This project is the first to develop a DISI multi-cylinder hydrogen ICE system aimed at combining high power output and low NOx generation.
Technical Paper

A Study of High Power Output Diesel Engine with Low Peak Cylinder Pressure

2010-04-12
2010-01-1107
This study examined a high-speed, high-powered diesel engine featuring a pent-roof combustion chamber and straight ports, with the objective of improving the specific power of the engine while minimizing any increase in the maximum cylinder pressure (Pmax). The market and contemporary society expect improvements in the driving performance of diesel-powered automobiles, and increased specific power so that engine displacement can be reduced, which will lessen CO2 emissions. When specific power is increased through conventional methods accompanied with a considerable increase in Pmax, the engine weight is increased and friction worsens. Therefore, the authors examined new technologies that would allow to minimize any increase in Pmax by raising the rated speed from the 4000 rpm of the baseline engine to 5000 rpm, while maintaining the BMEP of the baseline engine.
Journal Article

Analysis of Oil Film Generation on the Main Journal Bearing Using a Thin-Film Sensor and Elasto-Hydrodynamic Lubrication (EHL) Model

2013-04-08
2013-01-1217
Reducing friction in the crankshaft main bearings is an effective means of improving the fuel efficiency of reciprocating internal combustion engines. To realize these improvements, it is necessary to understand the lubricating conditions, in particular the oil film pressure distributions between crankshaft and bearings. In this study, we developed a thin-film pressure sensor and applied it to the measurement of engine main bearing oil film pressure in a 4-cylinder, 2.5 L gasoline engine. This thin-film sensor is applied directly to the bearing surface by sputtering, allowing for measurement of oil film pressure without changing the shape and rigidity of the bearing. Moreover, the sensor material and shape were optimized to minimize influence from strain and temperature on the oil film pressure measurement. Measurements were performed at the No. 2 and 5 main bearings.
Technical Paper

Study of NOx Emissions Reduction Strategy for a Naturally Aspirated 4-Cylinder Direct Injection Hydrogen ICE

2010-10-25
2010-01-2163
Hydrogen engines are required to provide high thermal efficiency and low nitrogen oxide (NOX) emissions. There are many possible combinations of injection timing, ignition timing, lambda and EGR rate that can be used in a direct-injection system for achieving such performance. In this study, NOX emissions of natural aspirated 4 cylinders engine with management strategies involving the injection timing, ignition timing, lambda and the EGR rate were evaluated under a Japanese JE05 emissions test cycle. Finally, the paper projects the potential of direct injection hydrogen engine for obtaining high output power and attaining low NOX emissions of 0.7 g/kWh under the emission test cycle.
Technical Paper

A Study on the Feature of Several Types of Floating Liner Devices for Piston Friction Measurement

2019-04-02
2019-01-0177
The friction reduction of a piston/piston-ring assembly is effective for fuel economy of an engine, and a friction measurement method is required for developing low friction pistons, piston-rings and lubricants. Most suitable method for friction measurement for piston assemblies is “floating liner method”. It has load sensors between a floating cylinder liner and cylinder block, and the sensors can detect friction force acting on the liner. Many apparatuses using floating liner method are developed. They are roughly divided to two categories. In one of them, floating liner is supported by load-washers which axis is set parallel to the center line of the cylinder liner. In another type, floating liner is supported by three-component force sensors installed on the side face of the cylinder. In this paper, five types of floating liner devices were compared.
Technical Paper

Prediction of Piston Skirt Scuffing via 3D Piston Motion Simulation

2016-04-05
2016-01-1044
This paper describes the establishment of a new method for predicting piston skirt scuffing in the internal combustion engine of a passenger car. The authors previously constructed and reported a method that uses 3D piston motion simulation to predict piston slap noise and piston skirt friction. However, that simulation did not have a clear index for evaluation of scuffing that involves piston skirt erosion, and it impressed shortage of the predictive accuracy of a scuffing. Therefore, the authors derived a new evaluation index for piston skirt scuffing by actually operating an internal combustion engine using multiple types of pistons to reproduce the conditions under which scuffing occurs, and comparing with the results of calculating the same conditions by piston motion simulation.
Technical Paper

Influence of Shock Absorber Friction on Vehicle Ride-Comfort Studied by Numerical Simulation Using Classical Single Wheel Model

2018-04-03
2018-01-0692
Along with the suspension improvement in these two decades, it is well known that the suspension friction force became one of major parameters to affect ride comfort performance. However, it was difficult to carry out quantitative prediction on ride comfort improvement against friction force change with high correlation. It was difficult to analyze correlation between actual vehicle performance and simulation since there were difficulties in controlling damping force and friction individually. On the other hand, magneto-rheological shock absorber (MR Shock) has had several applications and widely spread to passenger vehicles. The large variation and high response of damping force especially in slow piston speed region contributes to achieve an excellent vehicle dynamics performance. However, MR Shock shows the high friction characteristics, due to the unique sliding regime of internal parts. It is said that this high friction characteristic is causing obstacles in ride-comfort.
Technical Paper

Quantitative Analysis of Leakage Suppression of DLC Coating on Piston Ring

2017-03-28
2017-01-0457
Piston ring wear in gasoline engine induces deterioration of emissions performance due to leakage of blow-by gas, instability of idling caused by reduced compression in combustion chamber, and to generate early degeneration of engine oil. We examined anti-wear performance of DLC coating on piston ring, which had been recently reported as an effective method for improving the abrasion resistance. As a result, wear rate remained low under the condition of DLC existence on sliding surface, but once DLC was worn out completely, wear of the piston ring was accelerated and its life became shorter than piston ring without DLC. In this research, we designed reciprocating test apparatus that operates at much higher velocity range, and characterized the frictional materials of the piston ring and sleeve and the DLC as a protective film, a vapor phase epitaxy (VPE) was actively used as a means to form certain level of convex and concave shape on its surface.
Technical Paper

Non-Destructive Measurement of Residual Strain in Connecting Rods Using Neutrons

2018-04-03
2018-01-1063
Increasing the strength of materials is effective in reducing weight and boosting structural part performance, but there are cases in where the residual strain generated during the process of manufacturing of high-strength materials results in a decline of durability. It is therefore important to understand how the residual strain in a manufactured component changes due to processing conditions. In the case of a connecting rod, because the strain load on the connecting rod rib sections is high, it is necessary to clearly understand the distribution of strain in the ribs. However, because residual strain is generally measured by using X-ray diffractometers or strain gauges, measurements are limited to the surface layer of the parts. Neutron beams, however, have a higher penetration depth than X-rays, allowing for strain measurement in the bulk material.
Technical Paper

Simple Prediction for Fuel Consumption and Cruising Distance of Internal Combustion Engine Vehicles with RFD Method

2019-04-02
2019-01-0893
In order to develop various parts and components of vehicles, understanding the effects of their structures and thermal performance on the fuel consumption and cruising distance is important. However, because of the limited information available to parts suppliers, it is not always easy to predict and study vehicle fuel efficiency and cruising range performance under arbitrary driving conditions. In this study, the authors have developed an RFD (Regression Fuel-consumption Diagram) method to predict the cruising performance of internal-combustion engine vehicles (ICEV) based only on the published information given to suppliers by using standard reference vehicles, which had been regressed and identified for control characteristics and fuel consumption diagrams. As an example of the application of the RFD method to realistic situation, the effects of the driving mode and air-conditioning on the fuel consumption of ICEV are studied.
Technical Paper

Designing for Turbine Housing Weight Reduction Using Thermal Fatigue Crack Propagation Prediction Technology

2019-04-02
2019-01-0533
Turbine housings in car engine turbochargers, which use costly stainless steel castings, account for nearly 50% of the parts cost of a turbocharger. They are also the component which controls the competitiveness of the turbocharger, in terms of both function and cost. In this research, focusing on thermal fatigue resistance which is one of the main functions demanded of a turbine housing, achieving reduction in wall thickness while securing sufficient thermal fatigue resistance, it is possible to reduce the amount of material used in the turbine housing and aimed for cost reduction. Therefore, we built a method to quantitatively predict, using 3D FEM, the lifespan from the initiation of thermal fatigue cracking to the formation of a penetrating crack which leads to gas leakage.
Technical Paper

Analysis of the Pressure Drop Increase Mechanism by Ash Accumulated of Coated GPF

2019-04-02
2019-01-0981
With accelerating exhaust gas regulations in recent years, not only CO / HC / NOx but also PN regulation represented by Euro 6 d, China 6 are getting stricter. PN reduction by engine combustion technology development also progresses, but considering RDE, PN reduction by after treatment technology is also indispensable. To reduce PN exhausted from the gasoline engine, it is effective to equip GPF with a filter structure. Considering the installation of GPF in limited space, we developed a system that so far replaces the second TWC with GPF for the TWC 2 bed system. In order to replace the second TWC with GPF, we chose the coated GPF with filtering and TWC functions. Since the initial pressure drop and the catalyst amount (purification performance) of coated GPF have a conflicting relationship, we developed the coated GPF that can achieve both the low initial pressure drop and high purification performance.
Journal Article

Ag-Type PM Oxidation Catalyst with Nd Added to Increase Contact Property between PM and Catalyst

2018-04-03
2018-01-0328
Honda diesel engine vehicles that go on the market in 2018 will be equipped with a newly developed silver (Ag)-type catalyzed diesel particulate filter (cDPF). Ag has high particulate matter (PM) oxidation performance, but conventional catalyst-carrying methods cause weak contact property between PM and Ag; therefore, the newly Ag-type cDPF was developed on the concept of enhancing the property of contact between PM and the catalyst to realize contact property enhancement at the macro, meso, and nano scales. As a result, the newly developed catalyst showed an enhancement of T90 performance by a factor of approximately 2 relative to the conventional Ag-type catalyst in fresh condition. Durability in the environment of an automobile in use was examined through hydrothermal aging, lean-rich (L/R) aging, sulfur (S) poisoning, and ash deposition. The results have confirmed that hydrothermal aging is the greatest factor in deterioration.
Technical Paper

Application of Image Converter Camera to Measure Flame Propagation in S.I. Engine

1989-02-01
890322
A combustion flame visualization system, for use as an engine diagnostics tool, was developed in order to evaluate combustion chamber shapes in the development stage of mass-produced spark ignition (S.I.) engines. The system consists of an image converter camera and a computer-aided image processing system. The system is capable of high speed photography (10,000 fps) at low intensity light (1,000 cd/m2), and of real-time display of the raw images of combustion flames. By using this system, flame structure estimated from the brightness level on a photograph and direction of flame propagation in a mass-produced 4-valve engine were measured. It was observed that the difference in the structure and the propagation of the flame in the cases of 4-valve and quasi-2-valve combustion chambers, which had the same in the pressure diagram, were detected. The quasi-2-valve configuration was adopted in order to improve swirl intensity.
Technical Paper

The Properties of Hybrid Fiber Reinforced Metal and It's Application for Engine Block

1989-02-01
890557
The weight-saving requirements for automobiles are important. In order to produce a lighter engine, an aluminum block with cast-iron liners and a hypereutectic aluminum-silicon alloy block have been developed. (1)*, (2), (3), (4), (5), (6) We developed a new aluminum engine block which has the cylinder bore surface structure reinforced with short ceramic fiber. We also established technology suitable for mass-production including a fiber preform process and a non-destructive inspection method. In this paper, the optimum properties and production technology of MMC engine blocks are introduced. A portion of the paper is dedicated to the results of a comparison study between a new light-weight aluminum engine block, a hypereutectic aluminum-silicon engine block and an aluminum engine block with cast-iron liners.
Technical Paper

Study on Engine Management System Using In-cylinder Pressure Sensor Integrated with Spark Plug

2004-03-08
2004-01-0519
There has been strong public demand for reduced hazardous exhaust gas emissions and improved fuel economy for automobile engines. In recent years, a number of innovative solutions that lead to a reduction in fuel consumption rate have been developed, including in-cylinder direct injection and lean burn combustion technologies, as well as an engine utilizing a large volume of exhaust gas recirculation (EGR). Furthermore, a homogeneous charge compression ignition (HCCI) engine is under development for actual application. However, one of the issues common to these technologies is less stable combustion, which causes difficulty in engine management. Additionally, it is now mandatory to provide an onboard diagnosis (OBD) system. This requires manufacturers to develop a technology that allows onboard monitoring and control of the combustion state. This paper reports on an innovative combustion diagnostic method using an in-cylinder pressure sensor.
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