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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

Liquid Phase Thermometry of Common Rail Diesel Sprays Impinging on a Heated Wall

2007-07-23
2007-01-1891
An experimental study was carried out on visualization of liquid phase temperature distributions in high-pressure diesel sprays impinging on a heated wall. Naphthalene/TMPD-exciplex fluorescence method and pyrene-excimer fluorescence method were utilized for the thermometry. The sprays were injected into a high-pressure and high-temperature gaseous environment. The nozzle hole diameter was 0.100 mm or 0.139 mm. The results showed that cool pockets were formed at the tip and in the impinging part of the sprays. The spray for the nozzle with 0.100 mm hole was heated up faster near the nozzle than for the nozzle with 0.139 mm hole.
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 Procedure for Interior Noise Performance by Virtual Vehicle Refinement, Combining Experimental and Numerical Component Models

2001-04-30
2001-01-1538
This paper summarizes the development of a predictive vibro-acoustic full vehicle model of a mid-size sedan and focuses on the engineering analysis procedures used to evaluate the design performance related to engine induced noise and vibration. The vehicle model is build up from a mixture of test-based and finite element component models. FRF Based Substructuring is used for their assembly. The virtual car model is loaded by engine forces resulting from indirect force identification. This force-set includes combustion, inertia, piston slap and crank bearing forces, for engine harmonics from 0.5 to 10th order. Such forced response analysis yields vibration levels at every component, at every interface between components, and interior noise predictions. The target is to provide the vehicle NVH manager with the insight required to identify major causes for peak noise levels and to set targets and develop an action plan for every component design team.
Technical Paper

Development of Hydraulic Servo Brake System for Cooperative Control with Regenerative Brake

2007-04-16
2007-01-0868
A new brake system, able to make efficient use of regenerative braking while maintaining excellent brake feel, has been developed to increase the fuel economy of hybrid vehicles. A hydraulic servo was used as a base to enable mechanical operation of the service brakes; solenoid valves and brake fluid pressure sensors were added to this base to make it possible to control brake line pressure as demanded. The use of a stroke simulator in the hydraulic servo prevents brake feel from being affected by the control of the brake pressure. In addition, high-accuracy brake pressure control that functions cooperatively with the regenerative brakes is enabled, resulting in stable braking effectiveness.
Technical Paper

Study on HCCI-SI Combustion Using Fuels Ethanol Containing

2007-10-29
2007-01-4051
Bio-ethanol is one of the candidates for automotive alternative fuels. For reduction of carbon dioxide emissions, it is important to investigate its optimum combustion procedure. This study has explored effect of ethanol fuels on HCCI-SI hybrid combustion using dual fuel injection (DFI). Steady and transient characteristics of the HCCI-SI hybrid combustion were evaluated using a single cylinder engine and a four-cylinder engine equipped with two port injectors and a direct injector. The experimental results indicated that DFI has the potential for optimizing ignition timing of HCCI combustion and for suppressing knock in SI combustion under fixed compression ratio. The HCCI-SI hybrid combustion using DFI achieved increasing efficiency compared to conventional SI combustion.
Technical Paper

Improvement of visibility for vulnerable parties in traffic accidents

2001-06-04
2001-06-0142
More than half of fatalities in traffic accidents in Japan are the vulnerable parties in such accidents (pedestrians, motorcycles, bicycles). In most of these accidents, the cause is collision involving automobiles. Therefore, reasoning that early detection of such vulnerable parties would lead to a reduction in accidents, we conducted research on the following three systems: - Honda Night Vision System - For night-time detection of pedestrians using infrared cameras. - Active Headlights - For assuring night-time field of vision by directing illumination in the direction of vehicle travel through lights coupled with steering wheel turn and so on. - Inter-Vehicle Motorcycle-Automobile Communication System (IVCS) - Notifies drivers of each other's presence by providing information through communications systems installed on both vehicles. The results from research on these systems show that their use can be expected to have a positive effect in reducing the occurrence of accidents.
Technical Paper

49 Development of Pb-free Free-Cutting Steel Enabling Omission of Normalizing for Crankshafts

2002-10-29
2002-32-1818
Crankshafts of motorcycles require high strength, high reliability and low manufacturing cost. Recently, a reduction of Pb content in the free-cutting steel, which is harmful substance, is required. In order to satisfy such requirements, we started the development of Pb-free free-cutting steel which simultaneously enabled the omission of the normalizing process. For the omission of normalizing process, we adjusted the content of Carbon, Manganese and Nitrogen of the steel. This developed steel can obtain adequate hardness and fine microstructure by air-cooling after forging. Pb-free free-cutting steel was developed based on Calcium-sulfur free-cutting steel. Pb free-cutting steel is excellent in cutting chips frangibility in lathe process. We thought that it was necessary that cutting chips frangibility of developed steel was equal to Pb free-cutting steel. It was found that cutting chips frangibility depend on a non-metallic inclusion's composition, shape and dispersion.
Technical Paper

Characteristics of Vaporizing Continuous Multi-Component Fuel Sprays in a Port Fuel Injection Gasoline Engine

2001-03-05
2001-01-1231
Vaporization models for continuous multi-component liquid sprays and liquid wall films are presented using a continuous thermodynamics formulation. The models were implemented in the KIVA3V-Release 2.0 code. The models are first applied to clarify the characteristics of vaporizing continuous multi-component liquid wall films and liquid drops, and then applied to numerically analyze a practical continuous multi-component fuel - gasoline behavior in a 4-valve port fuel injection (PFI) gasoline engine under warm conditions. Corresponding computations with single-component fuels are also performed and presented for comparison purposes. As compared to the results of its single-component counterpart, the vaporizing continuous multi-component fuel drop displays a larger vaporization rate initially and a smaller vaporization rate as it becomes more and more dominated by heavy species.
Technical Paper

Development of the Motor-Assist System for the Hybrid Automobile--The Insight Development of the Motor-Assist System for a Hybrid Car--Insight

2000-11-01
2000-01-C079
A motor-assist system has been developed and employed for the "Insight' hybrid car. The system consists of an internal combustion engine as the primary power source, with an electric motor placed around the engine's crankshaft. Such construction reduces the system's volume significantly and offers more flexibility for the power plant layout. The system's functions include regeneration during braking, an idle stop mechanism, driving power assistance, and power supply for the 12V electrical system. A proper energy management method for various driving modes has been established by combining these functions, and fuel economy is significantly improved as a result. As another control feature, an active motor vibration control system compensates the idling vibration that is unique to three-cylinder engines.
Technical Paper

Basic Understanding of Activated Radical Combustion and Its Two-Stroke Engine Application and Benefits

2000-06-19
2000-01-1836
For a better understanding of the auto-ignition phenomenon in internal combustion engines, consideration is given from the in-cylinder gas temperature aspect. Experimental results demonstrate that the in-cylinder gas temperature at the end of compression, namely, the “auto-ignition temperature” is deeply involved in the onset of auto-ignition. The relation between the gas exchange state and the auto-ignition temperature explains the mechanism of timing controlled auto-ignition, namely, Activated Radical (AR) Combustion. The auto-ignition temperature is maintained constant during the AR combustion state, thanks to the exhaust valve controlling the hot residual gas amount. Finally, the utilization of auto-ignition in gasoline engines is discussed from the methodology aspect.
Technical Paper

On-board Diagnostic Expert System via an Enhanced Fault Tree Model

2006-04-03
2006-01-1567
We propose to enhance reliability based diagnosis by enhancing the fault tree model with a sensor layer for capturing evidence. We recognized the need for an automated diagnostic process that can predict and report component failure in vehicles prior to total failure of any system in the vehicle. We also want to take advantage of evidence that can be derived from sensors to reduce the amount of tests required to identify failed components.
Technical Paper

Ignition and Combustion Simulation in HCCI Engines

2006-04-03
2006-01-1522
Combustion simulation is an effective tool in overcoming the issues associated with gasoline HCCI engines, controlling ignition timing and extending the operating range. The research discussed in this paper commenced by optimizing the reaction mechanism from the perspective of ignition delay using the genetic algorithm (GA) method. Simulations employing the optimized reaction mechanism were then able to more accurately reproduce the ignition timing of iso-octane and primary reference fuels (PRF). Ignition times obtained from simulations showed excellent correlation with ignition times measured using these fuels in shock tube experiments, and in engines with both homogeneous and non-homogeneous fuel distributions. The use of the PRF mechanism for gasoline with an equivalent octane number enables excellent reproduction of ignition timing even when EGR is employed.
Technical Paper

Research and Analysis of ISG Belt-drive System for Idling Stop System

2006-04-03
2006-01-1501
To enable a belt-driven Integrated Starter Generator (ISG) to be used in an idle-stop system, the belt system must be capable of both driving the accessories and of starting the engine. Conventional belt systems required a higher tension setting to accomplish this, and the associated increase in friction opposed the achievement of better fuel economy. In this research, an auto-tensioner with a contraction suppression function that utilizes the incompressibility of fluid as well as a belt system that enables the auto-tensioner to be optimally located were proposed. The behavior of the belt system was measured in detail by testing, and the cause of the fluctuation of the belt tension was clarified by analysis. A method of controlling the ISG torque to flatten out tension fluctuations was devised, and its effectiveness was confirmed by simulation and testing. From the overall results of the research, a belt system that does not require a high tension setting was realized.
Technical Paper

Development of Hybrid System for 2006 Compact Sedan

2006-04-03
2006-01-1503
An Integrated Motor Assist (IMA) system for the 2006 Civic Hybrid has been developed, with the goal of having class leading fuel economy among compact vehicles and enhanced driving performance. The IMA system has been enhanced for greater power and efficiency. Combining the 3-stage i-VTEC engine with a higher power, higher efficiency electric motor assist mechanism enables an increase in deceleration regeneration energy and a drive mode powered by the electric motor alone. The engine is a newly developed 3-stage i-VTEC, based on the 1.3L SOHC i-DSI engine. The new 3-stage i-VTEC engine incorporates both a VTEC mechanism that switches cam profiles in low and high engine speed ranges, and a cylinder deactivation mechanism. The CVT has both an expanded ratio range and a higher final gear ratio. Through these technological enhancements, we have achieved the highest levels of fuel economy in the compact class and enhanced acceleration performance.
Technical Paper

Investigations of Compatibility of ETBE Gasoline with Current Gasoline Vehicles

2006-10-16
2006-01-3381
Clarifying the impact of ETBE 8% blended fuel on current Japanese gasoline vehicles, under the Japan Clean Air Program II (JCAPII) we conducted exhaust emission tests, evaporative emission tests, durability tests on the exhaust after-treatment system, cold starting tests, and material immersion tests. ETBE 17% blended fuel was also investigated as a reference. The regulated exhaust emissions (CO, HC, and NOx) didn't increase with any increase of ETBE content in the fuel. In durability tests, no noticeable increase of exhaust emission after 40,000km was observed. In evaporative emissions tests, HSL (Hot Soak Loss) and DBL (Diurnal Breathing Loss) didn't increase. In cold starting tests, duration of cranking using ETBE 8% fuel was similar to that of ETBE 0%. In the material immersion tests, no influence of ETBE on these material properties was observed.
Technical Paper

R&D and Analysis of Energy Consumption Improvement Factor for Advanced Clean Energy HEVs

2005-10-24
2005-01-3828
Ultra-low energy consumption and ultra-low emission vehicle technologies have been developed by combining petroleum-alternative clean energy with a hybrid electric vehicle (HEV) system. Their component technologies cover a wide range of vehicle types, such as passenger cars, delivery trucks, and city buses, adsorbed natural gas (ANG), compressed natural gas (CNG), and dimethyl ether (DME) as fuels, series (S-HEV) and series/parallel (SP-HEV) for hybrid types, and as energy storage systems (ESSs), flywheel batteries (FWBs), capacitors, and lithium-ion (Li-ion) batteries. Evaluation tests confirmed that the energy consumption of the developed vehicles is 1/2 of that of conventional diesel vehicles, and the exhaust emission levels are comparable to Japan's ultra-low emission vehicle (J-ULEV) level.
Technical Paper

Study on Ignition Timing Control for Diesel Engines Using In-Cylinder Pressure Sensor

2006-04-03
2006-01-0180
As technologies for simultaneously maintaining the current high thermal efficiency of diesel engines and reducing particulate matter (PM) and nitrogen oxide (NOX) emissions, many new combustion concepts have been proposed, including premixed charge compression ignition (PCCI) and low-temperature combustion[1]. However, it is well known that since such new combustion techniques precisely control combustion temperatures and local air-fuel ratios by varying the amount of air, the exhaust gas recirculation (EGR) ratio and the fuel injection timing, they have the issues of being less stable than conventional combustion techniques and of performance that is subject to variance in the fuel and driving conditions. This study concerns a system that addresses these issues by detecting the ignition timing with in-cylinder pressure sensors and by controlling the fuel injection timing and the amount of EGR for optimum combustion onboard.
Technical Paper

Fuel Injection System of Air-cooled Engines for Small Displacement Motorcycles

2005-10-12
2005-32-0035
With the interest in global environmental issues growing in recent years, the demand for the reduction of exhaust gas emission and improvement in fuel consumption for small motorcycles has increased greatly. Recently, small motorcycles have been marketed equipped with an electronically controlled fuel injection system effective in reducing emissions and enhancing fuel consumption by accurately controlling the air-fuel ratio. The small motorcycles' market comprises mainly ASEAN countries, and the majority of the motorcycles consist of reasonably priced models with air-cooled engines. Fuel injection systems have already been adopted for motorcycles equipped with water-cooled engines in the markets of advanced countries, mostly in EU. Given the above situation, two issues must be addressed to adopt a successful fuel injection system for air-cooled, low-priced small motorcycles.
Technical Paper

Study of CNG Fueled Two-Wheeled Vehicle with Electronically Controlled Gas Injection System

2005-10-12
2005-32-0034
Owing to its combustion characteristics and chemical composition, natural gas features cleaner emissions and lower CO2 compared to gasoline under equal thermal efficiency. Natural gas can be a promising alternative energy source to respond to crude oil exhaustion and global warming issues. Focusing on the utility of natural gas, a feasibility study on CNG (Compressed Natural Gas) -fueled two-wheeled vehicles has been conducted. A proto-type two-wheeled vehicle was made based on a 125 cm3 class gasoline-fueled scooter. To adapt the engine to the use of CNG fuel, an electronically controlled gas injection system was applied to the fuel supply system. To provide abrasion resistance of engine valves and valve seats, the specific matter of gas-fuel was improved. Furthermore, a lubricant circulation passage was added to maintain the temperature of the pressure reducing valve.
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