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Technical Paper

Development of cabin air filter with aldehyde capture function

2000-06-12
2000-05-0343
Aldehydes are the cause of sick house syndrome or chemical sensitivity and have harmful influences for human beings. In the cabin of vehicle, aldehydes which are included in the volatilization gas from the interior materials, DE emission gas in intake air, cigarette smoke and so on spoil the comfortableness. Active carbon, which has been used as an adsorbent, shows an excellent removal efficiency for most of the gas components by physical adsorption. But for aldehydes, it has difficulty because aldehydes are hard to be adsorbed physically. We have developed new aldehydes adsorbent undergoing addition reaction with gaseous aldehydes on its surface. Aldehydes capture material (ACM) make use of the chemical reaction using a resorcin as a reagent and an H-type zeolite as a water-containing support, and active hydrogen is used as a catalyst to promote the reaction. In addition, we have applied ACM to cabin air filter (CAF) of vehicle.
Technical Paper

Influence of Mixture Stratification Patter non Combustion Characteristics in a Constant-Volume Combustion Chamber

1995-10-01
952412
A pancake-type constant-volume combustion chamber was used to investigate the combustion and NOx emission characteristics of propane-air and hydrogen-air mixtures under various charge stratification patterns, which were obtained by variations of the initial charge and injected mixture concentrations and the ignition spark timing. A planar laser-induced fluorescence from nitrogen dioxide as gas fuel tracer was applied to measure the mixture distribution in the test chamber. The second harmonic output of pulsed Nd; YAG laser was used as a light source for fluorescence excitation. The fluorescence images were corrected by a gated image-intensified CCD camera. The quantitative analysis of fuel concentration was made possible by the application of linearity between fluorescence intensity and NO2 concentration at low trace level.
Technical Paper

Development of V6 Miller Cycle Gasoline Engine

1994-03-01
940198
A gasoline engine with an entirely new combustion cycle deriving from Miller Cycle is developed. By delaying closing timing of intake valve and with new Lysholm Compressor which provides higher boost pressure, engine knocking is avoided while high compression ratio is maintained and approximately 1.5 times larger toque than that of a naturally aspirated(NA) engine of the same displacement is realized. This V6 Miller Cycle gasoline engine can be the alternative to a larger displacement NA engine because of its equivalent torque performance and its lower fuel consumption by the effect of smaller displacement.
Technical Paper

The Development of the Advanced Protocol for Automotive Local Area Multiplexing Network (Advanced PALMNET)

1994-03-01
940365
In order to expand the applicable range of in-vehicle LANs down to popular cars, drastic cost reduction is essential. In addition, an in-vehicle LAN with high transmission rate and advanced functioning is extremely important for the further spreading of vehicle electronics intended to enhance vehicle intelligence. We developed the Protocol for Automotive Low and Medium Speed Network (PALMNET) as an in-vehicle LAN system and put it into practical use in 1990. Based on this, we developed a new communication protocol and three ICs for an in-vehicle LAN called the Advanced Protocol for Automotive Local Area Multiplexing Network (Advanced PALMNET), which satisfies the above-mentioned requirements and covers the medium-to-low transmission rate (up to 125kbps) to high rate (up to 1Mbps).
Technical Paper

In-Cylinder Fuel Distribution, Flow Field, and Combustion Characteristics of a Mixture Injected SI Engine

1995-02-01
950104
In order to control the mixture formation, a mixture injected 4-valve SI engine was developed with a small mixture chamber and mechanically driven mixture injection valve installed into the cylinder head. The mixture injection valve was located at the center of the combustion chamber. The mixture was injected from the final stage of the intake stroke to the beginning of the compression stroke. The mixture distribution and in-cylinder flow field inside the combustion chamber were measured by a pair of laser two-dimensional visualization techniques. A planar-laser-induced exciplex fluorescence technique was used to visualize the in-cylinder mixture formation by obtaining spectrally separated fluorescence images of liquid and vapor phase fuel distribution. Particle image velocimetry (PIV) was used to obtain flow field images. In the case of the mixture injected SI engine, the mixture injected into the swirl center was retained during the compression stroke.
Technical Paper

Development of Magnesium Forged Wheel

1995-02-01
950422
Magnesium has the lowest specific gravity of all metals used for structural members. The application of magnesium for a road wheel leads to improved vehicle handling and drivability because of the reduction of an unsprung weight. The authors have developed new magnesium alloy which shows excellent mechanical properties and attained a magnesium forged road wheel that is 30% lighter than aluminum wheels.
Technical Paper

Mechanism of Improving Fuel Efficiency by Miller Cycle and Its Future Prospect

1995-02-01
950974
We have introduced a supercharged Miller Cycle gasoline engine into the market in 1993 as an answer to the requirement of reduction in CO2 emission of vehicles. Improvement in the fuel economy of a supercharged Miller Cycle engine is achieved by the reduction of friction loss due to a smaller displacement. The biggest problem of a conventional supercharged engine is knocking. In order to avoid the knocking, lower compression ratio, which accompanies lower expansion ratio, has been adopted by the conventonal engines and achieved insufficient fuel economy improvement. The Miller Cycle obtains superior anti-knocking performance as well as lowering compression ratio, while keeping the high expansion ratio. The decreased friction loss by the smaller displacement has completely lead to the improvement of fuel economy.
Technical Paper

Improving NOx and Fuel Economy for Mixture Injected SI Engine with EGR

1995-02-01
950684
A large quantity of recirculated exhaust gas is used to reduce NOx emissions and improve fuel economy at the same time. The effect of exhaust gas recirculation (EGR) was investigated under the stoichiometric and lean operating conditions and compared with the effect of lean operation without EGR. A mixture injected SI engine that has a mechanically driven mixture injection valve installed was prepared. In this engine, it is possible to charge combustible mixture independently from combustion air and recirculated exhaust gas introduced from intake port in order to stratify the mixture. The effect of the EGR ratio on NOx emissions and fuel consumption was measured under the stoichiometric and lean operating conditions. Due to the mixture distribution controlled by the mixture injection, a large quantity of recirculated exhaust gas could be introduced into the combustion chamber under the stoichiometric air/fuel ratio. The limit of EGR ratio was 48 %.
Technical Paper

Development of the Stratified Charge and Stable Combustion Method in DI Gasoline Engines

1995-02-01
950688
The new combustion method in DISC engine has been developed. It has a double structure combustion chamber characterized as ‘Caldera’. The chamber is constructed by a center cavity for the purpose of forming a stable mixture around a spark plug electrode, and by an outer cavity which has a role of a main chamber. This method makes possible a perfect un-throttling operation, and a fuel consumption equal to a diesel engine is achieved. With regard to an out-put of DISC engine, a stoichmetric combustion and a high torque are achieved by controling a fuel injection timing with an electro-magnetic injection system device. With regard to emission regulations, a heavy EGR include residual gas decreases greatly NOx and HC emissions simultaneously, and which suggests a possibility to achieve LEV/ULEV regulations.
Technical Paper

Development of Lean Burn Catalyst

1995-02-01
950746
A new type of three way catalyst for lean engine was developed in order to reduce hydrocarbon (HC), carbon-monoxide (CO) and nitrogen-oxides (NOx) in lean exhaust gas. This catalyst has a base support material of MFI zeolite loaded with active metals including platinum (Pt), iridium (Ir) and rhodium (Rh). It showed good catalytic activity and thermal durability on a lean engine. This catalyst made it possible to enlarge the lean operating region of the lean burn engine. It showed the NOx reduction of 51% in Japanese 10-15 mode emission test and the emissions were found low enough to satisfy the new Japanese emission standards. Consequently, fuel economy of the lean vehicle with this catalyst has been improved about 16% in comparison with a comparable current stoichiometric combustion vehicle. This catalyst has been mass-produced for Mazda 323 lean burn vehicle (Z-Lean) for the Japanese domestic market.
Technical Paper

Mechanism of Combustion Chamber Deposit Interference and Effects of Gasoline Additives on CCD Formation

1995-02-01
950741
Recently, an audible clattering noise has been noticed in some vehicles during cold engine starts, mainly in the U.S. The clattering is referred to by various names, such as “carbon knock,” “carbon rap,” “mechanical knock” and “combustion chamber deposit interference (CCDI).” CCDI is believed to be caused by the deposit formation in the combustion chamber. In the research effort described here, CCDI was successfully reproduced in a 2.5-liter multipoint injection engine with a polyolefin amine gasoline additive. It was determined that the CCDI was caused by mechanical contact between the piston top and the cylinder head deposits. The vibration due to CCDI originated mainly at the thrust side of the piston right after top-dead-center on compression stroke and was characterized by a high frequency response. Combustion chamber deposit (CCD) formation depends on many factors, including gasoline additives.
Technical Paper

Planar Measurements of OH Radicals in an S.I. Engine Based on Laser Induced Flourescence

1994-03-01
940477
The planar laser induced fluorescence (PLIF) technique was applied to two dimensional visualization of OH radicals in a combustion flame. A frequency doubled Nd:YAG laser pumped dye laser was used to form a laser light sheet which excited the OH X2Π-A2Σ transition. A fluorescence image of the OH radical and a visible image of a combustion flame were simultaneously imaged by a pair of CCD cameras with image intensifiers. Measurement of the OH radical in the combustion flame could be carried out by using this PLIF technique without Mie scattering lights from soot particles and other optical disturbances. The PLIF technique was employed to study the OH radical in the combustion chamber of a spark ignition (S. I.) engine using gasoline as fuel. Measurements of the OH radical fluorescence were carried out under various operating conditions of mass burned fraction, swirl ratio and air-fuel ratio.
Technical Paper

High Performance Active Noise Control System for Engine Noise in a Car Cabin

1994-03-01
940608
A very effective and practical technique for active control of engine noise in a car cabin has been developed. By utilizing the repetitiveness of the engine noise and introducing the idea of error scanning, a new control algorithm was developed that requires only 30-50% of the arithmetic operations of the filtered-x least mean square method. A system with only 3 microphones allocated on the basis of the spatial distribution of the noise is able to make the whole cabin space quiet. Experimental results show that a maximum noise attenuation of 8dB(A) has been achieved at each seat position.
Technical Paper

The Characteristics of Fuel Consumption and Exhaust Emissions of the Side Exhaust Port Rotary Engine

1995-02-01
950454
Mazda has been pursuing the research of side exhaust porting for its rotary engine in an effort to improve the engine's fuel efficiency and exhaust emissions characteristics. The side exhaust porting configuration provides greater flexibility in setting port timing and shape, as compared to the peripheral exhaust porting configuration, which is in use in the current-generation rotary engines; the side exhaust porting configuration enables the selection of a port timing more favorable to reduced fuel consumption and exhaust emissions. The side exhaust port rotary engine used in this research has its exhaust port closure timing around the top dead center (TDC) and has no intake-exhaust timing overlap. As a result, burnt gasses entering the next cycle of combustion are reduced, thus enhancing combustion stability; also, the air-fuel ratio can be set leaner for improved fuel consumption.
Technical Paper

Development of Capacitance-Loaded Window Antenna for AM/FM Car Radios

1995-02-01
950180
Mazda established an original design methodology combining a capacitive coupling technology and transmission line theory, to develop a high performance window antenna for AM/FM radios which construction is very simple to construct and requires no use of any antenna boosters or matching circuits. This paper introduces the design methodology and performance characteristics of the new antenna as well as its application to the production '95 model Mazda 929.
Technical Paper

Sequential Twin Turbocharged Rotary Engine of the Latest RX-7

1994-03-01
941030
Many sports cars have recently appeared on the market, and people's interest in and requirements for the cars are continuing to grow. The RX-7 was developed to be a first-class sports car that Mazda can be proud of worldwide as a trend leader for sports cars in the '90s. Among many innovations, its engine is the fruit of all the efforts Mazda has done to realize a “pure RE sports car” that takes every advantage of the rotary engine. This paper describes the aim of the development, main specifications, performance characteristics and major new technologies of the engine.
Technical Paper

Development of Disk Brake Rotor Utilizing Aluminum Metal Matrix Composite

1997-02-24
970787
Disk brake rotors require reduced unsprung weight and improved cooling ability for improved fade performance. Automotive brake rotors made from aluminum metal matrix composites (MMC) were evaluated by dynamometer and vehicle tests for the required improvement. The friction and wear performance and the thermal response during fade stops were compared with those of commercially produced gray cast iron (GCI) rotors. It was proved that MMC is a very effective material to replace GCI for brake rotor application, as it reduces unsprung weight and decreases maximum operation temperature of the brake system.
Technical Paper

Detection of Transient Noise of Car Interior Using Non-stationary Signal Analysis

1998-02-23
980589
A method to inspect the rattle generated in a vehicle cabin has been developed. In the method, the waveform of overall in-cabin noise is analyzed using Wigner distribution, a kind of time-frequency analysis, and the rattle component of the waveform is condensed and separated from the background shake noise. Then the rattle component is classified into three levels, strong, middle and not detected, using a neural network. Fuzzy inference is also used to select normal waveform data. Experimental results show that the correct classification ratio of the method is more than 90%, which equals the ability of skilled inspectors.
Technical Paper

A Study of Jump and Bounce in a Valve Train

1991-02-01
910426
Valve train motion was investigated with computer simulation technique. The application of a 5-mass model was found to accurately predict the valve train behavior. It was identified that valve train stiffness and close-side characteristics of valve lift curve have significant effects on bounce occurrence. A valve train with high stiffness tends to develop bounce after jump, while on one with low stiffness, bounce starts in the absence of jump. These findings allowed to develop a new cam form with use of harmonic curves for elevating the revolution limit of the valve train.
Technical Paper

Development of Lighter-Weight, Higher-Stiffness Body for New RX-7

1992-02-01
920244
To realize high levels of handling, driving performance, and NVH characteristics for a sports car, it is important to develop a lightweight and high-stiffness vehicle body. For the new RX-7, weight saving and higher stiffness were pursued as top priorities from the very first stage of the program. We were able to achieve 20% higher bending stiffness and 15% higher torsional stiffness with vehicle weight reduced by 30 kg, compared with the former model. The development of the lightweight, high-stiffness body for the new RX-7 is discussed under three subjects: 1. Contributions of vehicle components to vehicle stiffness 2. Effective procedure for developing vehicle high stiffness and lightweight construction with emphasis on calculation analysis 3. New RX-7's body structure and accomplishment
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