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Technical Paper

A Human Factors Analysis of Optical Distortion for Automotive Windshields

1994-03-01
940390
A very difficult problem exists regarding windshield shape, and that is to create a balance between aerodynamics and optical distortion. To assist in solving this problem, this study, concerning the characteristics of visual perception for the optical distortion when drivers receive visual information through a windshield, was carried out. In this study, the windshield area was divided into 4 zones from the viewpoints of the level of drivers' fixation frequency and types of objects observed. Distortion was defined as the gap angle ( distortion angle ), which crossed the lines of a grid board with and without a windshield, and distortion angles were measured on a total of 4 windshields. Four drivers indicated areas in each windshield in which they felt the area was distorted. As a result, the thresholds of optical distortion were shown as a function of the horizontal and vertical distortion angles by discriminatory analysis.
Technical Paper

A Multiplexing Communication IC for Automotive Body-Electronic Control

1994-03-01
940364
In the field of automotive body electronic control such as control of door locks, power windows, and wipers, there is a growing need of multiplexing communication to reduce the amount of wire harnesses. To meet this need, we developed a multiplexing communication protocol particularly suited to the body electronic control. Based on the developed protocol, we designed a communication control IC and a simple driver/receiver circuit with a few discrete components. The bus access method of the communication is the CSMA/CD with nondestructive bit arbitration, and its bit rate is 5 kbps. Its transmission media is a single wire. The communication IC has a multiplexing control block and a serial I/O block for an interface with a host CPU. It was fabricated using CMOS technology and has a chip of 2.6mm x 3.0mm in size that contains about 5,000 transistors. The driver/receiver circuit consists of one transistor, one capacitor and several resistors.
Technical Paper

A New Battery System for the Estima Hybrid Minivan

2002-03-04
2002-01-1090
Development of a new battery system for Toyota Estima Hybrid, the world's first minivan hybrid vehicle, has been completed. The battery pack that consists of 30 nickel metal hydride battery modules is compactly arranged under the 3rd seat in the cabin along with components such as the battery cooling blower and the ducts. This arrangement was designed in consideration of user's vehicle use, passengers' comfort and efficient battery-cooling performance.
Technical Paper

A Newly Developed Intelligent Variable Valve Timing System - Continuously Controlled Cam Phasing as Applied to a New 3 Liter Inline 6 Engine

1996-02-01
960579
To meet the requirements for higher horsepower and torque as well as lower fuel consumption and emissions, we have developed a new “Intelligent Variable Valve Timing (VV-i)” system. It gives continuously variable intake cam phasing by up to 60 degrees crank angle (CA) . This system not only increases WOT output by optimizing intake valve closing timing but also reduces fuel consumption and NOx/ HC emissions under part load by increasing intake and exhaust valve overlap on 4 stroke Spark Ignited engines. VVT-i has been applied to optimize a new 3-liter inline 6 engine for higher torque and at the same time better fuel economy with continuous and wide-range cam phasing.
Technical Paper

A Technology of Weight Reduction for the Aluminum Cast Wheel

1993-11-01
931885
In the field of automobile disk wheels, demands for aluminum wheels have been increasing for the reason of ride comfort and better appearance. And over 90 percent of luxurious passenger cars are equipped with aluminum wheels. This trend is spurred also by the demand for higher fuel efficiency for the cause of environmental protection, which calls for weight reduction of automobiles. This paper reports our research on manufacturing light-weight, high-quality aluminum cast wheels; covering the entire process from basic design to casting, and placing emphasis on the following three points. 1) Determination of optimum wheel configuration through computer simulation 2) Selection of optimum material composition 3) Optimization of the thin plate casting conditions Combination of the above technologies developed for the purpose of weight reduction resulted in the weight reduction of approximately 20% over the conventional aluminum wheels.
Technical Paper

Aerodynamic Effects of an Overtaking Articulated Heavy Goods Vehicle on Car-Trailer-An Analysis to Improve Controllability

1987-10-01
871919
It is well known and a common experience among drivers that controllability and stability of a car-trailer combination is affected when an articulated Heavy Goods Vehicle overtakes. In this paper, aerodynamic effects to a car-trailer combination when it is overtaken by an articulated HGV, have been analyzed experimentally using 1/20 scale models in wind tunnel, and a method to suppress this phenomenon has been investigated. The dynamic behaivor of a car-trailer combination is simulated by a simple mathematical model. The result shows that a car-trailer combination can be stable following the addittion of aerodynamic devices to each side of the vehicle. This simulated result is verified by the on-read test.
Technical Paper

Alert Method for Rear Cross Traffic Alert System in North America

2013-04-08
2013-01-0732
In recent years, a number of different Blind Spot Monitor (BSM) systems have become more and more popular in North American automotive market. The BSM system advises the driver of vehicles travelling in adjacent lanes when these vehicles are also in the driver's outside rearview mirror blind spots. Similarly, when the vehicle is backing up from a parking spot, cross-traffic vehicles can be in the driver's outside mirror blind spots. In this situation, the Rear Cross Traffic Alert (RCTA) system alerts the driver when the driver shifts the vehicle in the reverse gear and there are approaching cross-traffic vehicles. The benefits of RCTA system was presented by [1]. The RCTA alert studied in this paper is given by playing an audible sound and by flashing the outside mirror indicators. The RCTA and BSM systems share the same vehicle sensors and most of their vehicle components.
Technical Paper

An Analysis of Behavior for 4WD Vehicle on 4WD-chassis Dynamometer

2010-04-12
2010-01-0926
Technologies of 4WD chassis dynamometers (CHDY hereinafter) have advanced dramatically over the past several years, enabling 4WD vehicles to be tested without modifying their drive-train into 2WD. These advances have opened the use of 4WD-CHDY in all fuel economy and emission evaluation tests. In this paper, factors that influence the accuracy of fuel economy tests on 4WD CHDY are discussed. Fuel economy tests were conducted on 4WD CHDY and we found that most of the vehicle mechanical loss is the tire loss and that stabilizing the tire loss of the test vehicle is essential for the test reproducibility.
Technical Paper

An Experimental Set Up Development for Brake Squeal Basic Research

2013-09-30
2013-01-2032
The vehicle requires high brake performance and mass reduction of disc brake for vehicle fuel economy. Then disc brake will be designed by downsizing of disc and high friction coefficient pad materials. It is well known that disc brake squeal is frequently caused by high friction coefficient pad materials. Disc brake squeal is caused by dynamic unstable system under disturbance of friction force variation. Today, disc brake squeal comes to be simulated by FEA, but it is very difficult to put so many dynamic unstable solutions into stable solutions. Therefore it is very important to make it clear the influence of friction force variation. This paper describes the development of experimental set up for disc brake squeal basic research. First, the equation of motion in low-frequency disc brake squeal around 2 kHz is derived.
Journal Article

Analysis of Driver Kinematics and Lower Thoracic Spine Injury in World Endurance Championship Race Cars during Frontal Impacts

2017-03-28
2017-01-1432
This study used finite element (FE) simulations to analyze the injury mechanisms of driver spine fracture during frontal crashes in the World Endurance Championship (WEC) series and possible countermeasures are suggested to help reduce spine fracture risk. This FE model incorporated the Total Human Model for Safety (THUMS) scaled to a driver, a model of the detailed racecar cockpit and a model of the seat/restraint systems. A frontal impact deceleration pulse was applied to the cockpit model. In the simulation, the driver chest moved forward under the shoulder belt and the pelvis was restrained by the crotch belt and the leg hump. The simulation predicted spine fracture at T11 and T12. It was found that a combination of axial compression force and bending moment at the spine caused the fractures. The axial compression force and bending moment were generated by the shoulder belt down force as the driver’s chest moved forward.
Technical Paper

Analysis of Rotational-Angle Difference Between Gears for Gear Noise Under Transient State Using Hilbert Transform

2005-04-11
2005-01-1832
The authors developed a useful analysis method of the rotational-angle of gear under transient state using the Hilbert Transform because the conventional method was not available under the transient state. Here, under the transient state the gear revolution speed was changed from 600r/min to 2000r/min in 0.35 seconds. A key technology of this method was that Hilbert Transform method, which used to be applicable only for steady data was improved so that it could treat transient data. Hence, the following procedures were developed. 1. The rotation of gear-teeth was detected by a gap-sensor pair, which can cancel the measuring error due to fluctuation of gear shaft. 2. The frequency of such signals varied significantly by the gear-revolution speed. Transient gear-teeth detection signals obtained at a constant sampling rate were converted to almost-constant frequency signals over the data series axis using a trigger pulse obtained per gear revolution.
Technical Paper

Analysis of Sintered Silicon Nitride Grinding Damage

1993-03-01
930163
Sintered silicon nitride, particularly in structural ceramics, has superior properties such as low weight, heat resistance, wear resistance, etc. It is already being applied to automobile engine parts such as the swirl chamber and the turbine rotor. In recent years, the strength of silicon nitride has shown to be above 1000MPa. This has been achieved through advances in manufacturing technology such as materials powder, forming, sintering and so on. But the silicon nitride is easily damaged during grinding because it has less fracture toughness than metal. Consequently, the inherent strength of the material is not demonstrated in the actual products presently produced. It is assumed that the main cause of strength reduction is microcrack. In ordinary grinding methods, the length of microcrack has been estimated at approximately twenty micrometers by fracture mechanics analysis.
Technical Paper

Analysis of Visualized Fuel Flow inside the Slit Nozzle of Direct Injection SI Gasoline Engine

2003-03-03
2003-01-0060
In the direct injection spark ignition gasoline engine (D-4), thin fan-shaped high-dispersion, high-penetration and high-atomization spray formed by the slit nozzle generates a stratified mixture cloud without depending on a strong intake air motion, subsequently realizing stable stratified charge combustion. To improve fuel economy further in actual traffic, the region of stratified charge combustion in torque-engine speed map must be expanded by improving spray characteristics. Since the fuel flow inside the nozzle has a large effect on the spray characteristics, it was clarified this effect by visual analysis of the fuel flow inside the nozzle using an enlarged acrylic slit nozzle of 10 magnifications. Consequently, it was found that vortices are generated frequently within a sac even in the case of steady state conditions. The effect on the spray characteristics is corresponding to the vortex scale.
Technical Paper

Anti-Shudder Mechanism of ATF Additives at Slip-Controlled Lock-Up Clutch

1999-10-25
1999-01-3616
The anti-shudder effect of ATF additives and their mechanisms have been investigated. Anti-shudder durability was evaluated using an automatic transmission (AT) on an engine stand under continuously slip-controlled condition. The addition of over-based Ca-sulfonate and friction modifier (FM) remarkably improved the anti-shudder durability of ATF. The surface roughness of the contact area (contact area roughness) of the clutch plates was measured by an electron probe surface roughness analyzer. To evaluate the boundary frictional properties of the adsorbed film formed, the friction coefficient of the clutch plates in the absence of oil was examined after the anti-shudder durability test. It was found that shudder occurrence was strongly correlated with the contact area roughness and the boundary frictional property of the steel plate surface. Large contact area roughness and low boundary friction were preferred to prevent shudder.
Technical Paper

Application of a New Combustion Concept to Direct Injection Gasoline Engine

2000-03-06
2000-01-0531
A direct injection (DI) gasoline engine having a new stratified charge combustion system has been developed. This new combustion process (NCP) was achieved by a fan-shaped fuel spray and a combustion chamber with a shell-shaped cavity in the piston. Compared with the current Toyota D-4 engine, wider engine operating area with stratified combustion and higher output performance were obtained without a swirl control valve (SCV) and a helical port. This report presents the results of combustion analyses to optimize fuel spray characteristics and piston cavity shapes. Two factors were found to be important for achieving stable stratified combustion. The first is to create a ball-shaped uniform mixture cloud in the vicinity of the spark plug. The optimum ball-shaped mixture cloud is produced with a fuel spray having early breakup characteristics and uniform distribution, and a suitable side wall shape in the piston cavity to avoid the dispersion of the mixture.
Technical Paper

Classification and View of Automotive Power Supply Voltage for HEV, PHEV and EV

2011-05-17
2011-39-7227
In the twenty-first century, the development of vehicles has been proceeding towards electronics, electric propulsion and system integration in 5 big trends. Environment, Safety, Market Change, Energy Security and Natural Resources. Especially, “Electric Propulsion of Vehicles” is rapidly accelerated for countermeasure of global warming. In this paper, we will propose the current status analysis for automotive high power supply voltage and classification for future view of HEV(Hybird Electric Vehicle). PHEV(Plug-in Hybrid Electric Vehicle) and EV(Electric Vehicle).
Journal Article

Decoupled 3D Moment Control for Vehicle Motion Using In-Wheel Motors

2013-04-08
2013-01-0679
Vehicles equipped with in-wheel motors are being studied and developed as a type of electric vehicle. Since these motors are attached to the suspension, a large vertical suspension reaction force is generated during driving. Based on this mechanism, this paper describes the development of a method for independently controlling roll and pitch as well as yaw using driving force distribution control at each wheel. It also details the theoretical calculation of a method for decoupling the dynamic motions. Finally, it describes the application of these 3D dynamic motion control methods to a test vehicle and the confirmation of the performance improvement.
Technical Paper

Development of 3.5L V6 Gasoline Direct Injection Engine - ESTEC 2GR-FKS/FXS -

2015-09-01
2015-01-1972
The new 2GR-FKS / FXS engines were developed to achieve stringent fuel economy and emission targets and respond to recent innovations in the field. The major parts of the 2GR-FKS/FXS engines were re-designed based on the well-received dynamic performance and fuel economy aspects of the 2GR-FE engine. The aims of this development were as follows. 1 Best-in-class power performance 2 Environmental performance that maximizes thermal efficiency and complies with fuel economy and emission regulations in each country by a wide margin 3 Engine response typical of V6 engines through drastic weight reduction of moving parts To achieve these conflicting aims, the developed engines use a modified version of the D-4S fuel injection system, which enables selective use of direct and port injection, in addition to advanced technologies such as variable valve technology (VVT) with a mid-position lock system and an exhaust port cooling system.
Technical Paper

Development of Automatic Transmission Fluid for Slip-Controlled Lock-Up Clutch Systems

1995-10-01
952348
Slip-controlled lock-up clutch systems are very efficient and greatly improve fuel economy. On the other hand, these systems can cause unstable vibrations including those known as “shudder vibrations”. In this study, the authors made a theoretical analysis of these unstable vibrations to clarify the fundamental frictional properties of automatic transmission fluids (ATFs) required for slip-controlled lock-up clutch systems. Based on this analysis, we established lubricant technology having a sufficient anti-shudder property and high torque capacity. Further, we developed a new test apparatus to evaluate the anti-shudder durability for lubricant development.
Technical Paper

Development of Bearing with Composite Overlay for High-Performance Engines

1996-02-01
960988
Recently, there has been a tendency of high power and high speed in automotive engines. In addition they have been also required high reliability. And engine bearings have been required to be advanced in wear resistance as well as seizure resistance. Therefore, copper-lead alloy bearings with overlay, which have better seizure resistance, have been widely used for high speed engines up to the present. But it becomes very important for them to advance the overlay wear resistance. In this paper, the composite overlay is mainly researched to improve wear resistance regarding kind of hard particles and their amounts in the overlay.
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