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By developing a mechanical-firing sensor using rotational inertia effect, we have completed miniaturization of the sensor and have developed a new-type mechanical-firing airbag system. This airbag system has been confirmed to have superior occupant protection performance after conducting a variety of vehicle crash tests and sled tests.

Clutch judder phenomenon is known as a vehicle vibration caused by the drive torque fluctuation from the clutch unit at takeoff. In this paper, a novel strategy for improving clutch judder phenomenon caused by the movement/tolerance between mechanical parts comprising the clutch system is introduced. In order to simulate the movements of the clutch system and of the vehicle drivelines precisely, we used numerical analysis software and have achieved high-grade prediction of the clutch torque fluctuation and the vehicle vibration. Using this method, we have developed a high-quality clutch system that enables smoother clutch engagement, and at the same time, development efficiency has been improved.

Development of a system which utilizes technology for the recognition of a vehicle's surroundings. Research is currently taking place in many countries, the goals of which are to improve a vehicle's safety and convenience by reducing driver strain through the automation of the recognition, judgment, and operation capabilities that are needed when driving an automobile. To recognize the vehicle's surroundings, we have adopted an image sensor system which offers superior three-dimensional recognition capabilities. In this paper, we will introduce a inter vehicle distance control system which controls the vehicle's throttle and braking functions by detecting the position of the driving lane and the distance to the vehicle in front based on the images obtained by a CCD camera.

Recently two-mass flywheels have adopted in various types of engines to decrease torsional engine vibrations. A two-mass flywheel has a resonance frequency below the idle speed. Thus, it must be provided with an energy dissipating mechanism to avoid a resonance problem. Consequently, flywheel's damping effectiveness at practical engine speeds is decreased because the energy dissipating mechanism restricts relative displacement of the two-mass flywheel. In this work, a new prototype two-mass flywheel was evaluated and found to be effective in improving two important qualities of such devices; (1) its ability to decrease torsional vibrations (2) its ability to avoid resonance problems during engine startup.

Active-TRAC (A-TRAC) is the system for off-road 4WD vehicles. This system consists of independent four wheel brake control system and engine torque control system. This system applies the brake to any spinning wheel, and sends torque to the other wheels with grip. Therefore, the vehicle gets strong LSD(Limited Slip Differential) effect, and it has the same traction performance as a center and rear differential locked vehicle. Because the vehicle with A-TRAC does not have a differential locking mechanism, it no longer has the phenomenon of tight corner braking, and it frees a driver from operating the differential locking system. Therefore anyone can easily enjoy off-road driving with A-TRAC.

Brazing using arc-sprayed coatings was investigated for application to non-oxidation copper brazing. It was found that the more porous sprayed coatings have an excellent brazeability. This newly developed joining method is more suitable than conventional methods for brazing complicated parts. We have applied this method to fabricate a torque converter for practical use.

We have developed an electric rear-drive unit to enable all-wheel drive (AWD) applications to the compact FF hybrid passenger vehicles. The development is intended to provide a compact and low cost unit with low fuel consumption. The unit newly introduces a two-axis gear train that enables a compact design, an induction motor and an ATF (automatic transmission fluid) stirring resistance restraining structure that contribute to lower fuel consumption. This paper presents the features and performance of the electric rear-drive unit.

Over the past decades, the automotive industry has made significant efforts to improve engine fuel economy by reducing mechanical friction. Reducing friction under cold conditions is becoming more important in hybrid vehicle (HV) and plug-in hybrid vehicle (PHV) systems due to the lower oil temperatures of these systems, which results in higher friction loss. To help resolve this issue, a new internal gear fully variable discharge oil pump (F-VDOP) was developed. This new oil pump can control the oil pressure freely over a temperature range from -10°C to hot conditions. At 20°C, this pump lowers the minimum main gallery pressure to 100 kPa, thereby achieving a friction reduction effect of 1.4 Nm. The developed oil pump achieves a pressure response time constant of 0.17 seconds when changing the oil pressure from 120 kPa to 200 kPa at a temperature of 20°C and an engine speed of 1,600 rpm.

To develop Low-cost system, we used matrix function under the condition of the vehicle having symmetrical brake conduit and four-wheel control capability. As a result, 3 SOL system is a likely candidate for rear-wheel drive vehicles, and a 4 SOL system for front wheel drive vehicles by using a orifices instead of the Normal-Open solenoid. In developing a logic system, we used the learning control function with a duty pointer containing four hydraulic wave modes. The actuator weighs 2.2kg and has a volume of 1.2 liters (W90 × H105 × L133)

Electrification of the powertrain to improve vehicle fuel economy is a key technology to achieve strict fuel economy legislation. However, only limited numbers of small class vehicles such as a B segment adopt electric powertrain. This is presumed that cost effectiveness for fuel economy is small and mounting space for additional powertrain is limited. In this paper, the optimum solution of a strong hybrid system suitable for the small vehicles was studied. First, from the viewpoint of maximization of energy efficiency, we compared contributions of engine efficiency and transmission efficiency during mode cycle driving and selected automated manual transmission as a suitable transmission for small vehicles. In comparing the hybrid system function, we determined a motor generator connecting shaft and a necessary motor generator output power for attaining both fuel economy and drivability.

AISIN SEIKI CO., Ltd. Started the production of electronically controlled hydraulic automatic transmissions for medium-duty trucks and buses in 1989. The number of vehicles on the Japanese market in which this system is adopted is increasing steadily. After re-examining market needs, AISIN SEIKI CO., Ltd. has newly developed an electronically controlled hydraulic automatic transmission A580 which focuses on improved input capacity, driving performance and fuel economy for medium-duty trucks and buses and lessens learnt from experience.

Introduction of occupant classification system which has load sensor with a strain gauge built into the seat structure, and identifies occupant's physique by measuring weight on seat, and meets the United States FMVSS requirements (new FMVSS208 Requirement).

If a crash prediction system (Rear pre-crash safety) determines that a rear crash is unavoidable, this product reduces whiplash injury by reducing shock to the neck by quickly moving the front part of a head restraint forward thus shortening the distance between the head and the head restraint. Pre-crash intelligent head restraint systems were developed for safe vehicle. In this paper, the method to detect collision risk and how to protect passenger's heads was introduced. Also sensor idea and operating mechanism were explained.

As a process that enables the high-speed and continuous forming of lengthy materials with a constant cross-sectional configuration, roll forming offers much higher productivity than the stamping process. However, in case a change must be made to the shape of the cross section, the material must normally be stamped or joined with a part containing a separate shape. This affects productivity, increases the number of pieces, and degrades the material's appearance. This report describes the roll-forming technology that we developed, in which the cross section of the material can be changed gradually. This method adopts a system which uses a movable and rotatable roll-stand that enables high-speed, continuous roll-forming processes.

While exhaust gas emission standards are becoming severe, turbochargers which have a good performance and wide operating range are required. At Aisin Seiki, we have started development of the SJ (swirl jet) turbocharger to cope with these requirements without increasing costs. In this paper, we describe the features and effects of the SJ turbocharger.

Drive train components (transmission, differential gears, etc.) can be made smaller and lighter if the excessive torque exerted on them can be reduced during the quick start of a vehicle. An orifice put in the hydraulic clutch piping path is an effective method. However, increased oil viscosity at low temperatures (0°C or below) makes the “pedal feel” worse. In order to increase the orifice diameter for better “pedal feel”, a shape memory alloy spring, for operation at low temperatures, was developed by adding cobalt to the nickel-titanium alloy. Consequently, a Variable-Orifice valve, using the shape memory alloy spring, is practical.

Switched Reluctance Motor (SRM) mainly has two advantageous characteristics such as no magnet and simple construction. These characteristics contribute lower cost and higher reliability compared with other motor systems such as brushless permanent magnet motors or induction motors. However, acoustic noise and output torque ripple should be improved when the SRM is applied to a traction system for passenger electric vehicle since these characteristics directly affect vehicle quietness and drivability. In this paper, we describe a system configuration of the SRM traction system for passenger electric vehicle. The SRM traction system includes an electric motor, transmission gears and power inverter module. Then, an approach to improve acoustic noise and output torque ripple is introduced. Generation mechanisms of acoustic noise and output torque ripple are analyzed.

Exhaust emission regulation has become stricter year by year because of the global movements of environment protection. In consequence, turbocharger application to diesel engines became indispensable. Especially a variable geometry turbocharger (VGT) is perceived as the essential item. Of late years, the diesel engine has a trend of higher exhaust temperature to increase specific output. At the same time, needs of the turbocharger application to the gasoline engine has been rising again in order to reduce the size. In spite of this trend of the emission temperature increment, VGT of the variable nozzle vane type which is commonly available in the current market has problems of high temperature resistance due to its complex structure. AISIN SEIKI has developed a variable flow turbocharger (VFT), which is able to resolve those problems.

Recently, plastic air intake manifold (PAIM) has been adopted into gasoline and diesel engines as standard equipment. The advantages of the PAIM are light mass weight, low cost, high thermal-insulation efficiency and reduction of air pressure loss compared with a metal air intake manifold. However, in order to bring the advantages of the PAIM into play, many issues including static burst, noise and vibration, and so on should be settled in its design process. In this paper, the performance prediction and application example of PAIM are introduced.

Automating the inspection of the piston combustion chamber volume is difficult and prevents establishing an unmanned machining process of the piston in the future. So, we developed an inspection technique which uses a Range Finder, non-contact visual sensor, and calculate the chamber volume by integrating 3D position data. We applied this real-time measurement technique which enables 100 % inspection to our production lines. Then, we developed the “Defect Free Production Line”, which calibrates itself by feeding back the measured volume data to the machining process. Our paper will explain this inspection technique and our “Defect Free Production Line”.