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This paper describes the investigation into the contact pressure and incidental deformation on the contact surface of the piston skirt which comes in contact with the cylinder bore in operation. Focused on the single piston static tests in the first place, relationship between the contact pressure on said skirt and the strains developed inside the skirt, and the relationship between the deformation of skirt face and the strains inside the skirt were studied. Then, the dynamic contact pressure onto the skirt in operation and the amount of deformation were calculated based on the relationships mentioned above using the factor of dynamic strains measured on an engine in operation. The deformation of skirt calculated using said dynamic strains was verified by the direct measurement of the skirt deformation. It was demonstrated that the thrust side of a piston skirt was largely deformed due to enlarged contact pressure caused by the piston slap subsequent to firing top dead center.

The metal top is used for convertible cars since the exterior design when the rooftop is closed is also important. A retractable metal top system which can automatically retract and extract the metal top has been popular to increase commercial values for the luxury convertible cars. We have developed the metal top open-close system comprising metal top,package tray and luggage panel operation link-mechanism units driven by electric motors. The metal top can be retracted or extracted in approximately 25 seconds by controlling the metal top system and the side and quarter window motors. The roof panel is pre-load so that the cabin air-tightness for high speed driving is maintained. The metal top is compactly retracted since the slide and side package trays are synchronized. Enough luggage space is secured using the multi-link mechanism to open and close the luggage panel. This retractable metal top system is equipped with the LEXUS SC430. (Fig.1) [1]

This paper reports the results of a study into a preview control that uses the displacement of the road surface in front of the vehicle to improve for front and rear actuator responsiveness delays, as well as delays due to calculation, communication, and the like. This study also examined the effect of a preview control using the eActive3 electric active suspension system, which is capable of controlling the roll, pitch, and warp modes of vehicle motion.

A linear solenoid is an important element part which hydraulically controls a VVT(Variable Valve Timing) system, etc. The demanded feature of the solenoid is that it performs an electromagnetic force output being constant regardless of the stroke and being proportional to coil current. In order to minimize the size, the electromagnetic force per volume has to be improved but the linearity is contradictory to the electromagnetic force and the consistency therebetween is very difficult to be achieved. Currently, the magnetic field analysis is repeatedly performed with trial and error to eventually obtain optimal designing of a magnetic circuit. We will introduce herein the results of our development in optimization technology for a magnetic circuit which can be used to effectively design a compact linear solenoid upon development of a new VVT system for a vehicle.

Aiming at improved reliability and cost reduction of position sensors for automobiles, we tackled with the challenge of developing long life contact type potentiometer which has a simple construction and cost advantage. We made clear the wear characteristics of the resistor materials and the mechanism how noise occurs, and developed a long life, low noise resistor material, and the double - layer resistor structure which has excellent characteristic in durability. We also clarified the ways of using brushes according to applications through the investigation of the relationship between the contact shape and the amount of wear of the resistor. Based on these investigation, we have developed a highly reliable throttle position sensor and a long life vehicle height sensor.

In this paper, we discuss vehicle directional stability and introduce advanced stability control (ASTC) to stabilize the vehicle during severe cornering. Vehicle behavior in a transient steering condition during severe cornering was analyzed by computer simulation. It was found that applying an external yaw moment makes the vehicle more stable. The effect of controlling the brake force response is also evaluated by simulation to determine the brake actuator response criteria. The actual vehicle test was performed with a pylon slalom using a hydraulic brake actuator. It is verified that the ASTC stabilizes the vehicle for transient steering maneuvers.

When a clutch pedal is operated, the clutch pedal vibration and interior noise are mostly affected by the dynamic characteristics of the clutch cover assembly. We achieved a high correlation between vehicle test data and results using this method when exciting not only clutch system but also the engine system. Finally, we developed an excitation method to evaluate the dynamic characteristics of the clutch cover assembly.

It is well known that the self-aligning torque decreases before lateral force is saturated. Focusing on this self-aligning torque change, an estimation method has been developed to detect the friction condition between steered wheels and road surface before the lateral force reaches the friction limit. The lateral grip margin (LGM) is defined based on the self-aligning torque change, which is obtained using the EPS torque and motor current information. The LGM is theoretically analyzed based on the tire model and experimentally verified through the full-scale vehicle test. Moreover, the estimated LGM is applied for the chassis control systems to improve the vehicle dynamics performance.

Recently, for the aspects of ecology and economy, fuel efficiency improvement demand has been increased globally. And, various types of hybrid systems have been suggested. In response to this market demand, AISIN SEIKI has been developing Synchronizer-less hybrid automated manual transmission (HV-AMT) system aiming excellent transmission efficiency, excellent agility, and shift change quality like a step automatic transmission (AT). This hybrid system is constructed based upon a parallel 2-axis manual transmission (MT) which originally has high transmission efficiency. The synchronizer system of a MT is replaced by a Dog clutch system which does not spoil the transmission efficiency and never makes failure in synchronization. This Dog clutch system includes a modified detent function, a shift actuator of linear motor, advanced function controls for a clutch and a shift actuator.

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”.

There are such outside door handles called smart handles which have a transmitting antenna, a lock/unlock sensor, and a sensor detection circuit, with which operation of door lock is possible just by "touching" the electrostatic-capacitance type sensor of the handles.As the design of the outside handles, body color painting and Cr plating are adopted. However, if plating is applied over the entire surface of a smart handle, electromagnetic waves transmitted from the antenna will be blocked since plating material is electrically conductive. In addition to this, touching a part other than the sensor may change the electrostatic-capacitance of the sensor, which results in unwanted functioning of the lock/unlock sensor. Because of this, only part of the handle, which does not hinder the transmission of electromagnetic waves and does not cause unwanted functioning, is covered by plating, that is called, "Partially plated specifications" (Figure 1).

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.

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.

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.

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.

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.

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.

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.

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.

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)