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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.

One of the problems concerning T/M is conventionally how “Improving the input torque as the engine gets higher power” and “Making product lighter in weight and more compact to improve the fuel consumption” can be realized at the same time. To realize these things at the same time, it is needless to say that the gears must be stronger. For the “pitting fatigue strength” which is quoted as a problem lately, the fatigue mechanism has not been clarified, yet. Therefore, it is now a big problem how to achieve high strength. In the meantime, we tried to develop the production engineering for “finer crystal grains” and “fine-dispersion precipitation of carbo-nitrides,” and succeeded in improving “pitting fatigue strength” remarkably. Such results will be reported in the following sections:

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.

Rear steering system can improve vehicle stability using active control of the rear wheel angles. For designing the rear steering system, environmental conditions, performance deterioration due to aging and component variation as a result of manufacturing tolerance under mass production must be taken into consideration. We have applied two-degree-of-freedom (2DOF) feedback control with feedforward control for the motor servo control so that the rear steering actuator can track the target rear steering angle accurately and stably. The control system is designed based upon a nominal mathematical model and its variation range. As a result, the rear steering actuator can be controlled with excellent performance and high reliability. This paper describes the mathematical model construction in the frequency domain and a robust motor servo controller design based on 2DOF feedback control with feedforward control.

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.

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).

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”.

Responsiveness is one of the main characteristics of a brake booster. The design of a tandem booster, with its two boosting chambers, has a negative influence on high responsiveness. This report, using the CFD method for the air flow analysis, shows the way we found the most suitable air passage within the space of the given design of the current production tandem booster.

As a part of our process engineering (planning) steps and in order to shorten the initial flow control after the implementation of a production system, we have been adopting countermeasures for defects that have been forecasted by the application of FMEA. However, due to this having to be done with limited information (which is dependent upon the skill level of the operator) and due to the fact that the effects of each particular countermeasure are not fully understood, we cannot be certain that the measures implemented during the planning stages are thorough enough. The current situation is that countermeasures for most issues are being handled during the initial flow control stages based on the trial-and-error method. Given this situation, normally, it would take us more than three months from the time of line-off (start of production) to achieve our target rate of capacity utilization.

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.