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In the past we developed an injection-rate detector, however, it becomes no more applicable to modern high-pressure piezoelectric injection systems having functions of multi-stage injection due to the following problems: High-pressure injection generates shockwaves that induce pressure fluctuation, whose amplitudes of high-frequency components could be not effectively attenuated with a low-pass filter, in the detector. High-pressure injection also causes heterogeneous distribution of temperature in the detector, because the pattern of fuel flow from the injection nozzle to the discharge valve at fuel-discharging process is inappropriate. Accordingly, fuel temperature, which is necessary for identifying bulk modulus of fuel, in the detector could not be precisely obtained, thereby causing an unacceptable level of scattering for determining injection quantity. Hence, we developed a new detector in modifying its constructive design to solve the problems.

In this paper, we introduce a research of Steering Damper using MR fluid (Magnetorheological Fluid). In recent years, Steering Dampers have been used in motocross races on off road courses. Steering Dampers stabilize the front end of motocross bikes that are used in competitive races held on rough terrain. The advantage of a Steering Damper is increased stability, however hydraulic Steering Dampers give rise to the problem of ‘Heavy Steering’. In order to solve this problem, we used MR Fluid and developed an Electronic Control Steering Damper that does not use a valve like hydraulic damper. The damper design uses “Direct Shear Mode” and features a steering angle sensor built into the damper, which results in easier, smoother steering. To test the effectiveness of our new design, we installed our new Steering Damper on the YZ 450F (Yamaha's competition model). We then asked for feedback from riders both in Japan and overseas.

The injection rate meter based on W. Zeuch's method was improved to meet the recent requirement for precise measurement of the multiple injection rate and amount in CDI (Common rail Direct Injection) diesel engines. A pressure sensor with a high sensitivity was added to measure the small pressure increase due to the pilot injection and after injection. At the same time a flow meter having a high accuracy was installed in the discharge pipe line to obtain a correction factor to the modulus of elasticity of volume. As a result it became possible to measure the multiple injection amount at an accuracy of ±0.2mm3/stroke in a range up to 40mm3/stroke.

The largest portion of hydrocarbon and/or carbon monoxide emissions is released during engine cold-transient operation. To achieve closed loop control as quickly as possible, a fast light off (FLO) oxygen sensor is required. The heater, element and structure of the thimble-type oxygen sensor that has been used in the market for some time has been improved to achieve closed loop control within 15 seconds. The heater is improved by concentrating the heating area and by lowering its resistance. The heater life is similar to that of the current type by using new materials and adopting new heater temperature control strategies. In addition to the efficiency of heat transfer, the low temperature characteristics of the element have also been improved. The fast light off thimble-type oxygen sensors can now be put to practical use to achieve emission reductions.