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When developing a motorcycle exhaust system, it is important to predict the fatigue durability of the exhaust system during the design stage. We have been predicting fatigue durability using our own methods [1]. In recent years, however, in order to meet stricter emission regulations, the installation position of a catalyzer has been changed and the temperature of the exhaust system has been increased. Accordingly, the required fatigue durability of mufflers is at higher temperatures than before. With such a change in situation, a prediction method with higher accuracy for fatigue durability that can handle a higher temperature range, was required. The exhaust system temperature distribution and the physical properties of the material change depending on the temperature. Therefore, in the simulation model developed this time, the temperature distribution of the exhaust system is calculated by a heat conduction analysis method applying FEM.

This paper presents the structure, operation principle, and fabrication process of a novel type of flow-velocity sensor. Like the well known classical Pitot (Prandtl) tube, it realizes flow velocity detection by measurement of the pressure difference between stagnant fluid pressure in front of the sensor and static pressure in the flow around the sensor. This difference results in a deflection of a diaphragm suspended boss, that serves as the counter electrode of an integrated capacitor which is directly exposed to the fluid to be measured. Experimental results in the wind tunnel and in the gasoline direct injection experimental set-up confirm the sensor's operation principle and show good time response.

Monitoring motion parameters are increasingly important in automotive and robotics applications, where cheap sensors are highly desirable. A silicon micromachined structure 0.5X2cm in size was designed and fabricated, which can detect not only translational acceleration, but angular acceleration or rate simultaneously and independently, which has a particular merit since it theoretically allows single point detection of all 6 axis of freedom using only three sensors. This is accomplished by capacitive detection of the displacement and the tilt of the seismic mass, symmetrically suspended by two torsion bars. The expected linear dependencies of the output signal on translational and angular accelerations, as well as quadratic dependency on angular rate could be verified. It is shown, that the dynamic response is improved by vacuum packaging.