Variable valve lift (VVL) system for automotive engines is one of the key technologies to attain improvement of fuel economy and power output and a reduction of emission. This paper presents a highly reliable VVL mechanism controlled by a hydraulic 3-step rotary actuator. A 3-step VVL with a high-, middle- and low-valve lift of the inlet or exhaust valve, is realized by the pivot shifting of an intermediate cam placed between a camshaft and valve tappet. The hydraulic actuator with no electric device is installed in a cylinder head and its rotary positioning generates 3-step rotation of a specially-designed sprag cam. The actuator can work in low supply pressure of 0.2MPa from the engine oil pump and control 3-step angles within the interval in which the valve is at rest during camshaft rotation. This paper describes the analytical simulation model of the VVL system, and the experimental evaluation for the developed VVL mechanism and hydraulic 3-step rotary actuator.

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This paper describes the design, fabrication, and evaluation of a multi-purpose component for micro total analysis system (μTAS). The component achieves two functions for μTAS application. One is a micropump which transports the liquid and the other is a micromixer which stirs the liquid. With this component, it is possible to downsize a total system because there is no need to integrate pump and mixer separately. This paper proposes the pumping/mixing functions be achieved using ultrasonic vibrations. When operating as a pump, it uses a traveling vibration on ultrasonic vibrator, and when as a mixer, it uses a standing vibration. The ultrasonic vibrator is composed of a PZT disk (φ20mm×0.5mm), a brass disk (φ20mm×2mm) and a phosphor bronze disk (φ30mm×0.1mm). The liquid chamber is φ28mm×1mm. The mixing experiment confirms the effectiveness of the proposed mixing principle.

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This study focuses on the at-home wrist rehabilitation system aiming to achieve the situation where home-stay patients can accept rehabilitation from therapist in clinic. As the first stage, this paper discusses the development of the wrist rehabilitation by remote passive exercise for stroke patients. Firstly, based on the dynamic model of passive exercise, rehabilitation by remote passive exercise is proposed. Secondly, pneumatic pseudo-therapist which can realize the therapist’s rehabilitation actions and pneumatic pseudo-patient which can realize the patient’s resistance are designed and fabricated. Finally, based on the experimental result in clinic, the validity of the rehabilitation system developed in this paper is verified.

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