Abstract
In this paper, some new achievements of Kagawa's researches on pneumatic techniques and applications are introduced. One of them is concerned with a low noise pneumatic resistance. In regard to its basic principle, compressed air is blown out through a very thin radial slit structure to form laminar flow. By this means, aerodynamic noise caused by turbulence can be decreased to a much lower level comparing with other type resistances like orifice. The radial slit type resistance is applied to develop a new pressure regulator by making the gap thickness of radial slits adjustable, which is characterized by lower noise and less pressure fluctuation. Another proposal introduced in this paper is an unsteady mass flow generator which can continuously generate and control oscillatory flow at a frequency up to 50 [Hz]. An important component of the generator is an isothermal chamber in which the essential isothermal condition is preserved. Utilizing the mass flow generator yields many practical applications, for example, the developments of air power meter. Recently, Kagawa's research interest extended to analysis and development of pneumatic non-contact handling device. A new non-contact handling method called vortex levitation by using swirling air flow is analyzed in Kagawa's laboratory. Swirling air flow can form a parabolic negative pressure distribution to pick up a work piece and keep it stably levitate with a considerably thin gap under the device. Furthermore, it is confirmed that a work piece will vibrate while being picked up and its vibration can be damped to zero due to a damping effect.
