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We introduce a new particle excitation control valve that is driven by a vibration of a different direction from the previous particle excitation control valve. Conventional small hydraulic servo valves have some disadvantages such as a complex structure and waste of hydraulic energy. As a way to solve these disadvantages, we study a hydraulic small control valve using a piezoelectric vibrator. We confirmed that the proposed control valve was operated with low viscosity fluid in our previous research. However, the control valve was not operated with high viscosity fluid, because a force required to open the valve is increased due to rising of the viscosity. In this paper, we fabricate a new prototype valve driven by the perpendicular vibration to the flow direction in order to achieve the operation of the valve with the common hydraulic oil, and evaluate the characteristics of the valve due to changing the valve seat shapes. As a result, we found that the taper angle of the valve seat has an optimum value. When the taper angle of the valve seat is 100°, the prototype valve was opened by the lower voltage than the other taper angles. In addition, when the silicone oil was used as the working fluid, with kinematic viscosity values of 30㎟/s, which is nearly equal to the kinematic viscosity of the common hydraulic oil, we have succeeded in opening the valve at 0.8MPa. Since the previous particle excitation valve cannot be opened in the high viscosity working fluid, these results indicate the possibility for operating the proposed valve with the common hydraulic oil.

Hydraulic proportional valves generally suffer from their large size and heavy weight due to their complicated structures using large solenoids or motors. Therefore, they have some limitations of design or decrease mobility of hydraulic systems. In this paper, we present a small hydraulic flow control valve using particle excitation by a PZT vibrator. This valve can control the flow rate of water by the applied voltage to the PZT vibrator. The prototype of the proposed valve evaluated the relationship between the applied voltage, the impressed pressure, and the flow rate. This fundamental evaluation successfully indicated the flow-controllability of the proposed valve.

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