Akira Hibi

A Study on the Pressure Control of a Pipeline-Volume System Using High Speed On-Off Solenoid Valves

A pressure control system using high speed on-off solenoid valves is treated in this paper. In the treated system, solenoid valves are connected to a cylinder. Such a system is commonly used in the anti-skid system for automobile use. The pressure transient behavior in such a system is calculated numerically using a characteristics method. The numerical results coincided with the experimental results. This method, however, is inconvenient for the purpose of system design, because there are many governing parameters. Therefore a simple design method using approximate analyses is proposed in this paper. The approximate method can only predict parts of pressure transient behavior in the system, but is very effective for determining the values of governing paramters on the occasion of system design. Newly desinged high speed on-off solenoid valves with 1 ms response time were used in the experimental work of this study.

Dynamic Performance of Pressure and Flow Rate in Oil Hydraulic Pipe Line with Vibrating Valve System : Influence of Nonlinear Characteristic of Valve

In this paper, an oil hydraulic pipe line system terminated by a vibrating valve at one end and a constant pressure source at the other is discussed. The wave form of pressure pulsation and the mean flow rate of the system are calculated by an approximate method considering a nonlinear pressure-flow characteristic of the valve. In these systems, in spite of sinusoidal inputs of valve orifice areas, higher harmonics are generated and the mean flow rate is changed according to the frequency even if the mean valve orifice area and the mean pressure difference remain constant. Using a hydraulic pipe line-spool valve system, the pressure wave form and the mean flow rate are examined experimentally. And the results are compared with the calculating results. Agreement of both results is fairly good.