A PRECISION DRIVING SYSTEM COMPOSED OF A HYDRAULIC CYLINDER AND HIGH-SPEED ON/OFF VALVES
Keywords:
hydraulic driving table, on/off control system, on/off valve, precision processing, micro-processing machinesAbstract
In manufacturing technology, the predominant tendency in recent years has been for machine tools, for exam-ple, turning-, milling-, and drilling-machines, to employ electrically operated actuators such as a servo-motor equipped with a ball screw. There are, however, various problems with these electric driving systems; they are excessively large-sized with complex machinery, and their application is expensive, as seen, for example, in the case of the NC-machine. In order to solve these problems, this study aims to develop a precision driving system actuated by a hydraulic cylinder. The hydraulic driving system consists of a cylinder and four ON/OFF solenoid valves. The valves are the same as those used in a fuel injector of an automobile, which are capable of high speed switching, as fast as 1.5 ms. It was confirmed in experiments that the developed system had a moving resolution of 1.2 μm and, as a result, was applicable to a precision driving table for micro-processing.
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References
Hesse, H. and Möller, H. 1972. Pulsdauermodulierte Steuerung von Magnetventilen. Ölhydraulik und Pneumatik. Vol. 16, No. 11, pp. 451-457.
Mansfeld, G. and Tersteegen, J. 1978. Elektro-hydraulischer Positionierantrieb mit schnell-schaltenden Magnetventilen und pulsmodulierter Ansteuerung. Ölhydraulik und Pneumatik. Vol. 22, No. 11, pp. 647-652.
Mansfeld, G. 1981. Fast Switching Ball Valves as Digital Control Elements for an Electro-hydraulic Servo Actuator. 6th International Fluid Power Symposium. Paper G3, pp. 335-348.
Merrit, H. 1967. Hydraulic Control Systems. John Wiley & Sons, Inc.
Muto, T., Yamada, H. and Suematsu, Y. 1990. PWM-Digital Control of Hydraulic Actuator Utiliz-ing 2-way Solenoid Valves. The Journal of Fluid Control. Vol. 20, No. 2, pp. 24-41.
Muto, T. 1992. Dynamics and Control of Actuators. Corona Publishing Co., Ltd.
Sato, Y., Sato, S., Tanaka, H. and Yanai, Y. 1993. Influence of Eddy Current on the Dynamics of High Speed Switching Valve. Journal of the Japan Hy-draulic & Pneumatics Society. Vol. 24, No. 4, pp. 504-510.
Tanaka, H. 1985. Digital Control of Fluid Power Sys-tems. Journal of the Japan Hydraulic & Pneumatics Society. Vol. 16, No. 1, pp. 3-10.
Wennmacher, G. and Yamada, H. 1993. Prototyp eines dynamischen Schnellschaltventiles mit piezo-elektrischer Ansteuerung. Ölhydraulik und Pneu-matik. Vol. 37, No. 10, pp. 794-797.