3800吨全自动液压压砖机（主机)设计【cad高清图纸和说明书全套】.zip

ceramic industry DOI: 10.1007/s00170-003-1973-7 ORIGINAL ARTICLE Advanced Manufacturing Technology (2004) J.-C. Renn · C. Tsai Development of an unconventional electro-hydraulic proportional valve with fuzzy-logic controller for hydraulic presses Received: 23 May 2003 / Accepted: 22 September 2003 / Published online: 20 February 2004 Springer-Verlag London Limited 2004 Abstract In this study, an unconventional electro-hydraulic pro- portional flow control valve based on a switching solenoid and a fuzzy-logic controller is proposed for application to hydraulic presses. The main purpose of this study is the attempt to de- velop an electro-hydraulic proportional flow control valve with lowest cost. Since the switching solenoid possesses quite non- linear force/stroke characteristics, it is basically not suitable for the development of hydraulic proportional valves. Therefore, the fuzzy-logic controller is employed to linearize the force/stroke characteristics. The basic idea is the utilization of the numer- ically estimated pseudo-force as the feedback signal. Finally, this newly developed electro-hydraulic proportional flow control valve is installed in a hydraulic press. Experimental results show that the control of the ram velocity of the press cylinder using the proposed electro-hydraulic proportional flow control valve is quite successful. Keywords Fuzzy-logic controller · Hydraulic press · Linearization · Proportional valve · Solenoid actuator 1 Introduction Presses are perhaps the most commonly used machine tools for metal forming [1]. According to different types of actua- tion, they can be classified as mechanical and hydraulic presses. Some distinct advantages of hydraulic presses over mechani- cal ones are the simpler design and construction, the linearly variable output press force and ram velocity of the press cylin- der, the ready adjustment of the ram position and the more ef- fective protection from overload. Figure 1 shows two typical circuits of hydraulic presses [1]. The first (Fig. 1a) represents a pump-controlled system, in which a complex variable-dis- placement pump is used to control the output volumetric flow J.-C. Renn · C. Tsai (a117) Department of Mechanical Engineering, National Yunlin University of Sci- ence and Technology, 123, University Road, Sec. 3, Touliu, Yunlin, Taiwan 640, R.O. China Fax: +886-5-5312062 rate in a manner that is proportional to an applied electrical sig- nal. Consequently, the ram velocity of the press cylinder can also be linearly controlled. Besides, a pressure-relief valve is employed in the circuit to control the output press force of the press cylinder. In the second hydraulic circuit (Fig. 1b), how- ever, a simple fixed-displacement pump is utilized. The control of the volumetric flow rate and the ram velocity of the press cylinder is achieved by an electro-hydraulic proportional flow control valve. Therefore, this hydraulic circuit basically repre- sents a valve-controlled system. In add