一、前言电液比例阀的出现扩大了电控液压系统的使用范围。在此之前,液压系统的电控方式有两种:“双位控制”和“伺服控制”。双位控制或称开关控制,常用在普通的液压系统中,它的作用是使一个液压元件接入液压系统或从系统切除,或者只是简单的进行油路的切换,如常见的电磁换向阀。如果要对液压量进行连续的控制,那么就得采用伺服系统使用伺服阀。尽管电液伺服系统的优点很多,但由于它的价格昂贵,维护保养要求较严格,限制了这种系统的应用。然而,近十余年来人们所说的电液比例阀及 I. Introduction The emergence of electro-hydraulic proportional valve to expand the use of electronic control hydraulic system. Prior to this, there are two ways to control the hydraulic system: “two-position control” and “servo control.” Two-position control or switch control, commonly used in ordinary hydraulic system, its role is to make a hydraulic components into the hydraulic system or removed from the system, or simply switch the oil, such as the common solenoid valve . If you want continuous hydraulic pressure control, then you have to use the servo servo valve system. Although the advantages of electro-hydraulic servo system, but because of its high cost, more stringent maintenance requirements, limiting the application of this system. However, in the past ten years, people call the electro-hydraulic proportional valve and