七十年代初,出现了插装阀和利用插装阀设计的控制系统。国内首先由机械部某研究所设计了一套插装阀(以下简称旧阀),于1976年在合肥锻压机床厂试制成功并应用于该厂300吨四柱万能液压机上,后又用在500吨单动薄板冲压液压机、315吨、500吨、630吨等四柱万能液压机上。但这种老式插装阀先导控制元件多,结构复杂,造价昂贵,从而使该阀配 In the early 1970s, cartridge valves and control systems designed with cartridge valves appeared. In China, a set of cartridge valve (hereinafter referred to as “old valve”) was first designed by a research institute of the Ministry of Machinery. It was successfully trial-produced at Hefei Forging Machine Tool Factory in 1976 and applied to the 300-ton four-column universal hydraulic press of the plant, Single-action sheet metal stamping presses, 315 tons, 500 tons, 630 tons and other four-cylinder universal hydraulic machine. However, this old cartridge valve pilot control components, complex structure, high cost, so that the valve with