EX200-2型挖掘机采用微机控制,是日立公司推出的高度机电液一体化的产品。该机泵控部分结构简单,采用两只高速电磁阀控制双联伺服变量柱塞泵。变量系统发生故障时常导致整机工作失常,而最常见的故障现象就是发动机失速。所谓发动机失速就是由于发动机超载而导致转速下降或熄火,原因可能出自以下几方面。 1.高速电磁阀有故障 高速电磁阀5、6(见附图)是变量 The EX200-2 excavator is controlled by a microcomputer and is a highly electromechanical integrated product introduced by Hitachi. The pump control part of the machine is simple in structure and uses two high-speed solenoid valves to control the double servo variable piston pump. Failure of the variable system often leads to malfunction of the whole machine, and the most common failure phenomenon is engine stall. The so-called engine stall is due to engine overload caused by reduced speed or flameout, which may be due to the following aspects. 1. The high-speed solenoid valve is faulty The high-speed solenoid valve 5, 6 (see the attached figure) is a variable