流量控制式ECHPS系统转阀结构参数优化设计

Parameter Optimization of Rotary Valve in the Flow Control Type ECHPS System

在流量控制式电控液压助力转向系统(ECHPS)中,转阀结构参数对系统的可变助力特性有重要的影响。应用液阻网络理论对系统的等效通流面积和助力特性进行了分析。建立了转阀阀口通流面积与转阀主要结构设计参数(小坡口宽度、小坡口圆弧偏心距、阀芯键宽、小坡口轴向长度)之间的数学关系。对转阀的主要结构参数进行了优化设计,优化前为0.9mm、10mm、5.76mm和11mm,优化后为1.115mm、4.626mm、5.652mm和4.499mm。仿真计算结果表明优化后可变助力特性范围由1.2升为3,低速转向时最大手力达到了4N.m。

The rotary valve parameters have significant influences on the assist effort characteristics of the flow control type electronic controlled hydraulic power steering （ECHPS） system. The calculating procedures of the equivalent flow area and assist effort characteristics of a flow control type ECHPS system were analyzed using the principles of hydraulic resistance networks. The mathematical relations between the orifice area of the rotary valve and the configurable design parameters （the metering edge width, the metering edge eccentric distance, the flange width and the slot length of the input shaft） were deducted. Subsequently, the optimum parameters Of the rotary valve were obtained by optimization design technique. The values of these parameters were optimized from 0.9 mm, 10 mm, 5.76 mm and 11 mm to 1. 115 mm, 4.626 mm, 5.652 mm and 4.499 mm. The numerical simulation results show that the alterable assist effort range is increased from 1.2 to 3, and the maximal steering wheel force is 4 N·m in low speed.