凸轮-柱塞高压供油系统等压泵油特性研究  

Constant Pump Pressure Characteristics in Cam-Plunger High Pressure Fuel System

作　　者：刘福水[1,2] 杨子明 黎一锴 胡若[1] 沈宏继[3] LIU Fushui;YANG Ziming;LI Yikai;HU Ruo;SHEN Hongji(School of Mechanical and Engineering, Beijing Institute of Technology, Beijing 100081, China;Collaborative Innovation Center for Electric Vehicles, Beijing 100081, China 3. 63963 Force, Beijing 100072, China)

机构地区：[1]北京理工大学机械与车辆学院 [2]北京电动车辆协同创新中心 [3]63963部队

出　　处：《农业机械学报》2018年第6期393-399,共7页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金项目(51606010)

摘　　要：凸轮型线直接影响压油柱塞的运动规律,从而影响其泵油特性,是高压供油系统设计的关键。以电控单体泵(EUP)为研究对象,采用实验和仿真相结合的方法研究了凸轮型线与泵端压力间的动态关系,结果表明:在一定脉宽范围内,采用等速凸轮的柱塞泵峰值压力随喷油脉宽的增加而增加,但其增速随脉宽的增加逐渐变小,当喷油脉宽足够长时,压力将趋于一定值;采用降速凸轮的柱塞泵,利用压力先增大后减小的特性可以在较短的喷油脉宽内达到近似等压状态。最后以等压泵油特性为目标,提出了不同匹配转速下降速凸轮工作段加速度的计算方法,并为某型发动机匹配设计了供油凸轮型线,获得了良好的等压供油特性和最大循环喷油量。Cam profile is a key point to the design of high-pressure fuel system. It has a direct influence on the movement of the plunger, which affects the pressure characteristics of the pump. Based on the electronic controlled unit pump （EUP）, the dynamic relationship between the cam profile and the pumping pressure was studied by means of experiment and simulation. It was found that within a certain period, the peak pressure was increased with the increase of injection duration using a constant speed cam profile, but the rising rate was decreased with the increase of the injection duration, and the peak pressure tended to be a constant value if the duration was long enough. With deceleration cam profile, the pump can reach approximately constant pumping pressure within common engine injection duration by adopting the dynamic performance in transitional period, in which the pressure was increased firstly and then decreased. In order to evaluate the quality of the constant pressure performance, an evaluation parameter was put forward, which was called constant pressure coefficient, and the influence of the acceleration rate in working section on the constant pressure coefficient was studied. Finally, in order to reach the constant pressure characteristic, a selection method of the optimum cam profile was put forward for different matching speeds. A supply cam profile was designed for a certain engine with a -0. 013 mm/（°CA）^2 deceleration rate of working section and a good constant pressure characteristic （10- 15°CA injection duration） and maximum cycle injection volume （438 mm^3） at engine speed of 1 200 r/min were obtained.

关 键 词：柴油机 供油系统 等压喷射 凸轮型线 匹配设计 

分 类 号：TK421.4[动力工程及工程热物理—动力机械及工程]