超高压共轨喷油系统压力振荡的消除

Elimination of Pressure Oscillation for Ultra-High Pressure Common Rail Fuel Injection System

为消除超高压共轨喷油系统电控增压器增压室内压力振荡现象又不削弱增压能力,在阐明系统工作原理的基础上,通过在增压活塞上开设平衡油压节流孔的方式,设计了滑阀式增压活塞偶件结构,建立了改进后超高压共轨喷油系统的仿真模型,并通过超高压共轨喷油系统性能试验验证了模型的准确性,进而利用模型研究了平衡油压节流孔面积、形状和位置对消振效果的影响.仿真结果表明:平衡油压节流孔面积和位置对消振效果的影响大于平衡油压节流孔形状对消振效果的影响.最后,基于仿真结果试制了新型电控增压器,并利用超高压共轨喷油系统试验装置,开展了新型电控增压器和原电控增压器性能对比试验.结果表明:新型电控增压器能使其增压压力峰值比原电控增压器提高10MPa,同时在增压脉冲结束后,增压室内压力能够提前25ms左右回到基压(100MPa)并保持稳定,压力振荡现象得到了明显消除.

In order to eliminate the pressure oscillation in electric-controlled pressure amplifier pumping chamber of ultra-high pressure common rail fuel injection system while not diminish the pressurizing capacity, on the basis of introducing the system working principle, the slide-valve piston coupled parts were designed through the method of opening a balance-oil-pressure throttle orifice on the pressurizing piston. The simulation model of the improved ultra- high pressure common rail fuel injection system was established. The accuracy of the model was also verified by the performance test of the ultra-high pressure common rail fuel injection system. Effects of the area, shape and position of the balance-oil-pressure throttle orifice on the pressure oscillation elimination performance were studied based on the simulation model established. The simulation results show that effects of the area and position of the balance-oil- pressure throttle orifice on the pressure oscillation elimination performance are greater than the effect of its shape. At last, the prototype of a new-type electric-controlled pressure amplifier was developed and manufactured based on the simulation results. The performance comparison experiment of the new-type and the primary electric-controlled pres- sure amplifier was carried out on the ultra-high pressure common rail fuel injection system test equipment. The ex- perimental results show that compared with the primary one, the new-type electric-controlled pressure amplifier can increase the peak pressure in pumping chamber by 10 MPa. At the same time, the pressure in pumping chamber can return to the base pressure（100 MPa）in a time advance of 25 ms and keep stable at the end of pressurization pulse. This indicates that the pressure oscillation phenomenon in pumping chamber has been obviously eliminated.