| 摘要 |
<p>A pressure difference type variable valve control system is disclosed, which comprises a hydraulic supply means, a hydraulically operated device, a valve, and a spring controlling the balance of the piston. Said hydraulically operated device includes a hydraulic cylinder, a piston and a piston rod. Said piston rod moves with the valve. Said piston divides the hydraulic cylinder into an upper chamber and a lower chamber. Said hydraulic supply means is communicated with the upper chamber through an oil-introducing pipe, while said lower chamber is communicated with said hydraulic supply means through a pressure difference proportional relief valve. Because the pressure difference proportional relief valve is used as the key control element, the lift of the valve is not dependent on the pressure in the system and the pressure difference between the upper and the lower chambers is changeable just by varying the electronic signal so that the timing and lift of the valve can be changed at any time. Thus, the response speed of the system is very fast, and the system is simple in construction, is low in cost, is reliable and is small in interference. The system according to the invention can satisfy the requirement of the internal combustion engine having higher speed and therefore can be popularized in the internal combustion engine widely.</p> |
