| 摘要 |
PURPOSE: A pulsation preventive vacuum EGR(Exhaust Gas Recirculation) valve is provided to adjust a stable EGR flow rate through preventing the vibration of the valve caused by pulsation in an exhaust system. CONSTITUTION: In a normal state, a vacuum pressure is formed between an upper portion of a valve body(14) and a first diaphragm(16) for the first diaphragm to compress a first return spring(18). The first diaphragm is elevated with a rod(22) for elevating a second diaphragm(24). Then, an exhaust gas communicating hole(20) is opened for recirculating exhaust gas to an intake pipe. In case of elevation of the rod by pulsation of exhaust gas, the first diaphragm is pulled. Moreover, the second diaphragm is elevated by a central flange(28) of the rod. Herein, a second return spring(26) prevents the motion of the second diaphragm while repressing drop of the first diaphragm by a pulley(36). Therefore, the first diaphragm is stopped to stop the rod.
|
