| 摘要 |
PURPOSE:To prevent jumping of a plunger without deteriorating the pressure damage thereof and stabilize the injection characteristic of the pump by setting the pressure of a high pressure chamber path in a period, in which the lift acceleration of a cam profile becomes negative, at a high value. CONSTITUTION:The delivery pressure of a vane pump is supplied to a cut-off port chamber 26 through a pressure control chamber 25 and the high pressure paths 27a, 27b. According to this constitution, the pressure of the cut-off port chamber 26 becomes higher than the same of a pump chamber 22, the releasing resistance of fuel from a fuel releasing port 40 is increased, the fuel pressure of the high pressure chamber path 33 becomes higher than the same of the pump chamber 22 at least and the fuel pressure is kept in a level higher than a predetermined level. Accordingly, even if the acceleration of cam lift becomes negative, the plunger 35 is held under being pressed against the cam surface of an internal cam 36 surely and the jumping of the plunger 35 may be prevented. |
