The invention provides a
common rail oil
injector capable of reducing leakage. The
common rail oil
injector comprises an oil cavity A and an oil cavity B, wherein the oil cavity A and the oil cavity Bare formed by a control
piston and a pore plate; when the control
piston ascends and descends, a high-pressure oil passage communicates with a low-pressure oil passage through two oil passages of theoil cavity A and the oil cavity B. After the lift of the control
piston reaches the maximum value, the communication between the oil cavity B and the low-pressure oil passage through a throttling ring belt is
cut off, high-pressure oil only passes through a throttling hole and the oil cavity A to be leaked to the low-pressure oil passage through an oil outlet hole, so that the flowing resistanceis increased, and oil return during oil spraying, heating of the oil
injector and
oil supply pump
power loss are reduced. Meanwhile, the
flow ratio of the oil outlet hole to an oil inlet hole can be larger, so that the oil
drainage time of a control cavity and the oil injection
delay of the oil injector are reduced. After the communication of a passage, flowing through the throttling ring belt, between the oil cavity B and the low-pressure oil passage is
cut off, and the oil cavity B only communicates with the low-pressure oil passage through the throttling hole and the oil cavity A, so that the flowing resistance of the low-pressure oil passage is increased, and the oil cavity B is kept higher in pressure, the pressure of the control cavity is restored faster after an
electromagnetic valve is powered off, the oil spraying closing
delay is shorter, and the oil spraying sensitivity of the oil injector is improved.