Patent ID: 9605635
Date: 2017-03-28
CPC Classifications: F02D,F02M,Y02T

Claim:
1. A dual fuel injection valve comprising: a fuel valve block; a hybrid nozzle block coupled to an end of the fuel valve block; a primary cylinder passage formed by the fuel valve block and the hybrid nozzle block such that a first portion of the primary cylinder passage extends through the fuel valve block and a second portion of the primary cylinder passage extends through the hybrid nozzle block; a primary fuel passage formed to introduce a primary fuel to the primary cylinder passage; a primary nozzle hole formed in an end of the hybrid nozzle block; a primary needle valve disposed inside the primary cylinder passage and having a cylindrical hole formed inside an upper portion of the primary needle valve along a central axis thereof; a secondary cylinder passage formed by the fuel valve block and the hybrid nozzle block such that a first portion of the secondary cylinder passage extends through the fuel valve block and a second portion of the secondary cylinder passage extends through the hybrid nozzle block, wherein the secondary cylinder passage is formed separately from the primary cylinder passage and disposed outside the primary cylinder passage; a secondary fuel passage formed separately from the primary fuel passage and introducing a secondary fuel through an upper portion of the primary cylinder passage to the secondary cylinder passage; a secondary nozzle hole formed in the end of the hybrid nozzle block separately from the primary nozzle hole; a secondary needle valve disposed inside the secondary cylinder passage; a first chamber disposed in the secondary cylinder passage so as to correspond to a middle portion of the secondary needle valve and formed by an inner surface of the secondary cylinder passage and an outer surface of the secondary needle valve; a second chamber disposed between the first chamber and the secondary nozzle hole and formed to surround the secondary cylinder passage; a bush disposed between the second chamber and the secondary cylinder passage to separate the second chamber from the secondary cylinder passage and preventing the primary fuel from mixing with the secondary fuel; a primary fuel movement hole disposed inside the hybrid nozzle block and connecting the primary cylinder passage and the second chamber; a primary fuel pressing piston disposed inside the primary cylinder passage coaxially with the primary needle valve and having a primary fuel piston spring disposed inside the primary cylinder passage to support the primary fuel pressing piston; a pressure piston disposed inside the primary cylinder passage and on a top of the primary fuel pressing piston, the pressure piston configured to press the top of the primary fuel pressing piston by pressure of the secondary fuel passing through the secondary fuel passage; and a residual pressure maintaining valve connected to the secondary fuel passage in order to restore the pressure piston.