TWO STAGE INJECTION TYPE FUEL INJECTION DEVICE

• Main Author: SHINGUU KENJI
• Format: Patent
• Language: English
• Published: 18.11.1987
• Subjects: BLASTING; COMBUSTION ENGINES; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; LIGHTING; MECHANICAL ENGINEERING; SUPPLYING COMBUSTION ENGINES IN GENERAL, WITH COMBUSTIBLEMIXTURES OR CONSTITUENTS THEREOF; WEAPONS

PURPOSE:To make it possible to precisely adjust and set the pressurized characteristic of a two stage injection type fuel injection device with the use of a simple arrangement, by adopting a pressure boost piston mechanism as a means for finally pressurizing fuel, and by adopting a solenoid valve mechanism as a means for controlling the operation of the pressure boost piston mechanism. CONSTITUTION:Fuel discharged from a pump 2 is regulated in pressure by a pressure regulating valve, and is fed into a pressurizing chamber 73 from a passage 12 through a passage 13 and a check valve 14 after the pressure of the fuel is made to be uniform in an accumulator 4. At this time, when a solenoid 62 in a solenoid valve mechanism A is energized, a valve member 61 is lifted up to open a communication hole 64 so that hydraulic pressure in a internal cavity 58 is relieved into a passage 16. Accordingly, a valve member 51 is separated from a valve seat 56 while an annular groove 59 isolates a passage 15 from the passage 16. As a result a working chamber 72 in a pressure boost piston mechanism B is pressurized to lower a piston 70, and therefore, a plunger 71 pressurizes fuel in the pressurizing chamber 73. Thereby fuel is delivered from a delivery valve 9 to a fuel injection valve through a coupling 93 and the like.