초록 ▼

Check valves (500) are incorporated into a fuel injector so as to form a controlling orifice in the system between the solenoid vales which direct fuel to the respective injection and timing chambers of the fuel injector and the chambers themselves. The precision fuel metering capability of the valv

Check valves (500) are incorporated into a fuel injector so as to form a controlling orifice in the system between the solenoid vales which direct fuel to the respective injection and timing chambers of the fuel injector and the chambers themselves. The precision fuel metering capability of the valve (500) is determined by an annular clearance created between the plunger (512) of the valve and the valve body (510) when the valve is in its maximum stroke. For achieving a bi-stable operation of the valve, the ratio of the plunger valve seat (510d) area to the maximum plunger valve (512b) area and the spring (514) are key parameters. The check valves (500) are formed as cartridge type check valves that can be calibrated outside of the injector prior to the installation thereof.

대표청구항 ▼

[ We claim:] [1.] In a fuel injection system for providing combustible fuel to a cylinder of an internal combustion engine, a check valve comprising:a housing;a fluid passage extending through said housing, at least a portion of said passage having a predetermined cross-sectional area;a valve member

[ We claim:] [1.] In a fuel injection system for providing combustible fuel to a cylinder of an internal combustion engine, a check valve comprising:a housing;a fluid passage extending through said housing, at least a portion of said passage having a predetermined cross-sectional area;a valve member displaceably positioned in said portion of said fluid passage having said predetermined cross-sectional area, said valve member being displaceable between a closed position in which it engages a valve seat provided in said housing and a fully open position downstream of said valve seat in a fuel flow direction;positioning means for positioning said valve member with respect to said portion of said passage having said predetermined cross-sectional area; anda biasing means for applying a closure force to said valve member in a direction toward said valve seat;wherein a maximum diameter of said valve member is related to said predetermined cross-sectional area of said fluid passage in a manner producing a flow metering orifice of a predetermined size (Ao) between said valve member and said passage when said valve member is in said fully open position;wherein a ratio of a flow-through area of a valve opening of the valve seat to a maximum cross-sectional area of the valve member (As/Av ratio) is set large enough to form a means for producing a bi-stable positioning of the valve member in said fully open position when said closure force of the biasing means is overcome by fluid pressure at said valve seat and positioning said valve member in said closed position otherwise; andwherein when said As/Av ratio, a ratio of said orifice area to said area of the valve opening of the valve seat area (Ao/As ratio), and a ratio of a valve spring preload distance to a seat diameter (d/Ds ratio) are plotted on a three dimensional graph representing a surface defined by a variance of said ratios, the resulting plotted being above the defined surface.