US2144874A - Fuel injector - Google Patents

Description

Jan. 24, 1939. H. c. EDWARDS FUEL INJECTOR Filed April 5, 193'? um" @am Patented Jan.` 24, 1939 FUEL mmc'roa Herbert C. Edwards, Massillon, Ghia-assigner to The Timken Roller Bearing Company, Canton, Ohio, a corporation of Ohio Application April s, 1937, serial No. 134,787

3 Claims. `(Cl. 299- 107.3)

v This invention relates to fuel injectors for ginternal combustion engines, particularly compression-ignition oil engines. Its principal objects are to devise a simple and eicient injection nozzle of economical and durable construction and to obtain other advantages hereinafter appearing. The invention consists in the fuel injector and 'in the construction, combinations and arrangements of parts hereinafter described and claimed.

In the accompanying drawing, which forms part of this specification and wherein like symbols Jrefer to like parts wherever they occur,

Fig. 1 is a central longitudinal section through Aa fuel injection nozzle embodying myinvention,

the discharge valve being shown in closed position,

Fig. 2 is a view of the outer or discharge end of said nozzle;

Fig. 3 is a cross-section on the line 3-3 in Fig. 1, I

Fig. 4 is an enlarged fragmentary section, similar to Fig. 1, showing the discharge valve in closed position; and

Fig. 5 is a view, similar to Fig. 4', showing the valve in open position.

The fuel injector or nozzle shown in Figs. 1 to 5, inclusive, comprises a cylindrical nozzle member or portion I having an axial bore 2 extending therethrough and a plurality of circumferentially spaced longitudinally disposed fuel passageways 3 leading from an annular groove 4 in the inner or inlet end of said nozzle to an annular groove 5 in the outer or discharge end thereof, these grooves being disposed concentric to said axial bore. The axial bore 2 of the nozzle l is preferably ilared, a at t at the outer end thereof; and it is provided at the inner end of said nozzle with an enlarged internally threaded portion I adapted to cooperate with an externally threaded head 8 of a pin 9 that extends through said bore beyond the flared outer end 6 thereof. 'Ihe pin is formed with acallar I0 that seats against the bottom of the enlarged inner end portion 1 of the axial bore I of the nozzle and thus limits outward movement of said pin in vsaid bore.

The nozzle I has a cap I I threaded thereon that overlaps the outer end thereof and is'provided opposite the outer end of the nozzle pin 9 with a .flared central circular discharge orifice I2. Lc-

cated opposite the discharge ends of the longitudinal fuel passageways 8 of the nozzle is a valve comprising one or more annular disks I3 of thin resilient metal that seat within a'recess I4 provided therefor in the outer end of said nozzle member and close the annular discharge groove 5 therein. These superimposed annular disks or plates are rigidly held at their outer margins only between the bottom of the recess I4 and an internal annular clamping rib I5 formed 5 on the end wall of the nozzle cap Il. The free inner margin of the innermost annular disk bears resiliently against an annularvalve seat I6 provided therefor on the discharge end of the nozzle between annular dischargel groove 5 and the 10 flared end 6 of the axial bore 2 and thus normally prevents the escape of fuel from said nozzle.

The nozzle pin 9 extends beyond the outer end of the nozzle member into the vopenings in the resilient disks I3 where it terminates in a flared 15 -end portion I1. As shown in the drawing, the

opening in the innermost disk is made slightly permit passage of the fuel therebetween when said disk'is raised off its seat; and the openings 20 in the remaining disks are preferably of conl siderably larger diameter than the portion of the pin therein. By the arrangement described, when the pressure of the fuel in the longitudinal fuel passage- 25 ways 3, which are connected to a suitable fuel injection pump (not shown), is sumcient to overcome the pressure.. of the free inner margins of resilient disks I3 on theannular valve seat I6 of the nozzle, the innermost disk is forced away 30 from'said seat, thereby permitting the fuel to 4passbetween said disk and said seat and the annular space between the nozzle pin 9 and thence through the central opening in said plate.

At the beginning of the opening movement of the 35 annular valve plate or disk, the fuel passes betweenthe relatively narrow annular orifice be-l tween the nozzle pin and the opening in said disk,` whereby only a small quantity of fuel is injected. Further movement of said disk brings 4 the opening in said diskopposite the small end of the nozzle, thereby gradually increasing the quantity of fuel discharged due to the increased width of the annular orifice between said disk and said pin. This gradual increase in the quantity 45 of fuel discharged prevents a sudden pressure in- Y crease i'n the engine cylinder and gives smoothness to the running of the engine. When the fuel pressure is` reduced, the annular valve plate springs back into engagement with its annular varied by changing the shape of the portion cf 3g the nozzle pin that cooperates with the valve disk opening to form the annular fuel discharge orice.

What I claim is: 1. A fuel injector comprising a nozzle having an annular valve seat at its discharge end; and a resilient annular valve member having its outer t marginal portion rigidly fixed to said end of said nozzle and its other marginal portion left free and bearing resiliently against said annular valve seat, said end of said nozzle having a nozzle pin extending therefrom into the opening in said annular valve member and spaced from the edge of said opening to form an annular discharge orifice, said valve seat being formed integral with said nozzle and ,said nozzle pin being at all times clear of said valve member and said valve seat.

2. A fuel injector comprising a nozzle having a plurality of longitudinal circumferentially spaced fuel passageways and an axial bore all opening through the outer end thereof, a cap for said end of said nozzle having an axial discharge orifice, a Valve member comprising a plurality of superimposed resilient annular plates having their outer margins clamped between said cap and said nozzle and their inner margins left free with the innermost plate in position vto bear forming an annular valve seat in said end of said nozzle between said annular groove and the adjacent end of said axial bore, a cap for said end of said nozzle having an axial discharge orifice,

a valve member comprising a plurality of superimposed resilient annular plates covering said annular discharge groove with their outer margins clamped between said cap and said nozzle and their inner margins left free and the innermost plate in position to bear resiliently against the annular valve seat on said end of said nozzle between the axial bore thereof and said annular discharge groove, and a pin in said bore with its outer end portion disposed in and cooperating with the openings in said annular plates to form an annular discharge orifice, the entire pin being at all times clear of said annular plates.

i HRBERT C. EDWARDS.

Images