US2434151A - Fuel injection nozzle - Google Patents

Description

17:. M. FlsK 2,434,151

FUEL INJECTION NOZZLE Griginal Filed May 19, 1941 www ym? ATTORNEY Patented Jan. 6, 1948 FUEL INJECTION NOZZLE Edwin M. Fisk, Mission San Jose, Calif.

Original application May 19, 1941, Serial No.

Divided and this application November 15, 1943, serial No. 510,356

s claims. '(cl. 29e-107.6)

The invention relates to a solid-fuel injection nozzle for an internal combustion engine of the Diesel-cycle type, and this application comprises a division of my application Serial No. 394,097, filed May 19, 1941, said application having issued into Patent No. 2,334,185, on November 16, 1943.

An object of the invention is to provide an improved fuel injection nozzle which operates as a pressure-opened valve during the delivery of a charge therethrough.

Another object is to provide a nozzle having an improved atomizing action upon the discharging fuel.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth or be apparent in the following description of a typical embodiment thereof, and in the accompanying drawings, in which,

Figure 1 is a fragmentary section taken through the axes of an internal combustion engine cylinder and an injector nozzle extending radially of the cylinder.

Figure 2 is an enlarged axial section of the valve portion of the nozzle.

The injector nozzle 83 of my invention is particularly shown as installed for providing an atomizing pressure delivery of liquid hydrocarbon fuel through the fuel injection port 32 at the head end of a cylinder I8 of a Diesel cycle internal combustion engine, said nozzle receiving the liquid fuel under pressure from a suitable fuel pump througha tube 82. In the present arrangement, the nozzle terminates in an atomizing tip member 84 xedly (threadedly) mounted in the fuel injection port 32 for delivering an atomized spray of the liquid fuel to the head end of the cylinder I8 while supporting the nozzle assembly on the cylinder. At its forward end, the nozzle tip member 84 is provided with a conically flaring discharge port extending from a, chamber 8.6 at its inner end and which is of somewhat greater diameter than the port and is arranged to receive the fuel through a duct 81 of the nozzle body and tip which is connected to the tube 82. The tip member 84 is provided with an axial bore 88 of greater diameter than the inner end of the discharge port 85, and said bore slidably carries a cylindrical member 89 having a tapered forward needle point 9| which extends axially through the port 85 as a valve and atomizing tip thereat.

A spring 92 is operative in said nozzle body through a thrust rod 93 axially engaging the valve member 89 to urge and normally maintain a limiting forward and port-closing engagement of the Valve 89 with the inner end of the port 85. When a charge of liquid fuel from a fuel pump is forced into the chamber 86, the resulting pressure therein is operative to unseat the valve 89 and so permit the escape of the charge through the port 85 and about the point 9| for its discharge into the cylinder in atomized form.

The point 9| of the member 89 preferably has the somewhat hour-glass form shown in Figure 2 having its longitudinal surface elements concavedly curved to the nozzle extremity whereby the point 9| is of least diameter at a point inwardly of its extremity. When the valve 89 is in open position by reason of the fuel discharge pressure, the liquid fuel escaping from the chamber 86 is directed in a curved path along the point 9| and through the port 85 for its discharge into the cylinder bore in atomized form in a conically spreading stream having an apical angle determined by the angle of the flaring point portion. The diameter of the point extremity is preferably only just enough less than that of the port 85 to permit the mounting of the valve member 89 in its operative position through the bore 88. It is to be particularly noted that the discharge of fuel along the sweep of the smoothly curved surface of the point 9| through the port 85 avoids any sudden change of direction of the fuel flow and so conserves the discharge pressure for the performance of its atomizing function in the annular passage defined between the point 9| and the opposed flaring face of the port 85.,

From the foregoing description taken in connection with the accompanying drawings, the advantages of the construction and operation of the present fuel injection nozzle will be readily understood by those skilled in the art to which this invention appertains. While I have described the features and principles of operation of an assembly which I now consider to comprise a preferred embodiment of my invention, I desire to have it understood that the showing is primarily illustrative, and that such changes may be made, when desired, as fall within the scope of the following claims.

1. In a normally closed liquid-atomizing nozzle arranged for its opening by action of the pressure of the liquid to be discharged therefrom, a body providing a discharge chamber having a flaring discharge port extending directly from a circular seat at its inner end, an inwardly displaceable valve provided with a symmetrical point extending from within the chamber into the port, said valve point having a longitudinally concave and smoothly continuous side surface providing an tapering portion usarsi normally engaging said seat and an outer ilaring portion opposite the port bore and cooperative therewith when the valve is unseated to define a daring annular passage about the point for connedly directing the discharged fluid from the nozzle.

2. In a normally closed liquid-atomizing nozzle arranged for its opening by action of the pressure of the liquid to be discharged therefrom, a body providing a discharge chamber having a uniiormly flaring discharge port extending directly from a circular line seat at its inner end, an inwardly displaceable valve provided with a symmetrical point extending'from within the chamber into the port, said valve point having a longitudinally concave and smoothly continuous side surface providing an inner tapering portion normally engaging said seat and an outer fiaring portion opposite the port bore and cooperative therewith when the valve is unseated to define a Haring 20 1,934,296

annular passage about the point for connedly directing the discharged iluid from the nozzle.

3. In a normally closed atomizing nozzle, a body providing a discharge chamber having a flaring discharge port extending directly from a :dat chamber side to provide a circular line seat at its inner end and having the bore of the port define an acute angle with said chamber side, an inwardly displaceable valve provided with a symmetrica] point extending from within the chamber into the port, said valve point providing an inner tapering portion normally engaging said seat and an outer Haring portion opposite the port bore and cooperative therewith when the valve is unseated to deilne a ilaring annular passage about the point for connedly directing the discharged uid from the nozzle. f

EDWIN M. FISE.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name I Date 1,201,533 Wackenhuth Oct. 17, 1916 Dorner Nov. 7, 1933 2,183,284 Wiebicke Dec. 12, 1939 2,172,556 Edwards Sept. 12, 1939 1,778,223 Meng Oct. 14, 1930 FOREIGN PATENTS Number Country Date 589,552 Germany Dec. 11, 1933 200,143 Switzerland Dec. 16.1932

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