US1934580A - Fuel injection mechanism - Google Patents

Description

NOV- 7, 1933 L. M. wooLsoN 1,934,580

FUEL INJECTION MECHANISM Filed July 22, 1930 r4' AV V Y C, an atomlzingI device Patented Nov. 7, 1933 lullm'riezn STATES PATENT NOFFICE.

Mich., field Village, Mich.,

By Emma. F. Woolson, executrix, Bloomassignor to Packard Motor Car Company, Detroit, Mich., a corporation of Michigan Application July 22, 1930. v Serial No. 469,896

` 2 claims. 01. a99-107.6)

The present invention relates to liquid yfuel injection mechanisms for internal combustion engines, particularly engines of the Diesel type in which a predetermined quantity of liquid fuel is introduced into an engine cylinder at or near the compression stroke of the piston, against the high pressures obtaining in the cylinder at that period of the engine cycle. j

Numerous types of fuel injection mechanisms for engines of this class have been heretofore designed or suggested, and in the pending patent application of Hermann I. A. Dorner, Serial No. 365,094, a fuel injection mechanism is disclosed of simple character, rugged construction, and high eiiiciency in use. The present invention particularly contemplates an improvement upon a fuel injection mechanism of the Dorner type, and will be disclosedin connection with a fuel injection mechanism constructed along the lines of a Dorner fuel injector, but it will be appreciated that the principle of the invention may be embodied in numerous types of fuel injection mechanisms.

In the drawing:

Figure 1 is a longitudinal axial sectional view through a fuel pump and fuel atomizing device ln which the invention is incorporated, the atomizing member being shown being mounted upon the cylinderl wall of an engine;

Figure 2 `is a longitudinal section Ithrough the atomizing device alone, but illustrating certain of the parts ln positions which are diierent from those which they are shown to occupy in Figure 1; and

' Figure 3 is an axial section through portion ofthe fuel conduit of the fuel atomizing device, on a somewhat larger scale.

A portion of an engine cylinder `.is indicated at at A, and a fuel pump is generally indicated at P. The atomizing device comprises essentially a body portion 10, which is secured to the cylinder wall by any suitable means, and a nozzle-like projection 11 which extends through the cylinderl wall and terminates at' or about the inner. cylindrical surface of the wall. The pump P is disposed at right angles to the body-10 of the atomizer and comprises essentially a barrel 12 rigidly secured to the atomizer body10, as by means of threaded engagement of its upper end with a laterally extending cylindrical portion 10 of the atomizer body. The barrel 12 receives, with a close t, the interior sleeve 14, this interior sleeve in turn being axially aperturedy to receive, with a close sliding nt, the pump' plunger 15. This plunger is reciprocated within the sleeve by any suitable means, preferably by some means driven by the engine and in timed relationship to the movements of the piston incylinder C.

The lower end of plunger 15 is enlarged at 16, 50 and this enlargement is retained within a recess formed in a cross-head member l7. The crossJ head 17 slides as a piston in the hollow interior of the cylindrical lower end of barrel 12, ports 18 being formed in this portion of the barrel, above cross-head 17, to prevent the building up of air pressure above the cross-head. A coiled compression spring 19, which is housed Within the lower end of the barrel, normally opposes upward movement of the cross-head and is ntended to normally urge the cross-head to its lowermost position, which is that shown in Figure 1 of the drawing.

That portion 20 of the hollow interior of the sleeve 14 which lies above the upper end of the 75 plunger in reality constitutes a pump chamber,` fuel under low pressure being introduced into this chamber through lateral ports 2l, when the piston is in a lowered position, from the fuel supply chamber 22, and being entrapped in this chamber when the piston has moved upwardly, on its compression stroke, so far as to close the ports 21. Further upward movement of the plunger forces the entrapped uid upwardly through a conduit which connects the pump chamber and Ithe engine cylinder. 'In its upward passage the liquid passes the two check valves 25, 25, and then enters a relatively long, horizontally disposed passage 26 which is formed in part in the body 10 of the atomizer member and in part in the nozzle portion l1 thereof, this conduit also containing the movable atomizer member 27. Member 27 is spindle-like, or in the nature of an elongated rod, having a cap 28 adjustably mounted on the end thereof which is remote from the cylinder and a head portion 29 on the end adjacent the cylinder, head 29 being connected to the main portion-of the atomizer member by a reduced neck 30. A coiled compression spring 31 encircles the rear portion of the movable atomizer member, a portion of conduit 26 being enlarged to receive this spring, the forward end of the spring abutting against the end of this enlarged portion of the conduit, and the rear end abutting against a collar 32 carriedxby the atomizer member. The spring normally urges the atomizer member toward the right (Figure 1) and against an adjustable stop 33 which may be manually adjusted to advance or retract the atomizer member.

In the operation of the device the plunger 15 lll is intermittently actuated. When, in its upward stroke, it closes the port openings 21, the fluid in conduit 26 above the piston is placed under pressure and is caused to flow through this conduit and to be injected into the engine cylinder for so long a time as the plunger continues its upward movement after having closed the fuel inlet ports. Pressure built up in conduit 26 tends to thrust the atomizer member axially toward the engine cylinder, the c ap 28 comprising a piston having a considerable'end area upon which uid pressure is exerted. This movement is opposed., of course, by the action of spring 3l, and spring 31 is so designed that, at the proper instant in the travel of the atomizer member, it reaches its solid height, thus forming at this instant a positive limiting stop, halting the movement of this member.` The formation of the spring in such manner that it comprises not only a means yieldingly opposing movement of the atomizer member but also alimiting stop is an important feature of the invention.

That end of the fluid fuel conduit which opens into the cylinder'is substantially frusto-conical, and the circular head ofthe atomizing member 27 is intended to work axially of this frustoconical portion of the fluid conduit, without, however, emerging from without this portion at any time. Atomization is effected by discharge of the fluid under pressure in a thin annular stream which issues from the annular orice between the periphery of head 29 of the atomizer member and the wall of the discharge end of the conduit. The atomizer member is therefore effective, in all of the possible` positions -which it may assume, to eect atomization while the fuel injection plungeris moving in fuel feeding direction. Rearward movement of this member is so limited that the head 29 never contacts with the wall of the fuel conduit, and hence the fuel conduit is never quite closed to the cylinder, and forward movement of this member is so limited by the spring that the atomizer head 29 never protrudes beyond the mouth of the fluid conduit. Effective atomization is realized, therefore, for all positions of the atomizing member. Y

Having thus described the invention, what is claimed as` new and desired to be secured by Letters Patent is:

1. In a liquid fuel injection mechanism for internal combustion engines, in combination, a nozzle body member associated withrthe cylinder wall and having a liquid conduit therein which opens into the interior of the cylinder, the wall of said conduit at the discharge end thereof fiar- `head positioned inthe ing toward the cylinder, an atomizer member movably supported in said conduit and having a head positioned in the end of the conduit adjacent the cylinder wall, means for intermittently forcing iiuid under high pressure through said conduit toward the discharge end thereof, thereby urging said atomizer member to move in the direction of uid ow, mutually facing abutments on the nozzle member and atomizer member respectively, and a coiled compression spring in said conduit and between said abutments, said spring having a spring constant which will permit it to be compressed between said abutments to solid height when the atomizer member moves toward the cylinder under-the innuence of fluid pressure to positivelyhalt the movement of said member at a predetermined point and expanding to urge the atomizer in the opposite direction when the fluid pressure is relieved, the solid height of the spring being such that the head of the atomizer member is restrained from emerging from the flaring end of the conduit during fuel injection. A

2. In -a liquid fuel injection mechanism for internal combustion engines, in combination, a nozzle body member associated with the cylinder wall and havinga liquid conduit therein which Vopens into the interior of the cylinder, the wall of said conduit at the discharge end thereof flaring toward the cylinder, an atomizer member movably supported in said conduit and having a end of the conduit adjacent the cylinder wall, means for intermittently forcing uid under high pressure through said conduit toward the discharge end thereof, thereby urging said atomizer member to move in the direction of fluid 110W, mutually facing abutments on the nozzle member and atomizer member respectively, and a single resilient element in said conduit and between said abutments, said element having a stiinessvwhich will permit it to be compressed between said abutments to solid height when the atomizer member moves toward the cylinder under rthe influenceof fluid pressure to positively halt the movement of said member at a predetermined point and expanding to urge the atomizer in the opposite direction when the fluid pressure is relieved, the solid height of said member being such that the head of the atomizer member is restrained from emerging from the aring end of the conduit during fuel injection. A.

EMMA F. WOOLSON,

Executn'x of the Estate of Lionel M. Woolson,.De

ceased.

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