US2478500A - Fuel injector - Google Patents

Description

2 Sheets-Sheet 1 2 3 a M \m r w 9 E 2 n M i Aug. 9, 1949.

G. PARSONS FUEL INJECTOR Filed July 24, 1944 5. G. PARSONS FUEL INJECTOR Aug. 9, 1949.

2 Sheets-Sheet 2 Filed July 24, 1944 INVENTOR. J56 6? 7 41 50 75.

Patented Aug. 9, 1949 FUEL mmcron Ben G. Parsons, Grosse Pointe, Mlch., assignor to Fuel Charger Corporation, Detroit, Mich, a

corporation of Michigan Application July 24,4944, Serial No. 546,351

3 Claims. (01. 103-38) 1 The present invention relates to improvements in liquid pumping devices and particularly to improvements in fuel injectors for use with internal combustion engines.

One of the primary objects of the present invention is to provide improvements in singleplunger injectors, particularly for gasoline engines, which are eflicient in actual operation and relatively simple and economical to construct.

Another object of the present invention is to provide improvements in structures of the type mentioned having improved adjusting means for controlling the fuel metering for the amount of fuel delivered by the injector through the delivery port.

Otherobjects of the invention will become apparent from the following specification, the drawings relating thereto, and from the claims hereinafter set forth.

In the drawings, in which like numerals are used to designate like parts in the several views throughout,

Fig. 1 is a vertical cross-sectional view, with parts in elevation, of a single-plunger fuel injector embodying features of the present invention;

Fig. 2 is a cross-sectional view taken substantially along the line 2-2 of Fig. 1;

Fig. 3 is a cross-sectional and elevational view taken substantially along the line 3-3 of Fig. 1;

Fig. 4 is a partial view similar to Fig. 2, showing the cam adjusting means in a different position;

Fig. 5 is an elevational view of the structure shown in Fig. 1 and showing the injector diagrammatically connected to a fuel nozzle;

Fig. 6 is an exploded view of the injector, and

Fig. 7 is a cross-sectional view of the delivery valve taken substantially along the line 1-1 of Fig. 6.

Referring to the drawings, the injector structure includes a plunger housing I having a longitudinally extending plunger bore 2 formed therein and opening through the top of the housing I. The lower end of the bore 2 opens into a transversely extending circular opening 3.

,The housing I has an inlet aperture or port 4 and an outlet or return aperture or port 5 formed therein, such apertures being axially aligned with each other and communicating with the bore 2 through an enlarged annular recess 6 which is formed in the housing I intermediate the ends of the bore 2.

A hollow plunger 1 is reciprocally disposed within bore 2, and the upper edge of the rim 8 thereof is plane and lies in a plane normal to the axis of reciprocation of the plunger 1.

The 'bore 2 is of uniform diameter throughout its length, except for the enlarged recess 6, and the upper end thereof is adapted to have mounted thereon an outlet or delivery housing 8. A delivery valve housing or holder 9 has a depending, smooth, cylindrical portion which is telescopically received within the upper end of bore 2 and is formed with an annular flange I0 which is adapted to rest upon a gasket H which in turn rests upon the top of the housing I. The delivery housing 8 rests upon the top of valve housing 9 and has a gasket l2 interposed therebetween. The housing 8 is removably secured to the top of housing I by means of screws l3 which pass through openings and side flanges of housing 8 and are received within tapped openings in the top 01 housing I. By this structure, the bore 2 need not be internally threaded, and the parts are relatively simple to construct and may be readily assembled and disassembled.

The valve holder 9 is formed with a delivery port or passage l 4 therethrough which terminates adjacent the upper'edge in a conical valve seat [5 and terminates on the lower side in an annular, enlarged recess I6 which serves as a spring retainer. The passageway I4 is axially aligned with bore 2. formed therein which terminates at its upper end in a threaded portion l8 adapted for connection with the conduit coupling. The lower edge of port I! communicates with an enlarged, cylindrical recess IS, the port I! and recess l9 being aligned with discharge port M.

A delivery valve 20 is adapted to be received within valve holder 9 and has a depending stem portion 2i which is received within passageway I l. The stem portion 20 has three flattened sides, as best seen in Fig. 7, with portions of the peripheral edges of the sides retained and bearing against the sides of aperture l4 so that the valve 20 is maintained in alignment during its opening and closing movements. The valve 20 is formed with a conical valve portion 22 which is adapted to seat on conical valve seat It when the valve The housing 8 has a discharge port l1,

is closed. The upper end of the valve is formed with a projection 23 which serves to keep centered the lower end of a compression spring 24. The spring 24 is received within the recess l9 with the upper end of the spring abutting against the shoulder formed adjacent the discharge port [1. Thus, when the parts are assembled, as shown in Fig. 2, the valve is resiliently urged against valve seat l5.

A coil or compression spring is received within the bore 2 and extends downwardly within the hollow. cylindrical portion of plunger 1 abutting against the closed bottom thereof. The upper end of the spring is received within the annular recess [6 of holder 9 so that the plunger 1 is normally urged to its down position, and the returner intake stroke of the plunger is effected by the action of spring 25. v

In its reciprocation. the plunger 1 extends downwardly within the circular opening 3. and the reciprocation of the plunger 1 is controlled. by an adjustable drive means. The dr ve is effected by means of a drive shaft 26 which is mounted in ball bearing assemblies 21 and 28. Such assemblies 21 and 28 are mounted within a driv shaft housing 29. The housing 29 has a suitable flange 39 formed thereon for mounting on the engine to which the fuel is supplied. The end of the drive shaft 28 may be connected to one of the engine shafts in a suitable manner. The plunger housing I is mounted to the housing 29 with the axis of opening 30 aligned with the axis of drive shaft 26. The drive shaft 26 has an eccentric portion 3| which is circular in cross section. The eccentric portion 3| projects within the opening 3 in a position beneath plunger l. An adjustable cam means is interposed between the eccentric 3i and the bottom surface of plunger l providing the drive connection therebetween. Such cam means includes a cam 32 having a cylindrical recess 33 formed therein which envelopes and bears against the peripheral surface of eccentric 3|. The surface of eccentric 3| is preferably silver plated. The shape of cam 32 is best seen in Figs. 2 and 3, and it will be appreciated that such cam has a high portion which is shown at the ri ht of Fig. 2

posed upwardly in Fig. 4;. 1

InFig. 2, the capacity control cam 32 is shown in zero setting, while in Fig. 4 it is shown in its full capacity setting. The cam 32 is adapted to be turned or rotated with respect to the eccentric portion 32 through ninety degrees from the zero setting to the full capacity setting. In any of its settings, it will be appreciated that as the eccentric 3| is turned, it causes th delivery, or upward, stroke of plunger 1. The return or intake stroke is effected by the spring 25 which urges the plunger against the cam. The relative position of the plunger 1 with respect to the inlet port 4 and the delivery port at the beginning of the delivery stroke of plunger 1 is thus adjustably controlled by adjusting cam 32. The metering or amount of fuel delivered is thus controlled by adjustably setting the position "of the plunger 1 with respect to the inlet port 4 at the beginning of the delivery stroke. It will be understood that the length of stroke of the piston 1, caused by the extent of eccentricity of eccentric portion 3|, is uniform for all settings of the capacity control cam, but that the amount of fuel delivered is dependent upon the position of the upper or rim edge of the plunger with respect and in another adjusted position is shown dis- 4 to tle inlet port at the beginning of the delivery s ro e.

It will be appreciated that the cam 32. while in a fixed adjusted position. moves with the eccentric portion 3| upon rotation of shaft 26. Means are provided for adjustably setting the cam to the desired position while at the same time permitting this movement of the cam with the eccentric. Such means are mounted within a housing 34 which has an axial opening 35 therethrough and which is formed with an annular recess 36. An annular flange 31 is formed around the cylindrical recess portion and abuts against the adjacent side of the plunger housing I when the parts are assembled, as shown in Fig. 1. Bolts 38 may be passed through the flange of housing 39, the pump housing I. and the flange 31 to hold the parts in their assembled position.

A capacity control shaft 39 is rotatably mounted within the opening 35 and projects outwardly therebeyond. A control handle or lever 40 is fixed to the outer end of the shaft so that the shaft may be turned through an angle of 90 to efiect the adjustment desired. An oil seal 4| embraces the shaft 39 and is disposed in a cylindrical recess adjacent the outer face of housing 34 so as to prevent leakage along shaft 39.

The inner end of shaft 39 has an integral, transversely extending portion 42 which is rectangular in cross section. A floating coupling 43 is interposed between the cam 32 and the capacity control member 39, and such member 43 is formed with one transversely extending slot 64 which is complementary in shape and size to the shape and size of portion 42 and which slidably receives portion 22 therein. The member 63 is formed with another transversely extending groove d5 which is at right angles to the slot M and which is adapted to slidably receive therein a rectangular portion is of cam 32. The portion 36 is on a diametric axis across the low sides of the cam and is integral with or fixed to cam 32, so that upon turning of portion 46, the cam is correspondingly turned.

The elements just described are shown in their assembled relationship in Figs. 1, 2, and 4, and I in Fig. 1 the elements are shown in the position where cam 32 is in zero setting, and in Fig. 4 the cam is shown in full capacity setting. A portion of the cam is removed along one edge by turning on a dlametrlc adjacent portion 46, as indicated at so, so as to prevent interference with the bore flange on housing 34.. In either the zero or full capacity settings and in any intermediate settings, it will be appreciated that as eccentric portion 3i rotates, the cam is free to move therewith due to the crossed axis sliding or floating connection with the shaft 39. The relative position of the upper end or rim of plunger 1 with respect to the inlet port 4 is dependent upon the cam adjustment.

The cam may be formed symmetrical, if desired, to prevent any mistake in assembly. That is, the cam may be formed with another high portion diametrically opposed to that shown so that with high portions on opposite sides of the cam, it would not make any difference in assembly.

- upper edge of port I or the upper edge of recess 8, the fuel within bore 2 above plunger 1 is forced upwardly against the delivery valve 20 causing the delivery valve 20 to unseat and the charge of fuel is then, delivered through delivery port 11. The return is effected by spring 25 acting in co-operation with the cam and eccentric.

The member 8 has a coupling 41 threadably connected thereto which serves to mount one end of a tubular conduit 48. The opposite end of the tubular conduit 48 is connected to the inlet of an injector nozzle 49. Such nozzle 49 may be of suitable construction and may be of one of the constructions described in the copending application of Ben G. Parsons filed concurrently herewith, Serial No. 546,352, flled July 4, 1944, now abandoned.

With the cam 32 in the zero position shown in Figs. 1 and 2, the eccentricity of portion 81 is insuflicient to eflect a long enough stroke of plunger 1 to cut off the inlet port and deliver any fuel through the delivery port. with the cam seat in the position shown in Fig. 4, the plunger 1 is at its highest position with respect to the delivery port at the beginning of the delivery stroke so that maximum or full delivery is effected upon reciprocation of plunger 1. That is, plunger '1 is first dropped to a position to permit fuel to flow from inlet port 4 to the interior of the plunger and bore 2 and, upon the delivery stroke, the full delivery is effected. At intermediate settings, there will be intermediate amounts of fuel delivered upon each stroke of the piston 'I.

It is also pointed out, in connection with the adjustment shown in Fig. 4. or in other adjustments approaching full capacity setting, that.

there is always an opening permitting flow between ports 4 and 5 through the enlarged annular recess '8. This causes washing out of all air bubbles so that no vapor lock is present, and stops surging in'that the column of fuel is freeto move.

' It is also pointed out that one of the advantages of the above structure is that there is uniform or horizontal delivery by using the plane rim -or end of the plunger, in that spillback is permitted around 360.

What is claimed is:

1. In a fuel pump having a casing, a bore within said casing, fuel inlet and delivery-ports in said casing communicable with. said bore, a delivery plunger reciprocable in said bore in alternate delivery and return strokes, operating means acting to move said plunger in its delivery stroke to force fuel through said delivery port, said operating means including a driving shaft having an eccentric cylindrical portion disposed adjacent said plunger, means mounting said driv-. ing shaft for rotation about a fixed axis a cam embracing said eccentric portion and engaging said plunger, and means mounting said cam on said casing for reciprocation of said cam with respect to said bore upon rotation of said driving shaft, said last-named means including means to adjust the position of said cam with respect to said eccentric portion to control the position of the plunger with respect to the inlet port at the beginning of the delivery stroke thereby to control the amount of fuel delivered through said delivery port.

2. In a fuel pump having a casing, a bore with- Q in said casing, fuel inlet and delivery ports in said portion to control the position of the plunger with respect to the inlet port at the beginning of the delivery stroke thereby to control the amount of fuel delivered through said delivery port, said last named means including a shaft, 9. member connected to said shaft for turning therewith and for transverse sliding movement with respect thereto, and means interconnecting said cam with said member for turning movement therewith and for sliding movement with respect thereto in a direction ninety degrees displaced from the direction of the first mentioned slidins moveiment.

.3. In a fuel pump having a casing, a bore within said casing, fuel inlet and delivery ports in said casing communicable with said bore, a hollow delivery plunger reciprocable in said bore in alternate delivery and return strokes, the leading edge of said plunger lying in a plane normal to the axis of reciprocation, operating means acting to move said plunger in its delivery stroke to force fuel through said delivery port, said operating means including a driving shaft having an eccentric cylindrical portion disposed adjacent said plunger, means mounting said driving shaft for rotation about a fixed axis a cam embracing said eccentric portion and engaging said plunger, resilient means engaging said plunger to effect the return stroke thereof, and means mounting said cam on said casing for reciprocation of said cam with respect to said bore upon rotation of said driving shaft, said last-named means including means to adjust the relative rotative position of said cam with respect to said eccentric portion to control the. position of the plunger with respect to the inlet port at the beginning of the delivery stroke thereby to control the amount of fuel delivered through said delivery port.

BEN G. PARSONS.

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

UNITED TATES PATENTS Y Number Name Date 1,868,498 Gruman July 26, 1932 1,978,480 Svenson Oct. 30, 1934 2,048,524 Svenson July 21, 1938 2,247,922 Patter July 1, 1941 2,258,379 Eastey -21.--- Oct. '7, 1941 2,264,898 Bovard Dec. 2, 1941 2,284,139 Fitzpatrick May 28, 1942 2,286,928 Pipkins June 18, 1942 2,348,958

Celio- May 18, 1944

Images