US2481441A - Fuel injector - Google Patents

Description

Sept. 6, 1949. B, G, PARSONS 2,481,441

FUEL INJECTOR Filed May 11, 1945 3 Sheets-Sheet 1 INVENTOR. 3a)? 6? 2 /:50/75.

Sept. 6, 1949; B. G. PARSONS FUEL 'IuJEc'roa Filed May 11, 1945 3 Sheets-Sheet 2 INVENTOR.

BY I

B. G. PARSONS FUEL INJECTOR Sept. 6, 1 949.

3 Sheets-Sheet 3 Filed May 11, 1945 \Q a I r \W 4 mm mm H WW m Em \N KN rw n a Q QM. wh u BY M Patented Sept- 6, 1949 oFFi-cg ,Fuatmmc'ron V Ben G.Parsons, Grease Pointe,Mich.i,a ssignoi-'to Fuel- Charger corponfl corporation of Michigan Detroit, Mich., a

AppllcationMay 11, 1945, Serial nmseazst I scams. 193-113) The present invention relates to improvements in fuel injectors and particularly to improvements in multiplunger gasoline injectors for use with internal combustion engines.

One of the primaryobiects' of the invention is to provide improvements in the structure for adjustably controlling theamount' of fuel delivered by the plungers in injectors of the type mentioned. v

A further object of the invention is to provide a simplified injector construction of the type mentioned which lends itself to accurate, economical mass production.

Other objects 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 partsin'the several views throughout:

Figure 1 is a side elevational view of a fuelinjector embodying features of the present invention;

Figure 2 is an end elevational view ofthe structure shown in Figure land taken from the left end thereof;

Figure 3 is a cross-sectional view taken along the line 3-3 of Figure 2;

Figure 4 is an end elevational view of the structure shown in Figure 3 taken from the right end thereof, with parts broken away and illustrating such parts in cross section taken substantially along the line 44 of Figure 3;

Figure 5 is a separated view, showing certain of the parts in cross section and certain in elevation of the parts making up the assembly and showing such parts in their relationship for assembly;

Figure 6 is a view similar to Figure 5 and illustrating the remainder of the parts in their relationship for assembly to the right of Figure 5;

Figure 7 is a cross-sectional view of the ball cup for connecting the plunger to the swash p Figure 8 is an elevational view of the ball head screw;

Figure 9 is a cross-sectional view of the ball Figure 10 is a cross-sectional view of one of the plungers;

Figures '7, 8, 9, and 10 are illustrated in the drawing in their relative positions for assembly; and

Figure 11 is a fragmentary, elevational view of a portion of the wobble plate.

Referring 'toythe drawings, the fuel injector of thepresent invention is generally'indicated at I and comprises a pump or injector body 2 having a-plurality .of circumferentially' spaced, longitudinally extending plunger barrels -or-I bores 3. There. are nine ofsuch'plunger barrels 3 in the embodiment illustrated, the particular injector' here illustrated being designed for distributing fuel to nine cylinders. 'An inlet port 4 is formed through the wall of the body 2, for each of the bores 3, and communicating therewith. Anannular groove 5 is formed in the periphery of the body 2 around the inlet ports I so that all .of such ,portsare incommunication. An annular. tube fitting 61 embraces the body 2 surrounding-the groove 5 and has an inlet tubular projection; I :and a retum tubular projection 3 formed-thereon. The projection I is connected to a suitably flexible conduit leading to asource of supply and the tube 8 is connected toa suitable conduit returned to'the source. a The fitting 6 is mounted on the body 2 bymeans of a seal ring nut 9 which is threaded to the body 2. Seal rings III are disposed between the opposite sides of the fitting. 6 and a shoulder on the body 2 and the adjacent face of the nut 9, to provide a sealed connection for the ring 6 with the body 2.

An axially aligned outlet passage II is formed in the body 2 for each of the bores 3. One end of the passage communicates with the inner end of the bore 3 and the opposite end is formed with a valveseat I2. Another bore I3 is formed in the body'i adjacent each of the valve seats I2. Communication between bore 3 and the chamber formed by bore I3 is controlled by means of a valve I4 having avalve seating portion I5 which is adapted to be seated on valve seat I2. That portionv of the valve I4 which is received within the passage II is triangular in cross-section and has peripheral lands which slidably engage the wall of passage II with the intermediate flat portions providing passageways for. the passage of fuel from bore 3 into chamber I3,when the valve is open. The valve I4 is normally urged toward its seat by means of a compression spring I6, one end of. which bears against the adjacent end of valve I4 and the opposite end of which bears against a retaining screw plug I'I. The re taining screwl'l is'threadably .received within the body 2 and has a washer I8. disposed therebetween.

Each of the chambers I3 communicates with a longitudinally extending discharge passageway I9. formed in the body 2, through an intercon- 3 nectingpassagewayll. Thepamagewayslsare formedasborcsthroughoneendofthebodyi andarepluggedbyscrews II.

Each passageway ll communicates with another passageway 22 formed in an annular flange 23ofthebody2withanaxialopening34 formed therein. The injector i is suitably mounted on the engine by means of mounting bolts 23 which are passed through the openings 24. A drive shaft housing has a radially extending, annular flange IIwhich is mounted tothe adjacent face of the flange 23 and separated therefrom by a gasket 28. The flange 21 has openings 23 formed therein corresponding to openings 34, and the mounting bolts 25 extend through such openings 29. For the purpose of mounting the injector I to the engine, after the injector is assembled, the assembled parts, including the housing 23, are mounted to the body 2 by means of a plurality of equally spaced screws which are passed through aligned openings 3| formed in flanges 21 and 23. A distributor ring or tube ring (not shown) is mounted to the flange 21 by bolts 25. Such ring may be of the type disclosed in copending application of Ben G. Parsons. Serial No. 568,177 flied December 7, 1944 now Patent 2,405,163 granted Aug. 6,1946. The mounting bolts 25 pass through the openings 24 and 39 and corresponding openings in the distributor ring. Such bolts 25 have reduced portions 32 which form with the adjacent surfaces of the openings an annular chamber into which the corresponding passageways 22 open and communicate. Tubes mounted on the distributor ring communicate with their corresponding chambers and lead to their particular injector nozzles, which in turn are associated with their particular cylinders.

A plunger 33 is reciprocabiy and rotatably disposed in each of the bores 3. The inner end of each plunger 33 has a hollow axial recess 34 communicating through the open inner end thereof with the'bore 3. A helical groove 35 is formed in the periphery of the plunger 33 adjacent the inner end thereof and communicates with the hollow interior 34 through a plurality of openings 36 formed in the wall thereof. The opposite end of each plunger 33 has another hollow bore 31 formed therein which is tapped to threadably receive an adjusting ball screw 33. They inner end of the ball screw 38 is formed with resilient fingers indicated at 38 so it is of the locking type. The opposite end of the screw 38 has a ball head 40 formed thereon.

The plunger assemblies, including the plungers throat of the screw 38 is received within the groove. The width of the groove is slightly greater than the diameter of the adjacent throat portion of the screw 38 so that slight circumferential play is permitted between the swash plate 4i and the plungers. The ball heads 40 are received within the groove 42 and are slidably connected to the opposite faces of groove 42 by means of a ball cup 45 and a bail ring 43. The ball cup 46 is disposed on one side of the ball head 40 and the cup 48 on the opposite side. It will be appreciated that the cup 45 and ring 48 4 slidably engagethe opposite faces'of the groove 43 so that sliding movement. radially, is permittedbetweentheballheadsllandtheswash plate 4i as the swash plate assumes its diflerent angular positions.

The swash plate 4i is mounted on an eccen drive shaft 41. The drive shaft 41 has axially aligned bearing P rtions 43 and 43 with an intermediate eccentric portion 33, which is disposed at the desired angle with respect to the axis in order to give the desired stroke to the plungers.

The swash plate 4i has a bearing flange Ii which receives therein the outer race of a ball bearing assembly 32. The inner race of theball bearing assembly 53 is mounted on the eccentric ll of shaft 41.

Thus, upon rotation of shaft 41. which rotates relative to the swash plate 4|. the swash plate is caused to assume its different angular positions to effect reciprocation of the plungers.

In order to rotatably mount the shaft 41, and for other purposes to be hereinafter described, the body 2 is formed with a central axial opening 53 therethrough. A capacity control shaft 44 is rotatably receive within the opening 63 and has an enlarged hollow end SI which mounts therein the cage of a needle bearing assembly 43. The needle bearing assembly I3 rotatably receives therein bearing portion 49 of shaft 41 for rotatably mounting that end of the shaft. The opposite portion 43 of the shaft 41 is mounted to the inner race of the ball bearing assembly 53 which is mounted within an opening 33 formed in the drive shaft housing 28. The outer end of shaft 41 projects beyond the housing 28 and is suitably formed for driving connection to a suitable drive means.

In order to control the capacity of the injector. that is, to adiustably control the amount of fuel delivered upon reciprocation of plungers 33, means are provided for simultaneously rotating all of the plungers 33' about their own respective axes. It will be appreciated, as shown in Figure 3. that at the beginning of the delivery strokeof each plunger, the inner end of such plunger overlaps its inlet port 4. The amount of fuel delivered by the plungers depends upon the points at which the groove 35 overlaps or communicates with the port 4 for communicating the inlet with the bore 3. It will be understood that the stroke of the pistons is constant: but the effective stroke of the pistons, in relation to the time this communication is established between the bore 3 and the inlet port 4, varies according to the rotative positim of the groove 35 with respect to the D In order to accomplish this adjustment, each of the plungers 33 is formed with longitudinally extending gear teeth in the outer peripheral surface thereof which are adapted to mesh with the gear teeth 6i formed on the annular radial flange of the capacity control shaft 54. By rotating shaft 54 the gear teeth 6 on flange meshing with the gear teeth 60 will cause the plungers 33 to rotate about their axes. The shaft 54 has an axial portion 62 of a capacity control lever 63 splined thereto. The portion 62 of the control lever is rotatably received within an axial bore 64 formed in body 2 through one end and communicating-with the opening 53. The lever 33 may be fixed to the shaft 54 b means of a screw 65. In order to limit the rotation of shaft 64 it is formed with radially extending projections 36 which are received within diametrically opposed slots '1 formed in the body 2 between openings 64 and 53. The slots 61 are of predetermined width to give the desired limited movement.

In the operation of the device above described, with fuel constantly supplied to the inlet ports 4, rotation of shaft 41 effects reciprocation of plungers 33. Movement of the plungers 33 toward the left, viewing Figme 3, eifects an intake of fuel to bores 3 through openings 38. Movement. of the plungers 33 toward the right, viewing Figure 3, effects delivery of the fuel. Durin that portion of the delivery stroke in which the groove 35 communicates with port 4, the fuel withinbore 3 is returned through the inlet ports, or spilled back through such ports, and as the delivery stroke of the plungers continues, a point is reached where communication between bores 3 and ports 4 is cut off confining the fuel within the bores 3. Further movement of the plungers in their delivery strokes builds up the fuel pressure to delivery pressure at which time the pressure responsive valve I4 is unseated communicating the bores 3 with their respective chambers I3. The fuel is then delivered from chambers l3 to the respective cylinders through passageways 20, I9, 22 and through the distributor ring.

What is claimed is:

1. In a multicylinder liquid pump, a pump body having a plurality of circumferentially spaced, longitudinally extending plunger barrels, an inlet port communicating with each barrel through the side thereof, a delivery port communicating with each barrel through the inner end thereof, a pressure responsive valve in each delivery port, a delivery plunger disposed within each barrel having a hollow delivery chamber in the end facing said delivery port and said end terminating in a plane norma1 to the longitudinal axis of said plunger, means forming a helical recesspartly around the periphery of each plunger and spaced inwardly from said end, an opening through the base of each recess communicating with said chamber, said plungers being disposed in said barrels so that the inner ends thereof overlap said inlet ports, and means connected to said plungers to efiect reciprocation thereof, the construction and arrangement of said last-named means, said plungers and said openings being such that, upon reciprocation of said plungers, said inlet ports communicate with said chambers through said openings only.

2. In a multicylinder liquid pump, a pump body having a plurality of circumferentially spaced, longitudinally extending plunger barrels, an inlet port communicating with each barrel through the side thereof, means forming an annular groove in said pump body communicating with all of said inlet ports, an annular member having an inlet opening mounted on said pump body in surrounding relation to said annular groove and forming therewith an inlet passageway, a delivery port communicating with each barrel through the inner end thereof, a pressure responsive valve in each delivery port, a delivery chamber, said plungers being disposed in said barrels so that the inner ends thereof overlap said inlet ports, and means connected to said plungers to effect reciprocation thereof, the construction and arrangement of said last-named means, said plungers and said openings being .such that, upon reciprocation of said plungers,

said inlet ports communicate with said chambers through said openings only.

3. In a multicylinder liquid pump, a pump body, means forming a longitudinal central opening through said pump body, means forming a, I

plurality of oircumferentially spaced, longitudinally extending plunger barrels in said pump body surrounding said central opening, an inlet port and a delivery port communicating with each barrel, a pressure responsive valve in each delivery port, a delivery plunger disposed within each barrel with one end of each plunger projecting therebeyond, means formed adjacent the inner end of each plunger to control the amount of liquid delivered according to the relative rotative position of each plunger around its axis, the projecting end of each plunger having gear teeth thereon, a shaft rotatably mounted within said central opening, a gearmounted on said shaft for rotation therewith meshing with the teeth on all of said plungers, means to rotate said shaft, a drive shaft having its axis disposed on the axis of said central opening, a swash plate, means mounting said swash plate on-said drive shaft for relative rotation with respect thereto, means connecting said plungers to said REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PA'I'ENTS Number Name Date 1,342,569 Richer Jan. 26, 1932 2,160,735 Heifer May 30, 1939 2,215,827 Ditto Sept. 24, 1940 2,256,079 Dinzl Sept. 16, 1941 2,236,301 Parsons June 16, 1942 2,388,462 Beeh Nov. 6, 1945

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