US2593788A

US2593788A - Fuel pump

Info

Publication number: US2593788A
Application number: US591967A
Authority: US
Inventors: Ben G Parsons
Original assignee: FUEL CHARGER CORP
Current assignee: FUEL CHARGER Corp
Priority date: 1945-05-04
Filing date: 1945-05-04
Publication date: 1952-04-22
Anticipated expiration: 1969-04-22

Description

April 22, 1952 B. G. PARSONS 2,593,788-

FUEL PUMP Filed May 4, 1945 3 Sheets-Sheet l INVENTOR. Z6/7 )Va/150751 April 22, 1952 Filed May 4, 1945 B. G. PARSONS FUEL PUMP 3 Sheets-Sheet 2 Jegrecas- 7705-1222:

El EL 3 Sheets-Sheet 3 B. G. PARSONS FUEL PUMP IN V EN TOR. ,Be/7 6,' 774/150275.

BY M @4% vov-e fwn/MEMS.

Filed May 4, 1945 April 22, 1952 Patented Apr. 22, 1952 y OFFICE FUEL PUMP Ben G. Parsons, Grosse Pointe, Mich., assigner to Fuel yCharger Corporation, Detroit, Mich., a

corporation of Michigan Application May 4, 1945, Serial No. 591,967

1 Claim.

The present invention relates to improvements in liquid pumping devices and particularly to fuel injectors for use with internal combustion engines.

It is a primary object of the present invention to provide improvements in devices of the type mentioned in which improved means are provided for controlling the amount of liquid delivered during the delivery stroke of the pump plunger. v

A further object of the invention is to provide improvements in devices of the type mentioned inA which such devices are of a relatively simple construction and may be accurately and quickly produced in mass production.

yOther objects, advantages, and features of the present invention will become more clearly apparent from the following description, the drawings relating thereto, and from the claim hereinafter set forth.

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

Figure 1 is a side elevational view of a fuel injector embodying features of the present invention and showing such injector connected to an injector nozzle;

Fig. 2 is an end elevational view of the construction shown in Fig. 1, taken from the right end thereof; f

Fig. 3 is an end elevational view of the structure shown in Fig. l and taken from the left end thereof;

Fig. 4 is a vertical, cross-sectional view, with parts in elevation, of the structure shown in Fig. 1;

Fig. 5 is a cross-sectional view taken substantially along the line 5-5 of Fig. 4;

Fig. 6 is a cross-sectional view taken substantially along the line 6-'6 of Fig. 4;

Fig. 7 is a developed elevational view of the actuating cam employed with the structure shown in Fig. 4;

Fig. 8 is a separated or exploded view of certain of the parts making up the injector assembly, with certain of the parts shown in cross section;

Fig. 9 is a view similar to Fig. 8 and show-ing the remaining parts as they would be extended from the right end of Fig. 8; Y

Fig. 10 is a cross-sectional View of the actuating cam;

Fig. 11 is an end elevational view of the drive coupling shown in Fig. 8;

Fig. 12 is a side elevational view of the plunger shown in Fig. 8, and

Fig. 13 is a diagrammatic view illustrating the operation of the structure of the present invention.

The structure of the present invention is particularly adapted to be used on vthe type of injector disclosed in the copending application of BenG. Parsons Serial No. 568,177, filed December 14, 1944, now'Patent Number 2,405,163, dated August 6, 1946, although the broader aspects of the present invention are also applicable to other types of fuel injectors, such as a single plunger, single cylinder type. The structure disclosed in the copending application referred to is a single plunger, multi-cylinder type.

The present invention is illustrated in connection with a fuel injector which employs a single cylinder for distributing liquid fuel, such as gasoline, to a multiplicity of internal combustion engine cylinders. In the particular embodiment illustrated, the pump is designed to distribute to six cylinders, by way of example. It will be obvious that it could be constructed to deliver to more or less cylinders.

The fuel injector is generally indicated at l and comprises a plunger body 2 formed with a central axial bore 3 therethrough. 'I'he pump body 2 has formed therein a plurality of radially extending and equally spaced inlet bores or ports 4 which open into the bore 3. An annular, external recess or groove 5 is formed around the body 2 and communicates with the outer ends of ports 4. There are six of such ports in the embodiment illustrated.

An inlet tube fitting 6 embraces the pump body 2 around the groove 5 to form an annular inlet chamber therebetween. The fitting 6 has a tubular projection l thereon to which a flexible tube or conduit may be connected. The conduit (not shown) leads to the source of fuel supply.

The tting 8 is mounted on the body 2 and has rubber sealing rings 8 disposed on opposite sides thereof, one of the rings v3 abutting against a shoulder formed on the body 2, and the other ring 8 being disposed between the adjacent faces of the fitting 6 and a sealing ring nut 9. The n-ut 9 is threaded onto a threaded portion formed on the exterior surface of the body 2.

A plurality of annularly spaced discharge passageways or bores I0 are also formed in the pump body 2, the inner ends of which open into the bore 3. Such openings are in a plane axially spaced from the plane of the inlet ports 4. The opposite ends of passageways l0 communicate with axially extending openings Il formed in a radially projecting, annular flange l2 of the body asesinas 3 2. There are six of the discharge passageways I in the embodiment illustrated, one for each of the engine cylinders. Such passageways II! are circurnferentially aligned between the inlet ports 4. This relationship is best seen from a comparison of Figures and 6.

The injector assembly I is adapted to be mounted to the crankcase of the engine, as is disclosed in the above referred to copending application, by means of mounting bolts I3 which are passed through the openings II. A distributor ring or tube ring I4 is disposed between the.

CII

flange I2 and the adjacent face of the crankcase..

Sealing gaskets I5 are disposed between the facing surfaces of the ring I4, the crankcase, and the flange I2. Washers I5' are disposed between the heads of bolts I3 and the adjacent faces of flange I2. The mounting bolts I9 pass through openings formed in the camring I4 and have reduced portions IB, which form, with such openings and the opening I I, an annular chamber into which the corresponding passageways IIJ open and communicate.. Y

Distributor tubes or conduits I6, there being one for each cylinder, are xedly mounted on the ring I4 and lead to their respective injector nozzles Il. Such nozzles are of the pressure responsive opening type disclosed in the copending application of Ben G. Parsons, Serial No. 546,352, iiled July 24, 1944, now abandoned, which open to admit 'fluid to the cylinder at a predetermined nozzle opening pressure.

A hollow delivery plunger I8 is rotatably and reciprocably disposed within bore 3 and has an opening through the inner end thereof which is in open communication with the bore 3. The space within the hollow plunger is indicated at I9. The plunger I8 is formed with a plurality of equally spaced inlet openings through the wall thereof adjacent the open end and communicating with chamber I9. There are six of such openings 28 in the embodiment illustrated, one corresponding to each of the inlet. ports 4 and having the same equal spacing. The plunger I8 is also formed with a single delivery opening 2| through the wall thereof which communicates with chamber I9 and which is axially spaced from the ports 2l] and disposed circumferentially between two of the ports 20, as best shown in Figs. 4 and 8. The opening 2I is adapted to register with the inner open ends of ports or passageways Il) in succession, in a manner vthat will become more apparent from the following description, and in the manner disclosed in the above mentioned application Serial No. 568,177.

The plunger I8 is rotated and reciprocated within the bore 3 to eiect delivery of the fuel through the delivery passageways I0 in succession. The closed end of the plunger I8 has transversely extending tongue 22 with a curved end 23. The plunger I8 and tongue 22 project beyond the bore 3 within an enlarged space formed by an integral annular portion 24 of the pump body 2.V

A drive coupling 25 is disposed within the flange 24 and has a groove 26 formed in one end thereof which receives the tongue 22 therein. The opposite side of the coupling 25 has av groove 21 formed therein, which is displaced 90 from the groove 26 and which is adapted to be connected to the source of power for rotating the coupling 25 as disclosed in the above mentioned application Serial No. 568,177. The plunger I8 is thus rotated upon rotation of the drive coupling 25. The reduced end 23 formed on the tongue 22 is provided so that alignment of the plunger I8 within the bore 3 is not disturbed upon rotation of the coupling 25.

The coupling 25 has a pair of diametrically opposed stub axles 28 formed thereon which serve to mount rollers 30. The rollers 30 are retained on the stub axles 28 by means of snap rings 3 I. The rollers 30 are constantly held against the cam surface 32 of a cam ring 33. Cam surface 32 is designed to eiect proper reciprocation of the plunger I8 upon rotation thereof. in the present instance being designed with six crests and troughs. The cam ring 33 is mounted within the flange 24 and is held against axial displacement by means of a snap ring 34 which is received within an annular internal groove formed in the iiange 24. The cam 33 is located in its proper rotative position by means of a locating pin 35 which is received within a groove 36 in flange 24 and projects within an opening formed in the cam ring 33. n

It will thus be seen that upon rotation of the coupling 25 the plunger I8 is caused toV rotate and reciprocate. When the rollers 30 are on the crests of cam 32, the plunger I8 is at the beginning of the inlet or suction stroke; and the six inlet openings 4 are overlapped with the inlet openings 20 in the plunger to provide inlet communication with the interior space I9. At this time, there is no communication between the distributor openings 2| and any of the passageways I8, since the passageways I0 are aligned with ports 4 and opening 2I is displaced with respect to openings 2li.l When the rollers 30 are in the troughs of cam 32, the plunger I8 is at the end of the intake stroke and the beginning of the delivery stroke. Further rotation of the plunger I8 brings the opening 2| into communication with one of the passageways III. At this time the ports 4 are closed oi. There are thus six cycles of reciprocation of the plunger for each rotation thereof so that for one rotation of the plunger the opening 2I is brought into communication with all of the passageways I0 in succession.

A coil spring 38 is disposed within the hollow plunger I8 Vwith one end bearing against a centering button 39, which in turn Vseats within the end of space I9. The opposite end of the spring 38 abuts against a shoulder 40 formed in the body 2 adjacent the end of bore 3. Axial opening 4I communicates the bore 3 with a pressure chamber 42, formed in the body 2. The bore 4I adjacent the pressure chamber 42 is formed Vwith an annular valve seat 43 and a hollow valve 44 is disposed within the bore 4I. Such valve 44 has an annular tapered portion 45 adapted to seat on valve seat 43. An annular groove 46 is also formed in the valve 44 and a pair of diametrically opposed openings 41 are formed through the wall of the valve 44 in the base of recess 46, communicating with the interior hollow portion of the valve.

The valve is urged toward the valve seat 43 by means of a coil spring 48, one end of which bears against the closed end of the valve and the opposite end of which bears against the inner surface of a control nut 49. The control nut 49 is threadably received onto an externally threaded portion of pump body 2. A control lever 50 is xed to the nut 49 and may be rotated to control the spring pressure exerted on the valve 44 to urge it against its valve seat and to close communication between the bore 3 and chamber 42.' ,A

Passageways 5I are formed in the valve'body .5 2 which communicate with the chamber 42 and communicate with each of the ports 4, there being one of such passageways l for each of the ports 4. Thus, when the valve 44 is opened, iluid delivered by the plunger I8 will pass through opening 41 into chamber 42 and back to the inlet ports through passageways 59. The point at which such valve 44 is opened will thus determine the amount of fuel delivered through opening 2| during the delivery stroke of the plunger |8. If the nut 49 is turned so that pressure exlerted on it by the fuel pressure, built up during the delivery stroke of the piston I8, is less than the nozzle opening pressure, that is, the opening pressure of injector nozzle l1, all of the fuel delivered by plunger i3 will be returned to the inlet ports through passageways 5|. By adjusting the nut 49, the pressure required to open the valve 44 may be varied, so that if it is set above nozzle opening pressure, all the fuel will be delivered through the openings 2| and to the cylinders through the nozzles.

At any intermediate setting of the nut 49, the valve 44 is opened and fuel is returned through the passageways 5| until nozzle opening pressure is reached. After the plunger develops pressures higher than nozzle opening pressures, the fluid is introduced into the cylinders through the nozzles. Thus, by adjusting nut 49, the amount of fuel delivered through the nozzles may be adjustably set. The relationship of the different settings of nut 49 to vary the spring pressure in comparison with the nozzle opening pressure is illustrated in Fig. 13.

In the operation of the device above described, and assuming that the nut 49 is set for opening at a pressure above nozzle opening pressure, fuel is constantly supplied through the tube 7 so that there is a constant supply of fuel within space 5 and Within the inlet ports 4. With the plunger I8 in such a rotative position that the rollers 30 are on the crests of cam 32, the plunger is at the beginning of its intake stroke. As the rollers 30 move toward the troughs of the cam, the plunger 8 moves toward the left, viewing Fig. 4, with the openings overlapping and communicating with inlet ports 4. Fuel is thus drawn into the space I9. When the rollers reach the troughs in the cam 32, the plunger is at the end of the intake stroke and at the beginning of the delivery stroke. Further rotation of the plunger I8 causes the rollers to move to the crests of the cam, and at the beginning of such movement communication between openings 20 and 4 is cut oil, and opening 2| communicates with one of the passageways i9 delivering fuel to the injector nozzle H associated with that passageway through its particular conduit I6. As soon as nozzle opening pressure is reached, fuel is then delivered through the nozzle to its particular cylinder during those degrees of rotation of the plunger while the particular pressure above nozzle opening pressure is maintained. A uniform charge of fuel is thus delivered through the opening 2| to the delivery ports 4 in succession as the plunger |3 rotates and reciprocates, for a particular setting of the nut 49. The stroke of the piston I8 is constant, but the amount of fuel delivered through the nozzle may be adjustably controlled by adjusting the nut 49, which in eiect adjusts the pressure responsive opening of valve 44.

What is claimed is:

In a fuel pump having a pump body, a longitudinal bore within said body, inlet ports through said body communicating with said bore, delivery ports through said body axially spaced from said inlet ports and communicating with said bore, a hollow delivery plunger disposed Within said bore, means in said plunger communicating the interior of said plunger with the inlet ports, means in said plunger communicating the interior of the plunger with said delivery ports in succession, means to reciprocate and rotate said plunger to eifect delivery of fuel through said delivery ports in succession, and adjustable pressure responsive valve means directly communicable with said bore for controlling the amount of fuel delivered through the delivery port in each delivery stroke of the piston.

BEN G. PARSONS.

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

UNITED STATES PATENTS Number v Name Date 1,791,600 Onions Feb. 10, 1931 1,951,340 Bohuslav Mar. 20, 1934 1,974,851 Hurst Sept. 25, 1934 2,145,379 Vogelei et al. Jan. 31, 1939 2,219,002' Beeh Oct. 22, 1940 2,286,928 Pipkin, Jr June 16, 1942 2,333,698 Bremser Nov. 9', 1943 2,351,908 Beeh June 20, 1944 2,357,870 Beeh Sept. 12, 1944