US3446440A

US3446440A - Double injection system with one nozzle

Info

Publication number: US3446440A
Application number: US646032A
Authority: US
Inventors: Edward C Pelz Jr; Rudolf W Guertler
Original assignee: International Harverster Corp
Current assignee: Navistar Inc
Priority date: 1967-06-14
Filing date: 1967-06-14
Publication date: 1969-05-27
Anticipated expiration: 1986-05-27
Also published as: GB1177918A; DE1751534A1; DE6608699U

Description

E. c. PELZ, JR.. ET AL DOUBLE INJECTION SYSTEM WITH ONE NOZZLE 6 6 z/ gy??? 5%@ Y; S@ fN/ gy @Qges 52 S) F50 'Y c ,58 -E 32 54- FQ: 44 @22 546 40 24/ wz IO Filed June 14, 1967 RUDOLF W 'I/////X///1/ /NVENTRS EDWARD C. PELZ, JR.

W. GU RTLER tried US. Cl. 239-453 6 Claims ABSCT F THE DISCLOSURE A fuel injection nozzle having a plurality of orifices and valve means associated with the nozzle to permit independent injections through said orifices at predetermined fuel pressures. The nozzle is designed to provide a pilot spray through one orifice means and a main injection through another orifice means.

This invention relates to a fuel injection device and more specifically to a fuel injection nozzle having a plurality of orifices.

For certain applications it is desirable to have two fuel sprays into a combustion chamber which are independent of each other in time and direction. This could be achieved by the use of two injection pumps and two injection nozzles, but the uneconomical aspect of this yarrangement is apparent, Accordingly, it is herein proposed to provide a fuel injector device of simple construction in which two orifice means are provided to inject fuel at diderent predetermined times and in different predetermined directions and using only one fuel injection pump.

It is a principal object of this invention to provide a fuel injection device, having a plurality of orifice means each controlled by a -separate valve element.

Another object is to provide a fuel injection device which first can inject a pilot spray and then inject a main spray in response to different pressures of the liquid fuel in the injection device.

The above and other objects and advantages of the invention will be more readily lapparent when considered in connection with the accompanying drawings in which:

FIGURE 1 is an elevation View partially in section of a fuel injector device showing the valves thereof in a closed position;

FIGURE 2 is an eleva-tion view of a portion of a fuel injection pump; and

FIGURE 3 is an enlarged view of a portion of the fuel injection device showing the sleeve valve in an open position.

Referring now to the drawings wherein like reference characters in the several views represent the same parts, reference character designates a fuel injection device and 12 Va portion of a fuel injection pump which supplies pressurized fuel to the injector device 10. The injection pump 12 has a pumping plunger 14 actuated at its lower end by a cam (not shown). The plunger 14 moves up and down and :builds up enough pressure during its upward stroke as viewed in FIGURE 2 to open a fuel delivery valve and force pressurized fuel through conduit 16 to the injector device 1t? into an inlet passage, through a pair of valves and through spray orifices to the cylinder of an internal combustion engine with which the injector device is associated.

The injector device 1i) comprises a nozzle body 18 having an inlet fuel passage 20 formed therein, a fuel chamber 22, a second fuel passage 24 and a third fuel passage 26. The device 10 also includes first and -second orifice means 28 and 30, through which fuel is injected into the cylinder of an engine. The device 10 further inlii cludes a yfirst valve means in the form of a cylindrical sleeve valve member 32, for controlling the flow of fuel to orifice means 28 and a second valve means in the form of a needle valve 34 for controlling the flow of fuel to orifice means 30 and first and second compression spring -

means

36 and 38.

The injection `device 10 may be secured in the engine block by suitable means such -as the threads 40 formed on a portion of the nozzle body. The nozzle body may have formed therein Ia bore 42, somewhat larger in diameter than the needle valve 34 disposed therein to form 4the circumferential passage 26 which communicates with the fuel chamber 22 at its upper end and orifice means 30 at its lower end. A bore 44 is formed above the fuel chamber 22 to slidingly receive the sleeve valve member 32. Pressurized fuel in the fuel chamber 22 exerts `an upward force on the sleeve valve 32.

The sleeve valve 32 is formed with a bore 46 to slidingly receive the needle valve 34 therethrough. The sleeve valve 32 is also formed with =an enlarged head 48 at rthe upper end thereof to define a shoulder S0 which seats in a counterbore 52 formed in the upper end of bore 44. A fuel duct 54 extends through the wall of the sleeve valve 32 at its lower end. Liquid fuel reaches this duct 54 through counterbore 56 formed on the lower end of the sleeve valve 32. When fuel pressure acting on the lower end of sleeve valve 32 moves the latter upwardly, the duct 54 is brought into registry with fuel passage 58 which is in communication with fuel passage 24.

The needle valve 34 has an enlarged portion 60 formed at its upper end which defines a shoulder 62 against which the upper end of sleeve valve 32 is adapted to seat during its upward movement. This shoulder 62 acts as a stop for the sleeve member 32 to restrain its upward movement so long 'as the fuel pressure on the lower end of the sleeve valve is below a predetermined amount. When the fuel pressure rises above such predetermined amount, the upward movement of the sleeve valve is transmitted to the needle valve 34 to raise the latter from its seat. The upper portion of the needle valve and the

compression spring members

36 and 38 are disposed in a .bore 63 in upper part of the' nozzle body. A radially extending flange 64 is formed on the upper portion 60 of the needle valve 34 and spring means 36 and 38 act against opposite sides of this flange. The compression yspring means 36 surrounds upper portion 60 and seats on the flange 64 and upper surface of sleeve valve 32. It urges sleeve valve 32 toa closed position, i.e., seated on the shoulder 50 to hold the fuel duct 54 out of registry with fuel passage 58 and positioned below passage 38 as viewed in FIGURE 1. Compression spring 36 is a weaker spring than compression spring 38 thus allowing the sleeve valve 32 to be raised by a relatively small fuel pressure without disturbing the needle valve from its seated position. The compression spring 38 is a relatively strong member and is `disposed between the upper side of flange 64 and a reaction member 66 seated in `a nozzle body cap member 68. The latter may be threaded onto the upper part of the nozzle body. A leak-off channel `69 may be provided in the nozzle body to carry leakage fuel back to the fuel supply reservoir (not shown). The lower end of the needle valve may have a valve face 70 formed thereon to seat on a complementary valve seat 72 formed in the nozzle to con-trol the opening -to mlain injection orifice means 30.

Orifice means 28 may comprise a single orifice or a plurality of orifices in communication with fuel passage 24, and orifice means 30 may comprise a single orifice or a plurality of orifices adapted to be controlled by needle valve 34. The orifice means 28 is positioned to direct a certain amount of fuel into or close to a high temperature source. Its purpose is to provide a pilot injection to help ignite the main spray. The main injection is provided by orifice means 30, and this orifice means 30 is directed into or close to the fiame created by the combustion of the pilot injection. The two valves, sleeve valve 32 and needle valve 34, open in succession in response to the different pressures built up in an injection pump such as pump 12.

Injection pump 12 is the subject of copending application for U.S. Letters Patent, Ser. No. 646,033, filed on June 14, 1967. Injection pump 12 will be described here only generally. The pump -12 comprises in part a housing 80, defining a bore 82 in which pumping plunger 14 is disposed for reciprocating movement in response to the action of a cam (not shown), at its lower end. The pump 12 also comprises a fuel chamber 84 adapted to be connected to and receive fuel from a fuel supply reservoir (not shown). A delivery valve 86 normally closed by the action of compression spring 88 is adapted to be opened by an increase of fuel pressure in a pumping chamber 90 wherein pressure is built up as the plunger 14 moves upwardly. With this increase in pressure, fuel under pressure is sent to the fuel injector device through conduit 16 connected to the injection pump. It will be observed that the upper portion of pumping plunger 14 has a narrow notch 92 and a substantially triangular notch 94 communicating by passage means (not shown) in the plunger 14 with the pumping chamber 90. Spill port means, one of which is shown at 96 in the housing 80, provides flow communication between the fuel chamber 84 and the pumping chamber 90 whereby fuel fiows from fuel chamber 84 to pumping chamber 90. When the plunger 14 moves upwardly, a shoulder 98 on the upper end thereof blocks the flow of fuel from the fuel chamber through the spill port means 96. At that point, pressure begins to build up in pumping chamber 90 and fuel is -forced past the delivery valve 86 against the force of spring 88 through conduit 16 to the fuel injector device 10. The notch 92 is provided to relieve the pressure in the pumping chamber as it moves into registry 4with spill port means 96. As the plunger 14 continues to move upwardly, a land 100 in the form of a helix between the

notches

92 and 94 again seals off the spill port 96 and pressure in the pumping chamber 90 continues to build up.

While the operation of the injector device is probably apparent from the above description of its construction, a brief summary of its operation will now be given. When the plunger 14 of the injection pump moves upwardly to the point where the shoulder 98 cuts off the spill port means 96, pressure is built up in the pumping chamber 90, opening delivery valve 86 and sending pressurized fuel through conduit 16 to the injector device 10. The pressurized fuel moves through inlet fuel passage 20 to the fuel chamber 22 and acts on the sleeve valve 32 to move it upwardly against the shoulder 62 on the needle valve. In doing so, the fuel duct S4 of the sleeve valve is brought into registry with fuel passage 5S and fuel is sent to orifice means 28 via passage 24. This occurs at a predetermined relatively low fuel pressure such, for example, as about 1500 p.s.i., because the spring 36 is made relatively weak. This provides a pilot spray to give a high energy source for the main injection. As the plunger 14 continues to move upwardly, the notch 92 in the plunger registers with spill port means 96 and fuel flows from the pumping chamber 90 back to the fuel chamber S4, relieving the pressure in the system. Then spring 36 reseats the sleeve valve 32 on shoulder 50, closing off fluid communication with the fuel duct 58. As the plunger 14 continues to move upwardly, land 100 again blocks spill port 96 and pressure in the pumping chamber continues to build up. The construction of the plunger is such that fuel pressure can now build up to a considerably higher amount such, for example, as 3000 p.s.i. This fuel pressure moves the sleeve valve 32 up against the shoulder 62 with sufiicient force to overcome the relatively stronger spring 38 and lift the needle valve 34 from its seat 72 thus permitting fuel to pass through orifice means 30. This is the main injection and the velocity and quantity of fuel pumped during this main injection generally will be larger than during the pilot injection. As the sleeve valve 32 moves up with the needle valve 34, the lower edge of the sleeve valve closes off duct S8 feeding orifice 28. As the plunger 14 moves downwardly at the end of the pumping stroke, the pressure is decreased, of course, and the

valves

32 and 34 are reseated, and the cycle is then repeated.

It will be appreciated that the quantities of fuel to be injected through each orifice means and the duration of the respective injections are independently variable. These can be varied by controlling the spring strengths of

springs

36 and 38 as well as the notch formations in the pumping plunger which provides for relief of pressure in the pumping chamber of the fuel injection pump.

Thus it will be apparent that we have advantageously provided a fuel injection device of relatively simple construction, which is capable of providing two injections of fuel through separate orifices independent of each other, one being a pilot or prespray and the other a main injection. The device uses a minimum of parts, and, as can readily be seen, the parts are uncomplicated structures.

We claim:

1. In a fuel injection device adapted to receive pressurized fuel from a source of supply and to inject the fuel into an internal combustion engine, the combination cornprising: a nozzle body; first fuel passage means in said nozzle body adapted to be connected to a source of pressurized fuel; first and second orifice means in said nozzle body for injecting fuel into the engine; first and second valve means for controlling the iiow of pressurized fuel to said first and second orifice means respectively; yieldable biasing means associated with said first and second valve means to hold said first and second valve means in a closed position; bore means in said nozzle body; second fuel passage means in communication with said first orifice means and said bore means; said first valve means comprising a cylindrical sleeve valve slidably disposed in said bore means, and adapted to have fluid pressure act on one end thereof, said first valve means including, first means therein for establishing fluid communication between said first fuel passage and said second fuel passage means including, a fuel duct adapted to be placed in communication with said second fuel passage means in response to pressurized fuel acting on said sleeve valve.

2. A fuel injection nozzle for an internal combustion engine, comprising: a nozzle body having central bore means extending longitudinally thereof, said bore means partially defining a chamber in fluid communication with a source of pressurized fuel; first fuel ejection orifice means in said nozzle body in fluid communication with one end of said bore means; first valve means operatively interposed between said first fuel ejection orifice means and said bore means for controlling the flow of pressurized fuel through said first fuel ejection orifice means; second fuel ejection orifice means in said nozzle body; recess means formed in a wall portion of said bore means; fuel passage means in said nozzle body providing fluid communication between said second fuel ejection orifice means and said recess means; second valve means operatively interposed between said bore means and said recess means for controlling the flow of pressurized fuel through said second orifice means, said second valve means including a valve element disposed within said bore means and movable longitudinally with respect to said nozzle body between a lfirst closed position wherein fluid communication between said bore means and said recess means is disestablished, an intermediate open position wherein fiuid communication between said bore means and said recess means is established, and a second closed position wherein fiuid communication between said bore means and said recess means is disestablished; yieldable biasing means associated with said first and second valve means for urging said first valve means closed and said valve element of said second valve means toward its first closed position, said valve element being responsive to the pressure of the fuel in said bore means and movable to said intermediate open position upon the attainment of fluid pressure in said bore means at a rst predetermined magnitude and movable to said second closed position upon the attainment of uid pressure in said 4bore means of a second predetermined magnitude, said rst valve means being responsive to the pressure of the fuel in said bore means to open only upon the attainment of uid pressure in said bore means of said second predetermined magnitude.

3. A fuel injection nozzle as set forth in claim 2, wherein said valve element slidingly engages said bore means and includes a cylindrical sleeve-like end portion, said end portion covering said recess means when said valve element is in its iirst and second closed positions, said end portion having a radially extending aperture formed therethrough, said aperture being in radial registration with said recess means only when said valve element is in its intermediate open position.

4. A fuel injection nozzle as set forth in claim 3, wherein said first valve means includes an elongated needle valve extending longitudinally through and engaging said valve element for relative sliding movement; and interengagng abutment means carried by said needle valve and said valve element Ifor limiting sliding movement of said valve element with respect to said needle valve in one direction, said valve element being in its intermediate open position when said interengaging abutment means are in engagement and said iirst valve means is closed.

`5. A fuel injection nozzle as set vforth in claim 4, wherein said needle valve is formed with an enlarged end section;

and said interengaging abutment means includes the annular shoulder formed at the juncture of said enlarged end section and the reduced diameter main body portion of the needle valve.

6. A fuel injection nozzle as set forth in claim 5, wherein said enlarged end section of said needle valve is provided with a radially extending, annular ilange intermediate its ends; and said biasing means includes a first helically wound compression spring encircling said needle valve and having one end abutting said annular ange and its opposite end bearing against said valve element of said second valve means, and said bearing means further including a second helically wound compression spring encircling said needle valve and having one end abutting said annular ange and a stationary part of said nozzle body, said second spring exerting a relatively greater force on said annular flange than said first spring.

References Cited UNITED STATES PATENTS 3,339,848 9/ 1967 Geiger 239-533 FOREIGN PATENTS 926,643 4/ 1955 Germany. 792,775 4/ 1958 Great Britain.

EVERETT w. KIRBY, Primary Examiner.`

U.S. Cl. X.R. 123-32.61; 239-533