US2602702A - Injector and pump - Google Patents

Description

July 8, 1 F. KOVACH INJECTOR AND PUMP Filed Dec. 20, 1946 NIH piston is H. to the cylinder as at l4 and preferably has a Patented July 8, 1952 s PATENT OFFICE INJECTOR AND PUMP Frank Kovach, Lincoln, Nebr.

Application December 20, 1946, Serial No. "71'7,421

Claims.

'Thisinvention relates'to pumps and has for its principal object the provision of a simple and efficient pump which may be operated by the pressure in an engine to discharge fuel, water or other liquid into the engine. A second object is to provide a fuel injector having a minimum number of parts.

' .A still further but important object of the invention is to provide a pump or fuel injector particularly suited for use for discharging a fairly viscous inexpensive fuel oil intoa-relatively slow speed engine such as used for farm tractor engine, and having means whereby the discharge 2 ing the springzfi, and unless the adjustable stop has been lowered, drives the piston against the sleeve 26. This action has cut off the fuel line at II and compresses the fuel in the upper portion of the bore 8. The check valve as opens and the central bore 3! of the plunger is therefore filled of fuel may be controlled by limiting the travel of the plunger .01' other discharge member.

The present invention is suited for any type of internal combustion engine but preferably is to be used with an engine utilizing a fuel similar to diesel oil and having some means for igniting the fuel separate from the diesel efiect of igniting by theheat generated in compression.

- My injector provides a high efficiency, particularly where the fuel is admitted into the injector at a relatively low pressure.

In the drawings:

Figure l is a vertical section through the preferred form of my device.

Figure 2 is a modified form. I

In Figure l the engine cylinder is 59 and its The injector body I2 is threaded conical discharge mouth H3. The fuel inlet pipe I6 discharges through an inlet opening I! to a central bore is. The lower portion of the injector body has a fairly large chamber 26, and in this chamber a piston 2! travels, being exposed at its bottom to the pressure in the cylinder lil but constantly urged in a contrary directionfby the spring 25. A central sleeve 26 forms a stop to limit theupward travel of the piston 2| at full power output but an adjustable screw'2'l having a knurled head 28,- can be moved to limit further the upward travel of the piston when so desired, and consequently to lessen the quantity of fluid delivered to the engine. I 7

Integral with the piston 2! is a hollow plunger 32! having a central bore 3| completely through the plunger and piston. The top 32 of the plunger 30 closes the inlet'port I! and forms a cut-off. A spring-pressed one-way valve 36 is mounted near the top of the plunger and a similar valve 36 is located near the bottom of "the plunger just above the discharge orifice 31.

As the piston H rises in the cylinder iii; the pressure passes through the narrow passage 38 and acts on thebottom of the piston 2| compresswith the fuel which has been trapped from the major supply. The spring 25, as the piston ll descends, presses the piston 2| down to its bottom stop 39 uncovering the inlet port l1 and again filling the upper portion of bore G8 with fuel. On the next compression stroke the trapped fuel within the bore 3| is discharged into the cylinder as the piston 21 rises. As the piston 2! thus moves the spring closed valves 34 and Y36 successively open and the trapped fuel is discharged through the injector opening 31 as a spray. At the top of the strokes of the pistons II and H, the valve 36 closes sharply under the urge of its spring while the parts are momentarily still and this gives what might be called a sneezing action, the air expelled from the pressure chamber of the injector body forming a conical stream directed across the discharge orifice 31 and obviating any dripping of fuel.

In the modified form shown in Figure 2, the pressure in the engine cylinder is applied at the top of the injector body'and this modification merely illustrates one of the great number of different ways in which the invention can be carried out. In this Figure 2, the cylinder is M), the engine piston M, the spark plug 42, and the fuel inlet pipe is 43. The port 44 is closed by a downward movement of the lower end 45 of the plunger 38 which in this case is spring-pressed upwardly The stop is 48' and the piston of the preferred form is here replaced by adiafram 50 against which the plunger 46 is held by its spring 41 positioned by a spring seat on head 53 on the plunger. .A pipe 55 leads from the engine cylinder 40 through a hole 56 in the top of the injector body 5! and thus causes the diafram to bend downwardly at the center as the engine piston 4| rises in its cylinder 40.

Since plunger 66 in this modified form moves downwardly and cuts off the fuel as it passes the fuel intake port A4, the two cut-off valves 60 and Bl corresponding in purpose to the valves 34 and 36 are in a small member 62 secured in any desired manner to the lower portion of the body of the injector. The fuel dischargeorifice 63 sprays the fuel into the engine cylinder as the plunger 46 moves downwardly after closing the intake port 44. In this case the reduction of pressure in the upper chamber of the injector body does not pass air around the injector discharge 3 port but the spring 41 does create a vacuum in the bore of the member 62 and this effectively prevents undue discharge of fuel as the engine piston 4| moves downwardly subsequent to the firing of the charge by the plug 42.

While I have described the invention in its preferred form as discharging fuel into the cylinder it is obvious that m pump can be used equally well in discharging water or any other fluid into the engine cylinder.

Having described my invention, what I claim is:

1. In a fuel injector for internal combustion engines, a body having therein a central bore, a

fuel inlet leading to said bore near the upper end thereof, a pressure chamber, and a cylindrical passageway of less diameter than the pressure chamber, communicating with the chamber and having a conical discharge portion at its free lower end; a piston in the chamber movable in one .direction by pneumatic pressure acting through said passageway, spring means for moving the piston in the opposite direction, a hollow plunger in said bore movable with said piston and having its upper end moving in a path to pass said inlet and its lower end moving in the passageway to provide'an annular air passage between the plunger and the passageway and to discharge fuel from the hollow of the plunger adjacent said conical portion, a one-way valve in the plunger adjacent the upper inlet end and a second one-way valve in the plunger adjacent the lower end, whereby as the spring mean moves the piston, the air below the piston will cross the path of the fuel and thus avoid dripping.

2. A fuel injector for a slow speed engine of the farm tractor type using a fairly viscous fuel at low pressure, including: an injector body having an intermediate bore, a large bore and a smaller bore communicating therewith, a piston mounted in said larger bore with its lower surface constantly open to a variable pressure, a spring urging the piston against said pressure, aplunger slidable in said smaller bore and movable with said piston, a fuel supply line having a port opening into the smaller bore near the closed end thereof, an extension of. the plunger having a fuel discharging nozzle and projecting into the intermediate bore so as to leave an annular space, a one-way valve located near the upward and of the plunger, a one-way valve near the discharge end of the nozzle, said plunger moving at all times in accordance with said pressureandmoving to cut off said port as the pressure rises, said piston discharging air' thru said annular space around the injector nozzle as the injector piston lowers under springipressure as the'press'ure lowers. V

3. A fuel injector for a slow speed engine using a fairly viscous fuel under low pressure, adapted for mounting in the cylinder block of the engine above the engine piston, including a body having 7 a relatively large diameter chamber, abore communicating therewith and a passageway establishing free and unrestricted admittance of pressure to the chamber, a pressure responsive member within the chamber, a fuel line having a port opening into said bore, a plunger sliding in the bore and moved by said member to position to out off the fuel port orifice upon high pressure, spring means to move. the plunger to fuel port opening position when the pressure. is lowered, an injector nozzleat, the bottom of said body, and a pair of coaxial one-way valves located in a passageway forming: a fuel space in said body between the fuel entrance orifice and the injector nozzle, spaced one at each of the two ends of said fuel space and each one-way valve being springpressed to prevent pressure passing from the injector nozzle thru the fuel space to the bore and yielding to permit fiow of fuel from the bore to the injector nozzle when the fuel port orifice is closed by the plunger, which compresses the fuel trapped in the bore, whereby said fuel space between the two-one-way valves is filled with fuel at all times.

4. An injector comprising a two-piece body the lower portion of which includes a bore of relatively large diameter providing a piston chamber and a smaller diameter communicating bore to admit air into the lower portion of said chamber, an upper portion of said body having therein a blind bore of relatively small size, a fuel inlet port leading to said blind bore, a hollow cylinder plunger within the blind bore having an upper end serving as a cutoff for thefuel inlet port and having a lower portion extending into the intermediate bore and out of contact therewith to provide an injector nozzle, a pressure operated piston flange on said plunger engaging the wall of the piston chamber, resilient means-urging the piston and the plunger towards discharge position, and one-way spring pressed valves at opposite ends of the plunger.

5. An injector comprising a lower bodyv of two diameters, the smaller diameter portion having a conical nozzle, said body having a major bore and a pressure admitting intermediate bore com municating therewith, the latter having a conically restricted margin form a discharge jet through the nozzle, an upper body having a small blind bore therein and having a fuel inlet port leading to said small bore, a hollow piston in the larger bore having a smaller cylindrical extension on each side, the upperextension fitting the smaller bore and serving as acut-off for said fuel inlet port and the lowerextension having a conical fuel discharge nozzle leaving an annular space between the lower extension and the inside wall of the nozzle, resilient means for moving the piston downward and spaced valve means within said extensions for discharging fuel asthe piston moves upwardly, downward movement of piston forcing a gaseous stream thru the annular passageway and across the path of the injected fuel.

6. The device of claim 3 in which the plunger and the member are integral with an axial bore extending through the plunger and through the member and terminating with a restricted conical discharge portion at the bottom, and the valves are located proximate the top and the bottom of the plunger.

7. The device of claim 3 in which a sleeve extends downwardlyinto the large diameter chamber to form a stop for the member, and an adjustable stop projects into the path of the member to further limit the travel of the member when so desired.

8. The device of claim 3 in whichthe member is a diafram.

9. The device of claim 8 in which therspring means acts to oppose movement of the member by the pressure and to draw fuel into the bore (References on following page) REFERENCES CITED Number The following references are of record in the 2,371,787 file of this patent: UNITED STATES PATENTS 5 215411443 Number Name Date 1,162,789 Loane, Jr. Dec. 7, 1915 1,972,881 Geisse Sept. 11, 1934 Number 1,995,4 9 Olsen Mar. 26, 1935 179,553 2,052,459 Geiser Aug. 25, 1936 10 379,045

2,135,925 Tuscher Nov. 8, 1938 Name Date Ward Mar. 20, 1945 Unsworth Sept. 18, 1945 Frenck 'July 25, 1950 Smith Feb. 13, 1951 FOREIGN PATENTS Country Date Great Britain Apr. 26, 1923 France Aug. 29, 1907

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