US2020627A - Fuel injection valve for internal combustion engines - Google Patents

Description

NOV. 12, 1935. I vmc -r 2,020,627

FUEL INJECTION VALVE FOR INTERNAL COMBUSTION ENGINES Filed April 23, 19 31 2 Sheets-Sheet l ,2. Wvczwz ATTORNEY.

E. T. VINCENT Nov. 12, 1935.

FUEL INJECTION VALVE FOR INTERNAL COMBUSTION ENGINES Filed April 25, 1931 2 Sheets-Shet 2 I N VEN TOR.

III.

/ ATTORNEY.

Patented Nov. 12, 1935 PATENT OFFICE,

FUEL INJECTION VALVE FOR INTERNAL COMBUSTION ENGINES Edward T. Vincent, Detroit, Mich, assignor to Continental Motors Corporation, Detroit, Mich., a corporation of Virginia Application April 23, 1931, Serial No. 532,261

9 Claims. (Cl. 123-32) My invention relates to fuel injection engines and more particularly to engines of the compression ignition type and to the valve operating means for controlling the fuel injection.

Two well known systems of fuel injection for engines of this type are the constant pressure system and the jerk system. The former system gives the most power but more skill is required in maintaining the working parts in proper adjustment and the slightest wear of the timing and control mechanism, the cam in particular, may completely out out one of the cylinders thereby reducing the engine power and overloading the other cylinders. Even though the wear is notsuflici'ent to cut out the cylinder, the power of the cylinder associated with the worn cam is materially reduced. The latter system is adapted for operation without frequent adjustments, but these-adjustments are of a delicate and complicated nature requiring considerable skill and knowledge on the part of the mechanic. To be more specific it might be noted that the constant pressure fuel injection system is provided with means for mechanically opening and closing the valve for controlling the injection of fuel into the cylinders, while the jerk system is provided with means for automatically opening and closing the valve in response to fuel pump operation, and usually provides an individual fuel pump for each cylinder which measures and delivers a pre-determined amount of fuel. These pumps are relatively expensive besides providing a multiplicity of parts which are subjected to wear.

It is the object of my invention to construct an engine of the fuel injection type having the advantages of both injection systems without the disadvantages by providing a fuel injection control mechanism having improved operating characteristics and which can be readily and quickly assembled, or disassembled with an engine of the aforesaid type.

Another object of my invention is to construct an engine of the compression ignition t provided with an improved mechanically released valve means controlling the injection of fuel into the engine cylinders and with means responsive to a predetermined fall of fuel pressure in the sourceof fuel supply for automatically closing said valve when a predetermined charge of fuel has been injected into the cylinder.

For a more detailed understanding of my invention, reference may be had to the accompanying drawings which illustrate one form which my invention may assume and in which:

Figure 1 is a transverse vertical sectional view of a compression ignition engine constructed in accordance with my invention and showing the fuel injection valve closed, said section being taken substantially on the line l--l of Figure 2,

Figure 2 is a plan view of the valve actuating 5 mechanism,

Figure 3 is a transverse vertical sectional view thereof showing the valve released and open,

Figure 4 is a detail view partly in section illustrating the manner in which the atomizer may 10 be assembled or disassembled, and

Figure 5 is a side elevational view of a multicylinder internal combustion engine of the compression ignition type and showing the fuel sup.- ply means. 15

An internal combustion engine of the fuel injection type and in particular one of the compression ignition type may be constructed of any suitable engine block structure l0 having one or more cylinders II in which the usual form of 20 pistons l2 are reciprocated, said pistons adapted to be connected in the usual way with the engine crankshaft I3. In the aforesaid type of engine, the fuel is sprayed into the cylinder where it ignites when coming into contact with the com- 25 pressed air in the cylinder. The means for atomizing the fuel and the means controlling the injection of the fuel into the cylinder are preferably supported by the cylinder head It having suitable water jackets l5 communicating with the water 30 panying drawings is preferably provided with a 40 pillar l1 integrally formed with the cylinder head casting and arranged concentrically with respect to the cylinder axis, the pillar being bored out or otherwise constructed with a recess to receive. the fuel nozzle and valve structure. The fuel 45 nozzle I 8 may be of any standard construction, the same having a. central opening l9, a valve seat 20, and one or more openings 2| in the tip of the nozzle. A valve guide, casing, or'support 22 is secured in the head by means of bolts 23 or 50 other suitable means. In the illustrated embodiment of my invention, the valve structure is preferably constructed of a pair of upper and lower valve portions 24 and 25 respectively, the lower valve portion 25 provided with a valve element 26 at its lower end, a bead or flange 21 at its upper end, and longitudinal or spiral grooves 28.

The upper valve portion 24 is guided directly in the valve guide or support and is arranged to 5 abut the top face of the head 21 carried by the lower valve portion.

Thevalve structure is held on its seat by the pressure of the spring 6 0 acting through the lever mechanism A. The valve is released 10 on actuating the mechanism thereby permitting the fuel pressure in the fuel supply line 31 or reservoir, commonly known as a rail to openathe valve for injecting the fuel into the cylinder. Preferably this lever mecha- 'nism consists of a pair of cooperatively associated elements, such as the rocker arms 30 and 3|, the

former being pivotally supported on the rocker shaft 32 which is supported by the cylinder head l4 and actuated by cam 33 through the agency of the push rod 34 which engages one arm portion of the rocker arm through the agency of the adjustable ball and socket connection 30. The cam 33 is driven in timed relation to the engine, by

means of a camshaft 33. The spring 60 is inter- I posed between the other arm portion of the rocker arm and the cylinder head l4, suitable spring abutments 6| being associated therewith, said spring abutments having balls 62 adapted for engagement within recesses 63 and 64 in the cylinder head l4 and rocker arm 30 respectively. The rocker arm 3| is pivotally supported as at 3| to a bracket 22' carried by the valve guide.

22 and preferably integrally formed therewith. One arm portion of the rocker arm 3| is yieldingly forced upwardly by spring 60 thereby yieldingly urging the other arm portion into engagement with the upper end of valve portion 24 to yieldingly hold the valve closed. On actuating the push rod, the spring 60 is compressed thereby releasing the force holding the valve closed and permitting the fuel pressure to open the valve.

By employing the lever mechanism as described above a relatively light spring may be employed due to the fact that this construction permits the multiplication of forces and I have found that approximately a 200 lb. spring is generally sufficient for my purpose.

It will be noted that the atomizing device including the valve structure and associated mechv anisms together with the rocker arm 3| may be readily assembled or disassembled from the cylinder head without disturbing the position of the rocker arm 30 or spring 60. Figure 4 illus- I trates how this unitary sub-assembly may be lifted .out after the bolts 23 or other fastening devices which secure the sub-assembly to the cylinder head are removed. This assembly permits the engine to be readily and conveniently serviced,

since one element of the control mechanism is 50 removable with the valve, without disturbing the assembly of the other element or the spring and push rod associated therewith.

The fuel is conducted to a pump 35, through a pipe or conduit 36 from a fuel tank (not shown) or other source of fuel supply and thence forced into a fuel supply line or "rail 31. Branch pipes or conduits 38 connect the rail with each of the cylinders, and if desired suitable valves 39 may be employed for respectively shutting off the 70 supply of fuel to any one of said cylinders. A

. pressure regulating valve 40 may be employed to maintain a predetermined initial fuel pressure'in the fuel line or rail at the beginning of the injection. I preferably connect the fuel pump up with the engine mechanism in such a way as to actuate the pump to immediately bring the fuel pressure up to a predetermined maximum at the time of each injection. One or more strokes may be given to the pump, and one or more pump cylinders may be employed, but preferably the 5 pump is constructed so that each stroke of the pump will bring the fuel pressure up to the required amount so as to provide a predetermined constant pressure in the rail at the time of injection. m

The branch pipes or conduits 33 are arranged to be connected with a passage 4| in the valve guide by a union 42 or other suitable fitting. The passage 4| communicates with an enlarged bore 43 within the valve guide, the bore 43 being slight- 15 1y larger than the head of the lower valve portion 25 to permit the fuel to flow freely past the head. A compression coil spring 44 bears on the head 21 yieldingly urging the valve on its seat. The fuel may flow through the groove 23 in the 90 valve portion 25 into the nozzle chamber 45 formed by the reduced end portion of the valve portion 25.

Thus when the spring 50 is compressed, releasing the rocker arm, the fuel pressure may then :5 lift the valve, this pressure exertinga lifting force on the valve portions 24 and 25 greater than the remaining forces tending to seat the valve structure. Immediately on lifting of the valve the fuel is sprayed into the cylinder under pressure, and so the pressure of the fuel in the rail will rapidly fall, as well as the fuel pressure in the bore 43 that is in open communication with the rail". When the fuel pressure fails a predetermined amount sufficient to allow the spring 44 to over- :5 come the differential in pressure action on the valve portion 25, thespring 44 will force the lower valve portion 25 downwardly and separate the valve portions 24 and 25. The lower valve portion which carries the valve is quickly snapped 40 down because as soon as the valve portions are separated, there is a bigger area exposed to the remaining fuel pressure tending to lower the valve. Thus I have obtained a quick automatic closing of the valve in response to a predeter- 4,5 mined fall of fuel pressure. Even though the fuel pressure in the rail" is built up before the upper valve portion is lowered again by the spring actuated rocker arm 3| the lower valve portion will remain seated, because of the differential in pressures acting down on the same. After the upper valve portion'is forced down and seated on the head 21 of the lower valve portion by relieving readily varied by varying the fuel pressure in the rail or supply line at the beginning of the fuel injection period by means of the control valve 40.

It may be further noted that it is not necessary to provide a finely adjusted mechanism for,eontrolling the valve lift as the same is maximum amount at each operation of the fuel injection means, whatever the engine speed or load may be. Thus I have provided what may be termed as a constant stroke means timed with the engine for controlling the opening of the fuel 15 the lo injection valve and independent means regulating the quantity of fuel injected into the cylinder.

- A 'quick return of the rocker arm is not neces sary as the valve is automatically closed independently of the valve releasing or opening mechanism.

Another advantage of my construction is that in the event of the failure of the spring 60 to function, or the failure of the upper valve portion to seat on the lower valve portion, the lower valve portion 25 will automatically cut off the .cylinder associated therewith from the fuel supply line or rail as the valve remains closed due to the pressure of the spring 44 and the differential in fuel pressure acting in the direction of the valve seat.

The successful operation of an engine of the fuel injection type and in particular one of the compression ignition type depends largely on the proper timing and control of the fuel injection and my construction is simple but very effective in providing such a control without frequent adjustment. Wear such as will materially affect the operation of an ordinary engine having a constant pressure fuel injection system, will not affect the operation of my engine.

It will be further noted that my construction is well adapted for use with an engine of the heavy oil compression ignition type as well as with other fuel injection engines employing light fuel oils or other similar fuel.

Although I have illustrated but one form of my invention and have described in detail but a single application thereof, it will be apparent to those skilled in the .art to which my invention pertains that various modifications and changes may be made therein without departing from the spirit of my invention or from the scope of the appended claims.

What I claim as my invention is:

- 1, A fuel injection apparatus for engines of the compression ignition type comprising, a fuel injection valve, a valve controlling shaft, a rocker arm pivoted to the engine and having a long arm and a short arm, a rod between said shaft and said long arm, a spring for loading said short arm, and a second'rocker arm transmitting the load of said spring to said valve, said second rocker arm having a relatively long arm adapted for engagement with and actuation by the short spring loaded arm of said first rocker arm.

2. In a fuel injection apparatus for compression ignition engines, a fuel injection valve, a valve controlling shaft, first and second pivoted levers each having a long arm and a short arm, yielding means loading the short arm of the first lever and the long arm of the second lever, said second lever transmitting the load of the yielding means to actuate said valve, said first lever being adapted for actuation by said shaft independently of said valve actuating" lever.

3. A fuel injection apparatus for engines of the compression ignition type including, a fuel injection valve unseated by fuel pressure, a valve controlling shaft, a compound lever mechanism adapted for actuation by said shaft and including a first lever having oppositely extending long and short arms, a spring-for loading said short arm, the other of said arms being actuated by said shaft, and a second load multiplying lever having oppositely extending long and-short arms, the long arm of said second lever overlapping the short spring loaded arm of said first lever and thereby loaded by the spring, the short arm of said second lever loading the valve to seat the same. 1

4. A fuel injection apparatus for engines of the compression ignition type including, a fuel injection valve unseated by fuel pressure, a valve controlling shaft, a compound lever mechanism adapted for actuation by said shaft and including a first lever having oppositely extending long and short arms, a spring for loading said short arm, the other of said arms being actuated by said shaft, and a second lever having oppositely extending long and shortarms, the long arm of 10 J said second lever being loaded by the short spring loaded arm of said first lever, the short arm of said second lever loading the valve to seat the same, said lever arms of both levers being arranged to extend substantially in a common 15 plane at right angles to the valve axis.

5. A fuel injection apparatus for engines of the fuel injection type including, a fuel injection valve unseated by fuel pressure, a valve controlling device, a spring; and a lever mechanism con- 20 sisting of first and second pivoted levers each having long and short arms, the short arm of said first lever engaging said spring and directly actuated by said device independently of said second lever to compress the spring, the short 25 arm of said second lever engaging said injection valve and having its long arm actuated by said spring to seat the valve.

6. A fuel injection apparatus for engines of the fuel injection type including, a fuel injection 30 valve unseated by fuel pressure, a valve controlling device, a spring, and a lever mechanism consisting of first and second pivoted levers, said-first lever having a short arm for engaging said spring and an oppositely extending long arm directly 35 actuated by said device independently of said second lever to compress the spring, said second lever having a short arm engaging said injection valve and an oppositely extending long arm actuated by said spring to seat the valve. 40

7. A fuel injection apparatus for engines of the ,fuel injection type including, a fuel injection f valve unseated by fuel pressure, a valve controlling device, a spring, and a lever mechanism consisting of first and second pivoted levers, said 45 first lever having a short arm for engaging said spring and an oppositely extending long arm directly actuated by said device independently of said second lever to compress the spring, said V second lever having a short arm engaging said )0 injection valve and anoppositely extending long arm actuated by said spring to seat the valve,

, said long arm of said second lever engaging the short arm of said first lever.

8. A fuel injection apparatus for engines of the 55 fuel injection type including, a fuel injection valve unseated by fuel pressure, a valve controlling device, a spring, a lever mechanism cooperating therewith and consisting of first and second pivoted levers each having long and short arms, the short arm of said first lever engaging the spring and having its long arm directly actuated by said device independently of said second lever to compress the spring, the short arm of said second lever engaging said injection valve 65 and having its long arm actuated by said spring to seat the valve, and a casing supporting said valve on said engine and removable axially therefrom, said first lever having a clearance with respect to the axial projection of said casing, said 70 second lever being pivoted on said casing and removed with said casing independently of said first lever.

9. A fuel injection apparatus for engines of the fuel injection type including, a fuel injection 75 valve unseated by fuel pressure, a valve controlling device, a spring, a lever mechanism cooperating therewith and consisting of first and second pivoted levers, said first lever engaging the spring and directly actuated by said device independand a casing removably supporting said valve on said engine, said second lever having one arm overlying an arm of said first lever and being pivoted on said casing, said second lever being removable with said casing independently of said 5 first lever.

EDWARD T. VINCENT.

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