US2280386A - Combined engine cylinder valve and fuel injector - Google Patents

Description

pril 21.1 2. 41mm "2,280,386

couaximn mm cYLmnER mm: AND FUEL mmc'ron Filed April 9, i941 2 Sheets-Sheet 1 3nventor April 2l, 1942. J. DICKSON 2,280,386

COMBINED ENGINE CYLINDER VALVE AND FUEL INJECTOR -F iled April 9, 1941 2 Sheets-Sh'et 2 m 4 a 7v 3nventor 210/222 ,Wzc'ksozz/ Patented Apr. 21,

" UNITED STATE COMBINED ENGINE CYLINDER VALVE AND FUEL INJECTOR John Dickson, Ferndaic, Mich., assignor to Gen? eral Motors Corporation, Detroit, Micin, a corporation of Delaware Application April 9, 1941, Serial No. 337,710

Claims. (Cl. 123-139) This invention relates to internal combustion engines with injection. of fuel into the engine cylinders, and particularly to a combined engine cylinder valve and fuelinjector for such an engine.

In compression ignition engines especially, with combustion chambers of small volume, it is sometimes difficult to find space for the injector and the necessary engine cylinder valves communicating with the combustion chamber. When the injector is centrally disposed in the cylinder head, as it is desirable thatlt should be, there is frequently insuflicient space left for valves of adequate area.

The object of the invention is an engine poppet valve'combined with a fuel injector so that both the valve and the fuel injector may bearranged in the space taken up by the valve alone, in the wall of the combustion chamber, and both may be centrallydisposed in a cylinder head.

Another object of the invention'is a construction in which the plunger of the injection pump and the valve are actuated by means common to both of them.

Another object of the invention is a. combined engine valve and fuel injector, containing a fuel reservoir for the injector, through which fuel is continuously circulated to cool the valve.

A further object of the invention is a construction in which the pump plungerand a'spindle for the valve are both reciprocable in a stationary fuel pump cylinder. v

A more specific object of the invention is a construction in which the pumping space is between the pump plunger and the valve spindle,

and the valve is opened by direct thrust of the plunger on the spindle after delivery of fuel to an injection valve has been terminated by the opening of a port through the pump cylinder wall by the plunger.

The above and other objects of the, invention will be apparent as the description proceeds.

According to the invention, the valve spindle extends into a stationary fuel pump cylinder, and there is aduct through the valve spindle from the pump pressure space to the injection valve embodied in the valve head and the injection nozzle which extends through the center thereof.

The valve is provided with a tubular stem enclosing the fuel pump cylinder barrel, and provldingan annular space therearound which constitutes a fuel supply reservoir for the fuel pump and a cooling chamber for the exhaust valve.

A collar on the tubular valve stem forms a seating for spring means normally holding. the valve closed,, while spring meansbetween the tubular valve, stem and the pump plunger normally hold the latter in a position spaced fromthe spindle to provide a pumping space therebetween. Means are provided to move the plunger towards the valve spindle to pump fuel from said space and then to open the valve by direct thrust of the plunger on the spindle. I h

The thrust of the pump plunger on the valve spindle is cushioned by displacement of the fuel remaining in the space between the pump plunger and thevalve spindle, after the injection of fuel into the engine cylinder has been terminated.

The drawings show the application of the invention to a two+cyc1e Diesel engine having piston controlled inlet ports in the cylinder wall and a fuel injector which is generally of the kind shown in U. S. Patent No. 1,981,913, embodied'in the exhaust valve in the cylinder head.

In the drawings-, a

Figure 1 is a sectional elevational view show- .ing the combined exhaust valve and injector" the end of its delivery stroke), and the exhaust I valve fully open.

, The engine frame I includes a cylinder 2 within which is a piston 2'. Secured-to the engine frame l, by bolts such as 3, i the cylinder head 4.

Mounted in the cylinder head 4 is an exhaust valve 5 for a port 6 through which, when the valve is open, the exhaust gases pass from the engine cylinder 2 through the passage 1 -to the exhaust manifold 8 and thence to the atmos phere. The cylinder head is provided with suitable water cooling passages such as 9.

The exhaust valve 5 has a tubular stem portion III of relatively large diameter, sliding in a tubular guide It having a flange portion l2 in a pocket It drained by a duct IS in the cylinder head 4.

The valve 5 is normally held closed on its seating l6 .by springs l1 and It.

The springs I1 and I8 bear on the flange I 2, with their opposite ends thrusting against a col- .lar II which is held on the tubular stem portionl8 of the valve by the two halves of a split ring 28 which engage an annular groove in the exterior circumference of the tubular stem portion l8, and the shoulder ofa counterbore in the collar I8.

Thep'ocket II has a cover 25 having a boss ortion 28 extending into the tubular stem l8 8 of the valve.

. The boss portion 28 serves as an additional guide for the valve on the inside of the tubular stem l8.

An extension 88 of the portion 28 is of reduced diameter and projects further into the tubular stem I8 of the valve, there being an annular space 8| betweexrtheextension 88 and the tubular stem. The extension 88 constitutes a fuel pump cylinder barrel for a plunger 85 which reciprocates in a cylinder bore 88 through the parts 25, 28 and 88.

The bore 38in'thje cover form a pocket 81 for a pinion 88. The plunger 85 is splined in the pinion 88 so that it may is counterbored to lower surface is bounded by the bottom circumferential edge 8| and a circumferential'edge 82. while the uppersurface has a helical edge 83. A duct 85 in the plunger connects the annular space 88 between theffedges 82 and 88 with the.

pumping space 88 between the plunger and the valve spindle.

A drilled hole or duct 81 in the valve spindle 82 connects the pumping space 88 with the injection nozzle 88 through a chamber 88 in the valve seat pieceil and a chamber 88 in the nozzle piece 88.

There is a disc type check valve 8| in the chamber 88, and an injection valve 82. loaded by a spring 83 seated on a filling piece in the chamber 88. The filling piece 88 is grooved for the flow of 'fuel'therethrough to the nozzle 88,

and reduces the volume of the chamber 88 to a desired minimum. The check valve 8| freely permits flow of fuel to the injection valve 82 while preventing back flow through the duct 81 which might occur if the injection valve failed be'tumed thereby, but is capable of longitudinal reciprocation therethrough. The pinion 88 is retained in the pocket 81 by a plate 88, and may be angularly turned for. adjustment of the beginning of injection in known'manner by a rack 88 which can slide back and forth in a groove in the cover 25.

Secured to the head 85 of the plunger by a spring ring 88 is a seating collar 81 for a spring 88. .The seating collar 81 is guided in a tubular extension of the cover 25, and is retained therein by a spring ring 88.

The spring 88 does not react on the cover 25,

but is seated, at its end opposite to the seating collar 81, on a seating 58 through which the plunger 85 slides. The seating 58 is subtended on three legs such as 58 at 120 to each other, which slide in holes through the cover 25 and, in effect, are an extension of the tubular stem l8 through the cover 25..

The head of the exhaust valve 5 is. bored and counterbored for a nozzle piece 88, a valve seat piece 8|, and a spindle 82 for the exhaust valve, all seemed therein by a screwed sleeve 88. The

exhaust valve spindle 82 reciprocates in the bore 88 for the end of which it is a movable closure. Two spaced ports 18 and 1| connect the bore 38 of the cylinder barrel 88 with the annular space 8|, the end of which is closed by the boss portion 28. The port 18 is provided wth a readily renewable shroud or spill deflector 12, which shields the side of the tubular stem M from the high pressure discharge through this port when it is opened by a control edge on the plunger to relieve the pressure in the pumping space to terminate injection.

A duct, comprising drilled holes 18 and 15, in the cover 25 and the boss portion 28 respectively, serves for the supply of fuel to the annular chamber 8| from any suitable low pressure source of supply, and a similar duct comprising drilled holes 11 and 18 through these parts serves for the return of excess fuel to the source of supply. There is thus at all times a continuous flow of fuel through the annular chamber 8|,

so that the valve is effectively cooled while the to seat at .such times as the pressure in the engine cylinder 2 exceeds the pressure in the fuel system.

The plunger is actuated on its downward delivery stroke by any suitable driving means such as the cam 81 with push rod 88 and rockin lever 88 with roller I88. It will be noted that the cam is of the requisite form to give injection delivery stroke movement of the plunger 85, followed by further exhaust valve opening movement thereof, with suitable dwell periods between these movements.

In operation, fuel at a small head of pressure 7 from any suitable source of supply (not shown) is supplied to the annular chamber 3| through theduct 18, 15. In the position shown in Figure 2, the plunger 35 is at the top of its stroke (i. e., the end of its suction stroke), and has uncovered the port 18 allowing fuel oil to flow into the pumping space 88 over and above the fuel always remaining in the duct 81, and the chamber 88, and to rise through the duct 85 and into'the annular space 88 in the plunger. As the plunger descends, the edge 8| first covers the port 18, and then fuel oil and any air or gas bubbles mixed therewith is pumped from the space 88 up through the duct 85 and out through jected into the engine cylinder through the nozzle 88.

The injection continues under the influence of the downwardly moving plunger, until the edge 82 uncovers the port 18 which now functions as a pressure relief 'port terminating the injection and bypassing the remaining fuel oil delivered by the plunger from the pumping space, through the duct 85 into the annular space 88 and back into the annular chamber 8|.

Upon further downward movement of the plunger, the fuel oil in the space between the plunger 85 and the valve spindle 82 is displaced out through the port 18 until there is no longer any such space and the plunger 35 is in contact with the valve spindle 82. Up to this point, movement of the pump plunger has been accompanied by compression of the spring 88, the

I the pressure of springs l1 and I8, to the position shown in Figure 3, without further compression of spring 48, because there is no longer any relative movement between the plunger 35 and the exhaust valve 5, and the spring 48 is mounted therebetween. I

From the position shown in Figure 3, and as the highest part of the cam 91 moves away from the'push rod 98, the springs II, I8, and the spring 48, successively close the exhaust valve 5 and return the plunger 35 to the end of its suction stroke, ready for the next cycle of oporation.

I claim:

1. In a combined engine cylinder valve and fuel injector, a stationary fuel pump cylinder, a pump plunger, a spindle for said valve, said plunger and spindle being reciprocahle in said pump cylinder, means normally holding the valve closed, means normally holding the pump plunger ina position spaced from'the spindle to provide a pumping -space therebetween, and

means to move the plunger towards the spindle to pum fuel from said space and then to open valve in said duct.

said valve by direct thrust of the plunger on said spindle. 1

' 2. The combination according to claim 1 in which the valve has a tubular stem enclosing the stationary fuel pump cylinder and providing an annular space therearound, there being a fuel inlet and a fuel outlet to said space through which fuel is continuously circulated to cool said space, and at least one port through the wall of the pump cylinder, controlled by the pump plunger, for the' new of fuel between the said annular space and the pumping space within the pump cylinder.

3. The combination according to claim ,1 including an injection valve to which fuel is pumped from the pumping space, and a port in the wall of the fuel pump cylinder controlled by the plunger; said plunger having an annular groove inrcommunication with the pump pressure space, and said port being opened by an edge ofthe annular groove to terminate delivery of fuel to the injection valve before the plunger makes contact with the spindle.

4. The combination according to claim 1, in which thereis an injection nozzlein the head of the valve: and a duct through the valve spindie from the pumping space to said nozzle.

5. The combination according to claim 1, in which there is an injection nozzle in the head of the valve, a duct through the valve spindle from the pumping space to said nozzle, and a Jenn DICKSON.

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