US1511484A - Combination metering pump and fuel spray valve - Google Patents

Description

Oct. 14, 1924. 151 4 4 H. B. PETERSON COMBINATION METERING PUMP AND FUEL SPRAY VALVE Filed Oct. 25 1922 IN VEN TOR.

HO WARD a PETfP-SO/M Patented Oct. 14, 1924.-

UNITED STATES- HOWARD IB. PETERSON, or SAN FRANCISCO, CALIFORNIA.

COMBINATION METERING PUMP AND FUEL SPRAY VALVE.

Application filed October 25, 1922. Serial No. 596,708.

To all whom it may concern: 1

Be it known that I, HOWARD B. PETERSON, a citizen of the United States, residing at the city and county of San Francisco and State of California, have invented new and useful Improvements in a Combination Metering Pump and Fuel Spray Valve, of which the following is a specification.

This invention relates to a Diesel type of internal combustion engine, and especially to a combination metering pump and fuel spray valve, which is particularly adapted for small horse-power units where solid injection is employed.

The object of the present invention is to generally improve and simplify devices of the character described; to provide a combined metering pump and fuel spray valve, which may be constructed as a single compact unit and directl attached to the cylinder head of an engine; to provide means for advancing or retarding the time of injection, and simultaneously increasing or decreasing the quantity of fuel injected; to provide a metering pump which also serves the function of a fuel or injector pump, and which is designed to receive oil from the fuel feed line under comparatively low pressure and inject at high pressure; to eliminate severe duty on the-pump stufling box by subjecting it to the low pressure of the feed line only; to provide a structure which permits by-passing and return of all leakage oil from the pump and fuel spray valve to the low pressure feed line; and further to automatically actuate the fuel spray valve in conjunction with the fuel pump and without resorting to the use of exterior actuating mechanism, stufling boxes, etc. Other objects will hereinafter appear.

One form which my invention'may assume is exemplified in the following descri tion and illustrated in the accompanying rawings, in which Fig. 1 is a side elevation in section showing the combined metering pump, and fuel spray valve, said view also illustrating the mechanism whereby a reciprocal movement is imparted to the pump plunger and whereby the stroke is increased or decreased, and the time of the stroke advanced or retarded.

Fig. 2 is a cross section on line 22,

fieferring to the drawings in detail, A indicates the cylinder head of a Diesel type of engine, B the cam shaft, and C the combined metering pump and fuel spray valve. The metering pump and fuel spray valve consists of a casing 2, which is secured to the cylinder head in any suitable manner or as here shown by a screw collar 3. Formed in the casing 2 is a central cylinder chamber 4, and slidably mounted therein is a seat is a spring 8 and a removable plug 9.

Formed on'the lower end of the pump cylinder is a fuel valve 10. This valve is of the needle valve type and is arranged to normally engage a seat 11 formed at the upper end of a fuel spray orifice or nozzle 12. The fuel or needle valve indicated at 10 is reduced in diameter when comparison is made with the pump cylinder 5, and an annular chamber 13 is therefore formed in the lower end of the main cylinder which with the fuel delivering passage 6 communicates. Reciprocally mounted in the pump cylinder is a plunger 14, and forming communication between the pump cylinder and the annular chamber 13 is one or more passages such as indicated at 15. The plunger 14 extends upwardly through the main cylinder chamber 4 and passes out through a stuffing box generally indicated at 16. The upper end of the pump plunger is headed as at 17 and a spring is interposed between the head and the upper end of the stufiing box as at 18. The pump cylinder 5 divides the main cylinder into two chambers, to-wit, the lower annular chamber 13 and an upper chamber 19. This chamber is in constant communication with the fuel delivery line through a port indicated by dotted lines at 20. The chamber serves two functions, first that of a by-pass chamber through which any leakage oil escaping from the plunger 14 or the fuel valve 10 may be returned to the fuel line, and secondly that of a housing and guide for a spring 21, which is interposed 7 between the upper end of theffiplump cylinder also serves a second function, to-wit, that of determining the final pressure under which the oil is injected into the cylinder, as will hereinafter be described.

To reduce leakage through the stufiing box 16 to a minimum, it'will be stated that it is only subjected to the fuel line pressure and in fact is not at all times even subjected to this pressure as a seat is formed on the lower end of the head 22, as indicated at 23, which is engaged by a valve member 24 formed on the pump plunger. This seat prevents leakage when the pump plunger assumes its raised position and it can therefore be seen that the stuffing box is only subjected to pressure when theplunger is 'depressed, and as the line pressure is comparatively low, severe duty as far as the stufling box is concerned is practically eliminated.

The plunger shown in the present instance serves two functions, first that of a metering pump, and secondly that of an injector. It is therefore necessary that means be employed for imparting a reciprocal movement to the plunger, and also that means be provided for increasing or decreasing the stroke, and also for advancing or retarding the time of the stroke. This is accomplished in the present instance as follows: Secured on the cam shaft B is a cam 25. Turnably mounted on the .cam shaft is a bell crank 26. Journaled in the upper arm of the bell crank is a roller 27 through which reciprocal movement is imparted to a roller 28 and a tappet 29, and extending through the lower arm of the bell crank is a shaft 30, on which is secured a governing eccentric 31. The shaft, together with the eccentric, may be manually turned or actuated by a governor. Any rotary movement imparted will, of course, transmit a rocking movement to the bell crank and this movement will not only increase or decrease the stroke of the tappet, but it will also advance or retard the time of the stroke. The movement of the tappet may be transmitted to the pump plunger 14 in any suitable manner, or as here shown by an interposed rocker arm 32. If the engine is operating under a full load, the bell crank, together with the roller 27 and the eccentric 31, will assume the position shown in Fig. 1, but if a reduced load is desired, rocking movement will be imparted to the bell crank in the direction of arrow a. Roller 27 will in that instance move away from the center line drawnthrough the cam shaft and tappet, as indicated at 3333, and as such will not only decrease the stroke of the tappet as it moves away from the same, but it will also retard the time of the stroke, as the cam will engage the roller 27 later than when it assumes the full line position shown in Fig. 1. In this manner it is possible to simultaneously increase or decrease the stroke of the plunger 14 as it is actuated by the tappet through-means of the rocker arm, and it is similarly possible to advance or retard the time of injection.

The present device is particularly adapted for automobiles,.trucks, tractors, marine engines, etc., employing comparatively small horse-power engines, but may of course be employed in larger units if desired. The entire mechanism employed is exceedingly simple and the structure is so compact that it may be directly attached to the cylinder head of practically any standard make of high pressure internal combustion engine.

The advantages of the structure are manifold and will hereinafter be referred to. A brief description of its operation will, however, be rendered so that the advantages obtained will be appreciated,

In operation we will assume that the fuel line pressure is 1000 pounds and that it is desired to inject the oil into the cylinder un der a pressure of 4000 pounds. In that instance it can readily be seen that a pressure of 1000 pounds will be exerted in the chambers 19 and 13 of the main cylinder and that the pump cylinder will be balanced as the pressure on each end will be equalized. This is due to the fact that chamber 19 is in communication with the fuel line through the by-pass 20 and that chamber 13 is in communication with the fuel line through th passage 6. During the upstroke of the plunger 14, oil will pass the check valve 7 and enter chamber 13 through passage 6, and it will also enter the chamber of the pump'cylinder 5. During reverse movement of the plunger, the check valve seats and prevents return movement through the passage 6 and as this is the case, the pressure will increase in chamber 13 until thetension of the spring 21 is overcome.

rection, and as the fuel valve is directly connected therewith, it will lift from the seat and will permit the oil to discharge through the orifice 12. The moment reverse movement' is imparted to the .plunger 14, the pressure will instantly ceas and pressures in the respective chambers will again balance, thus permitting the spring 21 to return the pump cylinder to normal position and the valve 10 to engage the seat. This particular The pump cylinder 5 will then move in an upward di-' movement of the fuel valve and pump cylinder, in conjunction with the plunger, is important as it eliminates the use of exterior mechanism for raising or lowering the fuel valve. In other words it might be stated that the fuel valve is hydraulically actuated and that this hydraulic operation is dependcut on the movement of th pump plunger. This structure is of further importance as any leakage which may take place between the pump cylinder and the plunger will enter th upper cylinder chamber, and similarly any leakage which may escape from the chamber 13 and upwardly around the pump cylinderr5; this leakage of oil being returned to the fuel line through the bypassage 20. The stufiing box is at no time subjected to th high pressure created in the pump cylinder or in the annular chamber 13 as fuel line pressure is always maintained in the upper end of the cylinder. To prevent surging in the fuel line or through the by-pass 20, a pair of air pockets 38 is formed in the lower end of the head member 22. These pockets form 'air cushions for the body of oil maintained-in the upper end of the cylinder and this air will compress when upward movement is imparted to the c linder 5 during downward movement 0 the plunger 14. The upward movement of the cylinder 5 is, however, very slight as the pressure in chamber 13 is high and therefore rapidly relieves itself when valve 10 unseats. In actual practice themovement of the valve and the cylinder 5 will probably not exceed 2 or 3/1000 of an inch. Any

tendency to produce a surge in the fuel line is therefore very small, but even this is revented by providing the cushioning cham- The tension of the spring 21 may be increased so that the injecting pressure may be raised as desired, this being accomplished by inserting larger springs, and conversely smaller springs if it is desired to reduce the injecting pressure. The spring 18 could in many cases be eliminated as the pressure in the upper end of the cylinder is in most cases sufficient to return the I lunger -14 to its upper normal 'tion. he spring 17 may therefore be a owtension spring as its duty is merel that of an auxiliary employed to return t e ump lunger.

By the use 0 the present design and structure, a definite amount of fuel is injected to the cylinders. This amount may be varied to suit increase or decrease in loads, and the-time of injection me also be advanced or retarded as desired. he fuel valve is lifted from its seat without any ex ternal means other than that-which operates the meterin or injecting plunger. Leakage past the p unger and pump cylinder is returned to the feed line and as such is not lost. Comparatively low pressures may be carried in the fuel line, thereby reducin load and wvere strains in fuel pump and connected mechanism, and similarly relieving the stufiing gland of severe duty. The Y structure permits absolute control of the fuel spray entering the cylinder, and it also controls the quantity injected, the time of inj ection, and the pressure of injection. With' that microscopic lifts generally employed when governing the fuel valve are entirely eliminated as the lift of the fuel valve is in this instance hydraulically actuated during the movement of the plunger.

While certain features of the present in vention are more or less specifically illustrated, I wish it understood that various changes in form and proportion may be resorted to within the scope of the appended claims, similarly that the materials and finish of the several parts employed'may be such as the experience and judgment of the manufacturer may dictate or various use ma demand.

aving thus described my invention, what I claim and desire to secure by Letters Patent is-' 1. A device of the character described comprisin a casing having a cylinder chamber formed therein, and a spray orifice in its lower end, a passage formed in the cylinder for delivering liquid fuel under pressure to the cylinder, a check valve in said passage, a pump cylinder slidably mounted in the cylinder and having a needle valve on its lower end engaging the spray orifice, a combined metering and injecting plunger reciprocally mounted in the pump cylinder, means for imparting a reciprocal stroke to the plunger, and means for increasing or decreasing the stroke of the plunger and simultaneously advancing or retarding the time of the stroke.

2. A device of the character described I chamber under pressure, passages formed in 1 the pump cylinder connecting the annular chamber and the pump cylinder chamber, and a plunger reciprocally mounted in the pump cylinder.

3. A device of the character described mounted in the pump cylinder, means comprising a casing having a cylinder chamber formed therein and a spray orifice in its lower end, a pump cylinder slidably mounted in the cylinder, a fuel valve of reduced diameter carried by the pump cylinder and normally engaging a seat in the spray orifice, said fuel valve forming an annular fuel receiving chamber in the cylinder in communication with the spray orifice, means for delivering a liquid fuel to said annular chamber under pressure, passages formed in the pump cylinder connecting "the annular chamber and the pump cylinder chamber, a combined metering and injecting plunger or imparting a reciprocal movement thereto, and means for increasing or decreasing the stroke of the plunger and simultaneously advancing or retarding the time of the stroke. i

4. A device of the character described comprising a casing having a' cylinder chamber formed therein and a spray orifice at the lower end of the cylinder, a pump cylinder slidably mounted in the cylinder and dividing the cylinder into an upper and a lower chamber,a fuel valve carried by the pump cylinder and engageable with the seat in the spray orifice, means for delivering a liquid fuel under pressure to the upper and lower ends of the cylinder chamber, a plunger reciprocally mounted in the pump cylinder, means forming communication between the pump cylinder and the lower cylinder chamber to admit fuel to the pump cylinder, means for imparting a reciprocal movement to the plunger, and a spring interposed between the upper end of the cylinder and the upper end of the pump cylinder.

5. A device of the character described comprising a casing having a cylinder chamber formed therein and a spray orifice at the lower end of the cylinder, a pump cylinder slidably mounted in the cylinder and dividing the cylinder into an upper and a lower chamber, a fuel valve carried by the pump cylinder and engageable with the seat in the spray orifice, means for delivering a liquid fuel under pressure to the upper and lower ends of the cylinder chamber, a plunger re ciprocally mounted in the pump cylinder,

means forming communication between the.

pump cylinder and the lower cylinder chamber to admit fuel to the pump cylinder, means for imparting a reciprocal movement to the plunger, a head member forming a closure for the upper end of the cylinder, a stufling box in the head member through which the pump cylinder plunger extends, and a spring in the upper cylinder chamber interposed between the head and the pump cylinder. w

6. A device of the character described comprising a casing having a cylinder chamber formed therein and a spray orifice at the lower end of the cylinder, a pump cylinder slidably mounted in the cylinder and dividing the cylinder into an upper and a lower chamber, a. fuel valve carried by the pump cylinder and engageable with the seat in the spray orifice, means for delivering a liquid fuel under pressure to the upper and lower ends of the cylinder chamber, a plunger reciprocally mounted in the pump cylinder, means forming communication between the pump cylinder and the lower cylinder chamber to admit fuel to the pump cylinder, means for imparting a reciprocal movement to the plunger, a head member forming a closure for the upper end of the cylinder a stuffing box in the head member through which the pump cylinder plunger extends, a spring in the upper cylinder chamber interposed between the head and the pump cylinder, a valve on the pump plunger, and a seat formed in the head below the stufling box with which said valve is adapted to engage.

7 device of the character described comprising a casing having a cylinder chamber formed therein and a spray orifice at the lower end of the cylinder, a pump cylinder slidably mounted in the cylinder and dividing the cylinder into an upper and a lower chamber, a fuel valve carried by the pump cylinder and engageable with the seat in the spray orifice, means for delivering a liquid fuel under pressure to the upper and lower ends of the cylinder chamber, a plunger reciprocally mounted in the pump cylinder, means forming communication between the-pump cylinder and the lower cylinder chamber to admit fuel to the pump cylinder, means forimparting a reciprocal movement to the plunger, a head member forming a closure for the upper end of the cylinder, a stufiing box in the head member through which the pump cylinder plunger extends, a spring in the upper cylinder chamber interposed between the head and the pump cylinder, a valve on the pump plunger, a seat formed in the head below the stuffing box with which said valve is adapted to engage, and air cushioning pockets formed in the cylinder head in com- IIOnunication with the upper cylinder cham- 8. In a device of the character described the combination with the main cylinder and a stationary spray orifice formed in the lower end thereof, of a pump cylinder slidably mounted in the main cylinder, a fuel valve carried by the pump cylinder and engageable with a seat in the spray orifice, a spring engaging the pump cylinder and normally maintaining the fuel valve on its seat, and means for hydraulically raising the fuel valve from its seat.

9. In a device of the character described a stationary spray orifice formed in the seat, a pump plunger reciprocally mounted lower end thereof, of a pump cylinder slidin the pump cylinder and extending through ably mounted in the main cylinder, a fuel the main cylinder, and means for imparting 10 valve carried by the pump cylinder and movement from the pump plunger toraise 5 engageable with a seat in the spray orifice, the fuel valve from its seat;

I a spring engaging the pump cylinder and normally maintaining the fuel valve on'its A HOWARD B. PETERSON.

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