US2309074A - Fuel injection pump - Google Patents

Description

' Jan. 19, 1943. H. c. EDWARDS FUEL INJECTION PUMP Filed Aug. 2, 1940 Z Sheets-Sheet l w fl a s 9 n u 1 m r1 4 i n/ MC? Z Ms 41-1-0 Ewen;

Jan. 19, 1943, l; ED RDS 2,309,074

FUEL INJECTION PUMP Filed Aug. 2, 1940 2 Sheets-Sheet 2 Patented Jain- 19, 1943 UNITED S S PATENT OFFICE Herbert 0. Edwards, Massillon, Ohio, asslgnor to The Timken Roller Bearing Company,- Canton,

Ohio, a corporation of Ohio Application August 2, 1940, Serial No. 349,532

6 Claims.; (01103-41) This invention relates to pumps, particularly single cylinder fuel injection pumps of the kind having a reciprocating plunger that is rotated in itscylinder to vary the quantity of fuel delivered.

It has for its principal objects .to provide a strong and durable smoothly operating light-weight pump of simple, economical and compact construction that can be quickly and easily assembled, adjusted and serviced and thatwill accurately meter the fuel charge. The invention con-- sists in the construction, combinations and arrangements of parts hereinafter described and claimed.

In the accompanying drawings, which form part of this specification and wherein like symbols refer to like parts wherever they occur,

Fig. l. is a plan view of a fuel injection pump embodying my invention,

Fig. 2 is a front elevational view of said pump,

Fig. 3 is a side elevation oftheupper portion of said pump,

. Fig. 4 is'a view similar to Fig. 3 looking at the opposite side of the pump,

Fig. 5 is a central vertical section through the upper portion of the pump on the line 5-5 in Figs. 1 and 2,

Fig. 6 is a central vertical section on the line in Fig. 1, v Fig. 7 is a horizontal section on the line 1--'l ofFig.8,

Fig. 14 is a longitudinal section through said sleeve on the line i l-l4 in Fig. 13,

Fig. 15 is an end view of the pinion for rotating said plunger rotating sleeve, 1

Fig. 16 is a central longitudinal section through said pinion on the line IS-J6 of Fig. 15,

Flgrrl'? is a detail view, showing the manner 2 is a cylinder 3 having a head portion 4 seated on a gasket 5 resting on an annular seat 6 in said bore, and reciprocable in said cylinder is a plunger or piston I.

Located in the-bore 2 of the housing I is a tubular member 8 having a base flange 9 that seats on the upper end of the cylinder 3. This tubular member has a seat Ill at itsupper end for a discharge valve II. The valve seat member 8 fits loosely in the lower end of a tubular fitting l2; .and said fitting is threaded into the upper end of the bore 2 of the housing i and thus serves to hold'said valve seat member 8 down on the upper end of the cylinder 3 and said cylinder down on its seat in said bore.

spring l3 that normally holds the discharge valve ll down against the seat Ill provided therefor at the upper end of the valve seat member-8. A gasket It is interposed between the lower end of the fitting l2 and the base flange 9 of the valve thereof.

in which the locking stud cooperated with the measured charges of fuel to the cylinder of a compression ignition engine. Said pump comprises an upright cast metal housing I having a 'central'vertical bore 2 extending therethrough from toptobottom thereof. Mounted in the bore seat member 8 to prevent leakage therebetween. The fitting l2 has its upper end threaded for connection with a fuel line (not shown) that leads to a fuel lnjectorinot shown).

The bore 2 of the housing I has a substantially C-shaped groove l5 cast therein opposite the head 4 of the cylinder 3, said groove cooperating with said head of said cylinder to form a suction chamber is around the greater portion The housing I has a horizontal fuel inlet passageway 11 that opens into the c-shaped suction chamber l6 midway of the ends thereof; and the cylinder 3 has two radial, circumferentially spaced inlet and overflow ports l8 and I9, respectively, therein that establish communication between said opposite sides of said chamher and the plunger receiving bore of said cylinder. Rotation of the plunger 1 in the bore 2 of the housing I is prevented by means of a screw 20 that is threaded into said housing and has a reduced inner end portion 2| that extends into the overflow port [9 which is enlarged, as at 22, to provide a clearance space for the passage of fuel around the inner end of said screw.

The plunger has an annular groove 23 therein near the upper end thereof that communicates through a longitudinal groove 24 with the pres-- sure space 25 in the cylinder 3 and has an inclined or helical upper edge 26, whereby the delivery stroke of the plunger 1 may be regulated by turning said plunger to vary the point in the pressure stroke of said plunger in which the overflow port I9 is placed in communication with said pressure space through the grooves 23 and 24 to The fitting I2 also serves asa holder for a coil compression relieve the pressure in said space and thereby permit the delivery valve II to seat and terminate the fuel delivery. By this arrangement, delivery of fuel begins as soon as the plunger during its up-stroke covers the ports l8 and i9 and ends as soon as the helical edge 26 of the annular groove 23 in the plunger 1 opens the overflow port l8 and relieves the pressure in. the space 25 above the plunger.

The mechanism for turning the plunger 1 on its axis to vary the amount of fuel delivered comprises a fuel control or feed rod 28, having teeth 28a intermeshing with a pinion 29 rotatable about the axis of the cylinder 3, and a sleeve 30 which is fixed to said plunger and extends upward around the cylinder 3 and has an axially slidable but non-rotary connection with said pinion. The lower end of the plunger rotating sleeve 30 has a non-rotary connection with the plunger 1 comprising a fiat-sided portion 3| thereof that fits a similarly shaped opening 32 in the lower end of said sleeve. The axially slidable but nonrotatable connection between the upper end of the sleeve 39 and the pinion 29 comprises diametrically opposed upstanding fingers or tongues 33 at the upper end of said sleeve that have a sliding fit in diametrically opposed longitudinal grooves 34 in the pump cylinder receiving bore of said pinion.

Surrounding the driving sleeve 30 is a coil compression spring 35 that serves to retract the plunger 1 and hold the pinion 29 upwardly in the housing bore 2, whose lower end portion is enlarged, as at 36, to accommodate said pinion and said spring and to slidably support a tappet cup 31. The tappet cup 31, which is operated in one direction by a rotary cam or tappet (not shown), is spaced outwardly from the sleeve 39 so as to accommodate the retracting spring 35 for the plunger I and said tappet cup. A washer 38 supports the pinion 29 and is held against an annular shoulder 39 provided therefor in the bore 2 of the housing I by means of the piston retracting spring 35. The plunger 1 is provided below the bottom of the driving sleeve 39 with an annular groove 49 and terminates below said groove in a flatsided head portion 4|. The lower end of the piston retracting spring 35 seats upon a O-washer 42 mounted on the plunger I. Theupper portion of the washer 42 receives the groove portion l4 of the plunger I and the lower portion of said washer is widened to receive the head 4| at the lower end of said plunger. The washer 42 seats on the bottom of the tappet cup 31 and is held against axial movement relative to the plunger but allows free rotation of the latter. The tappet cup 31 is retained in the bore of the pump housing by means of a snap ring 43 that seats in an annular groove formed in the wall of said bore adjacent to the lower end thereof. I v

with multi-cylinder engines, one of the above pumps is provided for each cylinder of the engine and the rack rods of the several pumps are linked together for simultaneous operation; and the links must be adjusted so that each pump will deliver the same quantity of fuel during simuled in a horizontal bore 44 in the housing I, which bore opens into the vertical bore 2 of the pump 7 housing at one side of the pinion 29 therein; and one side of this bushing is cut away. as at 44a, to permit the rack teeth 28a of the rack rod 29 to intermesh with said pinion. The rack rod bushing 43 is inserted in and removable from the bore 44 from either end thereof and is rigidly clamped in said bore by means of a stud 45 that fits within a horizontal bore provided therefor in the housing I above the bushing supporting bore 44 and opens into the upper portion of the latter. The stud 45 has its underside notched, as at 46, to straddle the upper portion of the rack rod supporting bushing 43 and has its exposed outer end portion screwthreaded to receive a nut 41, the tightening of which exerts an endwise pull on said stud thereby rigidly clamping the bushing 43 in said bore. The bushing 43 has its ends beveled, as at 48, and the rack rod 29 has a scale 49 marked thereon longitudinally thereof adapted to cooperate with one end of said bushing. The instructions for longitudinally adjusting the rack rod state that the fuel delivery of each pump should start at a specified distance from the zero mark on the scale 49, so that when the pump is tested and the start of injection in terms of rack position has been determined, the

rack rod supporting bushing 43 is slipped lengthwise in its supporting bore 44 until such mark is in register with the end of said sleeve. The bushing 43 may then be clamped in the desired position of longitudinal adjustment by tightening the nut" on the stud 45.

The above described fuel injection pump has several important advantages. The plunger rotating sleeve 39 is rigidly fixed to the plunger 1 and is rotatably supported thereby. The cylinder 3 serves as a bearing for rotatably supporting the pinion 29. This pinion is positioned axially in the bore 2 of the housing between an annular shoulder therein and the upper spring seat 38 for the piston retracting spring 35. The longitudinal tongue-and-groove connections between the upper end of the sleeve 30 and the pinion 29 provide a simple and efficient axially slidable, nonrotary connection between said sleeve and said pinion which is simple and easy to manufacture and which requires a minimum amount of space axially of the pump. The 6- shaped groove ii in the bore of the pump housing may be cast in said housing and cooperates with the head 4 of the cylinder 3 to form the correspondingly shaped suction chamber II. The suction chamber extends part way around the cylinder 3 and the inlet port I9 is on one side of said chamber, the overflow port ID in the other side thereof and with the inlet passageway ll opening into said chamber intermediate the ends thereof. This arrangement prevents the fuel by-passed into the suction chamber I. through the overflow port I9 from interfering with the flow of the fuel from said chamber into the inlet port IS. The rack bar scale 49, which cooperates with the longitudinally adjustable rack rod supporting bushing 43, permits all pumps of a. series to be set to have the same timing and metering characteristics; and it also makes it possible to shift the bushing to any new position should the pumps require readjusting after being reconditioned.

Obviously, numerous changes may be changed without departing from the spirit of my invention. Therefore, I do not wish to be limited to the precise arrangement shown and described.

What I claim is:

1. A fuel injection pump comprising a cylinv 2,309,074. der, a plunger reciprocable in said cylinder and projecting therebelow, a pinion rotatably mounted on said cylinder, and asleeve fixed to said plunger below said cylinder and having an axially slidable but non-rotatable connection with said pinion, said connection comprising circumferentially spaced tongues on said sleeve that extend upwardly alongside said cylinder into the cylinder receiving bore of saidpinlon and are slidable in similarly spaced internal longitudinal slideways in said cylinder receiving bore of said pinion.

2. A fuel injection pump comprising a cylinder, a plunger reciprocable in said cylinder and projecting therebelow, a pinion having an axial bore through which said cylinder extends, a sleeve fixed to said plunger below said cylinder and having a, portion surrounding said cylinder into said bore of said pinion and have direct, axially slidable but non-rotary connections with said bore, a spring seat-mounted on said plunger below said sleeve, a spring seat mounted around said upstanding tongues of said sleeve and supporting said pinion, and. a plunger actuating spring surrounding said sleeve and bearing against said spring seats.

3. A single cylinder. fuel injection pump comprising a housing, a cylinder therein, a plunger reciprocable in said cylinder, said cylinder having a substantially c-shaped groove cast therein around said cylinder andcooperating therewith to form a similarly shaped suction chamber, an

inlet passageway leading into said C-shaped sucin said cylinder disposed one on each side of said inlet passageway.

4. A'fuel injection pump comprising a housing, a cylinder therein, a plunger reciprocable in said cylinder, a pinion rotatable about' the. axis of .said cylinder, a member fixed to said plunger and having an axially slidable ibut non-rotary connection with said pinion, a bushing mounted in said housing at one side of said pinion transverse to the axis thereof for axial adjustment g 3 relative to said housing, a rack rod reciprocable in said bushing and intermeshing with said pinion, and means for'locking said bushing in said housing in the desired position of axial adjustment, said rod having a scale thereon extending longitudinally thereof and said bushing having an exposed index portion adapted to be brought into register with a certain graduation of said scale in a predetermined positionof said rack rod by adjusting said bushing axially in said housing.

5. 'A fuel injection pump comprising a housing, a cylinder therein, aplunger reciprocable in said cylinder, a pinion rotatable about the axis of said cylinder, a member fixed to said plunger and having an axially slidable but nonrotary connection with said pinion, a bushing mounted in said housing at one side of said pinion transverse to the axis thereof for axial adjustment relative to said housing, a rack rod reciprocable in said bushing and intermeshing with said pinion, and means for locking said bushing in said housing in the desired position of axial adjustment, said rod having a scale thereon extendinglongitudinally thereof and said bushing having an ex.- posed index portion adapted to be brought into register with a certain graduation of said scale in a predetermined position of said rackrod by adjusting said bushing axiallyiin said housing, said locking means comprising a pin mounted in said housing crosswise of said bushing and having a notch that straddles said "bushing; and a nut threaded on said pin and bearing against said housing. 6. A fuel injection pumpcomprising a cylinder, a plunger. reciprocable and rotatable in said cylinder and projecting therebelow, a pinion rotatably mounted on said cylinder, and a sleeve sleeve having a portion';. that extends upwardlybetween said cylinder and-said pinion andhas an axially slidable but nonrotary connection with

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