US2895420A - Fuel injection pump - Google Patents

Description

July 21, 1959 original Filed June 19, 1952 T. D. Hl-:ss

FUEL INJECTION PUMP 3 sheets-sheet;

THOMAS D.

HESS

T..D. HESS FUEL INJECTION PUMP July 21, 1959 3 Sheets-Sheet 2 originan Filed June 1.9, 1952 ATTO PNEY July 21, 1959 Typ. HESS vFUEL. INJECTION PUMP original' Filed June 19, 1952 INVENTOR ATTORNEY 2,895,428 Patented `luly 21, 1959 .ntic

FUEL INFECTION PUMP `Thomas 1). Hess, Agawam, Mass., assignor to American Bosch Arma Corporation, a corporation of New York Original application June 19, 1952, Serial No. 294,516, now Patent No. 2,773,683, dated December 11, 1956. Divided and this application October 4, 1956, Serial No. 613,994

4 Claims. (Cl. 10S-2) This invention relates to fuel injection apparatus and has particular reference to a new and improved injection which is relatively compact, simple and economical in construction and eicient in operation.

Another object is to provide a new and improved governing device for fuel injection apparatus.

Another object is to provide a governing apparatus for providing torque control or lugging power which apparatus is relatively simple and economical in construction and eflicient in operation.

Another object is to provide a governing apparatus of the type set forth which is capable of employment in connection with relatively simple, compact and inexpensive fuel injection pumps of the distributor type and also fuel injection apparatus comprising separate injection pump and fuel distributor means.

Another object is to provide a fuel injection apparatus of the type set forth which is capable of employment with t relatively low fuel supply pressure.

Another object is to provide fuel injection apparatus of the type set forth which does not require any delivery valve.

Another object is to provide a new and improved distributor for fuel injection apparatus which is adapted to function both as an inlet distributor to the fuel injection pump and a high pressure outlet distributor from the injection pump.

Another object is to provide an apparatus of the type set forth which is of the spill or fuel bypass type.

j Another object is to provide a fuel apparatus which does not require the use of a fuel supply pump `as a part thereof. t

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings. It will be understood that many changes may be made in the details of construction and arrangement of parts shown and described, as the preferred form has been given by way of illustration only.

Referring to the drawings: Fig. 1 is a longitudinal sectional view of a fuel injection apparatus embodying the invention;

Fig. 2 is a schematic view of a modified governor arrangement and illustrating the high idle position thereof;

Fig. 3 is a view generally similar to Fig. 2 but illustrating the full load position thereof; and

i Fig. 4 is a fragmentary sectional view similar to Fig. 1, but on a larger scale.

i Referring more particularly to the drawings wherein -sirnilar reference characters designate corresponding parts throughout, the device in Fig. 1 embodying the invention comprises a housing or casing 10 having open ends, one of which is closed by the closure 11 and the other of which is closed by 'the hydraulic head 12 and on the rside of housing 10 is provided governor housing 13.

The drive shaft 14 extends into the housing and is provided with the hub drive 15 adapted to be secured to the driving gear of the engine with which the device should be employed by being bolted thereto by bolts extending through openings in said hub 15. The mounting flange 16 is provided for securing the pump assembly in position on the engine.

The hydraulic head 12 has the distributor bore 17 in alignment `with drive shaft 14 and in bore 17 is positioned the combined inlet distributor and high pressure distributor 18 having the shaft 19 positioned within the hub 20 of face-cam member 21 and keyed thereto by means of key 22 and with said shaft 19 retained in hub 20 by means of nut or the like 23 adapted to be secured to the threaded end of said shaft 19 and hub 20 is connected to drive shaft 14 by means of the spline connection 24.

The coupling 25 is provided in communication with the distributor 18 and said coupling 25 is adapted to receive fuel from a source of fuel which can have a very low supply pressure and possibly even at gravity pressure, although a conventional fuel supply pump can be employed if higher supply pressures are desired.

Distributor 18 has a hollow central portion 26 adapted to receive fuel from said source of fuel through port 27 in coupling 25 and distributor 18 and face cam 21 are urged toward roller 35 by means of spring 28. Distributor 18 is provided with the spaced inlet ports 29 which extend into grooves 3h for supplying fuel into the injection pump as hereinafter described, and distributor 18 is also provided with the distributing slot 31 communicating with annular groove 32 and adapted to supply fuel received from the injection pump to each of the outlets 32a through ports 33 and outlets 32a are each connected by pipe lines to one of the combustion chambers of the internal combustion engine or the like, which is adapted to receive fuel from the injection apparatus.

` Face-cam 21 is provided with the spaced cam lobes 34, each adapted to engage roller 35 successively and upon such engagement, face-cam will be moved longitudinally thereby effecting longitudinal movement of distributor 18 in its bore 17 and thereby distribute wear evenly over the suiface of distributor 18.

Hydraulic head 12 is also provided with the injection pump comprising the bore 36 preferably parallel with bore 17 for the distributor 1-8, and in injection pump bore 36 is positioned the injection pump plunger 37 which has its end adjacent face-cam 21 in engagement with shoe 38 which rides on face-cam 21 and takes any load off of the end of plunger 37 which is held in engagement with shoe 38 by means of the spring 39.

Injection plunger 37 is provided with the axial bore 40 which communicates through port 41 with peripheral groove 42 which communicates through ports 43 and 44 with inlet ports 29 and distributor groove 32 in distributor 18 respectively. It will be noted that the length of peripheral groove 42 on plunger 3'7 is greater than the length of the common port formed by the junction of ports 43 and 44.

Axial bore 4t) in plunger 37 communicates with pressure chamber 45 through port 46 and is in communication therewith at all times.

Plunger 37 is also provided with bypass or spill port 47 which is radial to and communicates withaxial 1bore 40 and which is controlled by sleeve 48 surrounding .assenso plunger 37 adjacent port 47 and sleeve 48 is connected to end 49 of pivoted lever 50 which is pivotally connected at 51 to governor rod 52.

This spill or bypass arrangement through port 47 provides a variable beginning of injection and the ending of injection is constantly maintained by means of radial port 53 adapted to communicate` with bypass port 54 to spill or bypass fuel at the end of the injection stroke.

It will be seen from the foregoing that with the arrangement shown, the injection pump bore is lilled on the suction or return stroke of the plunger thus allowing the use of very low fuel supply pressures and possibly eliminating the necessity of a separate fuel supply pump unless higher fuel supply pressures are desired, and also that While in the arrangement shown the injection apparatus is provided with a variable beginning and constant ending of stroke, that this arrangement could be reversed to provide a constant beginning of injection and variable ending of injection.

It is also pointed out that with the arrangement shown, the necessity for a delivery valve in the injection apparatus is eliminated.

The governing apparatus is of the centrifugal type comprising the balls 56 and cages 57 and 57a which are mounted on drive shaft 14 and cage 57a is adapted to rotate therewith. Also on drive shaft 14 is the ball bearing 58 adapted to be actuated by centrifugal action when the balls 56 are moved outwardly against the inclined ends 59 of cages 57, which effects movement of bearing 58 against governor lever 60. If desired, instead of the balls 56 and cages 57 and bearing 58, pivoted centrifugal weights mounted for pivotal movement on a sleeve on drive shaft 14 could lbe employed but it is believed that the arrangement shown provides a more compact and simplified construction.

Governor lever 60 is provided with the slot 61 through which extends the pin 62 which is secured to the housing and about which governor lever 60 is pivoted.

Governor lever 60 is pivotally connected at 63 to governor r'od 52 and at 64 to rod 65 which rod has its opposite end pivotally connected at 66 to a rod 67 of adjustable length which lever is pivotally mounted at 68 to fuel control rod 69. Lever 67 is pivotally connected adjacent its opposite end at 70 to spring extension 71 which is connected to governor spring 72 which is also connected at its opposite end to spring extension 73 which in turn is pivotally connected to governor block 74 which is vertically adjustable by means of slot 75 and set screw 76 to adjustable position stop 77 in desired height relative to the free end 78 of lever 68.

In Fig. 2 is shown the high idle position with centrifuga-l weights 79 pivotally mounted at 88 and having their opposite ends 81 engaging sleeve 82 for actuating said sleeve 82, which is adapted to slide on drive shaft 14.4 Sleeve 82 enga-ges governor lever 60 through a slot and pin arrangement 83 and 84 and governor extension spring 85 directly connects governor lever 60 which as stated above, is pivoted on fixed pin or pivot 62. 'I'he maximum fuel stop 86 is contacted by the fulcrum lever cam '87 during the full load operation range and cam 87 can be verticallyradjusted relative to lever 60 by means of screw 88. In this construction, the adjustable cam 87 is provided on lever 60 rather than on governor block 89, as shown in Fig. 1.

In the full load position, as shown in Fig. 3, the forces of spring 85 and weights 79 are in equilibrium at governed speed, and the cam 87 just contacts maximum fuel stop 86 and the pivot pin 62 for lever 60 is still at the right end of the slot 61. As the engine speed drops below the governed speed, the weights 79 continue to collapse and the sliding sleeve 82 continues to move to the right. The governor lever cam 87 then becomes the xed pivot point instead of pivot 62 and the `fulcrum or governor lever 60 is pivoted about said cam 87 and is moved to the right by the governor spring 85 and the lever 60 is moved relatively to pivot 62, so that the left end of slot 61 approaches pivot pin 62 and during this motion fuel control rod 90 has alsomoved from position 91 to position 92 which results in an increased fuel delivery with a drop in engine speed. In this manner, a declining fuel delivery curve is produced and hence engine torque back-up.

The amount of fuel build-up or torque 'back-up can be adjusted by adjusting screw 88 and raising the cam 87 to produce greater fuel increase for a given speed range. To obtain a flat delivery curve, the cam 87 should be positioned close to the control rod 98. The governor spring must be connected to the governor or fulcrum lever 68 below the point where the cam 87 contacts maximum fuel stop 86.

In the operation, fuel enters distributor 18 through inlet 25 and passes through one of the inet ports 29 and grooves 38 to port 43, peripheral groove 42 and port 41 into high pressure chamber 45.

Upon reciprocation of plunger 37 by means of facecarn 34 engaging roller 35, fuel is forced under high pressure through port 46 to port 48 and again through port 41 and peripheral groove 42 to outlet port 44 lfrom which it passes through peripheral groove 32 on distributor 18 to distributing groove or slot 31 which, upon rotation of distributor 18, is aligned with each of the outlet ports or ducts 33 successively to distribute fuel to each of said outlets in proper sequence.

It is pointed out that grooves 30 and distributing slot 31 are not in phased relation and that when any one of grooves 38 is in communication with port 43, that distrib uting slot 31 will be out of communication with all of the outlet ports 33 and vice versa, when distributing slot 31 is in communication with any of outlet ports 33, that port 43 will be out of communication with all of the grooves 30.

Also, as port 44 communicates with distributing slot 31 through annulus 32, fuel from port 43 can enter am nulus 32 through port 44 during the filling of the pumping chamber and will till the annulus 32 and distributing slot 31 but cannot be delivered 'because distributing slot 31 is out of alignment with outlet port 33 at such time.

This cycle is repeated during the operation of the 21D- paratus.

The quantity of fuel delivered is controlled by the setting of quantity control sleeve 48 relative to spill port 47, as previously described, and injection continues until port 53 and its peripheral groove are in communication with spill port 54 at which time injection is discontinued until the next pumping stroke of the plunger.

The setting of quantity control sleeve 48 is controlled through governor rod 52, as previously described.

In the form of the invention of Fig. 1, the pin 84 engages the edge of bearing 58 rather than ride in a slot 83 as in Figs. 2 and 3. The pin is retained in engagement with the edge of the bearing by the balanced action of the governor Weights against governor spring 72.

Lever 60 is controlled through control rod 69 which is connected to the throttle through link 65` which is cor. rected through spring 72 and line 67 for proper speed and load.

In the operation of the governor mechanism of Fig. 1 wherein lever 60 is Ishown in full load position, spring 72 pivots link 67 in a direction whereby the end 78 of lever 61) engages stop 77. Further reduction in the speed of the engine and shaft will allow further collapse of the centrifugal weights and allow lever 60 to be pivoted about stop 77 to the extent that slot 61 may ride over pin 62 and simultaneously link 52 adjusts sleeve 48 on plunger 37 to increase the fuel quantity delivered.

In the operation of the governor mechanism, when the governor lever is in idle position, as shown in Fig. 2, the governor action is similar to a typical overspeed governor and the fulcrum or governor lever 60 simply pivots to a point where pivot pin 62 is at the right of elongated slot 61. At low idle speed the governor spring 85 is positioned to provide less tension than at high idle speed. In the full load position, as shown in Fig. 3, the spring and weight forces of the governor are in equilibrium at governed speed and the fulcrurn lever cam 87 just contacts the maximum fuel stop 86. The lower pivot pin 62 is still at the right end of the fulcrum lever slot 61. As the engine speed drops below the governed speed the weights continue to collapse and the sliding sleeve 82 continues to move to the right. The fulcrum lever cam 87 then becomes the xed pivot point for the governor lever instead of pivot pin e2 and the entire lever is moved to the right by the governor spring S5 and the left end of the fulcrum lever slot el approaches pivot pin 62. During this motion the fuel control rod 9@ has also moved from position 91 to position 92 which results in an increased fuel delivery with a drop in engine speed and thus provides increased torque or lugging power.

In this manner, a declining fuel delivery curve is produced and hence engine torque back-up. The amount of fuel build up can be adjusted by adjusting screw 88. Raising the cam 87' produces more fuel increase for a given speed range. To obtain a flat delivery curve, the cam should be positioned close to the control rod 93. The governor spring S5 must be connected to the fulerum or governor lever 60 below the point where the cam contacts the maximum fuel stop S6.

It is pointed out that with the adjustable rod or lever 67 in Fig. 1 it is possible by changing the effective length of this `lever 6] to adjust the speed droop and that by adjusting block S9 in the construction shown in Fig. l, that the same effect will be obtained as is obtained by adjusting cam 37 through screw in the arrangements shown in Figs. 2 and 3.

It is pointed out that with the apparatus of the present invention through the proper adjustment, arrangement or elimination of parts, it is possible to eliminate the torque control and speed droop features or they can be obtained by the arrangement shown. Also it is possible to have the torque control feature without the speed droop feature and it is also possible to have the speed droop feature without the torque control feature.

From the foregoing, it will be seen that I have provided simple, eicient and economical means for obtaining all of the objects and advantages of the invention.

I claim:

1. In a device of the character described, a housing having spaced parallel bores, a drive shaft journalled in said housing, a face cam operatively connected to said drive shaft and driven thereby, a rotary fuel distributor in one of said bores and a fuel injection pump in the other of said bores, said distributor being operatively connected to and driven by said drive shaft, said pump being reciprocated by said face cam upon rotation of said drive shaft, a fuel inlet and a plurality of fuel outlets communicating with said bore containing said fuel distributor, and a fuel passage in said housing between said bore containing said distributor and said bore containing said fuel injection pump, said passage having a common portion communicating with said bore containing said prump and separated portions communicating with said bore for said distributor with one of said separated portions being adapted to supply fuel from said fuel inlet to said pump and the other of said separated portions being adapted to supply fuel from said pump to said distributor.

2. A fuel injection pump as set forth in claim 1 wherein the fuel distributor has spaced ports adapted to communicate successively with said fuel passage in the housing upon rotation of said fuel distributor for supplying fuel to the injection pump.

3. A fuel injection pump as claimed in claim l wherein the fuel distributor has a peripheral groove in constant communication with the said separated passage from the pump and said fuel distributor has a fuel distributing slot communicating with said peripheral groove.

4. A fuel injection pump as set forth in claim 2 wherein the fuel distributor has a peripheral groove in constant communication with the said separated passage from the pump and said fuel distributor has a fuel distributing slot communicating with said peripheral groove.

References Cited in the le of this patent UNITED STATES PATENTS

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