US2922371A

US2922371A - Fuel injection pump

Info

Publication number: US2922371A
Authority: US
Inventors: Waldemar O Bischoff
Original assignee: American Bosch Arma Corp
Current assignee: Ambac International Corp
Priority date: 1957-07-05
Filing date: 1957-07-05
Publication date: 1960-01-26
Anticipated expiration: 1977-01-26

Description

Jan- 26 1960 w. o. BlsczHoFF` 2,922,371

FUEL INJECTION PUMP Filed July 5, 1957 65 69 65 23 '5 INVENTOR.

6a WALDEMAP @Blaat-orr- A TTOP/VE United States Patent O FUEL INJECTION PUMP Waldemar 0. Bischoff, Holyoke, Mass., assig'uor to American Bosch Arma Corporation, a corporation of- New York Application July 5, 1957, Serial No. 670,178 s claims. (ci. 10s- 2) This invention relates to distributor type fuel injection pumps and has particular reference to a new and improved pump of the type set forth whichis relatively simple, compact and economical in construction, yet eilicient in operation.

Thel principal object of the invention is to provide a new and improved fuell injection pump of the type set forth Yhaving simplied and economical Vconstruction means.

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 changes may be made in the details of construction and arrangement of parts shown and described without departing from the spirit of the invention, as set -forth in the accompanying claims, as the preferred form of the invention has been given by way of illustration only.

Referring to the drawings:

Fig. 1 is a longitudinal sectional view in a fuel injection apparatus embodying the invention;

Fig. 2 is a sectional view taken on line 2-2 of Fig. 1, looking in the direction of the arrows; v

Fig. 3 is a fragmentary sectional view taken on line 3 3 of Fig. 1, looking in the direction of the arrows; and

Fig. 4 is a fragmentary sectional view taken von line 4 4 of Fig. 1, looking in the direction of the arrows.

Referring more lparticularly to the drawings 'wherein ysimilar reference characters designate corresponding parts throughout, the apparatus shown embodying the invention includes a housing in which is positioned hydraulic head 11, which could be vformed in the housing and lwhich has a bore 11a in which is mounted the rotary Vmember or rotor 12 adapted to be driven by the drive shaft 13 which is journaled in the housing. I

The rotor 12 has the pumpingl portion 14 and .the fuel distributing portion 15.

Thepumping portion has cylinder means consisting of a i radial bore 16 in which is positioned piston means consisting of the opposed plungers i7, which are adapted to 'be urged outwardly on their suction stroke by the spring 18, which is positionedv between the plungers and extends into bores in the adjacent surfaces of the plunger.

Surrounding the pumpingA portion 14 is the internal cam 18 having opposed lobes for effecting simultaneous reciprocation of plungers 17 and between the cam 18 and plungers 17 is provided the tappets 19y and rollers 20.

The rotor 12 has a bore 21, the outer end of which is l adapted to be closed by the plug 22 which has a reduced extension 23 extending intothe portion of bore 21 adjacent pumping portion 14.

The housinglu has the fuel inlet 23a adapted to be connected to a source of fuel, whichfuel passesV throug'hrinlet 23a toy annular sump 24 surrounding hydraulic head 11 and is adapted to supply yfuel to bore 21 by means of fill ports 25, which por-ts can be lof desired number;

Hydraulic head 11 is provided with a plurality of outlets 26, eachV of which is4 adapted' to be' connected 'toV a respective engine cylinder or combustion chamber for ICC supplying fuel thereto, and the outlets 26 are adapted to receive `fuel through ports 27 from distributing groove or slot V28 on the distributing portion of the rotor which, inturn, receive fuel through annular groove or slot 29 which communicates therewith and also communicates with fuel passage 30 from, the delivery valve 31, which valve is normally retained in closed position by valve springiSZ. The delivery valve is adapted to receive fuel from cavity 66 through distributing port or Vpassage 33 and annulus 29a. Fuel enters said cavity 66 from the discharge end of shuttle piston 35 through ports 65, one of which ports is provided for each two engine cylinders.

The hydraulic head 11 is provided with the cross bore 34 in which is positioned the shuttle piston 3S. Bore 34 is adapted to communicate withvrotor cavity 68 through ports A36 and 36a, which connect with said bore`34 adjacent the opposite ends thereof. y

' Shuttle'piston i35`has the inclined orhelical end 37 adjacent'metering or spill port 67. Shuttle piston 35 is adapted to be rotated about its airisto adjust the position of helicalsurface 37,A relative'toV port 67,'A by an Veccentric pin 40 on shaft 41 vwhereby said shuttle piston 35 may be adjusted to `control theV spilling Vof lfuel'throughport 67 to control thefuel quantity. This controls one end of injection.v Spilli'ng through? port 38 limitsthe other end of injection. n v n Rotating'shuttle'piston 35 changes theV fuel quantity by changing the effective stroke-ofthe shuttle pistonby varying" the -relationship between metering port 67 and heueal'enn'sl. Y v n The adjustment of shuttle piston 35 is controlled 'through the gove'rcorlprising the movable governor sleeve 46 on drive shaft 13 and which is adjusted along ythe, rotor or drive shaft by thelcentrifugal weights 47, only'one'ofwhih is shown,-and pivoted lever 48 which has an end49 engaging said Asleeve 46 whereupon move- `ment`o`f the sleeve 46 of lever 48 is pivoted about its ixed pivot 50, and the end 51 of lever 48 which isconnected to vshaft `41 through lever 52 controls theposition of the sleeve 39'.

For automatic control,- the ygovernor spring 53 is adjustedthrough adjustment of lever 54 to which one end of spring 53 is connected-and which lever is adapted to Vbe adjusted by movement of an operatinglever externally of casing or housing 10 whereupon shaft 56 and lever `54 are pivoted to adjust the tension on spring 53 which has an end operatively connected to lever 48 adjacent the end thereof 51 for adjusting the governor lever in the usual manner. Y n

vIn the operation ofthe device, fuel enters the housing 10 through inlet port 23a into sump 24. During the suction stroke ofthe plungers- 17, ports 25a in the rotor are in communication with fill ports 25, which communicate withsump 24.v The plungers 17 are forced outwardly by the plunger spring 1 8 andfuel is sucked 'into ports 25 and 25a into bore 68 and into the'spa'ce between plungersV 17.

On 'first .part of the injection stroke of the 'plunger-s, when the pl-ungers 17 are forced towards each other by the lobes on the cam 18, fuel flows for a short time from the cavity or bore 68 around the .plunger grooves 60 through-lspill port 61'in the roto'r to spill port 62 back to the sump 24.

By the time groove 60 is closed fromport 61, the ll ports 25a are closed'from ports'ZS and `pressure can be developed fin the' pumping chamber. The 'rotor is providedV with one port 64 for each two engine cylinders and theselp'orts are equally spaced and always in communication" with-the pumping chamber.

Ports

36 and 36a are solariranged that first one and then the other is successively openelto onev of the ports 64fduring succeeding'injection strokes. The opposite ends of

ports

36 and 36a 3 are connected to bore 34 adjacent the opposite ends thereof respectively.

The rotor is also provided `with one port 65 Ifor each two engine cylinders. The ports 65 are equally spaced and always in communication with cavity 66. Ports 69 and 69a are so arranged that first one and then the other is successively opened to one of the ports 65 during succeeding injection strokes. The opposite ends of ports 69 and 69a are connected to bore 34 adjacent the opposite ends thereof respectively. The number of

ports

65 and 64 would be equal in number with the same spacing, but not necessarily with the same angular relationship. Ports 65 open to ann-ulus 66 which connects to port 33, to annulus 29a to delivery valve 31.

On the iirst injection stroke the piston 35 will be in the position shown in Fig. 2 with ports 36a and 69 closed. Fuel flows through port 64 and port 36 into bore 34 applying pressure to the adjacent end of piston 35. This pressure causes pis-ton 35 to move .forcing fuel out of bore 69a.

From passage 69a fuel passes through port 65 through annulus 66, port 33 to annulus 29a to the delivery valve 31 from which the fuel goes through port 30 to annulus 29 to the distributor slot 28 on the rotor and then is delivered to one of the outlets 26. Fuel continues to flow in this direction until spill port 38 is uncovered by adjacent end'of piston 35.

On the second injection stroke ports 36a and 69 will be open and

ports

36 and 69a will be closed. Fuel flows passages adapted to connect the opposite ends of said' through port 64 and port 36a into bore 34 applying pressure to the adjacent end of piston causing piston'35 to be displaced and forcing fuel out of bore 69 into port 65 and thence to the next outlet 26. Fuel continues to ow in this direction until spill port 67 is uncovered by helical edge 37. The high pressure fuel can now escape from port 67 to sump 24 and piston 35 will not'mo've any fur- -ther in this direction because the fuel pressures against the opposite ends of the piston are practically equal until the instant of spill and, thus, spill port 67 limits the distance of travel of the piston. Uncovering of spill port 38 limits the piston travel in the opposite direction. Varying the angular relationship between helical end 3 and port 67 will vary the fuel quantity spilled thereby varying the distance of travel of the piston 35 and varying the fuel quantity delivered. It will be seen that whateverV distance the piston travels in one direction for one injection stroke, it must travel backward exactly the same amount for the next injection stroke, if the sleeve position is not changed. Therefore, the amount of fuel injected b'y the forward stroke of the shuttle piston is equal to the amount injected by the backward stroke and changing the sleeve position changes the fuel quantity the same amount for the both strokes.

With Vthe present arangement, means is provided for hydraulically balancing the shuttle piston forces and pro- Viding a control for metering on the shuttle piston. This control requiresronly very light forces to change its position for easier governor control and fuel metering.

It will be seen that with the present arrangement i'as shown, the hydraulic balancing of the pressure eliminates the need for positive mechanical stops.

From the foregoing it will be seen that I have provided new and improved means for obtaining all of the objects and advantages of the invention.

I claim:

l. In a distributor type fuel injection pump for internal combustion engines, a housing having a longitudinal bore, a rotor mounted for rotation in said bore, lsaid rotor having pumping and distributing portions, said pumping portion having radial cylinder means and piston means mounted for reciprocation in said radial cylinder means, cam means operatively associated with said piston means for effecting reciprocation of said piston means upon rotation of said rotor, said rotor having an axial bore conn ecting said pumping and distributing portions, the provision of a shuttle piston bore in said housing and adapted shuttle piston bore to said axial bore in said rotor through peripherally spaced ports in said rotor, a plurality of outlets in said housing, a distributing port in said rotor and communicating with said axial bore in'said rotor through said shuttle piston bore and adapted to communicate with each of said outlets successively upon rotation-of said rotor whereby upon rotation of said rotor, fuel pumped by said pumping portion will be delivered through said axial bore to said distributing portion and then through each of said passages alternately to said shuttle piston bore and through said peripherally spaced ports in said rotor and eiect movement of said shuttle piston to effect delivery of fuel from the opposite end of said shuttle pistonbore through the passage to said distributing portion whereby it will be delivered to one of said outlets, an annular sump in said housing, a fuel inlet communicating ,withsaid sump, and fuel passage means connecting said Asump with said axial bore in said rotor, and spill port means adapted to communicate with said radial cylinder means and with said annular sump.

necting said pumping and distributing portions, the provision of a shuttle piston bore in said housing and adapted to communicate with said axial bore upon rotation of said rotor, a shuttle piston mounted for reciprocation in said shuttle piston bore, spill passage connecting said shuttle piston bore adjacent opposite ends of said shuttle piston Ywith an area of lower pressure, said spill passages being controlled by the opposite ends of said shuttle piston, fuel passages adapted to connect the opposite ends of said shuttle piston bore to said axial bore in said rotor through `peripherally spaced ports in said rotor, a plurality of out- .lets in said housing, a distributing port in said rotor and communicating with said axial bore in said rotor through said shuttle piston bore and adapted to communicate with each of said outlets successively upon rotation of said rotor whereby upon rotation of said rotor, fuel pumped by said pumping portion will be delivered through said axial bore to said distributing portion and then through each of said passages alternately to said shuttle piston bore and through said peripherally spaced ports in said rotor and effect movement of said shuttle piston to effect delivery of fuel from the opposite end of said shuttle piston bore through the passage to said distributing portion whereby it will be delivered to one of said outlets, and means for adjusting said shuttle piston to vary the spilling ythrough one of said spill passage means to thereby control the fuel quantity delivered.

tion of said rotor, said rotor having an axial bore connec'tingVV saidV pumping and distributing portion, the provision of a shuttle piston bore in said housing and adapted to communicate with said axial bore'upon rotation of said rotor, a shuttle piston mounted for reciprocation in said shuttle piston bore, spill passages connecting said shuttle piston bore adjacent opposite ends of said shuttle piston with an area of lower pressure, said spill passages being controlled by the opposite ends of said shuttle piston, fuel passages adapted to connect the opposite ends of said shuttle piston bore to said axial bore in said rotor through peripherally spaced ports in said rotor, a plurality of outlets in said housing, a distributing port in said rotor and communicating with said axial bore in said rotor through said shuttle piston bore and adapted to communicate with each of said outlets successively upon rotation of said rotor whereby upon rotation of said rotor, fuel pumped by said pumping portion will be delivered through said axial bore to said distributing portion and then through each of said passages alternately to said shuttle piston bore and through said perpherally spaced ports in said rotor and effect movement of said shuttle piston to effect delivery of fuel from the opposite end of said shuttle piston bore through the passage to said distributing portion whereby it will be delivered to one of said outlets, said shuttle piston having a metering edge at one end thereof and means for adjusting said shuttle piston to vary the spilling through one of said spill passage means to thereby control the fuel quantity.

References Cited in the tile of this patent UNITED STATES PATENTS 2,542,389 Broderick i. Feb. 20, 1951 2,641,238 Roosa June 9, 1953 2,674,236 Humber Apr. 6, 1954 2,683,445 Seaver July 13, 1954