US2564830A - Fuel injection apparatus - Google Patents

Description

Aug. 21, 1951 Filed Nov. a, 1945 INVENTOR W :7 61mm 094% ATTORNEY.

Patented Aug. 21, 1951 2,564,830 FUEL INJECTION srranarns Albert T. Bremser, Sidney, N. Y., assignor to Bendix Aviation Corporation, New York, N. Y., a

corporation of Delaware Application November 8, 1945, Serial No. 627,360

1 Claims. This invention relates to pumps and more particularly to pumps of the cylinder and reciproeating plunger type for pumping liquids, such as liquid fuel into the cylinders of internal combustion engines.

One of the objects of the present invention is to provide a pump which through novel construction thereof is rendered more flexible to control the quantity of liquid fuel injected thereby into the engine cylinders.

Another object of the invention is to provide a novel high pressure fuel injection pump, or the like, wherein the relative positions of the fuel in- .iecting and metering plunge; and the by-pass port in the plunger cylinder may be adjusted with extreme accuracy.

Another object is to provide a novel pump of the above character wherein the fuel injection and metering plunger and the cylinder associated with said plunger are both capable of rotary adjustinent relative to each other for controlling the quantity of fuel delivered by said pump to the engine cylinders.

A further object is to provide novel eccentric means associated with the plunger cylinder for rotatably adjusting the latter relative to the liquid injecting and metering plunger.

A still further object is to provide a fuel injection pump having means of novel construction for effecting angular adjustment of the fuel injecting and metering plunger and for facilitating setting of said plunger in an initial predetermined Position.

Another object is to so construct a multi-unit high pressure fuel injection pump that delivery of equal quantities of fuel by all the units will always be assured despite errors or irregularities in the dimensions of the various parts which inevitably occur in the manufacture and upon continued use thereof.

Still another object is to provide a novel fuel injection pump so constructed that assembling, inspection and replacement of various parts thereof may. be quickly and conveniently accom-- plished, and wherein tampering with certain parts after final accurate adjustment thereof is prevented.

. The above and-further objects and novel features of the invention will more fully appear from the following detailed description when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not intended as a definition of the limits of the invention, references for this latter purpose being had primarily to the appended claims.

In the drawings, wherein like reference charz acters refer to like parts througheut the several views, Fig. 1 is a side elevation, partly in section, showing one form of a multi-unit fuel injection Dump embodying the present invention;

Fig. 2 is an enlarged fragmentary end elevation,

looking from the left of Fig. 1 and partly in sec tion, of said pump; ing'ig. 3 is a detail side elevation of a pump cyl- Fig. 4 is a detail end elevation of pump cylinder adjusting means; and

Fig. 5 is an enlarged fragmentary transverse section taken substantially on the line 5-5 of Fig. 1 and showing rack and gear means for adjusting the pump plunger.

Referring to the drawings, the present invention is herein illustrated, by way of example, as being embodied in a fuel pumping apparatus adapted to deliver solid liquid fuel into the cylinders of internal combustion engines, said apparatus embodying a separate pump unit for each cylinder and actuating means and adjusting or control means therefor. As illustrated, said apparatus comprises a substantially rectangular casing or housing 5 constructed to contain a plurality of vertically disposed, longitudinally spaced and aligned pump units 6. For this purpose. housing 5 is formed therein with a plurality of vertically disposed, longitudinally spaced and aligned bores or recesses I which open at their upper ends into separate annular chambers 8, and at their lower ends into a common elongated chamber 9 extending longitudinally of said housing and opening outwardly through one side thereof. Chambers 8 are of a diameter larger than the diameter of bores l and open at their upper ends into separate smaller diameter bores or recesses III that open outwardly through the upper end of housing 5. Chambers "8 are connected with a common fuel supply chamber or conduit II which is formed in and extends longitudinally of housing 5 and is so located that it passes centrally through each chamber 8. Conduit I'l opens outwardly through opposite sides of housing 5 and is internally threaded at each end to receive one end of a fuel supply line 12 a and a plug l3, respectively. The liquid within supply line I2 is preferably, but not 11,

let and by-pass ports I and II, respectively, which communicate with chamber 8 and with the interior of said cylinder for directing the flow of fuel to and from the cylinder in a manner to more fully appear hereafter. Cylinder I4 is normally held in rigid engagement with shoulder I5 and against rotation, and while any suitable means may be employed for this purpose, that herein illustrated and preferably utilized is an adapter element II which is disposed within bore and constitutes a guide and seat for a pressure responsive fuel delivery valve I 5. Adapter l rests upon the upper end of cylinder l4 and is normally held in fluid-tight engagement therewith by a holder 20 for said adapter and valve l3 which is threaded in bore III in housing 5. A gasket 2| is disposed between holder 2|) and an external flange 22 on adapter II to .urther insure fluid tightness. The upper end of holder 2| is formed with a reduced externally threaded portion or nipple 23 having an axial passage 24 therein whereby a delivery conduit (not shown) leading to the fuel injection nozzle may be attached -for communication with the interior of holder 24.

Valve adapter II is provided with an axial passage through which the flow of fuel from the upper end or pressure chamber 25 of cylinder l4 into the interior of holder 25 is controlled by delivery valve I! which is of fluted or other suitable form and has a tapered lower end portion adapted to engage a valve seat provided in adapter ll. Valve I8 is normally yieldably held in closed position by suitable resilient means, such as a coil spring 26 which is contained within an axial annular bore or recess 21 formed in holder 20 and is centered in said recess by a projection 24 formed on valve I! at the upper end thereof. Oneend of spring 25 engages an external flange 29. onvalve I I, and the opposite end of said spring engagesv the wall of holder 20 at the upper end of recess 21. The latter is in constant communication with passage 24 to direct the flow of fuel from pressure chamber 25 into the delivery conduit when valve I9 is lifted or unseated by the pressure of the fuel thereon.

Fitted for reciprocation in the bore of cylinder i4 is a pump plunger orpiston 30 which also functions as a slide valve for controlling the flow of fuel through ports l5, H and to apply pressure to the fuel admitted into pressure chamber 25 of cylinder l4. Plunger 3|) is provided with an axially extending passage 3| and a radial passage 32 which continuously connects the pressure chamber 25 with a helical groove 33 formed in the surface of plunger 35. Groove 33 is adapted to cooperate with port ll when plunger 35 moves upwardly and constitutes a metering bypass or cut-off groove which determines the effective pumping stroke of said plunger, as well understood in the art.

Reciprocating motion is imparted to the plunger 34 of pump units 5 at proper predetermined intervals by separate cams 34, one only being shown, which are secured to or formed integrally with a cam shaft 35 at spaced points therealong. Shaft 35 extends longitudinally of housing 5 and is journalled in suitable bearings in the end wall of said housing, said shaft being rotated from any suitable source of power, such as the engine, and by any suitable means connected therewith. Each cam 34 engages a roller or follower 35 which is journalled in suitable hearings in a tappet 31 that is slidably mounted in a bore 38 formed in housing 5 and coaxially with the bore I for 07111 der l4. Tappet 31 may be held against rotary movement'in housing 5 by any suitable means well-known in the art, such as by means of a screw (not shown) which threadedly engages housing 5 and projects into an axially extending groove in the outer surface of the tappet. Threaded in the upper end of tappet 31 and projecting upwardly into chamber 9 is a tappet screw 33 which engages an enlarged head portion 40 formed on the reduced lower end 4| of plunger 34. One or more shims 42 of the proper thickness are positioned between tappet 3'! and the head of tappet screw 39 to obtain accurate vertical setting of plunger 30 relative to cylinder l4 and the ports I6 and I1 therein.

Follower 35 is maintained in engagement with cam 34 by a coil spring 43 which is disposed within chamber 9 and has its upper end engaged with a flange 44 formed on a ring 45 that is also disposed within chamber 9 and surrounds the lower projecting end of cylinder l4. Ring 45 is held by spring 43 in rigid engagement with an internal shoulder 45 within chamber 5, and may be held against rotary movement by any suitable means well known in the art. such as by a screw (not shown) which is threaded in housing 5 and projects into an opening or recess formed in the wall of said ring. The lower end of spring 43 bears against a slotted washer 4! which surrounds the reduced end 4! of plunger 30 and engages the upper shoulder of head 40. Thus, upon rotation of shaft 35, each plunger 3|) is lowered by spring 43 and raised by cam 34 at a predetermined time once during each cycle of operation of the pump assembly to uncover port l5 and permit fuel to flow from chamber 8 into pressure chamber 25 and to thereafter close said port and apply pressure to the fuel admitted into pressure chamber 25 whereupon delivery valve is is unseated and the fuel is forced past said valve into the delivery conduit through recess 21 and passage 24.

Novel means are provided for angularly adjusting the plunger 30 of each pump unit 5 in order to change the relation between the metering groove 33 and the cut-off or by-pass port I! and thereby vary the effective pumping stroke of said plunger, and for initially setting the plunger of each unit in a predetermined angular position, said adjusting and setting means acting simultaneously on all the plungers so that the latter will occupy the same initial predetermined position and that like variance in the effective pumping stroke thereof will be obtained. As shown, the plunger adjusting and setting means comprises a rack .bar 48 which is located within chamber 3 and is slidably mounted for longitudinal reciprocation in suitable hearings in the opposite ends of housing 5. Rack 48 is guided for longitudinal movement and held against rotary movement in housing 5 by one or more screws 49 which threadedly engage housing 5 and project into a longitudinally extending groove in the adjacent side of said rack. Any suitable means (not shown) connected at 5| with rack 45 at one or the other or both ends thereof may be employed for operating said rack.

The teeth 52 of rack 43 mesh with teeth 53 formed on the upper ends of separate sleeves 54 which are located within chamber 5 and loosely surround 'the lower projecting ends of the separate cylinders I4, there being one sleeve for each pump unit B. Each sleeve 54 is held against axial movement relative to cylinder l4 by the internal shoulder 45 within housing 5 and by the flange 44 accuse of ring 45 which engages an external annular shoulder 55 formed on said sleeve. Ring 45 surrounds the teeth 53 of sleeve 54 and has a portion thereof removed to permit rack 48 to project therethrough and mesh with said teeth. The lower end of each sleeve 54 is formed with diametrically opposite slots 56 for slidably receiving the ends of a cross bar 51 which is secured to or formed integrally with plunger 30 and is of a length slightly less than the diameter of bore I for cylinder l4.

It will thus appear that upon reciprocation of rack 48 each of sleeves 54 will be moved angularly in a direction depending upon the direction of movement of said rack and each of plungers 34 will have a corresponding angularmovement imparted thereto through the connections 56, 51 with said sleeve, thus effecting angular adjustment of all the plungers simultaneously without affecting the longitudinal or pumping movement thereof. It will be noted that since the length of the cross bar 51 on plunger 30 is slightly less than the diameter of the bore I for cylinder I4, and since the bore III in housing is slightly greater in diameter than the diameter of cylinder M, the latter and the plunger of each pump unit 6 may be inserted into and removed from the housing through the top thereof. In this manner, assembling of the various parts of each pump unit is greatly facilitated, and repair and replacement of a pump plunger 30 may be easily and convenientl accomplished without having to disassemble the cam shaft 35 and the plunger tappet 31. In the removal of a plunger 30 from housing 5 for repair or replacement purposes, the split washer 41 is disengaged from said plunger through the open side of chamber 9, and the delivery valve l8, l9 and holder 20 therefor is unscrewed from housing 5. Thereupon the plunger 30 and its associated cylinder l4 may be raised as a unit and removed endwise from housing '5 through the bore H] at the top thereof. Similarly, when plunger 30 and cylinder l4 are removed from housing 5 as described, the plunger spring 43, adjusting sleeve 54 and spring ring 45 may be easily removed from housing 5 through the open side of chamber 9 by merely compressing the upper end of said spring until ring 45 is sumciently clear of housing 5 to permit tilting of said ring, sleeve 54 and spring 43 forwardly out of housing 5. The open side of chamber 9 is normally closed by a cover plate 58 which is removably secured to housing 5 by one or more bolts 59;

As shown in Fig. 5, the teeth 52 of rack 48 are so formed that one of said teeth at the point of engagement with the teeth 53 of each adjusting sleeve 54 is of a larger size as indicated at 60.

In the illustrated embodiment, tooth 60 is of a thickness equal to the thickness of three of teeth 52 measured on the pitch line. In other words, the thickness of tooth 60 is equal to the overall distance between two adjacent teeth 52 measured on the pitch line. Each large tooth 60 is adapted to project into a single correspondingly large space 6| formed between two pre-selected teeth 53 on each sleeve 54. Thus, since tooth 60 can only enter the space 6| in sleeve 54, said tooth and space serve as locating or key means for setting each plunger 30 in an initial predetermined angular position relative to its associated cylinder l4 and ports l6, I1 therein, whereby all of the plungers will occupy the same initial angular position and calibration of the entire pump assembly is greatly simplified. It will be understood that the large tooth 60 and space 6| may, if desired,

8 in formed in the sleeve 44 and rack 43, respecively. I

Novel simplified means are provided for effecting individual adjustment of the quantity of fuel delivered by each plunger 30 so that all the pump units will have the same fuel injection characteristics and will deliver equal quantities of fuel at any one setting of the rack 48. This adjustment compensates for slight errors and discrepancies in the dimensions of corresponding parts of each pump unit which inevitably occur in the manufacture and upon continued use thereof; it provides for delivery of a definite quantity of fuel at definite control rack settings; and enables calibration of any one pump unit wherein a replacement cylinder and plunger have been installed so that said unit will correspond with the remaining pump units in the quantity of fuel delivered thereby.

As shown, this adjustment is effected by rotatably adjusting the cylinder l4 of each pump unit 5 relative to its associated plunger 30 and the novel simplified means provided for this purpose comprises an externally threaded bushing 62 formed at one end thereof with an enlarged circular flange 63 that is provided on its top or outer surface with a plurality of radially extending grooves 64. Bushing 52 is engaged in a threaded bore 65 which is formed in housing 5 at the side thereof opposite that containing the control rack 48 and opens into chamber 8. The outer end of bore 55 opens into a groove 66 which is formed in and extends longitudinally of housing 5 to receive the flange 63 of each bushing 62. Bushing 62 is threaded into bore 65 and tightened by applying a suitable tool in the grooves 64. A gasket 61 is preferably disposed between housing 5 and the flange 63 of bushing 62 to provide a fluid-tight seal. Bushing 62 may be locked in tightened position by means of a plug (not shown) which projects through a notch in the periphery of flange 53 and into a suitable opening in housing 5.

Rotatably mounted in the non-threaded bore 68 of bushing 62 and projecting beyond opposite ends of said bushing is a threaded adjusting stud 69 provided at its inner end with an enlarged circular head or flange 10 on which is eccentrically formed a circular knob or projection H. The outer end of stud 69 is provided with a slot 12 to receive a screw driver or other manipulating tool. Eccentric knob ll projects into an axially extending groove 13 which is formed in the outer surface of cylinder I 4 and is preferably, but not necessarily, located that it extends vertically across the inlet and by-pass ports l6 and I1, respectively, in said cylinder for a slight distance above and below the same. Stud 69 is made of hardened steel to prevent wearing of the flange l0 and knob H by the high pressure fuel, said stud serving in place of the erosion resisting screw or insert heretofore employed in pumps of the character described and, hence, the preferred location of the groove 13 in cylinder l4.

It will thus appear that upon loosening delivery valve holder 20 one or two turns to free cylinder l4 for rotation in housing 5, said cylinder may be minutely rotated in either direction relative to its associated plunger 30 to any definite position within a limited range, by rotating the stud 69 in opposite directions, thereby locating the fuel cut-ofi or by-pass port IT in cylinder l4 in a definite position with respect to the helical groove 33 in plunger 30 and effecting accurate adjustment of the pump unit so that the latter will deliver a desired amount of fuel upon each operation thereof and an amount equal to the amounts delivered by the remaining pump units. Stud 69 is locked in adjusted positions by a lock nut II that is threaded on the outer end of said stud, and by a lock washer ll disposed between said nut and the flange I of bushing 62, said lock washer being formed with laterally projecting ears 16-which are bent to project into one or more of the grooves 64 in flange 63 and to engage one or more fiat sides of the nut II. The adjusting studs 69 for the pump units 6 are normally concealed to prevent tampering thereof, by a cover plate II which closes the longitudinal groove 66 in housing I and is removably secured to said housing by one or more screws 18.

There is thus provided a novel multi-unit fuel injection pump apparatus which, through the provision of angularly and individually adjustable plungers and plunger cylinders, may be controlled with extreme accuracy to obtain delivery of equal amounts of fuel by all the pump units regardless of variation in the dimensions of corresponding parts of each pump unit. The pump apparatus contains novel simplified eccentric means for efi'ecting individual angular adjustment of each pump cylinder. Additionally, the pump apparatus includes novel means for simultaneously effecting angular adjustment of the pump plungers and for setting each plunger in an initial predetermined angular position whereby calibration of all the pump units is facilitated. There is also provided a 'novel fuel injection pump wherein removal of certain parts thereof for repair and replacement purposes may be quickly and conveniently accomplished.

Although only a single embodiment of the invention has been illustrated in the accompanying drawings and described in the foregoing specificatiomit is to be expressly understood that the invention is not limited to said embodiment and may be incorporated inother types of pumps. For example, the invention may be incorporated in a single unit pump which has to be calibrated to deliver a definite quantity of fuel at definite control rack settings, and in a pump having a single port for controlling both the inlet and bypass of fuel or other liquid. Various other changes might also be made, particularly in the design and arrangement of the parts illustrated without departing from the spirit and scope of the invention, as will now be readily apparent to those skilled in the art. For a definition of the limits of the invention, reference is had primarily to the appended claims.

What is claimed is.

. 1. A fuel injection apparatus comprising a housing, a cylinder rotatably mounted in said housing, said cylinder having axially spaced inlet and by-pass ports therein anda groove in the periphery thereof extending axially across said -inlet and by-pass ports, a plunger reciprocable in said cylinder for controlling flow to said cylinder through said groove and inlet port and having a helical groove therein for controlling fiow from said cylinder through said bypass port and first-named groove, and means for rotating said cylinder relative to said plunger and housing comprising a bushing fixed in said housing, and a stud rotatably mounted in said bushing and having an eccentric knob on the inner end thereof projecting into the axially extending groove in said cylinder.

2. A pump comprising a housing, a cylinder supported in said housing, a plunger reciprocable in said cylinder. the latter having an axially extending groove in the outer surface thereof, and means cooperating with said groove for angulariy adjusting said cylinder in said housing about the longitudinal axis of the cylinder without imparting longitudinal movement thereto. said means comprising a cylindrical bushing threadedly mounted in said housing, a stud rotatably journalled in said bushing, said stud having an cecentric knob on the inner end thereof fitting into said groove and a circumferential flange engaging the inner end of said bushing, and a nut threaded onto the outer end of said stud and engaging the outer end of said bushing.

3. A pump as defined in claim 2 wherein means are provided for angulariy adjusting said plunger in the housing, said 'means including a pinion sleeve rotatably joumalled on the cylinder in a chamber in the housing, said sleeve having a slotted portion extending beyond the lower end of the cylinder for operative engagement with said plunger for angular adjustment thereof, a stepped supporting sleeve having a slotted eniarged end slidably fitting into a recess in said housing around the cylinder and partially surrounding said pinion sleeve and having a reduced end closely surrounding a reduced portion of said 'pinion sleeve to support and externally journal the latter, and a plunger retracting spring operatively interposed between said plunger and said supporting sleeve.

4. A pump comprising a housing having a stepped bore terminating at the lower end thereof in a chamber having an opening at one side thereof, a cylinder removably supported in said here and slidably extending through the smallest portion of said bore, a plunger reciprocable in said cylinder, means for angularly adjusting said plunger in said cylinder including a pinion sleeve rotatably joumalied on said cylinder in said chamber and having a slotted portion extending below said cylinder for operative engagement with said plunger to angularly adjust the latter, a stepped supporting sleeve having a slotted enlarged end slidably fitting into a recess formed by the lowermost enlarged portion of said bore and partially surrounding the toothed portion of said pinion sleeve and having a reduced end closely surrounding a reduced portion of said pinion REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,019,103 Thege Oct. 29, 1935 2,185,144 Edwards Dec. 26, 1939 2,185,146 Edwards Dec. 26, 1939 2,187,732 DeJuhasz 'Jan. 23, 1940 2,193,372 Buckwalter Mar. 5, 1940 2,222,593 Hurst et al. Nov. 26, 1940 2,244,306 Meiswinkel June 3, 1941 2,322,356 Hahn June 22, 1943 2,333,698 Bremser Nov. 9, 1943

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