US2380574A - Fuel injection pump - Google Patents

Description

July 31, 1945- L. BEEH ETAL 2,380,574

FUEL INJECTION PUMP Filed Sept. 27, 1944 2 Sheets-Sheet 1 BY wo/ FcA/vg MEYER July 31, 1945. l.. BEEH ETAL FUEL INJECTION PUMP Filed Sept. 27, 1944 2 Sheets-Sheet 2 Flc. 3. l

INVENToRs. Lou/s BEEH BY JOHN o. Fons TER WOLFGANG E. .v5 YER /77' 7 ORN 5 Y Patented Julysi, 194s UNITED STATES PATENT oFFlcE.

' l assume n v Long Island City, N. Y.,

New Haven, Conn.,

and Wolfgang E. Meyer. assignors to Bulova Watch Company, New York, N. Y.. a corporation of New York Application september- 21. 1944, serie: No. 555,914 1o clause (ci. 10s-17s) The invention relates to a multiple pump. and more in particular. to'a fuel injection pump for multiple cylinder engines, andcontemplates the provision of certain improvements applicable with particular advantages to that type of pumps in which a pluralityl of units essentially comprising each a plunger movable in a barrel, are arranged parallel to and equidistant from. a main axis, and in which a common drive reciprocates each plunger with a phase displacement in relation to the preceding one, once per each revolution of the drive shaft, as disclosed e. g. in the application for U. S. Patent, Serial No. 543,445 iiled by Louis Beeh on July 4, 1944. However, it will be understood that the invention is not limited in its application to that particular type oi' pumps.

The invention aims to provide means whereby the main driving forces are taken up by a block containing the barrels, without transmitting such forces to a housing or casing encompassing the barrel block. The invention also aims to provide means whereby the discharge oi the fuel from the pump takes place very close to the engin'.;i to which the pump is intended to be app e -The invention further aims to provide means whereby the barrel block can be secured with its lower portion to an engine to be charged by the pump, whereas the means for reciprocating the plungers are arranged on top of the barrels so as to allow for a direct connection of the pump discharge with said engine.

Further objects and details of the invention will be apparent from the description given hereinafter and the accompanying drawings showing embodiments thereof by way of example. In the drawings:

Fig. 1 is a longitudinal section of an embodiment of the invention. the section being taken along line I-I of Fig. 2:

Fig. 2 is a cross-section along line 2-2 of Fig. 1:'

Fig. 3 is a side elevation ci the metering valve ot the pump of Fig. 1.

Referring now to the drawings, the illustrated embodiment of a pump according to the invention is destined for use with a nine cylinder engine. The pump comprises a block in general denoted by Ill which consists of a substantially cylindrical portion I I with a iiange I2 at its lower end. and which has an axial bore I3 throughout its length. Nine other bores Il are provided parallel to and equidistant from the main pump axis a-a. They reach from the top face I! oi ber for a spring biased delivery valve 2|'.

'the block not quite to the other end face I6 which is the lower face of the ange I2 so that each bore Il constitutes a barrel with a. bottom I1. At a distance upward from the bottom I1, a radial port I8 opens from the barrel into the space of the bore I3, and a groove I9 in the interior of the barrel reaches from the port I8 downward tothe bottom Il. The ange I2 is provided with radial bores 20, one for each barrel, and communicating with the bottom end of the latter. Each bore 20 is so formed as to constitute a cham- The outer end of each bore 20 is closed by a plug 22. and a hollow screw bolt 23 crosses the bore 20 and serves the dual purpose of securing the pump to a iiange or other portion 24 of an engine, and of connecting the bore 23 to a conduit 25 leading to the nozzle (not shown) of an engine cylinder.

A substantially cylindrical Jacket or housing 26 bears on an outer shoulder 2l of the block I0 and also on a gasket ring 28 on top of flange I2. An annular fuel chamber 29 with an inlet 30 is formed between the' housing 26 and block I0, and radial conduits 3l in the block I0 intermediate said barrels connect said chamber and the inner bore I3 of the block I0. Interiorly of the bore I3, a valve 32 shaped as a hollow piston is arranged so as to be rotatable and axially shiitable for a purpose and by means to be described hereinafter. The valve, the side view of which is shown in Fig. 3 has a peripheral recess 33 with a land 34 therein to close the ports I3, one after the other during its rotation, for a shorter or longer part of each revolution depending on whether a narrower or wider part oi the land is in registry with the ports. However, it is to be noted that the recess 33 is in permanent communication with chamber 29 through at least some of the conduits 3l.

Coaxially with the block I3 and extending through valve 32, a hollow drive shaft 35 is arranged which is interiorly splined in its lower end portion at 36 in order to be coupled with a shaft 3l of the engine to which the pump is .to

v be applied. 'I'he shaft 35 is provided with an end collar or flange 38 and Journaled in a bearing 39 which in the illustrated embodiment is a ball bearing acting as a collar bearing as well as a thrust bearing. The latter quality is of importance from the viewpoint ot the invention, as it will be apparent from the description hereinafter. The outer race 40 o! bearing 33 engages a thrust ring 4I which in turn bears on an inner ilange 42 oi' a casing I3 secured to the lower face portion above the bearing 4B is externally splined o at 41, and the topmost end 48 is crew-threaded. To the splined portion, a shafthe d 49 is secured by means of a slitted nut Qi/iscrewed on the threading 48 and locked in position by a screw 5i which forces the slitted nut portions apart 10 or together so' as to deform a portion of the nut threading. The shaft head 49 has an outer cylindrical bearing surface 52 inclined with respect to the main axis a-a, andanother thrust bearing surface 53 at right angles to the surface B2. A is cup-shaped wobble or swash plate B4 engages both said bearing surfaces and is held in engaging position by a slitted nut 5B screwed into an interior threading I8 of the swash plate 54 and being supported by an upper bearing surfacel 51 of the 2o shaft head. The swash plate 54 is provided with a projection B8 which engages a stationary guide face il arranged parallel to the axis Aa--a interlorly of a housing' top part 80. Thus, when shaft l5 rotates, the swash plate will not partici- 2;,

pate in the rotation owing to the engagement of the projection 58 with the guide faces B9 but will accomplish a cyclical up and down motion.

In order to facilitate adjustments necessary to insure correct operation of the pump parts as it will be described hereinafter, indicator meansv may be provided in order to ascertain when a predetermined point of the swash plate is in its topmost position. For this purpose, the housing top 80 is provided with'a bore 6i in which a pin 35 8l is movable. A spring v63 tends to push the pin upward against a cap nut 84 screwed into the upper portion of the bore 8|. The upper end ofthe pin projects through a cover plate 85 of the housin rtion 60. When in 82 isl ressed 40 l s po p p land 34 of the valve during a portion of the com.

down by an operator the lower end of the pin will be in the path of the projection 58 and it can be noticed by finger pressure when the highest position of the projection is reached. When the pin is released it will be lifted by spring 83 es I into the illustrated position in which it cannot `be contacted bythe projection.

The swash plate Iis provided with nine ball sockets ll, i. e. as many as there are barrels in the block iii, so as to receive -therein the upper ball heads 61 of connecting rods 68 of plungers 8 0 which are reciprocatable in the barrels I4. Each plunger consists of a tubular body 1li with a lower head 1I screwed into the body end. The

plungers are omitted in Fig. 2 but one plunger 55 is clearly `shown in I i'ig. 1. The lower ball end 1I of each connecting rod ls secured-to an accordingly shaped recess of the head 1i of the associated plunger by a slotted washer 13 bearing against `an inner shoulder 14 of the plunger tube o 10. This washer is so dimensioned as to yield or break when the plunger gets stuck. However, it will be noted that the design avoids, as far as possible, the occurrence oi' any dangerous lateral stresses which might be the cause of the plungers 05 freezing in their barrels. v

In'order to rotate the metering valve while .the

plungers are reciprocated, a pin 1l is secured in the valve body and engages the drive shaft 3B in slots 14 which permit axial adjustment of the 7 valve relatively to the ports i4.

For the purpose of metering the quantity of fuel delivered by the pump, a tubular rod 11 is arranged interiorly of shaft and the pin 15 is wardly from theb drive shaft 35, an antifrictlon bearing is mounted so as to abut against the flanged head of a plug 8i screwed into the tubular rod 11. The bearing 80 is encased in a ring 82 having two diametrically opposite trunnions. which are engaged by a forked lever 84. The latter is mounted on a shaft 8l projecting outwardly of the housing part 80 so as to be turned by suitable means notv shown. Ihus. by turning shaft 85 the tubular rod 11 together with valve 32 can be raised against the restraint of spring 18 or lowered while being free to rotate together with the drive shaft 40. The'housing part BD which encloses the swash plate mechanism and the arijustment control, is connected to the lower housing 2B, the block flange i2, and the casing 4I by means of a number of screw bolts 88 as clearly shown in Fig. l. All conventional lubrication ducts have been omitted inthe drawing in order to avoid overcrowding of the latter. However, any suitable lubrication system for the movable parts of the pump may be applied as well known in the art.

The pump operates in the following manner: if the driveshaft is turned bythe engine shaft 31. the piungers will be reciprocated according to the cyclical oscillation of the swash plate, i. e. each plunger lagging in phase in respect to the preceding one and the phase lag being equal to 360 divided by the number of plungers. 'While the plungers are thus reciprocated the metering valve 32 rotates uniformly with the shaft 36. It is so adjusted in relation to the inclination of the shaft head 49 that. each port i8 will be covered by the pression stroke of the coordinate plunger 69 and the length of such stroke portion will be determined by the width which the land has according to its axial adjustment between its edges on the level of the ports i8. During the suction stroke of a plunger, fuel may therefore enter the coordinate barrel from space 28 through conduits 3i, valve recess 83 and port i8. While the latter is closed during a portion of the compression stroke a corresponding quantity'of fuel will be expelled by the plunger from its barrel through the delivery valve 2i, and during the remainder or the compression stroke a corresponding quantity of fuel will be returned on the same way as that on which fuel entered during the suction stroke. As to the axial forces occurring during the operation of the pump, the action during the compression stroke of a plunger is downward as to the connecting rod. Consequently, an upward reaction between Vthe shaft head 49 and nut 50 will tend to raise the drive shaft. This tendency is counteracted by the thrust bearing arrangement at the lower end of the shaft, whereby the upward force is transmitted to the lower face i6 of block Ill. On the other hand, the downward pressure ot' the connecting rod and plunger. acting on the fuel in the barrel is taken up by the barrel side walls and the bottom i1 which as well as the barrel walls is partof the block lil. The forces occurring dursecured to said rod so that the' valve and the rod u that in particular all housing parts are relieved from stresses. liurthermorer the arrangement of the swash plate mechanism above the pump barrels renders it possible to provide the delivery ports in close proximity of the engine to which the pump is applied, thereby avoiding all external conduits except those Vrequired to feed the pump.

Many alterations and modifications of the illustrated forms will be apparent to those skilled in the art, without departing from the spirit and essence of the invention which shall be limited only by the scope of the appended claims.

We claim: i

l. In a pump of the type described a substantially tubular block including a flange at one of its ends and embodying in its wall a plurality of pump barrels parallel to the block axis and closed at their ends adjacent said flange, plungers reciprocatable in said barrels, a drive including a shaft extending coaxially through said block and means attached t said shaft outside the other block end to reciprocate said plungers, and means in connection with said shaft outside the flanged block end and bearing upon said flanged block end to transmit thereto axial reactions of plunger pressures.

2. In a pump of the type described, a substantially tubular block including a flange at one of its ends and embodying in its wall a plurality of pump barrels parallel to the block axis and closed at their ends adjacent said flange, plungers reciprocatable in said barrels, a drive including a shaft extending coaxiaily through said block and a swash plate device attached to said shaft outside the other barrel end and connected to the plungers so as to reciprocate the latter upon rotation of said shaft, and a thrust bearing between said shaft and the outside of said flanged barrel end.

3. A device as claimed in claim 2 further comprising a housing encasing at least the major portion of said block and said swash plate, and an indicator means attached to the housing and operative from the outside so as to engage said swash plate thereby to indicate the swash plate position relatively to a predetermined point of said block.

4. In a pump of the type described, a substantially tubular block including a flange at one of its ends and embodying in its wall a plurality of pump barrels parallel to the block axis, said flange being provided with a plurality of substantially radial delivery conduits, one for each barrel and communicating therewith, valvecontrolled conduits in said block to admit fuel to said barrels, plungers reciprocatable in said barrels, a drive including a shaft extending co axially through said block and a swash plate attached to said shaft outside the other barrel end 3 to said axial bore, a rotatable valving means in said axial bore so as to control said other conend portion of said rod.

and connected to the plungers so as to reciprocate the latter upon rotation of said shaft, and a thrust bearing between said shaft and the outside of said flanged barrel end.

5. A device as claimed in claim 4, further comprising a plurality of delivery valves, one in each of said radial conduits.

6. In a pump of the type described a block including a substantially cylindrical portion and a flange at its one end, said block being provided with an axial bore throughout its length and with a plurality of other bores parallel to its axis and closed at their bottoms so as to constitute pump barrels, said flange being provided with radial bores, one for each barrel and communicating therewith, so as to constitute delivery conduits, other conduits connecting each of said barrels duits, means vto supplyl fuel to said valving means for admission to said other conduits one after the other, reclprocatable plungers in said barrels, a drive shaft coaxial with and extending through said valve and connected therewith, and means outside the other end of said block and connected to said shaft and said plungers to reciprocate the latter once per each shaft revolution and with equal phase displacements as to one another.

7. A vdevice as claimed in claim 6, said valving means comprising a substantially cylindrical, metering valve body, a control rod, and a connecting pin, said valve body being adjustable in axial direction and provided with an axial bore, said shaft being hollow and extending through said axial bore of said valve body, said control rod being axially shiftable lnteriorly of said shaft and projecting therefrom with one cf its ends, and said pin extending in substantially radial direction through longitudinal slots in said shaft and being secured to said valve body and the other 8. A fuel injection pump for multiple cylinder engines comprising a block including a substantially cylindrical portion and a flange at its lower end, said block being provided with an axial bore throughout its length and with a plurality of other bores parallel to its axis and closed at their bottoms so as to constitute pump barrels, said flange being provided with radial bores, one for each barrel and communicating therewith, so as to constitute delivery conduits, a housing member secured to the top of said flange and encasing the cylindrical block portion so as to form a, fuel chamber between said member and said cylindrical block portion, a set of passages in said block between said chamber and said axial bore, a second set of passages between said barrels respectively and said axial bore, a' rotatable valve in said axial bore so as to control the passages of said second set one after the other, reciprocatable plungers in said barrels, a drive shaft shaft coaxial with and extending through said valve and connected therewith, and means on top of said -block and connected to said shaft and said plungers to reciprocate the latter once per each shaft revolution and with equal phase displacements as to one another.

9. A pump as claimed in claim 8, further comprising a bearing, and said shaft embodying a collar at its lower end portion, said bearing being located between said collar and the lower face of said flanged block end and adapted to transmit axial forces from said shaft to said block.

10. A fuel injection pump for multiple cylinder engines comprising a block including a substantially cylindrical portion and a, flange at its lower end, said block-being provided with an axial bore throughout its length and with a plurality of other bores parallel toits axis and closed at their bottoms so as to constitute pump barrels, said flange being provided with radial bores, one for each barrel and communicating therewith so as to constitute delivery conduits, a housing member secured to the top of said flange and encasing the cylindrical block portion so as to form a fuelv chamber between said member and said cylindrical block portion, conduits in said block from said chamber and from said barrels to said axial bore, a rotatable and axially adjustable metering valve in said axial bore so as to control said conduits, reciprocatable plungers in said barrels, a hollow drive shaft coaxial with and extending through said valve and connected therev on top of said swash plate to shift said rod and with for common rotation, a swash plate device said valve axially, and a cover for said housing on top of said block and connected to said shaft so as to encase said swash plate and said shifting and said plungers to reciprocate the latter, a. rod means.

axially shiftable interiorly of said shaft and up- 5 LOUIS BEEH. wardly projecting therefrom and connected to JOHN O. FOR/STER.

said valve through slots in said shaft, means in l WOLFGANG E. MEYER. operative connection with said rod and arranged n n

Images