CA1052649A - Fuel injection system - Google Patents
Fuel injection systemInfo
- Publication number
- CA1052649A CA1052649A CA273,801A CA273801A CA1052649A CA 1052649 A CA1052649 A CA 1052649A CA 273801 A CA273801 A CA 273801A CA 1052649 A CA1052649 A CA 1052649A
- Authority
- CA
- Canada
- Prior art keywords
- distributor
- fuel
- pump
- valve
- delivery
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M41/00—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor
- F02M41/02—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor being spaced from pumping elements
- F02M41/04—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor being spaced from pumping elements the distributor reciprocating
- F02M41/042—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor being spaced from pumping elements the distributor reciprocating by means of mechanical drive
Abstract
Abstract The specification describes a fuel injection pump in which a distributor assembly is used with a pump unit for the distribution of equal fuel quantities to the cylinders of a multi-cylinder internal combustion engine. The pump unit operates such that the number of deliveries of fuel metered by the pump equals the number of firing strokes in the engine with the distributor assembly connecting each of the cylinders within the engine in turn to the pump unit by means of delivery channels. Only one cylinder is in communi-cation via the distributor with the pump unit at any one time.
Description
~OS;~6~9 1 Field of the Invention This invention relates to a distributor of a fuel injection pump which distributes metered amounts of fuel pumped by a pump unit for use in a multi~ylinder internal combustion engine.
Background of the Invention There are presently two general types of fuel injection systems including the common in-line system and the distributor system. The effectiveness of both systems is limited due to the face that the degree of pressure and the amount of fuel delivered to each cylinder changes over time which results in an unequal supply of fuel and an untuned engine. Some of the cylinders burn too lean and the others burn too rich, so there is excess fuel consumption, a loss of engine power and smoking at lower R.P.M. The unequal dis-tribution occurs as a result of wear on the system components , which increases the more the system is used.
It is therefore a prime object of the present inven-tion to provide a fuel injection system of the distributor type which is highly durable and which supplies equal quantities of fuel charges to each cylinder of an internal , combustion engine.
;~;' It is another object of the present invention to . ., ~ provide a fuel injection system of the type described above , in which the metered amount of fuel delivered to each cylinder is consistent from cylinder to cylinder throughout the working or life span of the fuel injection pump.
~05"649 A further object of the ~rcs~nt invention is to ~rovi~e an improved high-pressure distributor type fuel injection pump including a distributor assembly for distributing fuel charges metered and pumped from a pump unit to a multi-cylinder internal combustion engine.
Brief Summary of the Invention The above objects are achieved according to this ` invention by providing a distributor assembly including a - plurality of plunger type valves used for the sole purpose of distributing fuel from a pump unit to the cy1inders of a multi-cylinder internal combustion engine. The purpose ; `of the pump is to pump and meter fuel to the distributor.
The pump unit itself is not involved in the distribution of fuel.
... . .
~ach of the cylinders in the multi-cylinder engine is provided with a delivery channel, and that delivery channel is connected to the pump unit by the distributor assembly.
... . .
Only one delivery channel is in communication ~ith the pump unit at any one time, so that the delivery channels of the ., :~, .
various cylinders are connected to the pump unit in sequence.
'"'' The individual delivery channels are connected to the pump ~ I
unit for every delivery stroke of the pump plunger.
According to a preferred embodiment, each of the - distributor plunger type valves is operated by means of a - : .
25 ~ flat-faced distributor cam lobe. As a result of the construction of the cam lobe, the distributor plunqer valves . .
are held in a stationary position while connecting the delivery channels to the pump unit throughout the entire delivery stroke of the plunger of the pump unit. Due to the - 30 stationary position of the distributor plunger valves
Background of the Invention There are presently two general types of fuel injection systems including the common in-line system and the distributor system. The effectiveness of both systems is limited due to the face that the degree of pressure and the amount of fuel delivered to each cylinder changes over time which results in an unequal supply of fuel and an untuned engine. Some of the cylinders burn too lean and the others burn too rich, so there is excess fuel consumption, a loss of engine power and smoking at lower R.P.M. The unequal dis-tribution occurs as a result of wear on the system components , which increases the more the system is used.
It is therefore a prime object of the present inven-tion to provide a fuel injection system of the distributor type which is highly durable and which supplies equal quantities of fuel charges to each cylinder of an internal , combustion engine.
;~;' It is another object of the present invention to . ., ~ provide a fuel injection system of the type described above , in which the metered amount of fuel delivered to each cylinder is consistent from cylinder to cylinder throughout the working or life span of the fuel injection pump.
~05"649 A further object of the ~rcs~nt invention is to ~rovi~e an improved high-pressure distributor type fuel injection pump including a distributor assembly for distributing fuel charges metered and pumped from a pump unit to a multi-cylinder internal combustion engine.
Brief Summary of the Invention The above objects are achieved according to this ` invention by providing a distributor assembly including a - plurality of plunger type valves used for the sole purpose of distributing fuel from a pump unit to the cy1inders of a multi-cylinder internal combustion engine. The purpose ; `of the pump is to pump and meter fuel to the distributor.
The pump unit itself is not involved in the distribution of fuel.
... . .
~ach of the cylinders in the multi-cylinder engine is provided with a delivery channel, and that delivery channel is connected to the pump unit by the distributor assembly.
... . .
Only one delivery channel is in communication ~ith the pump unit at any one time, so that the delivery channels of the ., :~, .
various cylinders are connected to the pump unit in sequence.
'"'' The individual delivery channels are connected to the pump ~ I
unit for every delivery stroke of the pump plunger.
According to a preferred embodiment, each of the - distributor plunger type valves is operated by means of a - : .
25 ~ flat-faced distributor cam lobe. As a result of the construction of the cam lobe, the distributor plunqer valves . .
are held in a stationary position while connecting the delivery channels to the pump unit throughout the entire delivery stroke of the plunger of the pump unit. Due to the - 30 stationary position of the distributor plunger valves
- 2 -9 ~3-I,i throughout the delivery stroke of the plunger the wear on the individual distributor plungers, bores and drilling ports is less than the wear on distributor systems in which the distri-butor is constantly moving. In the present system, the quantity of fuel distributed to each cylinder is consistent from cylin-der to cylinder over time as the unit operates.
Brief Description of the Drawings The aforementioned and other objects, advantages and ; features of the present invention will become apparent in the following detailed description of the preferred embodiments according to this invention, having reference to the accomp-anying drawings in which:
Figure 1 is a cross-sectional view of a fuel injection -pump head according to this invention.
Figure 2 is a representative section of the fuel injection pump head of Figure 1 taken along the lines 2-2.
Figure 3 is a representative sectional view of the fuel injection pump head of Figure 1 taken along the lines 3-3.
Figure 4 is a front elevational view of the fuel injection pump head of Figure 1 mounted on a pump housing.
Figure 5 is a f~ont elevational view of a cam mechan-ism for operating the distributor valve plungers according to this invention.
Figure 6 is a sectional view of a pump unit for pumping and metering fuel according to this invention.
` Figure 7 is a front elevational view of the pump unit of Figure 6 when adjusted to meter a different quantity of fuel.
Figure 8 is a side elevational view representative of the bottom portions of the pump unit shown in Figures 6 and 7.
Figure 9 is an enlarged exploded view of the means for adjusting the pump plunger bushing shown in Figures 6 and 7.
, 105'~649 Figure 10 is a sectional view of a distributor valve according to this invention.
Figure 11 is a part sectional elevational view of another embodiment of a fuel injection pump head according to this invention showing an alternative method of delivering fuel from the distributor to the cylinders of an engine.
Detailed Description of the Preferred Embodiments ~ccordinq to this Invention ~ .
Referring primarily to Figure 1, a fuel injection pump comprises a hydraulic pump head generally indicated at P
including a pump head casing ,1 and a pump unit having a pump plunger 5 reciprocable within a cylinder bore formed b~ -' , bushing 6, as bést shown in Figure 6. Located below the pump plùnger is a camshaft follower roller 3 rotatably mounted in , 15 its camshaft follower 2.
~; , The fuel injection pump head is mounted in a pump housing as shown in Figure 4. The pump housing, which does not constitute part of the present invention, includes a cam shaft 39 provided with a cam lobe 40. The cam shaft is `~' 20 driven by an engine (not shown~ and the cam lobe reciprocates pump plunger 5 within its cylinder bore through roller 3 and followex 2. Th~e pump unit meters and pumps fuel to the ~ distributor assembly arranged around it.
,, ~ Provided in the pump housing is a shaft 43 provided '^~ 25 with a pinion gear 44. Shaft 43 and gear 44 are driven by means of a reduction gear assembly generally indicated at G.
,' Pinion gear 44 meshes with ring gear 25 of distributor cam 23 mounte~ at the base of the fuel injection pump head. Cam 23 is,~rovidcd with a flat-faced distributor cam lobe 24.
~0 DistributQr cam -23 rotates about ~earin~3s 26. The distributor ._. A._ cam and its bearings ~re secured to the pump head casing by means of retaining nuts 27.
Arranged around pump plunger S are a p.lurality of distributor valves including valve plungers 16 mounted in S the~ir respective cylinders formed by means of bushings 15.
Each of the distributor valve plungers 1~ is provided at its lower end with a distributor cam follower 28 and a distrib-utor follower roller 29, rotatably mounted therein. The distributor valve plungers are reciprocated within their respe~ctive cylinders in succession by cam lobe 24 of distributor cam 23 through rollers 29 and followers 28.
Fuel is supplied by means of a low pressure supply pump (not shown) to fuel reservoir 12 through fuel supply duct 11, as shown in Figure 3. Duct 11 extends from inlet lla to reservoir 12 and back to outlet port llb to a pressure equalizer check valve 13, which is ~ounted at the outlet port-for equalizing pressure in the system so as to provide fuel - circulation with a fuel tank (not shown) for pump cooling and ~ air venting.
20 The fuel (under low pressure) which is in the pump fuel . reservoir 12 enters the pump cylinder chamber through inlet -~ drillings 7 while the pump plunger 5 is held in its lowest ~:. position by means of plunger pressure spring 4. As cam shaft . 39 is rotated, lobe 40 lifts pump plunger S through roller 3 . 25 and follower 2 upwardly through a delivery stroke to its uppermost position, as shown in Figure 1. The fuel, which is under pressure throughout the delivery stroke, lifts pump check valve 51 up off its seat in pu~p check. valve body SO, . against th~ pressure of spring 52. As the fuel passes from the pump cylinder it enters a plurality of delivery ducts 14 .. - 5 -lo5~649 which are drillings in the pump casing extending from the ~heck valve through the pum~ casing to the distributor valves.
The number of delive-ry ducts equals the number of cylinders in the engine. ~
Pump plunger 5 includes two opposing helical slots 8 (only one of which can be seen in the drawings). Slots 8 are machined in the upper part of the pump plunger in the area of inlet drillings 7. The purpose of the slots is to meter fuel - as follows. The relation of the helical slots with respect to the inlet drillings 7 changes wlth partial rotation of pump plunger 5, thereby determinina the effective part of the delivery stroke of the pump plunger. In Figure 6, the effective length of the delivery stroke is indicated by the length of arrow A. In Figure 7, the effective length of the delivery stroke is indicated by arrow B. In Figure 7 the delivery part of the stroke is completed bcfore the pump ;~ plunger reaches its top position because the inlet drillings are unveiled by the two helical siots. ~he fuel, which is delivered into the pump chamber but which is not pumped by the pump, flows back to fuel supply reservoir 12.
Pump plunger 5 is rotated partially through the axial movement of control rack 10 provided with gears lOa which ~esh with gears 9a of control sleeve 9, as shown in Figure 2.
~,~ Pump plunger 5 includes at its lower end a pair of radial - 25 extensions 62 which are engaged in slots of the control sleeve formed by downward extensions 61, as shown in Figure 8.
Therefore, the pump plunger moves with the control sleeve.
Also provided in the pump head lS a pump bushin~
- adjusting sleeve having two toothlike projections 56 at its lower end which extend into slots 56a provided at the upper _ 6 -` iO5'~649 end of bushing 6. Adjusting sleev~ 55 includes at its upper end a flange provided with extended slots 63 through which extend securing bolts 57. Threaded into sleeve 55 is a check valve retainer 53 housing the check valve spring and having a vent drilling 54 sealed by sealin~ cap 58 having a : vent screw 59.
Due to the provision of the extended slots, sleeve 55 can be partially rotated to provide the initial setting for the metering of fuel. If proper adjustment cannot be achieved through the use of control rack 10, then further metering can be accomplished through the adjustment of sleeve 55. Therefore when metering through the use of the rack, control sleeve 9 and plunger 5 are rotated with respect to bushing 6. When metering through the use of the adjustment sleeve, bushing 6 is rotated relative to the : control sleeve and pump plunger.
. Referring to Figure 10, the distributor valve includes . .
. drilling 18 which passes through bushing 15 to form a contin-uation of one of the delivery ducts 14. Located at the upper `~. 20 end of drilling 18 is an annular channel 31, only half of -~ which appears ln Figure 10. Located above bushing 15 is a delivery valve body 20 having an annular channel 32 at its lower end in communication with channel 31. Extending upwardly from channel 32 are drillings 33 leading to the -` 25 interiar of the delivery valve body. Bushlng 15 and delivery valve body 20 are retained by fitting 22.
.. ~ .
Each of the distributor valve plungers includes an annular groove 17. When the individual distributor valve ; plungers are in a distributing position, groove 17 is aligned with drilling 18. Annular channels 31 and 32 as well ., r~
105'~649 as drillings 33 form a continua~ion of the delivery duct and drilling. The tubular valve plungers also include drillings 34 for the purpose of breathing during operatlon of the distributor. An annular groove and outlet drilling 35 S is providcd in bushing 15 for collecting any possible seeping fuel, some of which lubricates the valve plunger.
Drilling 35 is connected with drilling 36 extendlng through the pump casing and leading to the pump fuel reservoir 12.
Each of the distributor valves operates in the following manner: As distributor cam 21 is rotated, the flat-faced distributor cam lobe 24 lifts cacll of thc cam follower rollers and its follower 28 of the distributor valves in succession, thereby lifting each of the distrib-utor valve plungers in sequence within their bushings. While one of the distributor valve plungers is in an upper open position held by cam lobe 24, the remaining distributor valve plungers are held, by pressure springs 30, in their lowermost closed positions on cam 23 through their followers and follower rollers, as indicated by the distributor valve . 20 plunger shown in the left-hand portlon of Figure 1. The distributor valve plunger in the right-hand portïon of Figure 1 is in its uppermost open position. As is to be understood from the drawings and due to the close fit between each of the valve plungers and its respective bushing, drillings or delivery passages 18 are cut off from delivery ducts 14 when the distributor valve plungers are in their - lowermost position. However, when a distributor valve pIunger is lifted by means of cam lobe 24 of cam 23, the distributor valve plunger annular groQve 17 is in alignmcnt ~30 with drilling 18, thereby making a continuous path around '' lOSZ649 the valve plun~er body so that fuel flows from the pump unit through duct 14 and drilling 18 via annular groove 17. As earlier mentioned, although all the ducts are full of fuel un~er pressure, fuel cannot pass around more than one distributor valve body plunger at any one time because distributor cam 23 is only provided with one cam lobe.
The reason for the flat upper face of the cam lobe is to provide a distributing system in which the successively operated distributor valve plungers remain stationary when in the distributing position. The length of cam lobe 24 is such that the plungers are held in the distributing position throughout the entire delivery stroke of the pump plunger.
In conventional systems, the fuel under pressure acts as an abrasive against the ports of the fuel passage as the components move during the distribution of fuel. In the present system there is no abrasion because the distributor ~ -valve plungers are stationary during distribution. Therefore, :: .
referring to Figure 1, the delivery valve plunger shown on the right hand portion of the drawing is maintalned in a position where annular groove 17 is in alignment with channel 18 through the entire upstroke of plunger 5.
Returning to Figure 4, the pump housing, which may . , .
` contain a governor (not shown) includes a control lever shaft 48. A pump control lever 49, which may be operated : ,~ .
- 25 manually is connected with positioning rack 10 through :: -intermediate linkage 46 and intermediate lever 47 mounted on the control lever shaft. The fuel output of the fuel pump is determined by the positioning of the pump control lever 49, which may be positioned to provide for a ma~lmum or minimum R.P.M. position. The pump control l~vcr is held g 105'~649 in idle position by idle stop piston screw 45, which may be pressed inwardly to permit the control rack to be moved to a - stop or neutral position in which no fuel is delivered.
In summarizing the operation of the mechanical fuel pump according to this invention, only one of the distributor valves is held in an open position by flat-faced distributor cam lobe 24 at any one time. When the distributor valve is in its open position t~e pump plunger S moves upwardly through a delivery stroke, and fuel passes around valve 51 through delivery duct 14 to the delivery valve via drilling 18 extending through distributor valve bushing 15. Annular groove 17 permits passage of the fuel around the distributor valve plunger when it is in the open position. Groove 17 therefore forms a continuation of delivery passage 18. From there the fuel passes via annular channels 31 and 32 to drilling 33 into the bore of delivery valve body 20. The - fuel which is under pressure forces delivery valve 19 against : spring 21 off its seat and thereafter flows from the distributor through the passage provided in fitting 22. The . ~ . .
same sequence of events occurs each time distributor cam 23 provided with cam lobe 24 moves each of the distributor ... - ..
~ ~ valves to an open position.
: .
Each of the distributor valves is held in an open position connecting -the -channel 18 throughout the entire delivery stroke of pump plunger 5. The diameter of the distributor cam would of course be increased~with an increasing number of distributor valves, and the number of distributor valves would equal the number of cylinders in the multi-cylinder engine in which the injectlon fuel pump is to be used. ~ -105;~649 Furthermore the distribu~or system according to tllis invention may be operated in con~unction with any suitable pump unit or a pumping system including a plurality of pumping pistons. It is also feasible to provide a pump unit employing a different type of metering device from that descri~ed above.
According to another embodiment of the invention, Figure 11 shows a different distributor valve arran~em~nt which operates on the same principle as that shown in Figures 1 through 10. A mechanical fuel pump generally indicated at P2 includes a distributor valve 65 which operates in the same manner as distributor valve 16. I~owever, -according to this embodiment, the distributor valve cylinder . 66 is simply a bore within the pump casing itself and does not include a bushing. Distributor valve 65 is reciprocating in a close fit in its bore.
Fuel is metered and pu~ped by a pumping unit (not shown) through fuel delivery passage 67 to the cylinder bore. When the distributor valve is in a closed position, i.e., its : .:
- lowermost position, no fuel can pass around the distributor valve plunger. However, when the distributor valve plunger ' ~ lS in its upper open position, fuel flows around qroove 71 to ~passage 69, which in this embodiment extends laterally rather than vertically of the distributor assembly. Threaded into the side of the pump casing is a nipple 73 having an internal passage 75 which is connected to passage 69. Fitted illtO
- nipple 73 is a tubular fitting-77 provided with a delivery ~ passage 79. Delivery passage 79 is in turn connected to -;~ passage 75. When distributor val~e 65 is in its open position, the fu~l passing around annular ~roove 7I flows 105'~649 through Later~l pass~ges 69 and 75 and u?wardl~! t~roug~
vertical delivery passage 79.
There are of course many alternative-methods and structures for delivering the fuel after it has passed around the distributor valve, and it will be appreciated by those s~illed in the art that variations may be made to the construction.s described above while remaining within the spirit of the invention and the scope of the appended claims.
' ; ~ , '~:``'' .' ~ .". :
: , .~. . . .
Brief Description of the Drawings The aforementioned and other objects, advantages and ; features of the present invention will become apparent in the following detailed description of the preferred embodiments according to this invention, having reference to the accomp-anying drawings in which:
Figure 1 is a cross-sectional view of a fuel injection -pump head according to this invention.
Figure 2 is a representative section of the fuel injection pump head of Figure 1 taken along the lines 2-2.
Figure 3 is a representative sectional view of the fuel injection pump head of Figure 1 taken along the lines 3-3.
Figure 4 is a front elevational view of the fuel injection pump head of Figure 1 mounted on a pump housing.
Figure 5 is a f~ont elevational view of a cam mechan-ism for operating the distributor valve plungers according to this invention.
Figure 6 is a sectional view of a pump unit for pumping and metering fuel according to this invention.
` Figure 7 is a front elevational view of the pump unit of Figure 6 when adjusted to meter a different quantity of fuel.
Figure 8 is a side elevational view representative of the bottom portions of the pump unit shown in Figures 6 and 7.
Figure 9 is an enlarged exploded view of the means for adjusting the pump plunger bushing shown in Figures 6 and 7.
, 105'~649 Figure 10 is a sectional view of a distributor valve according to this invention.
Figure 11 is a part sectional elevational view of another embodiment of a fuel injection pump head according to this invention showing an alternative method of delivering fuel from the distributor to the cylinders of an engine.
Detailed Description of the Preferred Embodiments ~ccordinq to this Invention ~ .
Referring primarily to Figure 1, a fuel injection pump comprises a hydraulic pump head generally indicated at P
including a pump head casing ,1 and a pump unit having a pump plunger 5 reciprocable within a cylinder bore formed b~ -' , bushing 6, as bést shown in Figure 6. Located below the pump plùnger is a camshaft follower roller 3 rotatably mounted in , 15 its camshaft follower 2.
~; , The fuel injection pump head is mounted in a pump housing as shown in Figure 4. The pump housing, which does not constitute part of the present invention, includes a cam shaft 39 provided with a cam lobe 40. The cam shaft is `~' 20 driven by an engine (not shown~ and the cam lobe reciprocates pump plunger 5 within its cylinder bore through roller 3 and followex 2. Th~e pump unit meters and pumps fuel to the ~ distributor assembly arranged around it.
,, ~ Provided in the pump housing is a shaft 43 provided '^~ 25 with a pinion gear 44. Shaft 43 and gear 44 are driven by means of a reduction gear assembly generally indicated at G.
,' Pinion gear 44 meshes with ring gear 25 of distributor cam 23 mounte~ at the base of the fuel injection pump head. Cam 23 is,~rovidcd with a flat-faced distributor cam lobe 24.
~0 DistributQr cam -23 rotates about ~earin~3s 26. The distributor ._. A._ cam and its bearings ~re secured to the pump head casing by means of retaining nuts 27.
Arranged around pump plunger S are a p.lurality of distributor valves including valve plungers 16 mounted in S the~ir respective cylinders formed by means of bushings 15.
Each of the distributor valve plungers 1~ is provided at its lower end with a distributor cam follower 28 and a distrib-utor follower roller 29, rotatably mounted therein. The distributor valve plungers are reciprocated within their respe~ctive cylinders in succession by cam lobe 24 of distributor cam 23 through rollers 29 and followers 28.
Fuel is supplied by means of a low pressure supply pump (not shown) to fuel reservoir 12 through fuel supply duct 11, as shown in Figure 3. Duct 11 extends from inlet lla to reservoir 12 and back to outlet port llb to a pressure equalizer check valve 13, which is ~ounted at the outlet port-for equalizing pressure in the system so as to provide fuel - circulation with a fuel tank (not shown) for pump cooling and ~ air venting.
20 The fuel (under low pressure) which is in the pump fuel . reservoir 12 enters the pump cylinder chamber through inlet -~ drillings 7 while the pump plunger 5 is held in its lowest ~:. position by means of plunger pressure spring 4. As cam shaft . 39 is rotated, lobe 40 lifts pump plunger S through roller 3 . 25 and follower 2 upwardly through a delivery stroke to its uppermost position, as shown in Figure 1. The fuel, which is under pressure throughout the delivery stroke, lifts pump check valve 51 up off its seat in pu~p check. valve body SO, . against th~ pressure of spring 52. As the fuel passes from the pump cylinder it enters a plurality of delivery ducts 14 .. - 5 -lo5~649 which are drillings in the pump casing extending from the ~heck valve through the pum~ casing to the distributor valves.
The number of delive-ry ducts equals the number of cylinders in the engine. ~
Pump plunger 5 includes two opposing helical slots 8 (only one of which can be seen in the drawings). Slots 8 are machined in the upper part of the pump plunger in the area of inlet drillings 7. The purpose of the slots is to meter fuel - as follows. The relation of the helical slots with respect to the inlet drillings 7 changes wlth partial rotation of pump plunger 5, thereby determinina the effective part of the delivery stroke of the pump plunger. In Figure 6, the effective length of the delivery stroke is indicated by the length of arrow A. In Figure 7, the effective length of the delivery stroke is indicated by arrow B. In Figure 7 the delivery part of the stroke is completed bcfore the pump ;~ plunger reaches its top position because the inlet drillings are unveiled by the two helical siots. ~he fuel, which is delivered into the pump chamber but which is not pumped by the pump, flows back to fuel supply reservoir 12.
Pump plunger 5 is rotated partially through the axial movement of control rack 10 provided with gears lOa which ~esh with gears 9a of control sleeve 9, as shown in Figure 2.
~,~ Pump plunger 5 includes at its lower end a pair of radial - 25 extensions 62 which are engaged in slots of the control sleeve formed by downward extensions 61, as shown in Figure 8.
Therefore, the pump plunger moves with the control sleeve.
Also provided in the pump head lS a pump bushin~
- adjusting sleeve having two toothlike projections 56 at its lower end which extend into slots 56a provided at the upper _ 6 -` iO5'~649 end of bushing 6. Adjusting sleev~ 55 includes at its upper end a flange provided with extended slots 63 through which extend securing bolts 57. Threaded into sleeve 55 is a check valve retainer 53 housing the check valve spring and having a vent drilling 54 sealed by sealin~ cap 58 having a : vent screw 59.
Due to the provision of the extended slots, sleeve 55 can be partially rotated to provide the initial setting for the metering of fuel. If proper adjustment cannot be achieved through the use of control rack 10, then further metering can be accomplished through the adjustment of sleeve 55. Therefore when metering through the use of the rack, control sleeve 9 and plunger 5 are rotated with respect to bushing 6. When metering through the use of the adjustment sleeve, bushing 6 is rotated relative to the : control sleeve and pump plunger.
. Referring to Figure 10, the distributor valve includes . .
. drilling 18 which passes through bushing 15 to form a contin-uation of one of the delivery ducts 14. Located at the upper `~. 20 end of drilling 18 is an annular channel 31, only half of -~ which appears ln Figure 10. Located above bushing 15 is a delivery valve body 20 having an annular channel 32 at its lower end in communication with channel 31. Extending upwardly from channel 32 are drillings 33 leading to the -` 25 interiar of the delivery valve body. Bushlng 15 and delivery valve body 20 are retained by fitting 22.
.. ~ .
Each of the distributor valve plungers includes an annular groove 17. When the individual distributor valve ; plungers are in a distributing position, groove 17 is aligned with drilling 18. Annular channels 31 and 32 as well ., r~
105'~649 as drillings 33 form a continua~ion of the delivery duct and drilling. The tubular valve plungers also include drillings 34 for the purpose of breathing during operatlon of the distributor. An annular groove and outlet drilling 35 S is providcd in bushing 15 for collecting any possible seeping fuel, some of which lubricates the valve plunger.
Drilling 35 is connected with drilling 36 extendlng through the pump casing and leading to the pump fuel reservoir 12.
Each of the distributor valves operates in the following manner: As distributor cam 21 is rotated, the flat-faced distributor cam lobe 24 lifts cacll of thc cam follower rollers and its follower 28 of the distributor valves in succession, thereby lifting each of the distrib-utor valve plungers in sequence within their bushings. While one of the distributor valve plungers is in an upper open position held by cam lobe 24, the remaining distributor valve plungers are held, by pressure springs 30, in their lowermost closed positions on cam 23 through their followers and follower rollers, as indicated by the distributor valve . 20 plunger shown in the left-hand portlon of Figure 1. The distributor valve plunger in the right-hand portïon of Figure 1 is in its uppermost open position. As is to be understood from the drawings and due to the close fit between each of the valve plungers and its respective bushing, drillings or delivery passages 18 are cut off from delivery ducts 14 when the distributor valve plungers are in their - lowermost position. However, when a distributor valve pIunger is lifted by means of cam lobe 24 of cam 23, the distributor valve plunger annular groQve 17 is in alignmcnt ~30 with drilling 18, thereby making a continuous path around '' lOSZ649 the valve plun~er body so that fuel flows from the pump unit through duct 14 and drilling 18 via annular groove 17. As earlier mentioned, although all the ducts are full of fuel un~er pressure, fuel cannot pass around more than one distributor valve body plunger at any one time because distributor cam 23 is only provided with one cam lobe.
The reason for the flat upper face of the cam lobe is to provide a distributing system in which the successively operated distributor valve plungers remain stationary when in the distributing position. The length of cam lobe 24 is such that the plungers are held in the distributing position throughout the entire delivery stroke of the pump plunger.
In conventional systems, the fuel under pressure acts as an abrasive against the ports of the fuel passage as the components move during the distribution of fuel. In the present system there is no abrasion because the distributor ~ -valve plungers are stationary during distribution. Therefore, :: .
referring to Figure 1, the delivery valve plunger shown on the right hand portion of the drawing is maintalned in a position where annular groove 17 is in alignment with channel 18 through the entire upstroke of plunger 5.
Returning to Figure 4, the pump housing, which may . , .
` contain a governor (not shown) includes a control lever shaft 48. A pump control lever 49, which may be operated : ,~ .
- 25 manually is connected with positioning rack 10 through :: -intermediate linkage 46 and intermediate lever 47 mounted on the control lever shaft. The fuel output of the fuel pump is determined by the positioning of the pump control lever 49, which may be positioned to provide for a ma~lmum or minimum R.P.M. position. The pump control l~vcr is held g 105'~649 in idle position by idle stop piston screw 45, which may be pressed inwardly to permit the control rack to be moved to a - stop or neutral position in which no fuel is delivered.
In summarizing the operation of the mechanical fuel pump according to this invention, only one of the distributor valves is held in an open position by flat-faced distributor cam lobe 24 at any one time. When the distributor valve is in its open position t~e pump plunger S moves upwardly through a delivery stroke, and fuel passes around valve 51 through delivery duct 14 to the delivery valve via drilling 18 extending through distributor valve bushing 15. Annular groove 17 permits passage of the fuel around the distributor valve plunger when it is in the open position. Groove 17 therefore forms a continuation of delivery passage 18. From there the fuel passes via annular channels 31 and 32 to drilling 33 into the bore of delivery valve body 20. The - fuel which is under pressure forces delivery valve 19 against : spring 21 off its seat and thereafter flows from the distributor through the passage provided in fitting 22. The . ~ . .
same sequence of events occurs each time distributor cam 23 provided with cam lobe 24 moves each of the distributor ... - ..
~ ~ valves to an open position.
: .
Each of the distributor valves is held in an open position connecting -the -channel 18 throughout the entire delivery stroke of pump plunger 5. The diameter of the distributor cam would of course be increased~with an increasing number of distributor valves, and the number of distributor valves would equal the number of cylinders in the multi-cylinder engine in which the injectlon fuel pump is to be used. ~ -105;~649 Furthermore the distribu~or system according to tllis invention may be operated in con~unction with any suitable pump unit or a pumping system including a plurality of pumping pistons. It is also feasible to provide a pump unit employing a different type of metering device from that descri~ed above.
According to another embodiment of the invention, Figure 11 shows a different distributor valve arran~em~nt which operates on the same principle as that shown in Figures 1 through 10. A mechanical fuel pump generally indicated at P2 includes a distributor valve 65 which operates in the same manner as distributor valve 16. I~owever, -according to this embodiment, the distributor valve cylinder . 66 is simply a bore within the pump casing itself and does not include a bushing. Distributor valve 65 is reciprocating in a close fit in its bore.
Fuel is metered and pu~ped by a pumping unit (not shown) through fuel delivery passage 67 to the cylinder bore. When the distributor valve is in a closed position, i.e., its : .:
- lowermost position, no fuel can pass around the distributor valve plunger. However, when the distributor valve plunger ' ~ lS in its upper open position, fuel flows around qroove 71 to ~passage 69, which in this embodiment extends laterally rather than vertically of the distributor assembly. Threaded into the side of the pump casing is a nipple 73 having an internal passage 75 which is connected to passage 69. Fitted illtO
- nipple 73 is a tubular fitting-77 provided with a delivery ~ passage 79. Delivery passage 79 is in turn connected to -;~ passage 75. When distributor val~e 65 is in its open position, the fu~l passing around annular ~roove 7I flows 105'~649 through Later~l pass~ges 69 and 75 and u?wardl~! t~roug~
vertical delivery passage 79.
There are of course many alternative-methods and structures for delivering the fuel after it has passed around the distributor valve, and it will be appreciated by those s~illed in the art that variations may be made to the construction.s described above while remaining within the spirit of the invention and the scope of the appended claims.
' ; ~ , '~:``'' .' ~ .". :
: , .~. . . .
Claims (7)
- THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
l. A fuel injection apparatus for use in a multicylinder, internal combustion engine, said apparatus comprising a pump head including a pump head casing, a central pump unit consisting of a pump plunger reciprocable in a pump plunger bushing and a fuel metering means so that said pump unit both meters and pumps fuel, a plurality of distributor valves including valve plungers, a distributor cam having a single flat distributor lobe for moving said valve plungers in suc-cession from a non-distributing to a stationary distributing position in sequence with a delivery stroke of said pump unit and for holding said valve plungers in said stationary distributing position through the entire delivery stroke of said pump unit, spring means for returning said valve plungers to said non-distributing position where they rest on said distributor cam through their respective cam followers, a fuel inlet extending through said casing and into said pump plunger bushing, delivery ducts extending from said pump unit to all of said distributor valves and cam and spring means for reciprocating said pump plunger, each of said distributor valves distributing, in succession, fuel metered and pumped by said pump unit. - 2. A fuel injection apparatus as claimed in Claim l wherein said fuel metering means comprises a helical slot on said pump plunger for metering the amount of fuel pumped by said pump plunger, a control sleeve mounted on said pump plunger for partially rotating said pump plunger and helical slot relative to said fuel inlet, and a control rack axially move-able in said pump head casing and engaged with said control sleeve for positioning said control sleeve and pump plunger.
- 3. A fuel injection pump as claimed in claim 2 further including a pump bushing adjusting sleeve for setting said pump bushing relative to said pump plunger for the metering of fuel.
- 4. A distributor for use with a pump unit metering and pumping fuel to said distributor, said distributor being provided with a plurality of distributor valves including valve plungers which distribute fuel to the cylinders of a multicylinder internal combustion engine, a distributor cam having a single flat distributor lobe for moving said valve plungers in succession from a non-distributing to a station-ary distributing position and for holding said valve plungers in said distributing position through the entire delivery stroke of a pump plunger, spring means for returning said valve plungers to said non-distributing position and a plurality of fuel delivery ducts extending to said distributing valves, each of said distributor valves distributing in succession fuel to its respective cylinder.
- 5. A distributor as claimed in cliam 4, wherein said distributor valves include distributor valve bushings with said valve plungers reciprocating in succession in a close fit in the bores of said valve bushings, said delivery ducts extending through said bushings and being interrupted by said distributor valve plungers when in their non-distributing positions, said valve plungers being provided with annular grooves which align with said delivery ducts when said valve plungers are in their distributing positions to permit the flow of fuel around said valve plungers from the pump unit to the cylinders of the multicylinder internal combustion engine.
- 6. A distributor as claimed in Claim 6 wherein said distributor valves are arranged about said pump unit, said valve plungers are tubular in shape and said distributor valve bushings include annular grooves for collecting fuel seeping along the sides of said valve plungers.
- 7. A distributor as claimed in Claim 6 further including a plurality of delivery valves and delivery valve bodies, each of said delivery valve bodies having an annular channel in communication with a delivery duct and a fuel passage extending from said annular channel to the bore of said delivery valve, said delivery valves being spring loaded to a closed position in the bores of said delivery valve bodies an moving to a delivery position when under pressure from fuel distributed by said distributor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA273,801A CA1052649A (en) | 1977-03-11 | 1977-03-11 | Fuel injection system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA273,801A CA1052649A (en) | 1977-03-11 | 1977-03-11 | Fuel injection system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1052649A true CA1052649A (en) | 1979-04-17 |
Family
ID=4108136
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA273,801A Expired CA1052649A (en) | 1977-03-11 | 1977-03-11 | Fuel injection system |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1052649A (en) |
-
1977
- 1977-03-11 CA CA273,801A patent/CA1052649A/en not_active Expired
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