EP0665373A1 - Kraftstoffeinspritzpumpe - Google Patents

Kraftstoffeinspritzpumpe Download PDF

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Publication number
EP0665373A1
EP0665373A1 EP94120704A EP94120704A EP0665373A1 EP 0665373 A1 EP0665373 A1 EP 0665373A1 EP 94120704 A EP94120704 A EP 94120704A EP 94120704 A EP94120704 A EP 94120704A EP 0665373 A1 EP0665373 A1 EP 0665373A1
Authority
EP
European Patent Office
Prior art keywords
lead groove
sub
plunger
port
fuel injection
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.)
Granted
Application number
EP94120704A
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English (en)
French (fr)
Other versions
EP0665373B1 (de
Inventor
Hiroaki C/O Zexel Corporation Kato
Hidekatsu C/O Zexel Corporation Yashiro
Tsuyoshi C/O Zexel Corporation Kodama
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bosch Corp
Original Assignee
Zexel Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from JP5349176A external-priority patent/JPH07189862A/ja
Priority claimed from JP34918193A external-priority patent/JP3174932B2/ja
Priority claimed from JP5349170A external-priority patent/JPH07189861A/ja
Application filed by Zexel Corp filed Critical Zexel Corp
Publication of EP0665373A1 publication Critical patent/EP0665373A1/de
Application granted granted Critical
Publication of EP0665373B1 publication Critical patent/EP0665373B1/de
Anticipated expiration legal-status Critical
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    • 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
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/20—Varying fuel delivery in quantity or timing
    • F02M59/24—Varying fuel delivery in quantity or timing with constant-length-stroke pistons having variable effective portion of stroke
    • F02M59/26—Varying fuel delivery in quantity or timing with constant-length-stroke pistons having variable effective portion of stroke caused by movements of pistons relative to their cylinders
    • F02M59/265—Varying fuel delivery in quantity or timing with constant-length-stroke pistons having variable effective portion of stroke caused by movements of pistons relative to their cylinders characterised by the arrangement or form of spill port of spill contour on the piston
    • 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
    • F02M45/00—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship
    • 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
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/20—Varying fuel delivery in quantity or timing
    • F02M59/24—Varying fuel delivery in quantity or timing with constant-length-stroke pistons having variable effective portion of stroke
    • F02M59/26—Varying fuel delivery in quantity or timing with constant-length-stroke pistons having variable effective portion of stroke caused by movements of pistons relative to their cylinders
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B3/00—Engines characterised by air compression and subsequent fuel addition
    • F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition

Definitions

  • a fuel injection pump in which the feed hole is constituted as a main port and a sub-port, an upper main lead groove is formed to communicate with the main port and an upper sub-lead groove is formed to communicate with the sub-port.
  • Fig. 4 shows a vertical sectional view of the fuel injection nozzle 6, which is of the throttling type.
  • the fuel injection nozzle 6 has a nozzle body 26, a chip packing 27, a holder body 28, a retaining nut 29, a needle valve 30, a pressure spindle 31, a pressure spring 32, an adjustment shim 33, and a bar filter 34.
  • the fuel injection nozzle 6 is further formed with a fuel passage 35 running the length of the chip packing 27 and the holder body 28 and connected with the fuel injection pipe 23, and with a fuel reservoir 36, a nozzle hole 37 and a leak-off connection 38.
  • Fig. 5 is an enlarged sectional view of the nozzle hole 37 portion at the tip of the nozzle body 26.
  • the nozzle hole 37 has a throttle-like configuration and a pin member 30A is formed to project from the tip of the needle valve 30.
  • the pin member 30A is positioned within a cylindrical wall portion 37A of the nozzle hole 37 and a tapered portion 30B of the needle valve 30 is seated on a seat portion 37B of the nozzle hole 37.
  • a small lift of the needle valve 30 produces a large change in the opening area. It is therefore relatively easy to control generation of black smoke and particulates by regulating this lift to control the fuel injection rate.
  • the opening area remains substantially constant during the first half of the fuel injection and, further, since combustion starts gradually in the divided-chamber combustion system diesel engine 1 or 8 owing to the small amount of air in the auxiliary combustion chamber 4 or swirl chamber 9 at the time of ignition, the arrangement is suitable for reducing combustion noise and the formation of nitrogen oxides.
  • this fuel injection is designed for use in combination with a hole-type fuel injection nozzle used in a direct-injection diesel engine, it is not suitable for use in a small divided-chamber combustion system engine.
  • the fuel injection pump taught by Japanese Patent Disclosure No. Sho 56-54957 is formed with large-diameter discharge port 8b constituting a main port, a small-diameter discharge port 8a constituting a sub-port, a plunger lead groove 15b for the large-diameter discharge port, and a plunger lead groove 15a for the small-diameter discharge port, and is used in combination with a variable retraction delivery valve.
  • large-diameter discharge port 8b constituting a main port
  • a small-diameter discharge port 8a constituting a sub-port
  • a plunger lead groove 15b for the large-diameter discharge port and a plunger lead groove 15a for the small-diameter discharge port
  • the fuel injection quantity is basically maintained but is reduced on the low-speed, low-load side.
  • This arrangement is disadvantageous, however, because it requires provision of both the main port and the sub-port as sets of discharge ports and also because the use of the small-diameter discharge ports 8a for spilling fuel on the low-load side tends to cause insufficient power output.
  • An object of the first and second aspects of the invention is to provide a fuel injection pump which is formed with a main port, a sub-port, a main lead groove and a sub-lead groove to be thereby imparted with the ability to achieve preflow effect at the start of fuel injection and the ability to achieve fuel spill control at the end of fuel injection and which overcomes the various problems of the prior art fuel injection pumps with preflow effect.
  • An object of the third aspect of the invention is to provide a fuel injection pump which enables the maximum fuel injection rate of pressurized fuel delivered to a throttling type fuel injection nozzle provided in an auxiliary combustion chamber of a divided-chamber combustion system diesel engine to be reduced particularly during low-speed, high-load operation, thereby reducing generation of smoke and particulates.
  • the fuel injection pump is of the type having a pump housing formed with a fuel reservoir, a plunger barrel mounted in the pump housing and formed with a fuel feed hole which communicates with the fuel reservoir, a plunger accommodated in the plunger barrel to be capable of sliding reciprocation and rotation therein and being formed with an inclined lead groove at a position for communication with the feed hole, and a fuel chamber formed between the plunger and the plunger barrel, wherein reciprocating movement of the plunger causes fuel to be sucked into the fuel chamber from the fuel reservoir and delivered under pressure to a fuel injection nozzle, and is characterized in that the feed hole in the plunger barrel is formed as a large-diameter main port and a small diameter sub-port whose upper edge lies no higher than the upper edge of the main port, a head portion of the plunger is formed with an upper sub-lead groove capable of communicating with the sub-port over a prescribed rotational range of the plunger and of maintaining communication with the sub-port even when the main port is closed by the upper end of the plunger, the
  • the second aspect of the invention achieves its object by providing a fuel injection pump formed with a main port and a sub-port for achieving a preflow effect and further featuring in combination therewith an upper main lead groove and a lower main lead groove which are capable of communicating with the main port and also in combination therewith an upper sub-lead groove and a lower sub-lead groove which are capable of communicating with the sub-port.
  • the fuel injection pump is of the type having a pump housing formed with a fuel reservoir, a plunger barrel mounted in the pump housing and formed with a fuel feed hole which communicates with the fuel reservoir, a plunger accommodated in the plunger barrel to be capable of sliding reciprocation and rotation therein and being formed with an inclined lead groove at a position for communication with the feed hole, and a fuel chamber formed between the plunger and the plunger barrel, wherein reciprocating movement of the plunger causes fuel to be sucked into the fuel chamber from the fuel reservoir and delivered under pressure to a fuel injection nozzle, and is characterized in that the feed hole in the plunger barrel is formed as a large-diameter main port and a small diameter sub-port whose upper edge lies no higher than the upper edge of the main port, a head portion of the plunger is formed with an upper sub-lead groove capable of communicating with the sub-port over a prescribed rotational range of the plunger and formed with an upper main lead groove capable of communicating with the main port over a prescribed rotational range of the plunger
  • the lower main lead groove and the lower sub-lead groove with slopes in the direction from the low-load side to the high-load side and in the downward direction of the plunger such that the slope of the lower main lead groove is greater than that of the lower sub-lead groove.
  • the fuel injection pump according to the third aspect of the invention as a specific configuration for ensuring that at the rotational position of the plunger during high-load operation the main port does not communicate with the lower main lead groove even when the sub-port communicates with the lower sub-lead groove and ensuring that at the rotational position of the plunger during low-load operation the sub-port does not communicate with the lower sub-lead groove even when the main port communicates with the lower main lead groove, it is possible, for example, to provide the lower main lead groove and the lower sub-lead groove with slopes in the direction from the low-load side to the high-load side and in the downward direction of the plunger such that the slope of the lower main lead groove is greater than that of the lower sub-lead groove.
  • the arrangement enabling the preflow effect involves the drawback discussed earlier. Specifically, since fuel is released from the sub-port during low-speed operation by an amount corresponding to the preflow stroke and fuel is delivered after the sub-port is closed, i.e. since fuel spill (delivery cutoff) is conducted by the sub-port and the sub-lead groove, the fuel injection rate becomes high during low-speed operation owing to the use of the high-speed portion of the cam.
  • this problem is overcome by the formation of the lower main lead groove and the lower sub-lead groove which, by enabling setting of the fuel injection cutoff time, make it possible to control fuel spill even during low-speed operation.
  • the amount of fuel injection advance during starting can be set as desired.
  • Fig. 1 is a schematic view of a part of a divided-chamber combustion system diesel engine 1 which uses an auxiliary combustion chamber 4 as a subsidiary combustion chamber.
  • Fig. 3 is a vertical sectional view of an ordinary fuel injection pump 5.
  • Fig. 4 is a vertical sectional view of an ordinary throttling type fuel injection nozzle 6.
  • Fig. 5 is an enlarged sectional view of the nozzle hole 37 portion at the tip of the nozzle body 26 of the fuel injection nozzle 6 of Fig. 4.
  • Fig. 6 is a graph showing how the opening area of the nozzle hole 37 of the fuel injection nozzle 6 varies with nozzle lift.
  • Fig. 7 is a vertical sectional view of a fuel injection pump 40 which is a first embodiment of the first aspect of the invention.
  • Fig. 8 is a vertical sectional view of an essential portion of the fuel injection pump 40 of Fig. 7.
  • Fig. 9 is a development of lead grooves at the head portion of a plunger 15 of the fuel injection pump 40.
  • Fig. 10 is a timing map shown within an N-Q characteristic diagram of the fuel injection pump 40.
  • Fig. 11 is a graph showing how fuel injection quantity Q varies with engine speed N in the fuel injection pump 40.
  • Fig. 12 is a graph showing how fuel injection quantity Q varies with engine speed N in the fuel injection pump 40 when a control rack 13 of the fuel injection pump 40 is immobilized.
  • Fig. 13 is a simplified development, similar to that of Fig. 9, for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 50 which is a second embodiment of the first aspect of the invention.
  • Fig. 14 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 51 which is a third embodiment of the first aspect of the invention.
  • Fig. 15 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 52 which is a fourth embodiment of the first aspect of the invention.
  • Fig. 17 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 58 which is a sixth embodiment of the first aspect of the invention.
  • Fig. 18 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 59 which is a seventh embodiment of the first aspect of the invention.
  • Fig. 19 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 60 which is an eighth embodiment of the first aspect of the invention.
  • Fig. 22 is a vertical sectional view of a fuel injection pump 70 which a first embodiment of the second aspect of the invention.
  • Fig. 24 is a development of lead grooves at the head portion of a plunger 15 of the fuel injection pump 70.
  • Fig. 25 is a timing map shown within an N-Q characteristic diagram of the fuel injection pump 70.
  • Fig. 26 is a simplified development, similar to that of Fig. 24, for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 71 which is a second embodiment of the second aspect of the invention.
  • Fig. 27 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 72 which is a third embodiment of the second aspect of the invention.
  • Fig. 28 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 74 which is a fourth embodiment of the second aspect of the invention.
  • Fig. 29 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 75 which is a fifth embodiment of the second aspect of the invention.
  • Fig. 30 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 76 which is a sixth embodiment of the second aspect of the invention.
  • Fig. 31 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 78 which is a seventh embodiment of the second aspect of the invention.
  • Fig. 32 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 79 which is an eighth embodiment of the second aspect of the invention.
  • Fig. 33 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 80 which is a ninth embodiment of the second aspect of the invention.
  • Fig. 34 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 82 which is a tenth embodiment of the second aspect of the invention.
  • Fig. 35 is an enlarged sectional view of an essential portion of the plunger barrel 14 and the plunger 15 of a fuel injection nozzle 90 which is a first embodiment of the third aspect of the invention.
  • Fig. 36 is a development of lead grooves at the head portion of a plunger 15 of the fuel injection pump 90.
  • Fig. 37 is a simplified explanatory view derived from Fig. 36.
  • Fig. 38 is a simplified development, similar to that of Fig. 37, for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 91 which is a second embodiment of the third aspect of the invention.
  • Fig. 39 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 92 which is a third embodiment of the third aspect of the invention.
  • Fig. 40 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 94 which is a fourth embodiment of the third aspect of the invention.
  • Fig. 41 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 96 which is a fifth embodiment of the third aspect of the invention.
  • Fig. 7 is a vertical sectional view of the fuel injection pump 40 and Fig. 8 is a vertical sectional view of an essential portion thereof.
  • the fuel injection pump 40 has basically the same structure as the fuel injection pump 5 described earlier with reference to Fig. 3, it differs therefrom in the configuration of the feed hole 22 portion formed in the plunger barrel 14 and the inclined lead groove 25 formed in the head portion of the plunger 15.
  • portions of the fuel injection pump 40 which are similar to those of the fuel injection pump 5 are assigned the same reference symbols as those of fuel injection pump 5 and are not explained further.
  • the plunger barrel 14 is formed with a large-diameter main port 41 and a small-diameter sub-port 42.
  • the upper edge 41A of the main port 41 and the upper edge 42A of the sub-port 42 are at the same height or horizontal level. They are formed over an interval of 180 degrees in the circumferential direction.
  • the upper edge 41A of the main port 41 can instead be located at a lower level than the upper edge 42A of the sub-port 42.
  • the fuel injection nozzle used is the throttling type fuel injection nozzle 6 (Fig. 4) suitable for use in a divided-chamber combustion system diesel engine such as the diesel engine 1 equipped with the auxiliary combustion chamber 4 (Fig. 1) or the diesel engine 8 equipped with the swirl chamber 9 (Fig. 2)
  • combustion proceeds gradually following partial fuel injection into the auxiliary combustion chamber 4 or 9, making it possible to keep combustion noise low and to suppress the generation of nitrogen oxides.
  • a small lift of the needle valve 30 produces a large change in the opening area, it is relatively easy to control generation of black smoke and particulates by regulating this lift to control the fuel injection rate.
  • Fig. 9 is a development of the lead grooves at the head portion of a plunger 15, showing the positional relationship between the main port 41 and the sub-port 42 at engine starting (broken lines) and at low-load operation and high-load operation (solid lines).
  • the peripheral surface of the plunger head is formed with a vertical main passage 43 communicating with the fuel chamber 21, an inclined lower main lead groove 44 communicating with the vertical main passage 43, a vertical sub-passage 45 communicating with the fuel chamber 21, an upper sub-lead groove 47 communicating with the fuel chamber 21, and an inclined lower sub-lead groove 48 communicating with the vertical sub-passage 45.
  • the lower main lead groove 44 and the lower sub-lead groove 48 are both formed at positions below the upper end 15A of the plunger 15, they control the time at which spilling of the pressurized fuel (delivery cutoff) occurs.
  • the lower main lead groove 44 is formed to have a sharper slope than that of the lower sub-lead groove 48.
  • the lower main lead groove 44 and the lower sub-lead groove 48 are formed to slope in the direction from the low-load side to the high-load side and in the downward direction of the plunger 15 such that the slope of the lower main lead groove 44 is greater than that of the lower sub-lead groove 48.
  • the slopes of the lower main lead groove 44 and the lower sub-lead groove 48 can be suitably determined for appropriately selecting the fuel injection characteristics.
  • the region within which the sub-port 42 is opposite the upper sub-lead groove 47 corresponds to an engine load range extending from low load to high load.
  • the region of the upper sub-lead groove 47 outside this region and the region of the upper end 15A of the plunger 15 outside that within which it is opposite the main port 41 correspond to the engine starting region.
  • fuel injection pump 40 fuel is drawn into the fuel chamber 21 from the fuel reservoir 20 through the main port 41 and the sub-port 42 as the plunger 15 moves down.
  • the part of the stroke of the plunger 15 from its bottom dead point to the start of fuel delivery is the prestroke and the part thereof from the closure of the sub-port 42 to the opening of the main port 41 is the effective stroke.
  • the depth (height) of the upper sub-lead groove 47 is the prestroke L1.
  • the prestroke L1 is also the engine starting fuel injection advance with respect to low-speed operation.
  • the upper sub-lead groove 47 is formed such that the upper end 15A of the plunger 15 is located above the upper edge 47A of the upper sub-lead groove 47, fuel injection is more advanced during engine starting than during low-speed/low-load operation.
  • the main port 41 can be brought opposite the upper end 15A of the plunger 15 and the sub-port 42 can be brought opposite the upper sub-lead groove 47.
  • the main port 41 is positioned to the left of the lower main lead groove 44 as seen in Fig. 9.
  • the effective stroke is therefore short and, moreover, since the sub-port 42 is in communication with the upper sub-lead groove 47, substantial delivery of pressurized fuel starts from the closure of the sub-port 42 by the upper edge 47A of the upper sub-lead groove 47.
  • the main port 41 remains to the left of the lower main lead groove 44 but the throttling effect of the sub-port 42 causes fuel delivery to start before the sub-port 42 is completely closed by the upper edge 47A of the upper sub-lead groove 47. As a result, fuel injection is advanced and the actual delivery stroke increased.
  • Fig. 10 is a timing map shown within an N-Q characteristic diagram. (In the following, the term “advance” will be used to mean “advance of the fuel injection point” and “retard” will be used to mean “retardation of the fuel injection point.”)
  • an advance characteristic can be obtained during both engine starting and high-speed operation.
  • the point at which fuel delivery starts is the same during both low-load operation and high-load operation.
  • the point at which fuel delivery ends however, on the low-load side fuel first spills from the main port 41 while on the high-load side fuel first spills from the sub-port 42.
  • the part of the stroke of the plunger 15 after spill from the sub-port 42 up to the start of spill from the main port 41 is the sub-port spill stroke.
  • the sub-port 42 On the low-load side, at the time that the main port 41 begins to spill fuel owing to the movement (rise) of the plunger 15 in the direction of fuel delivery, the sub-port 42 has still not come into communication with the lower sub-lead groove 48. It is therefore possible to achieve approximately the same injection characteristic as in the prior art fuel injection pump.
  • Fig. 11 is a graph showing how the fuel injection quantity Q varies with engine speed N.
  • the prior art fuel injection pump 5 (Fig. 3) is used in combination with an ordinary prior art throttling type fuel injection nozzle 6 (Fig. 4)
  • the relationship between the cam speed and the fuel injection rate ⁇ Q at the torque point during low-speed, high-load operation exhibits a steep point (the protruding maximum fuel injection rate of the solid line curve)
  • the fuel injection pump 40 according to the first aspect of the invention exhibits a flatter curve and greatly reduces the maximum fuel injection rate.
  • the fuel injection pump 40 is able to maintain approximately the same relationship between the cam angle and the fuel injection rate ⁇ Q as when the prior art fuel injection pump 5 is used in combination with the ordinary prior art throttling type fuel injection nozzle 6.
  • Fig. 12 is a graph showing how the fuel injection quantity Q varies with engine speed N when the control rack 13 for controlling fuel injection quantity (Fig. 3) is immobilized. As shown, the N-Q characteristic curve can be made to decline to the left during low-speed, high-load operation.
  • the first aspect of the invention is able to establish fuel injection advance during both high-speed operation and engine starting.
  • the upper end 15A of the plunger 15 is formed to be at a still higher position opposite the main port 41 and the sub-port 42 during engine starting.
  • the upper edge 41A of the main port 41 and the upper edge 42A of the sub-port 42 are at the same height or horizontal level, similarly to what is shown in Fig. 9. This point will not be mentioned again in the individual descriptions.
  • Fig. 13 is a simplified development, similar to that of Fig. 9, for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 50 which is a second embodiment of the first aspect of the invention.
  • the upper end 15A of the plunger 15 and the upper sub-lead groove 47 are the same as those in the first embodiment shown in Fig. 9, but the slope of the lower sub-lead groove 48 is larger than in the case of the first embodiment, although still smaller than that of the lower main lead groove 44.
  • Fig. 14 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 51 which is a third embodiment of the first aspect of the invention.
  • the upper end 15A of the plunger 15 and the upper sub-lead groove 47 are the same as those in the first embodiment shown in Fig. 9 and the second embodiment shown in Fig. 13, but, differently from in the first and second embodiments, the slope of the lower sub-lead groove 48 is larger than that of the lower main lead groove 44.
  • the fuel injection rate can be reduced during low-speed, low-load operation.
  • Fig. 15 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 52 which is a fourth embodiment of the first aspect of the invention.
  • the upper end 15A of the plunger 15 and the upper sub-lead groove 47 are the same as those in the first embodiment shown in Fig. 9, the second embodiment shown in Fig. 13 and the third embodiment shown in Fig. 14, but, differently from in the second and third embodiments, the slope of a lower main lead groove 53 corresponding to the lower main lead groove 44 and the slope of a lower sub-lead groove 54 corresponding to the lower sub-lead groove 48 are the same as in the first embodiment shown in Fig. 9.
  • a single vertical main passage 55 corresponding to the vertical main passage 43 is formed and only one end portion of each of the lower main lead groove 53 and the lower sub-lead groove 54 communicates with the vertical main passage 55.
  • Fig. 16 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 56 which is a fifth embodiment of the first aspect of the invention.
  • the upper end 15A of the plunger 15 is formed with an inclined upper sub-lead groove 57 for communicating with the sub-port 42 on the low-load side. Since the inclined upper sub-lead groove 57 slopes in the opposite direction from the lower main lead groove 44 and the lower sub-lead groove 48, the fuel delivery start point can be controlled from the low-load side toward the high-load side such that, particularly on the low-speed side, it is more retarded on the low-load side.
  • the slopes of the lower sub-lead groove 48 and the lower main lead groove 44 are the same as those in the first embodiment shown in Fig. 9, so that fuel spills first from the main port 41 on the low-load side and spills first from the sub-port 42 on the high-load side.
  • Fig. 17 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 58 which is a sixth embodiment of the first aspect of the invention.
  • the upper end 15A of the plunger 15 and the upper sub-lead groove 57 are the same as those in the fifth embodiment shown in Fig. 16, but the slope of the lower sub-lead groove 48 is smaller than in the case of the fifth embodiment. With this configuration, fuel spills first from the sub-port 42 on both the low-load side and the high-load side.
  • Fig. 18 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 59 which is a seventh embodiment of the first aspect of the invention.
  • the upper end 15A of the plunger 15 and the upper sub-lead groove 57 are the same as those in the fifth embodiment shown in Fig. 16 and the sixth embodiment shown in Fig. 17, but, differently from in the fifth and sixth embodiments, the slope of the lower sub-lead groove 48 is larger than that of the lower main lead groove 44.
  • Fig. 19 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 60 which is an eighth embodiment of the first aspect of the invention.
  • the upper end 15A of the plunger 15 is formed with an inclined upper sub-lead groove 61 for communicating with the sub-port 42 on the high-load side. Since the inclined upper sub-lead groove 61 slopes in the same direction as the lower main lead groove 44 and the lower sub-lead groove 48, the fuel delivery start point can be controlled from the low-load side toward the high-load side such that, particularly on the low-speed side, it is more retarded on the high-load side.
  • the slopes of the lower sub-lead groove 48 and the lower main lead groove 44 are the same as those in the first embodiment shown in Fig. 9, so that fuel spills first from the main port 41 on the low-load side and spills first from the sub-port 42 on the high-load side.
  • Fig. 20 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 62 which is a ninth embodiment of the first aspect of the invention.
  • the upper end 15A of the plunger 15 and the upper sub-lead groove 61 are the same as those in the eighth embodiment shown in Fig. 19, but the slope of the lower sub-lead groove 48 is smaller than in the case of the eighth embodiment. With this configuration, fuel spills first from the sub-port 42 on both the low-load side and the high-load side.
  • Fig. 21 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 63 which is a tenth embodiment of the first aspect of the invention.
  • the upper end 15A of the plunger 15 and the upper sub-lead groove 61 are the same as those in the eighth embodiment shown in Fig. 16 and the ninth embodiment shown in Fig. 20, but, differently from in the eighth and ninth embodiments, the slope of the lower sub-lead groove 48 is larger than that of the lower main lead groove 44.
  • the first aspect of the invention can be implemented in various other ways than described in the foregoing embodiments and, specifically, is able to achieve desired fuel injection characteristics by controlling the fuel injection start and cutoff times by appropriate selection of the slopes of the lower main lead groove 44 and the lower sub-lead groove 48 and the positions and slopes of the upper sub-lead groove (47, 57, 61) at the upper end 15A of the plunger 15.
  • the second aspect of the invention will be explained with reference to Figs. 22 to 34.
  • the fuel injection pump according to the second aspect of the invention differs from the fuel injection pump according to the first aspect of the invention basically in that it is provided with an upper main lead groove 46 (see Fig. 22 et seqq.) in addition to the upper sub-lead groove 47.
  • Fig. 22 is a vertical sectional view of the fuel injection pump 70 and Fig. 23 is a vertical sectional view of an essential portion thereof.
  • Fig. 24 is a development of lead grooves at the head portion of a plunger 15 of the fuel injection pump 70, showing the positional relationship between the main port 41 and the sub-port 42 at engine starting (broken lines) and at low-load operation and high-load operation (solid lines).
  • the peripheral surface of the plunger head is formed with a vertical main passage 43 communicating with the fuel chamber 21, an inclined lower main lead groove 44 communicating with the vertical main passage 43, a vertical sub-passage 45 communicating with the fuel chamber 21, an upper main lead groove 46 communicating with the fuel chamber 21, an upper sub-lead groove 47 also communicating with the fuel chamber 21, and an inclined lower sub-lead groove 48 communicating with the vertical sub-passage 45.
  • the lower main lead groove 44 and the lower sub-lead groove 48 are both formed at positions below the upper end 15A of the plunger 15, they control the time at which spilling of the pressurized fuel (delivery cutoff) occurs. This is the same as in the first aspect of the invention.
  • the lower main lead groove 44 is formed to have a sharper slope than that of the lower sub-lead groove 48.
  • the lower main lead groove 44 and the lower sub-lead groove 48 are formed to slope in the direction from the low-load side to the high-load side and in the downward direction of the plunger 15 such that the slope of the lower main lead groove 44 is greater than that of the lower sub-lead groove 48.
  • the slopes of the lower main lead groove 44 and the lower sub-lead groove 48 can be suitably determined for appropriately selecting the fuel injection characteristics.
  • the region within which the main port 41 is opposite the upper main lead groove 46 and the sub-port 42 is opposite the upper sub-lead groove 47 corresponds to an engine load range extending from low load to high load.
  • the region of the upper end 15A of the plunger 15 corresponds to the engine starting region.
  • fuel injection pump 70 fuel is drawn into the fuel chamber 21 from the fuel reservoir 20 through the main port 41 and the sub-port 42 as the plunger 15 moves down.
  • the depth (height) of the upper sub-lead groove 47 is the engine starting fuel injection advance level difference L1 with respect to low-speed operation.
  • the depth (height) of the upper main lead groove 46 is the engine starting fuel injection advance level difference L2 with respect to high-speed operation and the difference between L1 and L2 (L1 - L2) is the prestroke.
  • the upper main lead groove 46 is formed such that the upper end 15A of the plunger 15 is located above the upper edge 46A of the upper main lead groove 46, fuel injection is more advanced during engine starting than during low-speed/low-load operation.
  • the main port 41 can be brought opposite the upper main lead groove 46 and the sub-port 42 can be brought opposite the upper sub-lead groove 47.
  • the main port 41 is positioned to the left of the lower main lead groove 44 as seen in Fig. 24.
  • the effective stroke short is therefore short and, moreover, since the sub-port 42 is in communication with the upper sub-lead groove 47, substantial delivery of pressurized fuel starts from the closure of the sub-port 42 by the upper edge 47A of the upper sub-lead groove 47.
  • the main port 41 remains to the left of the lower main lead groove 44 but the throttling effect of the sub-port 42 causes fuel delivery to start before the sub-port 42 is completely closed by the upper edge 47A of the upper sub-lead groove 47. As a result, fuel injection is advanced and the actual delivery stroke increased.
  • Fig. 25 is a timing map shown within an N-Q characteristic diagram.
  • an advance characteristic can be obtained both during engine starting and during high-speed operation.
  • the point at which fuel delivery starts is the same during both low-load operation and high-load operation.
  • the point at which fuel delivery ends however, on the low-load side fuel first spills from the main port 41 while on the high-load side fuel first spills from the sub-port 42.
  • the part of the stroke of the plunger 15 after spill from the sub-port 42 up to the start of spill from the main port 41 is the sub-port spill stroke.
  • the sub-port 42 On the low-load side, at the time that the main port 41 begins to spill fuel owing to the movement (rise) of the plunger 15 in the direction of fuel delivery, the sub-port 42 has still not come into communication with the lower sub-lead groove 48. It is therefore possible to achieve approximately the same injection characteristic as in the prior art fuel injection pump.
  • the fuel injection pump 70 is able to maintain approximately the same relationship between the cam angle and the fuel injection rate ⁇ Q as when the prior art fuel injection pump 5 is used in combination with the ordinary prior art throttling type fuel injection nozzle 6.
  • the N-Q characteristic curve can be made to decline to the left during low-speed, high-load operation.
  • the second aspect of the invention is able to establish fuel injection advance during both high-speed operation and engine starting.
  • the upper end 15A of the plunger 15 is formed to be at a still higher position opposite the main port 41 and the sub-port 42 during engine starting.
  • the upper edge 41A of the main port 41 and the upper edge 42A of the sub-port 42 are at the same height or horizontal level, similarly to what is shown in Fig. 24. This point will not be mentioned again in the individual descriptions.
  • Fig. 26 is a simplified development, similar to that of Fig. 24, for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 71 which is a second embodiment of the second aspect of the invention.
  • the upper end 15A of the plunger 15 and the upper sub-lead groove 47 are the same as those in the first embodiment shown in Fig. 24, but, similarly to the fourth embodiment of the first aspect of the invention (Fig. 15), the slope of a lower main lead groove 53 corresponding to the lower main lead groove 44 and the slope of a lower sub-lead groove 54 corresponding to the lower sub-lead groove 48 are the same as in the first embodiment shown in Fig. 24.
  • a single vertical main passage 55 corresponding to the vertical main passage 43 is formed and only one end portion of each of the lower main lead groove 53 and the lower sub-lead groove 54 communicates with the vertical main passage 55.
  • Fig. 27 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 72 which is a third embodiment of the second aspect of the invention.
  • the upper end 15A of the plunger 15 is formed with an inclined upper sub-lead groove 73 for communicating with the sub-port 42 on the low-load side and the high-load side. Since the upper sub-lead groove 73 slopes in the opposite direction from the lower main lead groove 44 and the lower sub-lead groove 48, the fuel delivery start point can be controlled from the low-load side toward the high-load side such that, particularly on the low-speed side, it is more retarded on the low-load side.
  • the slopes of the lower sub-lead groove 48 and the lower main lead groove 44 are the same as those in the first embodiment shown in Fig. 24, so that fuel spills first from the main port 41 on the low-load side and spills first from the sub-port 42 on the high-load side.
  • Fig. 28 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 74 which is a fourth embodiment of the second aspect of the invention.
  • the upper end 15A of the plunger 15 and the upper sub-lead groove 73 are the same as those in the third embodiment shown in Fig. 27 but the lower main lead groove 44 is formed at a lower portion of the plunger 15 than in the third embodiment. With this configuration, fuel spills first from the sub-port 42 on both the low-load side and the high-load side.
  • Fig. 29 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 75 which is a fifth embodiment of the second aspect of the invention.
  • the upper end 15A of the plunger 15 and the upper sub-lead groove 73 are the same as those in the third embodiment shown in Fig. 27 and the fourth embodiment shown in Fig. 28, but, differently from in the third and fourth embodiments, the slope of the lower sub-lead groove 48 is larger than that of the lower main lead groove 44.
  • Fig. 30 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 76 which is a sixth embodiment of the second aspect of the invention.
  • the upper end 15A of the plunger 15 is formed with an inclined upper main lead groove 77 for communicating with the main port 41 on the high-load side. Since the upper main lead groove 77 slopes in the same direction as the lower main lead groove 44 and the lower sub-lead groove 48, the fuel delivery start point can be controlled from the low-load side toward the high-load side such that it is more retarded on the high-load side.
  • the slopes of the lower sub-lead groove 48 and the lower main lead groove 44 are the same as those in the first embodiment shown in Fig. 24, so that fuel spills first from the main port 41 on the low-load side and spills first from the sub-port 42 on the high-load side.
  • Fig. 31 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 78 which is a seventh embodiment of the second aspect of the invention.
  • the upper end 15A of the plunger 15 and the upper main lead groove 77 are the same as those in the sixth embodiment shown in Fig. 30 but the lower sub-lead groove 48 is formed at a higher portion of the plunger 15 than in the sixth embodiment. With this configuration, fuel spills first from the sub-port 42 on both the low-load side and the high-load side.
  • Fig. 32 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 79 which is an eighth embodiment of the second aspect of the invention.
  • the upper end 15A of the plunger 15 and the upper main lead groove 77 are the same as those in the sixth embodiment shown in Fig. 30 and the seventh embodiment shown in Fig. 31, but, differently from in the sixth and seventh embodiments, the slope of the lower sub-lead groove 48 is larger than that of the lower main lead groove 44.
  • Fig. 33 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 80 which is a ninth embodiment of the second aspect of the invention.
  • the upper end 15A of the plunger 15 is formed with an inclined upper sub-lead groove 81 for communicating with the sub-port 42 on the low-load side and the high-load side. Since the upper sub-lead groove 81 slopes in the same direction as the lower main lead groove 44 and the lower sub-lead groove 48, the fuel delivery start point can be controlled from the low-load side toward the high-load side such that, particularly on the low-speed side, it is more retarded on the high-load side.
  • the slopes of the lower sub-lead groove 48 and the lower main lead groove 44 are the same as those in the first embodiment shown in Fig. 24, so that fuel spills first from the main port 41 on the low-load side and spills first from the sub-port 42 on the high-load side.
  • Fig. 34 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 82 which is a tenth embodiment of the second aspect of the invention.
  • the upper end 15A of the plunger 15 is formed with an inclined upper main lead groove 83 for communicating with the main port 41 on the low-load side and the high-load side. Since the upper main lead groove 83 slopes in the opposite direction from the lower main lead groove 44 and the lower sub-lead groove 48, the fuel delivery start point can be controlled from the low-load side toward the high-load side such that it is more retarded on the low-load side.
  • the slopes of the lower sub-lead groove 48 and the lower main lead groove 44 are the same as those in the first embodiment shown in Fig. 24, so that fuel spills first from the main port 41 on the low-load side and spills first from the sub-port 42 on the high-load side.
  • the second aspect of the invention can be implemented in various other ways than described in the foregoing embodiments and, specifically, is able to achieve desired fuel injection characteristics by controlling the fuel injection start and cutoff times by appropriate selection of the slopes of the lower main lead groove 44 and the lower sub-lead groove 48, and the positions and slopes of the upper main lead groove (46, 77, 83) the upper sub-lead groove (47, 57, 81) at the upper end 15A of the plunger 15.
  • the third aspect of the invention will be explained with reference to Figs. 35 to 41.
  • the fuel injection pump according to the third aspect of the invention is similar to the fuel injection pumps according to the first and second aspects of the invention in the point that it is provided with the lower main lead groove 44 and the lower sub-lead groove 48, but differently therefrom, is configured specifically for use with a throttling type fuel injection nozzle 6 (Fig. 4) provided in an auxiliary combustion chamber of a divided-chamber combustion system diesel engine (e.g., in the auxiliary combustion chamber 4 of Fig. 1 or the swirl chamber 9 of Fig. 2).
  • a fuel injection nozzle 90 which is a first embodiment of the third aspect of the invention will now be explained with reference to the drawings.
  • Fig. 35 is an enlarged sectional view of an essential portion of the plunger barrel 14 and the plunger 15 of the fuel injection nozzle 90 and Fig. 36 is a development of lead grooves at the head portion of the plunger 15.
  • the plunger barrel 14 is formed with a large-diameter main port 41 and a small diameter sub-port 42 which together serve the purpose of the feed hole 22 of the prior art fuel injection pump (Fig. 3).
  • the upper edge 41A of the main port 41 and the upper edge 42A of the sub-port 42 are at the same height or horizontal level. They are formed over an interval of 180 degrees in the circumferential direction.
  • the upper edge 41A of the main port 41 can instead be located at a lower level than the upper edge 42A of the sub-port 42.
  • the peripheral surface of the plunger head is formed with a vertical main passage 43 corresponding to the vertical passage 24 and communicating with the fuel chamber 21, a lower main lead groove 44 corresponding to the inclined lead groove 25 and communicating with the vertical main passage 43, a vertical sub-passage 45 corresponding to the vertical passage 24 and communicating with the fuel chamber 21, and a lower sub-lead groove 48 communicating with the vertical sub-passage 45.
  • the lower main lead groove 44 and the lower sub-lead groove 48 are both formed at positions below the upper end 15A of the plunger 15, they control the time at which spilling of the pressurized fuel (delivery cutoff) occurs.
  • the lower main lead groove 44 is formed to have a sharper slope than that of the lower sub-lead groove 48.
  • the lower main lead groove 44 and the lower sub-lead groove 48 are formed to slope in the direction from the low-load side to the high-load side and in the downward direction of the plunger 15 such that the slope of the lower main lead groove 44 is greater than that of the lower sub-lead groove 48.
  • Fig. 37 is a simplified explanatory view derived from Fig. 36.
  • the left side of the figure corresponds to low-load operation and the right side to high-load operation.
  • the positions of the main port 41 and the sub-port 42 during high-load operation are shown in solid lines and the positions thereof during low-load operation are shown in broken lines.
  • the sub-port 42 On the low-load side, at the time that the main port 41 begins to spill fuel owing to the movement (rise) of the plunger 15 in the direction of fuel delivery, the sub-port 42 has still not come into communication with the lower sub-lead groove 48. It is therefore possible to achieve approximately the same injection characteristic as in the prior art fuel injection pump.
  • the fuel injection pump 90 is able to maintain approximately the same relationship between the cam angle and the fuel injection rate ⁇ Q as when the prior art fuel injection pump 5 is used in combination with the ordinary prior art throttling type fuel injection nozzle 6.
  • the N-Q characteristic curve can be made to decline to the left during low-speed, high-load operation.
  • the third aspect of the invention controls fuel delivery cutoff.
  • Fig. 38 is a simplified development, similar to that of Fig. 37, for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 91 which is a second embodiment of the third aspect of the invention.
  • the main port 41 is provided above the sub-port 42 and the upper end 15A of the plunger 15 is left flat. With this configuration, the sub-port 42 is closed first and the main port 41 is closed thereafter.
  • the fuel delivery cutoff point is determined in the same manner as in the first embodiment, namely by spilling fuel first from the main port 41 on the low-load side and first from the sub-port 42 on the high-load side.
  • the sub-port 42 is closed at all times that the main port 41 is closed by the upper end 15A of the plunger 15. Therefore, as regards the start of fuel delivery it is possible to obtain the same injection characteristics as in the case of the sub-port 42 not being provided.
  • Fig. 39 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 92 which is a third embodiment of the third aspect of the invention.
  • the main port 41 and the sub-port 42 are formed at the same level, an upper sub-lead groove 93 is provided in the plunger 15 at the rotational position thereof which can be brought opposite the sub-port 42, and the upper end 15A at the rotational position of the plunger 15 which can be brought opposite the main port 41 is left flat. With this configuration, the main port 41 is closed first and the sub-port 42 is closed thereafter.
  • fuel is delivered before the feed ports are closed (particularly before the sub-port 42 is closed) during high-speed operation owing to the preflow effect (dynamic effect or throttling effect).
  • a fuel injection timing advance characteristic can be obtained during high-speed operation, under both high-load and low-load.
  • Fig. 40 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 94 which is a fourth embodiment of the third aspect of the invention.
  • the main port 41 and the sub-port 42 are formed at the same level, the upper sub-lead groove 93 is provided in the plunger 15 at the rotational position thereof which can be brought opposite the sub-port 42 (similarly to the case of Fig. 39), the rotational position of the plunger 15 which is brought opposite the main port 41 during low-load operation being left as the flat upper end 15A and the rotational position thereof brought opposite the main port 41 during high-load operation being formed with an inclined upper main lead groove 95 which slopes in the same direction as the lower main lead groove 44 and the lower sub-lead groove 48.
  • the main port 41 closes first and the sub-port 42 closes thereafter, while during high-load operation the sub-port 42 closes first and the main port 41 closes thereafter. Since the portion of the inclined upper main lead groove 95 which communicates with the main port 41 varies depending on the degree of load between the low and high sides, it is possible to establish a fuel injection characteristic wherein the fuel injection time point is advanced during high-speed operation at low load and is gradually retarded as the load increases.
  • Fig. 41 is a simplified development for explaining lead grooves at the head portion of the plunger 15 of a fuel injection pump 96 which is a fifth embodiment of the third aspect of the invention.
  • the main port 41 and the sub-port 42 are formed at the same level, a vertical main passage 97 corresponding to the vertical main passage 43 is formed at the center, and the vertical main passage 97 is provided on its right (as seen in Fig. 41) with a lower main lead groove 98 formed at the rotational position of the plunger 15 which can be brought opposite the main port 41 and on its left with a lower sub-lead groove 99 formed at the rotational position of the plunger 15 which can be brought opposite the sub-port 42.
  • the sub-port 42 and the main port 41 are simultaneously closed by the upper end 15A of the plunger 15.
  • the fuel injection pump since the fuel injection pump utilizes the preflow effect obtained by the provision of a sub-port and an upper sub-lead groove and is formed with a lower main lead groove and a lower sub-lead groove whose slopes can be selected in an appropriate combination, it is possible to maintain a speed timer capability enabling control of the fuel injection timing during low- and high-speed operation while at the same time achieving a reduction in the generation of black smoke and particulates, particularly during low-speed, high-load operation, and also achieving an increase in fuel injection quantity that results in higher torque.
  • the fuel injection pump since the fuel injection pump utilizes the preflow effect obtained by the provision of a sub-port and an upper sub-lead groove, is formed with a lower main lead groove and a lower sub-lead groove whose slopes can be selected in an appropriate combination and is formed with an upper main lead groove which can communicate with the main port, it is possible to maintain a speed timer capability enabling control of the fuel injection timing during low- and high-speed operation and a fuel injection time advance capability during engine starting while at the same time achieving a reduction in the generation of black smoke and particulates, particularly during low-speed, high-load operation, and also achieving an increase in fuel injection quantity that results in higher torque.
  • the fuel injection pumps according to the first and second aspects of the invention make it possible to increase fuel delivery without increasing the fuel injection rate during low-speed operation, they enable an increase in the fuel injection rate (fuel delivery rate) during high-speed, high-load operation as well as an increase in power output and an improvement in fuel economy.
  • the fuel injection pump since the fuel injection pump is used in combination with a throttling type fuel injection nozzle, has a main port and a sub-port formed in the plunger barrel, has a lower main lead groove and a lower sub-lead groove formed in the plunger, and is configured to enable fuel to spill first from the sub-port on the high-load side and to spill first from the main port on the low load side, it is able to reduce the maximum fuel injection rate on the low-speed, high-load side, thereby reducing the generation of smoke in this operating region.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fuel-Injection Apparatus (AREA)
EP94120704A 1993-12-28 1994-12-27 Kraftstoffeinspritzpumpe Expired - Lifetime EP0665373B1 (de)

Applications Claiming Priority (9)

Application Number Priority Date Filing Date Title
JP5349176A JPH07189862A (ja) 1993-12-28 1993-12-28 燃料噴射ポンプ
JP34918193A JP3174932B2 (ja) 1993-12-28 1993-12-28 燃料噴射ポンプ
JP34918193 1993-12-28
JP34917093 1993-12-28
JP5349170A JPH07189861A (ja) 1993-12-28 1993-12-28 燃料噴射ポンプ
JP34917693 1993-12-28
JP349176/93 1993-12-28
JP349170/93 1993-12-28
JP349181/93 1993-12-28

Publications (2)

Publication Number Publication Date
EP0665373A1 true EP0665373A1 (de) 1995-08-02
EP0665373B1 EP0665373B1 (de) 2000-05-10

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Application Number Title Priority Date Filing Date
EP94120704A Expired - Lifetime EP0665373B1 (de) 1993-12-28 1994-12-27 Kraftstoffeinspritzpumpe

Country Status (3)

Country Link
EP (1) EP0665373B1 (de)
KR (1) KR960010290B1 (de)
DE (1) DE69424400T2 (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002048537A1 (fr) * 2000-12-13 2002-06-20 Yanmar Co., Ltd. Pompes à pistons de pompe d'injection de carburant
WO2010127613A1 (zh) * 2009-05-04 2010-11-11 Hong Xuanmin 一种柴油机用直列式燃油泵柱塞
US8752806B2 (en) 2010-02-05 2014-06-17 Hoerbiger Automatisierungstechnik Holding Gmbh Fluid-operated actuating drive on a valve

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55101761A (en) * 1979-01-26 1980-08-04 Mitsubishi Heavy Ind Ltd Fuel ejection pump
JPS59200060A (ja) * 1983-04-28 1984-11-13 Hino Motors Ltd 燃料噴射装置
EP0294822A2 (de) * 1987-06-10 1988-12-14 Klöckner-Humboldt-Deutz Aktiengesellschaft Einspritzpumpe mit Voreinspritzung

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55101761A (en) * 1979-01-26 1980-08-04 Mitsubishi Heavy Ind Ltd Fuel ejection pump
JPS59200060A (ja) * 1983-04-28 1984-11-13 Hino Motors Ltd 燃料噴射装置
EP0294822A2 (de) * 1987-06-10 1988-12-14 Klöckner-Humboldt-Deutz Aktiengesellschaft Einspritzpumpe mit Voreinspritzung

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 4, no. 150 (M - 037) 22 October 1980 (1980-10-22) *
PATENT ABSTRACTS OF JAPAN vol. 9, no. 67 (M - 366)<1790> 27 March 1985 (1985-03-27) *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002048537A1 (fr) * 2000-12-13 2002-06-20 Yanmar Co., Ltd. Pompes à pistons de pompe d'injection de carburant
WO2010127613A1 (zh) * 2009-05-04 2010-11-11 Hong Xuanmin 一种柴油机用直列式燃油泵柱塞
US8752806B2 (en) 2010-02-05 2014-06-17 Hoerbiger Automatisierungstechnik Holding Gmbh Fluid-operated actuating drive on a valve

Also Published As

Publication number Publication date
DE69424400D1 (de) 2000-06-15
KR960010290B1 (ko) 1996-07-27
DE69424400T2 (de) 2000-08-31
EP0665373B1 (de) 2000-05-10
KR950019165A (ko) 1995-07-22

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