EP0737809A1 - Kraftstoffpumpe für das Einspritzungsmittel eines Dieselmotors - Google Patents

Kraftstoffpumpe für das Einspritzungsmittel eines Dieselmotors Download PDF

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Publication number
EP0737809A1
EP0737809A1 EP96110036A EP96110036A EP0737809A1 EP 0737809 A1 EP0737809 A1 EP 0737809A1 EP 96110036 A EP96110036 A EP 96110036A EP 96110036 A EP96110036 A EP 96110036A EP 0737809 A1 EP0737809 A1 EP 0737809A1
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EP
European Patent Office
Prior art keywords
fuel
camshaft
pumping elements
chamber
pair
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.)
Withdrawn
Application number
EP96110036A
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English (en)
French (fr)
Inventor
Tiby M. Martin
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Individual
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Individual
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Publication date
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Publication of EP0737809A1 publication Critical patent/EP0737809A1/de
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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
    • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
    • F02M63/02—Fuel-injection apparatus having several injectors fed by a common pumping element, or having several pumping elements feeding a common injector; Fuel-injection apparatus having provisions for cutting-out pumps, pumping elements, or injectors; Fuel-injection apparatus having provisions for variably interconnecting pumping elements and injectors alternatively
    • F02M63/0225—Fuel-injection apparatus having a common rail feeding several injectors ; Means for varying pressure in common rails; Pumps feeding common rails
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/30—Controlling fuel injection
    • F02D41/38—Controlling fuel injection of the high pressure type
    • F02D41/3809—Common rail control systems
    • F02D41/3827—Common rail control systems for diesel engines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/30—Controlling fuel injection
    • F02D41/38—Controlling fuel injection of the high pressure type
    • F02D41/3809—Common rail control systems
    • F02D41/3836—Controlling the fuel pressure
    • 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
    • F02M55/00—Fuel-injection apparatus characterised by their fuel conduits or their venting means; Arrangements of conduits between fuel tank and pump F02M37/00
    • F02M55/02—Conduits between injection pumps and injectors, e.g. conduits between pump and common-rail or conduits between common-rail and injectors
    • 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
    • F02M55/00—Fuel-injection apparatus characterised by their fuel conduits or their venting means; Arrangements of conduits between fuel tank and pump F02M37/00
    • F02M55/02—Conduits between injection pumps and injectors, e.g. conduits between pump and common-rail or conduits between common-rail and injectors
    • F02M55/025—Common rails
    • 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
    • F02M55/00—Fuel-injection apparatus characterised by their fuel conduits or their venting means; Arrangements of conduits between fuel tank and pump F02M37/00
    • F02M55/04—Means for damping vibrations or pressure fluctuations in injection pump inlets or outlets
    • 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
    • F02M59/02—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type
    • F02M59/04—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type characterised by special arrangement of cylinders with respect to piston-driving shaft, e.g. arranged parallel to that shaft or swash-plate type pumps
    • F02M59/06—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type characterised by special arrangement of cylinders with respect to piston-driving shaft, e.g. arranged parallel to that shaft or swash-plate type pumps with cylinders arranged radially to driving shaft, e.g. in V or star arrangement
    • 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
    • F02M59/36—Varying fuel delivery in quantity or timing by variably-timed valves controlling fuel passages to pumping elements or overflow passages
    • F02M59/366—Valves being actuated electrically
    • 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
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
    • F02M61/20—Closing valves mechanically, e.g. arrangements of springs or weights or permanent magnets; Damping of valve lift
    • F02M61/205—Means specially adapted for varying the spring tension or assisting the spring force to close the injection-valve, e.g. with damping of valve lift
    • 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
    • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
    • F02M63/0003—Fuel-injection apparatus having a cyclically-operated valve for connecting a pressure source, e.g. constant pressure pump or accumulator, to an injection valve held closed mechanically, e.g. by springs, and automatically opened by fuel pressure
    • F02M63/0007—Fuel-injection apparatus having a cyclically-operated valve for connecting a pressure source, e.g. constant pressure pump or accumulator, to an injection valve held closed mechanically, e.g. by springs, and automatically opened by fuel pressure using electrically actuated valves
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D2200/00—Input parameters for engine control
    • F02D2200/02—Input parameters for engine control the parameters being related to the engine
    • F02D2200/06—Fuel or fuel supply system parameters
    • F02D2200/0602—Fuel pressure

Definitions

  • This invention is related to a fuel pump for a diesel engine fuel injection means.
  • Conventional fuel injection systems employ a "jerk" type fuel system for pressurizing and injecting fuel into the cylinder of a diesel engine.
  • a pumping element is actuated by an engine-driven cam to pressurize fuel to a sufficiently high pressure to unseat a pressure-actuated injection valve in the fuel injection nozzle.
  • the plunger is actuated by an engine driven cam to pressurize the fuel inside the bushing chamber when a solenoid is energized and the solenoid valve is closed.
  • the metering and timing is achieved by a signal from an electronic control module (ECM) having a controlled beginning and a controlled pulse.
  • ECM electronice control module
  • the fuel is pressurized by an electronic or mechanical pumping assembly into a common rail and distributed to electromagnetic nozzles, which inject pressurized fuel into the engine cylinders. Both the electronic pump and the electromagnetic nozzles are controlled by the ECM signal.
  • Standard fuel injection systems commonly have an injection pressure versus time curve in which the pressure increases to a maximum and then decreases, following a somewhat skewed, triangularly-shaped curve.
  • Such pressure versus time relationship initially delivers a relatively poor, atomized fuel penetration into the engine cylinder because of the low injection pressure.
  • the pressure curve reaches a certain level, the pressure provides good atomization and good penetration.
  • the decreasing pressure again provides poor atomization and penetration, and the engine discharges high emissions of particulates and smoke.
  • One of the objects of fuel injection designers is to reduce unburned fuel by providing a pressure versus time curve having a square configuration, with an initially high pressure increase to an optimum pressure, providing good atomization, and a final sharp drop to reduce the duration of poor atomization and poor penetration.
  • the broad purpose of the present invention is to provide an improved high pressure common rail fuel injection system.
  • the system employs a novel electromagnetic injector having a needle valve with an inner end attached to a spring cage, which is pressure assisted at the closing and slowed down at the opening by residual pressure maintained in a balancing chamber within the spring cage.
  • Fuel is delivered to the injector by a solenoid-actuated valve.
  • the high pressure fuel biases the needle valve to an open position.
  • the solenoid valve stops fuel pressure access to the needle and the pressure drops in the nozzle due to nozzle bleeding into the engine's combustion chamber.
  • a portion of the high-pressure fuel is bypassed to the balancing chamber to assist the spring and urge the needle valve towards its closed position.
  • the pressure assistance to needle valve closure is adjustable by sizing the orifice between the upper and lower chambers of the spring cage to restrict the fuel through the orifice to the required pressure for assistance.
  • a sized orifice in the lower balancing chamber will assist the needle opening at the next injection slowing it down to the engines requirements.
  • the system of the invention employs a novel multi-element fuel pump.
  • Four pumping elements are mounted about a camshaft having a pair of lobes disposed at 180 degrees apart. When the camshaft turns 90 degrees, it moves a first pair of opposed pumping means in a delivery motion, and the other two pumping means are in a suction motion. As the camshaft continues its rotation, the two pair of pumping elements alternate in delivering fuel toward the corresponding solenoid valve assemblies.
  • the pump is actuated by two solenoid valve assemblies in response to an electrical signal from an electronic control module. In another embodiment, the pumping elements are mechanically actuated.
  • the common rail has a one-piece metal housing having a rectangular shape. Fuel is delivered from the pump in one direction into the common rail and discharged at right angles to the injectors.
  • One form of common rail is applied to the engines having cylinders arranged in "V" configuration and has a central chamber where the fuel enters, and two side chambers where the fuel exits to the electromagnetic injectors. The central chamber is connected to the side chambers through cross-drilled holes. This will help to eliminate the pressure fluctuations in the central passage of the rail caused by the pumping strokes and reflected waves, and have a constant pressure and fuel distribution in the side chambers.
  • the common rail In diesel engines having the cylinders disposed in an "in line” configuration, the common rail has a central chamber and a side chamber, connected with cross-drilled holes.
  • the pressure in the common rail is monitored by the electronic control module through a pressure sensor mounted on the common rail.
  • the electronic control module will maintain the required pressure in the rail by adjusting accordingly the signal to the solenoid valve assemblies.
  • One embodiment of the present invention is a fuel pump for a diesel engine fuel injection means comprising a body adapted to receive fuel from a source, a rotatable camshaft supported in the body so as to be rotatable about an axis, and having a pair of cam lobes including a first cam lobe and a second cam lobe disposed 180 degrees apart and adapted to rotate in an annular path about the axis of rotation of the camshaft, at least one pair of reciprocating pumping elements mounted in the body perpendicular to the axis of rotation of the camshaft, each of the pumping elements including an elongated plunger having an axial passage, including a first end and a second end, the first end being connected to a source of liquid fuel, a structure slideably mounted on the plunger so as to form an expandable chamber at the second end of the axial passage, and being movable either to enlarge or reduce the volume of the chamber depending upon the direction of relative motion of the structure and the plunger, tappet means
  • FIG. 1 illustrates a high pressure common rail fuel injection system.
  • FIG. 2 is a cross-view of a preferred fuel pump assembly.
  • FIG. 3 is a longitudinal sectional view of the preferred fuel pump assembly of FIG. 2.
  • FIG. 4 is a view of a preferred solenoid valve assembly.
  • FIG. 5 is a sectional view as seen along lines marked Fig.5.-Fig.5. on FIG. 4.
  • FIG. 5A is an enlarged fragmentary view of the solenoid valve in closed position for delivering fuel to the common rail.
  • FIG. 5B is an enlarged fragmentary view of the solenoid valve in open position for bypassing the fuel back to the tank.
  • FIG. 6 is a side view of the preferred common rail of FIG. 1.
  • FIG. 6A is a cross-sectional view of preferred common rail with one central passage and two side passages.
  • FIG. 6B is a cross-sectional view of a common rail with one central passage and one side passage.
  • FIG. 7 is a longitudinal sectional view of a preferred electromagnetic injector.
  • FIGS. 7A and 7B are enlarged sectional views showing the inlet opening and closing of the injection fuel delivery passage by the injectors solenoid valve.
  • FIGS. 7C and 7D are views of the opening and closing of the fuel passage to the balancing chamber.
  • FIG. 7E is an enlarged view along lines 7E-7E of FIG. 7.
  • a preferred fuel injection system 10 comprises an electronic controlled pump means 12, solenoid valve assembly means 14A and 14B, a common rail assembly 16 and electromagnetic injector means 18. Fuel is delivered from a fuel supply 20 through conduit means 22 to solenoid valve assembly means 14A and 14B.
  • the two valve assembly means 14A and 14B are identical in construction, their function differing according to their fluid connection with pump means 12.
  • solenoid valve means 14A comprises a body 28 having a longitudinal passage 30 including halves 30A and 30B.
  • a transverse passage 32 extends at right angles to passage 30 and intersects passage 30.
  • One end of passage 32 is enlarged at 34.
  • a fuel inlet fitting 36 is mounted in enlarged passage 34.
  • a pair of fasteners 38 and 40 fasten fitting 36 to the body 28.
  • Fitting 36 has a passage 42 for receiving fuel from conduit means 22A (FIG. 1).
  • an electromagnetically operated solenoid 44 is mounted on the body 28 and is operatively connected to control valve 46, which is slideably disposed in passage 32 for reciprocatory motion.
  • Valve 46 has an annular groove 48, spaced from the outer end of the valve. The bottom of the enlarged end of the bore 34 is tapered at 50 to provide a seat for outer end 52 of control valve 46.
  • Solenoid 44 is operated to move the control valve 46 between a closed position (FIG. 5A) in which valve end 52 engages seat 50 to block fluid flow between passages 42 and 32, and an open position (FIG. 5B) in which the control valve 46 abuts fitting 36 to open fluid flow between passage 32 and a pair of passages 52A and 52B in fitting 36 to passage 42. In both positions, there is a fluid connection between the halves 30A and 30B of passage 30.
  • body 28 has an internal passage 56 forming an extension of passage 30A.
  • the body has a second passage 58 at right angle to and intersecting passage 56.
  • a fitting 60 is mounted on the body 28 and has an internal passage 62 forming an extension of one end of passage 58.
  • a second fitting 64 is mounted on the opposite side and has an internal passage 66 forming an extension of the end of passage 58.
  • conduit 68 forms a fluid connection between fitting 60 and pump means 12
  • another conduit 70 forms a fluid connection between fitting 64 and a pump means 12.
  • a nut 72 is mounted on the opposite end of the body 28.
  • Nut 72 has an internal chamber 74.
  • a threaded fitting 76 is mounted on nut 72.
  • Fitting 76 has a passage 78 connected to a conduit 80 (FIG. 1).
  • a cup-shaped member 82 is mounted in chamber 74.
  • Member 82 has a cylindrical internal wall, and an opening 84 communicating with passage 30B, which forms a valve seat 85 for slideably mounted, hollow check valve 86.
  • Check valve 86 has a conical end 88, which mates with valve seat 85 to close fluid flow from passage 30 into chamber 74.
  • a spring bias member 90 is mounted in the check valve 86 and biases check valve 86 toward its closed position.
  • check valve 86 has a square cross-section slideably mounted in the cylindrical internal wall member 82 to permit fuel flow from passage 30 into chamber 74 when conical end 88 is spaced from the valve seat 85.
  • solenoid means 44 when solenoid means 44 is electrically energized, it retracts control valve 46 away from fitting 36 to close fluid flow between passage 32 and passage 42.
  • the control valve 46 has an annular shoulder 94.
  • a washer 96 is mounted on the shoulder.
  • a return spring 98 is disposed between the washer 96 and a retainer 100 to bias the control valve 46 toward fitting 36 and the control valve's open position.
  • the second solenoid assembly 14B is identical in construction to solenoid 14A and includes a solenoid 110 mounted on a body 112.
  • a nut 114 is mounted on one end of the body and has an internal passage 116.
  • One end of passage 116 is connected by fitting 118 and conduit 120 to the pump means 12.
  • the opposite end of internal passage 116 is connected by fitting 122 and conduit 124 to the pump means 12 in a manner which will be described.
  • the body 112 has an internal passage means 126, one end of which is connected to internal passage 116 and the other end of which terminates with fitting 128.
  • a check valve 130 provides means for opening and closing fuel flow from the body 112 to a conduit 132, which is connected to common rail 16. Fuel is received from fuel supply 20 through a conduit 134.
  • Solenoid 110 moves control valve 111 to control fluid flow between internal passage means 116 and conduit 134 in the manner that control valve 46 controls flow between passage 30 and conduit 22A. Fuel is discharged from conduits 80 and 132 to common rail 16.
  • common rail 16 has a relatively flat metal body 150.
  • Body 150 has a central chamber 152B and side chambers 152A and 152C.
  • Body 150 has a rectangular cross-section bounded by end walls 154 and 156, and side walls 158 and 160.
  • End walls 154 and 156 have a pair of inlet fittings 162 and 164.
  • Inlet fitting 162 is connected to conduit 80 for receiving fuel from solenoid valve assembly 14A into the common rail central chamber 152B.
  • Fitting 164 is adapted to receive fuel from the solenoid valve assembly 14B through conduit 132 into the central chamber 152B.
  • Side wall 158 has fuel discharge fittings 166A through 166F.
  • the opposite side wall 160 has fuel discharge fittings 168A through 168F.
  • the side chambers 152A and 152C communicate with central chamber 152B through cross-drilled holes 165A through 165F.
  • the cross-drilled holes 165A through 165F create a constant pressure and a perfect pressure distribution in the side chambers and eliminate the pressure fluctuations which occur in the central passage because of the pumping strokes and reflected pressure waves.
  • the number of fuel discharge fittings 165, 166, 168, or the number of cross-drilled holes can vary depending on the engine application. For example, for a six cylinder engine, the common rail 16 will have only six discharge fittings and three cross-drilled holes (for an arrangement like that illustrated in FIG. 6A) or six fittings arid six cross-drilled holes (for an arrangement like that illustrated in FIG. 6B).
  • Each of the fuel discharge fittings 166A through 166F, and 168A through 168F is connected by a conduit, such as conduit 170, to an electromagnetic injector typified by injector means 18.
  • End wall 154 has an outlet 172.
  • a fitting 174 is mounted in the outlet opening and connected by a conduit 176 to an adjustable relief valve 178.
  • the adjustable relief valve 178 is adapted to protect and relieve the pressure in chamber 152A when it exceeds a maximum predetermined pressure level.
  • a pressure transducer 180 is also mounted in the end wall 154, and is connected to the Electronic Control Module 440, monitoring the pressure in chamber 152C.
  • a fuel pump means 12 comprises a housing 200.
  • a camshaft 202 is mounted in the housing and is connected by mechanical connection 204 to the engine 206 (FIG. 3).
  • the camshaft 202 has two identical lobes 208 and 210 mounted 180 degrees apart.
  • Four identically constructed pumping means 212, 214, 216, and 218 are mounted in the housing, spaced 90 degrees with respect to one another about the axis of rotation of the camshaft.
  • Pumping means 212 is typical of the four and includes a mounting flange 220 disposed in an opening 222 in the pump housing 200.
  • the flange 220 carries a fitting 228 having an internal passage 230, and a plunger 252 having an internal passage 260, which is a continuation of internal passage 230.
  • a tappet bushing 240 is slideably mounted in the inside end of the pump housing opening 222.
  • a tappet roller 244 is rotatably mounted on a pin 246 carried by the tappet bushing 240.
  • the roller 244 is rotatably engaged with the camshaft 202 such that the tappet bushing 240 is movable within opening 222 depending upon the position of the camshaft 202.
  • a bushing 250 is mounted on the top of the tappet bushing 240 and is in contact with a spring bias member 270, which has the other end engaged with the mounting flange 220.
  • the spring bias member 270 urges the bushing 250 and the tappet bushing 240 toward the camshaft 202, forcing the roller 244 to role on the two cam lobes 208 and 210 when the camshaft rotates.
  • the plunger 252 is slideably mounted within hushing bore 245 to form a pumping chamber 256, which expands and contracts depending upon the position of the tappet on the camshaft 202.
  • the plunger 252 has an internal passage 260 for passing fuel toward or away from pumping chamber 256.
  • the arrangement is such that as the tappet roller 244 rides up on either camshaft lobe 208 or lobe 210, tappet roller 244 moves the bushing 240 toward the plunger 252 to reduce the size of pumping chamber 256, thereby delivering fuel under pressure through passage 230.
  • a spring bias member 270 having one end engaged with the bushing 240, urges the bushing 240 towards the camshaft 202 to enlarge chamber 256.
  • pumping chamber 256 is enlarged, the chamber creates a low pressure area, drawing fuel into the chamber 256 through the passage 230 in the plunger 252.
  • camshaft 202 As the camshaft 202 is rotated, it simultaneously pumps fuel out of the pumping chambers of the pumping means 214 and 218, while drawing fuel into the pumping chambers of the pumping means 212 and 216. As the camshaft 202 continues its rotation, the fuel is drawn into the pumping chambers of pumping means 214 and 218, and pumped out of the pumping chambers of pumping means 212 and 216. This provides a pumping action having a balanced motion of the pumping components and eliminates the bending stresses on the camshaft 202.
  • a ball type check valve 242 is located close to the lower end of the plunger 252, and is opened and closed by the pressure in the pumping chamber 256.
  • check valve 252 When bushing 250 is moved down on a fuel drawing stroke, check valve 252 is unseated and the fuel leakages created between plunger 252 and bushing 250 are absorbed back into the system, eliminating the necessary fuel return outside lines.
  • the pressure in chamber 256 On the pumping stroke movement of the bushing, the pressure in chamber 256 will seat the check valve and close fuel access to the plunger-bushing contact area.
  • pumping means 212 and 216 are connected by conduits 124 and 120, respectively, to solenoid assembly 14B.
  • pumping means 214 and 218 are connected by conduits 70 and 68, respectively, to solenoid assembly 14A.
  • the pumping means 212, 216, 214 and 218 either pump fuel toward the common rail 16 or recirculate fuel to the fuel supply conduits depending upon whether the control valves 46 and 111 in the solenoid valve assemblies 44 and 110 are open or closed.
  • the solenoids on the solenoid valve assemblies 44 and 110 are energized or de-energized and are controlled by the Electronic Control Module 440, which is monitoring the pressure in the common rail 16 through pressure transducer 180. This way, the pressure in the common rail 16 can be preset for every engine speed by setting the right parameters for the Electronic Control Module.
  • a typical electromagnetic injector 18 comprises a body 300 having a nut 302 threadably mounted at its upper end, and a retaining cap 304 mounted at its lower end.
  • An electromagnetically actuated solenoid 306 is mounted on the nut 302.
  • the solenoid 306 has an armature 308 disposed in a chamber 310 and is sealed to nut 302 by means of an "O" ring 312.
  • the armature 308 of the solenoid 306 is connected to an elongated valve 314, which extends through a chamber 316 in the nut.
  • Valve 314 is slideably mounted in bore 318 in the body 300.
  • the valve has a longitudinal internal passage 320 and a cross passage 322 has its ends communicating with chamber 316 (FIG. 7E), which in turn communicates with passage 324 in fitting 326.
  • valve 314 has an annular groove 328.
  • An annular retaining plate 330 is mounted in the groove and has a thickness less than the width of the groove. Shims 332 are mounted adjacent the retaining plate.
  • FIG. 7A illustrates the valve 314 in its lowest position in abutment with retaining plate 330
  • FIG. 7B shows the valve in its upper position in abutment with the lower edge of retaining plate 330.
  • Valve 314 has an annular shoulder 334 disposed in chamber 316.
  • a return spring 336 (FIG. 7) is mounted in the chamber with one end in abutment with nut 302, and the other end in abutment with spring seat 335, seating on shoulder 334 to bias valve 314 toward the retaining cap 304.
  • the valve 314 has an annular passage 340 adjacent its lower end.
  • the body 300 has an internal passage 342 in communication with passage 340.
  • a threaded fitting 344 is mounted on the body 300 with an inlet passage 36 in communication with passage 342.
  • Passage 342 is connected through conduit 170 (FIG. 1) for receiving fuel from the common rail 16.
  • the body 300 also has a delivery passage 348 with an inlet opening 350 terminating at bore 318.
  • the location of opening 350 is such that when valve 314 is in its lowermost position, the valve blocks fluid through opening 350. When the valve 314 is in its upper position, it opens a fluid connection between annular passage 340 and inlet opening 350.
  • the body 300 also has a passage 360 and with passage 361 and 363 connects the bottom of the body 300 to bore 318.
  • a small chamber 362 is defined between the lower, extreme end of the valve 314 and the bottom of bore 318 to provide room for the valve motion and for fluid communicating between passage 320 and chamber 370 through passages 360, 361 and 363.
  • Retaining cap 304 has a large internal chamber 370.
  • Chamber 370 has a bottom opening 372.
  • An elongated spray tip 374 is disposed in the chamber 370 with its lower end extending through opening 372.
  • the outer end of the spray tip has opening means 376 for passing fuel to the engine cylinder (not shown).
  • the spray tip 374 has an elongated, slightly tapered passage 378.
  • the lower end of the passage 378 passes fuel to opening means 376.
  • the upper end of passage 378 is enlarged at 380 and is fluidly connected to a passage 382 in the spray tip 374.
  • Enlarged section 380 is tapered and terminates with a cylindrical bore 384, which extends through the upper end of the spray tip 374.
  • a needle valve 386 is mounted in passage 378.
  • the lower end of the needle valve 386 is tapered at 390 to seat against a tapered seat 392 in the spray tip 374 for opening or closing fuel flow through passage means 376.
  • the upper end of the needle valve 386 has a narrowed end 394.
  • a spring seat 396 has a bore 398 receiving the narrowed end 394 of the needle valve 386.
  • Spring seat 396 is movable in chamber 406 to define the travel of the needle valve 386 between its open and closed positions.
  • the spring seat 396 has a raised midsection 400 to limit the needle valve travel.
  • spring cage 402 is mounted in chamber 370.
  • the cage 402 has wall 404 separating a lower balancing chamber 406, and an upper balancing chamber 408.
  • a coil spring 410 in the lower chamber has its upper end engaging wall 404, and its lower end engaging spring seat 396 to urge spring seat 396 and the needle valve 386 toward the needle valve's closed position.
  • a coil spring 412 in the upper chamber has its lower end engaged with wall 404.
  • a valve 414 is mounted in the upper chamber and engages the upper end of spring 412.
  • Valve 414 has an annular section 418 and a tapered portion 416 seating on seat 417 of injector body 300.
  • the upper portion of valve 414 is engaging bore 450 in body 300 and has an inside threaded portion 452.
  • a piston-screw 420 is engaging valve 414 through a threaded portion 419, on the lower end, and has a securing nut 422 which secures its adjusted height to valve 414.
  • the piston-screw 420 is adjusted such that it maintains a preset clearance 423 to the lower end of valve 314 when the valve is lifted to its upper position by energizing the solenoid 306.
  • solenoid 306 When solenoid 306 is de-energized, valve 314 is lowered by spring 336 and pushes downwards piston-screw 420 and valve 414 unseating valve seat 416 from seat 417 allowing fuel from passage 430 and 421 to enter chamber 408 and chamber 406, through orifice 424.
  • Spring cage 402 has a passage 430 communicating on the upper end with passage 348, and on the lower end with passage 382 from spray tip 374.
  • the spring cage 402 also has a lateral orifice 440, which extends from lower chamber 406 to outside spring cage 402, communicating with chamber 370 along the inside wall of retainer cap 304.
  • a supply pump not shown
  • Each opposed pair of pumping means 212, 214, 216 and 218 of the pump means 12 draw the fuel into their pumping chambers as the camshaft 202 is turned, and then pump the fuel back to the corresponding solenoid valve assembly 14A or 14B.
  • the fuel from the pumping elements 212, 214, 216 and 218 passes through the solenoid valve assemblies 14A and 14B and is recycled to the fuel supply 20 depending upon the position of the solenoid control valves 46 and 111.
  • the solenoid valve assembly 14A is energized by a signal with a certain pulse coming from the Electronic Control Module 440, the solenoid armature 45 (FIG. 4) pulls the control valve 46 to its closed position, and the fuel coming from the pumping elements through passage 30 opens check valve 86 (FIG. 4) to pass fuel through fitting 76 toward the common rail 16.
  • the two solenoid valve assemblies 14A and 14B are alternatively energized, having been correlated to the timing of the opposed pumping elements.
  • the pumping process ends when the solenoids of the solenoid valve assemblies 14A and 14B are de-energized, and, for example, the control valve 46 forced by springs 98 opens tapered seat 50 and allows fuel passing 30A to pass into passage 42 and return to fuel tank, causing a pressure drop in passage 30B, which will cause spring 90 to seat valve 86, disconnecting the fuel flow from the pump to the common rail.
  • the fuel coming from the solenoid valve assemblies enters into the common rail central passage 152B through either fitting 162 or 164, depending upon which solenoid valve assembly is in the pumping mode.
  • the fuel is accumulated in the common rail at a predetermined pressure adjusted according to Electronic Control Module 440 commands.
  • the Electronic Control Module 440 monitors the common rail pressure with a pressure transducer 180 and according to the its preset input data, will adjust the signal to the solenoid valve assemblies to achieve the necessary common rail pressure.
  • the high pressure fuel from the common rail's central passage passes through cross-drilled passages 165A through 165F into side passages 152A and 152C.
  • the cross-drilled orifices will restrict the pumping stroke effect and fuel wave reflects and the side passages will have a constant high pressure all along the side passages, insuring an equal fuel and pressure distribution to all electromagnetic injectors through their corresponding outlet fitting.
  • This common rail construction illustrated in Figure 6A is used on diesel engines having their cylinders arranged in "V" configuration.
  • the number of cross-drilled passages is equal to half of the number of the side fuel exit fittings.
  • Figure 6B illustrates a common rail with one central passage 504B and only one side passage 504A, used for diesel engines having an "in line" cylinder arrangement.
  • the fuel enters the rail through fittings 508 and 518 mounted on the opposite sides of the central passage 504B.
  • the side passage 504A has a pressure transducer 506 mounted at one end and relief valve 516 mounted at the other end.
  • the number of cross-drilled passages 512A through 512F is equal to the number of side fuel exit fittings.
  • the number of common rail fuel exit fittings can change according to the number of diesel engine cylinders were this system is applied.
  • the fuel from the common rail is delivered to each of the electromagnetic injectors, entering the injector body through fitting 344.
  • the fuel flow stops at injectors solenoid valve annular passage 340 having opening 350 normally closed.
  • solenoid 306 is energized with a signal coming from the Electronic Control Module 440, the armature 308 and valve 314 are lifted, opening fuel flow through opening 350, passages 348, 421, 430, 382 and 378.
  • the solenoid valve is pressure-balanced by the upper and lower sides of annular passage 340.
  • the pressurized fuel continues downward to the spray tip 374.
  • the fuel pressure acts against the tapered section of the needle valve 386. The fuel pressure lifts the needle valve and permits the pressurized fuel to spray into the engine's combustion chamber through spray opening means 376.
  • piston 420 With solenoid 306 energized and valve 314 lifted, piston 420 is adjusted such that it maintains a small gap 423 to valve 314 on its upper end allowing valve 414 to seat with its tapered seat 416 on the body's tapered seat 417, stopping fuel from entering passage 412 and annular passage 418 to enter the spring cage's upper chamber 408.
  • solenoid valve 314 is moved downwards by spring 336 and it closes opening 350.
  • the fuel bleeding through spray holes 376 will cause a fuel pressure drop in chamber 378 and section 380, allowing spring 410 to seat needle valve 386 on seat 392, closing off fuel bleeding through spray holes 376 (FIG. 7).
  • solenoid valve 314 when solenoid valve 314 is lowered, the lower end of the solenoid valve eliminates gap 423 and pushes open valve 414, allowing pressurized fuel from passage 421 and annular section 418 to pass through to chamber 408. Pressurized fuel will continue through a pre-sized orifice 424 into chamber 406 on the top of seat 396, helping spring 410 to close the needle valve earlier and providing a sharp end of injection.
  • the pre-sized orifice 424 will determine how much pressure assistance will be applied on the top of the seat 396, helping to close the needle valve.
  • the pressure in chamber 406 is maintained to a certain level by sizing the bleeding orifice 440 on the side wall of the chamber 406. This residual pressure is necessary to slow the needle valve opening on the next injection according to the engine requirements.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Fuel-Injection Apparatus (AREA)
EP96110036A 1991-06-12 1991-06-12 Kraftstoffpumpe für das Einspritzungsmittel eines Dieselmotors Withdrawn EP0737809A1 (de)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP91810447A EP0517991B1 (de) 1991-06-12 1991-06-12 Elektronische Hochdruckeinspritzkraftstoffleitung für Dieselmotoren

Related Parent Applications (1)

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EP91810447.2 Division 1991-06-12

Publications (1)

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EP0737809A1 true EP0737809A1 (de) 1996-10-16

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Family Applications (2)

Application Number Title Priority Date Filing Date
EP96110036A Withdrawn EP0737809A1 (de) 1991-06-12 1991-06-12 Kraftstoffpumpe für das Einspritzungsmittel eines Dieselmotors
EP91810447A Expired - Lifetime EP0517991B1 (de) 1991-06-12 1991-06-12 Elektronische Hochdruckeinspritzkraftstoffleitung für Dieselmotoren

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DE (1) DE69124228T2 (de)

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DE10055271A1 (de) * 2000-11-08 2002-05-23 Bosch Gmbh Robert Druck/Hubgesteuerter Injektor mit hydraulischem Übersetzer
DE10060836C1 (de) * 2000-12-07 2002-07-25 Bosch Gmbh Robert Druckgesteuerter CR Injektor mit gestuftem Öffnungs- und Schließverhalten
WO2008037794A1 (de) * 2006-09-29 2008-04-03 Continental Automotive Gmbh Fluidsammelvorrichtung
US20120204834A1 (en) * 2008-10-16 2012-08-16 Stephan Jonas Injection System for an Internal Combustion Engine
WO2019137796A1 (en) * 2018-01-10 2019-07-18 Delphi Technologies Ip Limited Fuel common rail

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DE4313852B4 (de) * 1993-04-28 2004-11-25 Robert Bosch Gmbh Kraftstoffeinspritzeinrichtung für Brennkraftmaschinen
AU6945894A (en) * 1993-05-06 1994-12-12 Cummins Engine Company Inc. Compact high performance fuel system with accumulator
GB2283533B (en) * 1993-05-06 1996-07-10 Cummins Engine Co Inc Distributor for a high pressure fuel system
DE4414242A1 (de) * 1994-04-23 1995-10-26 Bosch Gmbh Robert Kraftstoffeinspritzeinrichtung für Brennkraftmaschinen
DE19508445B4 (de) * 1995-03-09 2004-07-08 Deutz Ag Kraftstoffeinspritzvorrichtung für eine selbstzündende Brennkraftmaschine
DE19532599A1 (de) * 1995-09-04 1997-03-06 Siemens Ag Common-Rail-Kraftstoffversorgungssystem
DE19640480B4 (de) * 1996-09-30 2004-04-22 Robert Bosch Gmbh Kraftstoffhochdruckspeicher
EP0985093B1 (de) * 1997-05-27 2002-10-23 Hydraulik-Ring GmbH Radialkolbenpumpe
DE19725564C2 (de) * 1997-05-27 2001-05-23 Hydraulik Ring Gmbh Radialkolbenpumpe
DE19729392C2 (de) * 1997-07-09 1999-05-06 Siemens Ag Kraftstoffspeicher mit Abdichtung
DE19739810C1 (de) * 1997-09-10 1998-12-03 Siemens Ag Einspritzsystem für eine Brennkraftmaschine
DE19907311A1 (de) * 1999-02-22 2000-08-31 Bosch Gmbh Robert Hydraulikpumpeneinheit
DE10042309B4 (de) * 2000-08-29 2005-04-21 Robert Bosch Gmbh Zumessventil
GB0224936D0 (en) * 2002-10-25 2002-12-04 Delphi Tech Inc Fuel pump assembly
CN113931763A (zh) * 2021-09-30 2022-01-14 东风商用车有限公司 一种高压共轨管
CN116951464B (zh) * 2023-06-12 2024-06-04 中国航空发动机研究院 一种喷油装置及加力燃烧室

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10055271A1 (de) * 2000-11-08 2002-05-23 Bosch Gmbh Robert Druck/Hubgesteuerter Injektor mit hydraulischem Übersetzer
DE10060836C1 (de) * 2000-12-07 2002-07-25 Bosch Gmbh Robert Druckgesteuerter CR Injektor mit gestuftem Öffnungs- und Schließverhalten
WO2008037794A1 (de) * 2006-09-29 2008-04-03 Continental Automotive Gmbh Fluidsammelvorrichtung
US20120204834A1 (en) * 2008-10-16 2012-08-16 Stephan Jonas Injection System for an Internal Combustion Engine
WO2019137796A1 (en) * 2018-01-10 2019-07-18 Delphi Technologies Ip Limited Fuel common rail

Also Published As

Publication number Publication date
EP0517991A1 (de) 1992-12-16
DE69124228T2 (de) 1997-08-21
EP0517991B1 (de) 1997-01-15
DE69124228D1 (de) 1997-02-27

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