Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • 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
  • F02M63/0005—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 valves actuated by fluid 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
  • F02M47/00—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure
  • F02M47/02—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure of accumulator-injector type, i.e. having fuel pressure of accumulator tending to open, and fuel pressure in other chamber tending to close, injection valves and having means for periodically releasing that closing pressure
  • F02M47/025—Hydraulically actuated valves draining the chamber to release the closing pressure

Definitions

• High-pressure storage systems are used today for injection systems on direct-injection crimping lcraft machines. These have the task of storing the fuel under high pressure. Pressure fluctuations that may arise from the pumping movement and the injection process are to be dampened by the fuel volume contained in the high-pressure accumulator.
• the fuel is injected into the combustion chambers of the nerbrennkraftkraftmaschinen by means of injectors. Start of injection and injection quantity are set on the injectors; these are preferably arranged on the cylinder head of a ner internal combustion engine.
• DE 198 35 494 AI relates to a pump nozzle unit. This is used to supply fuel to a nerburning chamber of direct-injection internal combustion engines with a pump unit for building up an injection pressure. Injectors are provided for injecting the fuel into the combustion chamber. Furthermore, the system comprises a control unit with a control valve, which is designed as an outwardly opening A-valve. A valve actuation unit for controlling the pressure build-up in the pump unit is also included. In order to create a pump-nozzle unit with a control unit, which has a simple structure, is small and, in particular, has a short response time, it is known according to the solution from DE 198 35 494 AI to design the valve actuation unit as a piezoelectric actuator ,
• DE 37 28 817 C 2 relates to a fuel injection pump for an internal combustion engine.
• This contains a drain part for pressurizing the fuel, a nozzle part for injecting the pressurized fuel and a control part arranged between the pressure part and the nozzle part.
• This crosses a fuel supply line connecting the pressure part to the nozzle part, a cylindrical channel, the central axis of which is the fuel supply line.
• Whose end is formed as a passing into a connected to a "fuel return duct opening control bore.
• a control valve member is provided in the channel, which can be moved by means of an electrical actuating device between an open position in which the fuel supply line and the fuel return channel are connected via the control bore and a closed position in which the control bore is closed.
• the actuating device contains a length-adjustable piezoelectric element which is connected to a drive piston, the free footprint of which is opposite a considerably smaller footprint of a drive tappet which mechanically adjusts the control valve member, separated by a cavity filled with incompressible fuel.
• a passage connecting the cavity with the fuel return duct is formed in the drive tappet, in which a check valve is located. This closes the passage when the pressure in the cavity exceeds the pressure in the fuel return channel and opens the passage when the pressure in the cavity is less than the pressure in the fuel return channel.
• an injector design can be achieved in an advantageous manner, which enables both stroke control of the injector body and its pressure control. This allows the latest requirements from the requirements of commercial vehicle engine manufacturers to be taken into account, which require injector control according to two separate principles in order to always be able to operate the internal combustion engine at the optimum operating point.
• the configuration of the 3/2-way valve via the stroke of the 3/2-way valve can suddenly relieve the pressure in the nozzle area of the injection nozzle.
• the sudden relief of the nozzle space causes pressure control of the injector in this operating state.
• the sudden relief of the nozzle chamber takes place when the valve body is controlled in the injector housing, covering the full stroke; on the other hand, if the injector is operated in partial pressure, one of the slides formed in the injector body can also be closed, while the other slide formed in the injector body is open at its control edge and thus permits a stroke.
• the slides are offset on the valve body which is movable in the vertical direction in the injector housing, so that a transition from stroke to pressure control and vice versa of the injector can be achieved in a simple manner and the vertical position of the injector body is defined relative to the injector housing.
• the vertical movement of the injector body in the housing of the injector takes place by means of a piezo actuator provided at one end of the valve body or another electrical actuating element with which the individual slider / control edge combination can be closed or opened differently under the influence of the shortest response times.
• Solenoid valves or piezo actuators can advantageously be used as actuators to relieve the pressure in the control room.
• the single figure shows a longitudinal section through an injector through a 3/2-way valve, on the injector body of which two slide edges offset from one another in the vertical direction are formed.
• the illustration according to the single figure shows the longitudinal section through an injector body on which two-slide / control edges are formed.
• the injector 1 shown in the illustration in FIG. 1 for injecting fuel under high pressure into the combustion chambers of a ner internal combustion engine is part of an injection system which comprises a high-pressure collecting chamber (common rail).
• the fuel is kept at an extremely high pressure level by means of a pump in order to use the fuel volume in the pump chamber as a damping element for drain flushing induced by the pump movement or pressure oscillation induced by the movement of the injector in the line system.
• the injector 1 resulting from the illustration according to FIG. 1 essentially comprises an injector body 3 which can be moved vertically in a housing 2.
• the injector body 3 is embedded as a rotationally symmetrical component in a bore in the housing 2.
• a drain rod element 4 At the bottom At the end of the injector body 3 there is arranged a drain rod element 4, which is opposite a piston 16, which in turn interacts with a control chamber 15 formed in the injector body 3.
• control chamber 6 At the top of the injector body 3, as shown in FIG. 1, there is a control chamber 6, the upper cylindrical end face of which is opposite.
• the control chamber 6 is constantly supplied with fuel under high pressure via a branch 8, so that it is ensured that always one there is sufficient control amount of fuel in the upper control chamber 6.
• a throttle element is let into the supply line 8, which on the one hand opens into the upper control chamber 6 and on the other hand branches off from the high-pressure collection chamber - inlet.
• the upper control chamber 6 can be relieved of pressure via a relief opening 7, to which an outlet throttle 9 connects.
• the pressure relief of the upper control chamber 6 and thus the induction of the vertical upward and downward movement of the injector body 3 in the housing 2 of the injector takes place through the actuation of an actuator element 10, which can be designed, for example, as a solenoid valve or as a piezo actuator and the pressure controls on the ball element serving as a closing element. If the spherical element acting as the closing element is relieved of pressure, its seating surface is free, so that a fuel volume which is established in accordance with the outlet throttle configuration 9 flows continuously out of the upper control chamber 6 via the relief opening 7, so that a vertical upward movement of the injector body 3 in the housing 2 of the injector 1.
• a high-pressure fuel is applied to a bore system provided in the interior of the injector body 3 via the high-pressure collecting space inlet 11, which opens into an annular space 20 that extends around the injector body 3.
• a transverse bore 12 which extends perpendicular to the line of symmetry of the injector body 3 and a central bore 13 which is connected thereto and runs coaxially to the line of symmetry of the injector body 3, an inlet throttle element 14 located at the end of the central bore 13 is supplied with fuel under high pressure - strikes.
• a control chamber 15 provided in the latter is acted upon by fuel under high pressure.
• the inlet throttle 14 opens into the upper boundary wall 30 of the control chamber 15, which on the other hand is delimited by the piston surface 17 of a piston 16 arranged coaxially to the axis of symmetry of the injector body 3.
• a cylindrical boundary wall 32 of the control chamber 15 is located between the two boundary surfaces 17 and 30.
• a movement of the injection nozzle from its seat can thus be achieved by pressurizing or relieving pressure in the control chamber 15, i. H. opening or closing the injector.
• control chamber 15 While the control chamber 15 is pressurized within the injector body 3 via the line system 11, 12, 13, 14, the pressure relief of the control chamber 15 within the injector 3 and thus a vertical upward movement of the piston 16 with its piston surface 17 into the control chamber 15 can thereby be achieved be that over the Druckentlastimg of the upper control chamber 6, the injector body 3 as a whole, a vertical drive-up movement is impressed.
• the control chamber 15 can be drained by a drain throttle 18 opening into its cylinder wall 32 and an adjoining bore with a corresponding upward movement of the injector body 3 via a pressure relief line 28, so that when the piston 16 moves upwards with its piston surface 17 into the control chamber 15 whose pressure relief an opening of the nozzle needle of the injector 5 can be achieved from its seat.
• the injector body 3 is placed in a position in which the nozzle feed line 21 is closed on the high-pressure side by the abutment of a seat surface 22 of the injector 3 on the housing 2. H.
• the high-pressure fuel volume contained in the annular space 20 is in contact with the control space 15 via the bores 12, 13, 14 and thereby closes the nozzle; on the other hand, there is no fuel under high pressure in the nozzle chamber of the injection nozzle 5, since the sealing seat 22 separates the nozzle inlet 21 from the high-pressure collecting chamber inlet 11 on the housing side.
• Relieving the pressure on the upper control chamber 6 by actuating the electric actuator 10 leads to a pressure relief of the upper control chamber 6.
• the cylindrical end face of the injector body 3 moves into the latter, so that a vertical opening movement of the injector body 3 in the housing 2 of the injector 1 occurs.
• a first slide 23 moves on the injector body 3 Via a first control edge 24 on the housing side.
• the injector body 3 can be opened further. This leads to the opening of the second slide 25 after passage of the control edge 26 provided on the housing side. If the second slide is open, pressure relief of the control chamber 15 by the outlet throttle 18 occurs in the annular space surrounding the injector body 3, which contains a drain line 28 , By opening the second slide when controlling the valve body 3, d. H. the generation of the full vertical stroke movement of the injector body 3 in the housing 2 surrounding it, an abrupt pressure relief of the control chamber 15 is possible, so that the piston 16 with its piston surface 17 moves into it. In this operating state, the nozzle needle of the injection nozzle 5 opens on its seat surface, so that the fuel volume present in the nozzle feed line 21 - the seat surface 22 of the injector body 3 is open - can be injected under high pressure.
• the injector is pressure controlled, while in the partial stroke mode, i.e. H. the generation of only one upward movement of the injector body 3, which corresponds to the stroke 27, the injector is stroke-controlled.
• a leakage oil chamber is identified by reference numeral 29, in which fuel from the control chamber 15 collects along the piston 16. This, like the control volume flowing out of the upper control chamber 6 via the relief line 7 and the control volume flowing out of the control chamber 15 provided in the injector body 3 via the outlet throttle 18 and the outlet line 28, is fed back to the fuel tank.
• both the high-pressure collecting chamber inlet 11 to the annular chamber 20 and the branch 8 to the upper control chamber 6 and the nozzle inlet 21 in the housing 2 of the injector 1 are designed as bores and the housing is made of high-strength metallic material. The same applies to the injector body 3 which can be moved up and down in the housing 2 of the injector 1.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Fuel-Injection Apparatus (AREA)
• Nozzles (AREA)

Applications Claiming Priority (3)

Publications (2)

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Cited By (1)

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• 2000
  • 2000-10-31 DE DE10053903A patent/DE10053903A1/de not_active Ceased
• 2001
  • 2001-09-21 DE DE50104994T patent/DE50104994D1/de not_active Expired - Lifetime
  • 2001-09-21 AT AT01992832T patent/ATE286208T1/de not_active IP Right Cessation
  • 2001-09-21 US US10/169,123 patent/US6848630B2/en not_active Expired - Lifetime
  • 2001-09-21 WO PCT/DE2001/003658 patent/WO2002036958A1/fr active IP Right Grant
  • 2001-09-21 EP EP01992832A patent/EP1334271B1/fr not_active Expired - Lifetime
  • 2001-09-21 JP JP2002539683A patent/JP2004512464A/ja active Pending

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