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
  • 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
  • F02M59/44—Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston
  • F02M59/46—Valves
• • 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
• • 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
  • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
  • F02M2200/21—Fuel-injection apparatus with piezoelectric or magnetostrictive elements
• • 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
  • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
  • F02M2200/70—Linkage between actuator and actuated element, e.g. between piezoelectric actuator and needle valve or pump plunger
  • F02M2200/703—Linkage between actuator and actuated element, e.g. between piezoelectric actuator and needle valve or pump plunger hydraulic

Definitions

• the invention relates to a fuel injection valve for internal combustion engines according to the preamble of claim 1.
• Such a fuel injection valve is known from DE 198 13 983 AI.
• This fuel injection valve is part of a storage fuel injection system and has an injection valve member through which at least one injection opening is controlled and which has a pressure shoulder delimiting a pressure space.
• Fuel under pressure can be supplied to the pressure chamber from a high-pressure fuel source via a pressure line, through which the injection valve member can be raised against a closing force to open the at least one injection opening from a valve seat.
• the movement of the E injection valve member is influenced by a control valve which has a control valve member actuated by a piezo actuator, which controls the pressure prevailing in a control pressure chamber connected to a pressure source and which acts on the injection valve member in its closing direction.
• the control pressure chamber can be connected to a relief chamber by the control valve member, as a result of which the pressure in the control pressure chamber drops and the injection valve member can be moved in the opening direction.
• the movement of the control valve member by the piezo actuator must take place against the pressure prevailing in the control pressure chamber, so that a large amount of force is required to move it.
• the fuel injection valve according to the invention with the features according to claim 1 has the advantage that the movement of the control valve member for connecting the control pressure chamber to the relief chamber does not have to take place against the pressure in the control pressure chamber and thus only a small force is required for the movement of the control valve member.
• This makes it possible to use a piezo actuator with small dimensions, as a result of which the size and weight of the control valve can be kept small.
• the opening stroke of the injection valve member can be infinitely limited by the control valve member.
• Storage fuel injection system in a schematic representation and Figure 2 shows a fuel injection valve of the storage fuel injection system in a longitudinal section.
• Storage fuel injection system has a high-pressure pump 10, through which fuel from a storage tank 12 is conveyed to a storage 14 under high pressure.
• the memory 14 is designed as a so-called rail, from which lines lead to fuel injection valves 16 which are arranged on an internal combustion engine.
• Fuel injection valve 16 has a control valve 18, by means of which the opening and closing of the fuel injection valve 16 is controlled.
• Storage fuel injection system also has a control device 20, to which signals are supplied via various operating parameters of the internal combustion engine and by means of which the control valves 18 of the fuel injection valves 16 are controlled to open or close them.
• FIG. 2 shows a fuel injection valve 16 with an associated control valve 18.
• the fuel injection valve 16 has a valve body 22, in which an injection valve member 24 is axially displaceably guided.
• the valve body 22 has at least one, preferably a plurality of injection openings 26 at its end region facing the combustion chamber of the internal combustion engine.
• the injection valve member 24 has at that
• End area facing the combustion chamber has, for example, an approximately conical sealing surface 28 which interacts with a valve seat 30 formed in the valve body 22, from which the injection openings 26 lead away.
• a valve seat 30 formed in the valve body 22, from which the injection openings 26 lead away.
• annular space 32 is formed surrounding the injection valve member 24, which is connected to a pressure chamber 34, which in turn is connected to the accumulator 14, so that the pressure generated by the high pressure pump 10 prevails in the pressure chamber 34.
• the injection valve member 24 has a pressure shoulder 36 arranged in the pressure chamber 34, via the pressure prevailing in the pressure chamber 34 exerts a force acting on the opening valve 38 of the injection valve member 24 on the latter.
• a pre-tensioned closing spring 40 acts on the injection valve member 24, by means of which the injection valve member 24 is acted against by the force acting in the pressure chamber 34 against the force m closing direction 38 due to the pressure acting in the pressure chamber 34 Closing spring 40 opening 38 movable and gives the
• E injection openings 26 free through which fuel m is injected into the combustion chamber of the internal combustion engine.
• the injection valve member 24 m is closed with its sealing surface 28 m and the valve seat 30 is pressed against the valve body 22 so that the injection openings 26 are closed
• a closing piston 42 which is part of the control valve 18, is arranged in the region of the end of the injection valve member 24 facing away from the combustion chamber.
• the locking piston 42 can be integrated with the
• Injection valve member 24 may be formed or as a separate part.
• the closing piston 42 is arranged at least approximately coaxially with the injection valve member 24 and is axially displaceably guided in a bore 44 in a housing part 48 of the control valve 18.
• a channel 46 is formed in the closing piston 40, which has a section 46a starting from the front side of the closing piston 42 facing away from the injection valve member 24 and running approximately coaxially to the longitudinal axis of the closing piston 42, and a section 46b adjoining the latter, approximately perpendicular to the longitudinal axis of the closing piston 42
• the mouth of the closing piston 42 near its end facing the injection valve member 24 is in the region of the mouth of the section 46b of the channel 46
• the closing piston 42 is arranged in a section 44a of the bore 44 with an enlarged diameter, while the region of the closing piston 42 facing away from the injection valve member 24 is tightly guided in a section 44b of the bore 44 with a smaller diameter.
• An enlarged diameter section 44a of the bore 44 has an annular space between it and the closing piston 42 with the mouth of the channel section 44b, which is connected to a relief space, which can be used, for example, as the storage tank 12.
• closing piston 42 delimits a control pressure chamber 50, which is connected to accumulator 14 via a throttle 52.
• the end of a control valve member 54 projects into the control pressure chamber 50 at least approximately coaxially to the closing piston 42 and to the section 46a of its channel 46.
• a sealing surface 55 is formed, which can be, for example, conical and which interacts with the correspondingly also conical opening 47 of the channel section 46a of the closing piston 42 as a valve seat.
• the opening 47 of the channel section 46a on the closing piston 42 can be opened and closed by the sealing surface 55 of the control valve member 54.
• Control pressure chamber 50 fuel flows out through the channel 46 in the closing piston 42 and there is a lower pressure in the control pressure chamber 50 than in the accumulator 14, so that the injection valve member 24 by the pressure acting on its pressure shoulder 36 against the force of the closing spring 40 and the force acting on the end face of the closing piston 42 can be opened by the pressure prevailing in the control pressure chamber 50.
• control valve member 54 protrudes through an opening 56 in an intermediate plate 57 of the control valve housing.
• a further housing part 58 of the control valve housing which has a stepped bore 60, adjoins the intermediate disk 57, with a section 60a with a larger diameter formed towards the intermediate disk 57 and a section 60b with a smaller diameter subsequently formed thereon.
• the control valve member 54 In its area arranged in the bore section 60a, the control valve member 54 has an annular collar 62 which is enlarged in diameter compared to the diameter of the end of the control valve member 54 which projects into the control pressure chamber 50.
• a prestressed spring 64 is arranged between the intermediate disk 57 and the annular collar 62 of the control valve member 54, by means of which the control valve member 54 is pulled away from the closing piston 4.
• the control valve member 54 again has approximately the same diameter as at its end projecting into the control pressure chamber 50 and passes through the bore section 60b in a tightly guided manner.
• Another housing part 66 adjoins the housing part 58 of the control valve 18 and has a bore 68 with a larger diameter than the bore section 60b, which is at least approximately coaxial with the control valve member 54.
• a control piston 70 is formed in its area arranged in the bore 68 with a diameter larger than the control piston 70 passing through the bore section 60b.
• a working space 72 is delimited in the bore 68 towards the housing part 58 by the control piston 70.
• On the housing part 66 is followed by a disk-shaped housing part 74, between which and the end face of the control piston 70 facing away from the working space 72, a prestressed return spring 76 is arranged.
• the work space 72 is connected to a piezo actuator 78 via a hydraulic transmission.
• the piezo actuator 78 is controlled by the control device 20 and changes its length depending on an electrical voltage applied to it.
• the piezo actuator 78 is arranged in a cylinder 79 and, when it changes in length, compresses or relaxes a hydraulic volume arranged in the cylinder 79.
• the hydraulic translation is achieved in that the hydraulic volume influenced by the piezo actuator 78 is reduced in diameter to that
• Piezo actuator 78 reduced piston 80 acts, which performs a stroke increased by the ratio of the diameter of the piezo actuator 78 to the diameter of the piston 80 when the length of the piezo actuator 78 changes.
• the piston 80 is arranged at least approximately coaxially with the piezo actuator 78 and is displaceably guided in a cylinder 81 corresponding in diameter.
• a working space 82 is delimited by the piston 80 and is connected to the working space 72 via a channel 83 with a smaller diameter in the housing part 66.
• the piezo actuator 78 and the piston 80 can be arranged anywhere on the circumference of the housing part 66 of the control valve 18 and can be inclined with their longitudinal axes approximately perpendicular to the longitudinal axis of the control valve 18 or, as shown in FIG. 2, to the longitudinal axis of the control valve.
• the spring valve 64 pulls the control valve member 54 away from the closing piston 42, while the control valve member 54 is pressed toward the closing piston 42 by the return spring 76.
• the bias of the return spring 76 is Greater than the bias of the spring 64, so that at low pressure in the working chamber 72, the control valve member 54 is pressed by the return spring 76 against the closing piston 42 and keeps the channel 46 closed, again by acting on the closing piston 42 in the control pressure chamber 50
• the piezo actuator 78 When the piezo actuator 78 is controlled by the control device 20, its length increases and the piston 80 displaces hydraulic volume from the working space 82 via the channel 83 into the working space 72, where the pressure rises until it reaches the control piston 70 Exerted force together with the force of the spring 64 can overcome the bias of the return spring 76 and the control valve member 54 is moved away from the closing piston 42. Through the control valve member 54, the mouth 47 of the channel 46 in the closing piston 42 is opened, so that there is a gap between the sealing surface 55 of the control valve member 54 and the mouth 47 of the channel 46, through which
• Control pressure chamber 50 fuel can flow through the channel 46.
• the pressure in the control pressure chamber 50 thus falls, so that the injection valve member 24 is moved in the opening direction 38 against the reduced pressure in the control pressure chamber 50 and against the force of the closing spring 40 by the pressure acting on the pressure shoulder 36 in the pressure chamber 34 and opens the injection openings 26.
• the closing piston 42 moves together with the injection valve member 24 in its opening direction 38, whereby the gap between the sealing surface 55 of the control valve member 54 and the mouth 47 of the channel 46 is reduced again. This results in a stronger throttling effect at the gap between the sealing surface 55 of the control valve member 54 and the mouth 47 of the channel 46, as a result of which the pressure in the control pressure chamber 50 rises again, since less fuel from the Control pressure chamber 50 can flow out.
• the closing piston 42 thus follows the position of the control valve member 54, the gap between the sealing surface 55 of the control valve member 54 and the mouth 47 of the channel 46 on the end face of the closing piston 42 being set such that the system of the control valve 18 is in equilibrium.
• the closing piston 42 can be formed in one piece with the injection valve member 24 or as a separate component which is connected to the injection valve member 24.
• a coupling between the closing piston 42 and the injection valve member 24 is also brought about by the pressure prevailing in the control pressure chamber 50, by means of which the closing piston 42 is pressed against the injection valve member 24. If the gap between the sealing surface 55 and the mouth 47 of the channel 46 were too small, the pressure in the control pressure chamber 50 increases and the closing piston 42 moves away from the control valve member 54.
• the opening stroke of the injection valve member 24 can be infinitely limited by the corresponding position of the control valve member 54.
• the pressure in the control pressure chamber 50 does not result in any force on the control valve member 54, since its cross-sectional area in the control pressure chamber 50 is equal to the cross-sectional area of the mouth 47 of the channel 46 of the closing piston 42.
• the control valve member 54 is thus force balanced.
• the piezo actuator 78 and the hydraulic one Translation can therefore be carried out with small dimensions.
• the time of opening, the duration of the opening and the size of the opening stroke of the fuel injection valve 16 are determined.
• a pre-injection can be realized by first opening the fuel injection valve only briefly and / or with a small opening stroke for the pre-injection, then closing it and then opening it for the main injection for a longer time and / or with a larger opening stroke.
• a specific course of the injection can also be achieved, in which, for example, the fuel injection valve is initially only opened with a small opening stroke and then opened with a larger opening stroke. Any other course of injection can also be achieved.

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

Applications Claiming Priority (3)

Publications (1)

Family

ID=7927183

Family Applications (1)

Country Status (7)

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Family Cites Families (9)

• 1999
  • 1999-10-28 DE DE19951964A patent/DE19951964A1/de not_active Withdrawn
• 2000
  • 2000-10-11 US US09/869,242 patent/US6527198B1/en not_active Expired - Fee Related
  • 2000-10-11 CZ CZ20012385A patent/CZ20012385A3/cs unknown
  • 2000-10-11 KR KR1020017008168A patent/KR20010093225A/ko not_active Application Discontinuation
  • 2000-10-11 EP EP00972631A patent/EP1203150A2/de not_active Withdrawn
  • 2000-10-11 WO PCT/DE2000/003565 patent/WO2001031191A2/de not_active Application Discontinuation
  • 2000-10-11 JP JP2001533309A patent/JP2003513195A/ja active Pending

Non-Patent Citations (1)

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