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
  • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
  • F02M61/04—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series
  • F02M61/042—The valves being provided with fuel passages
• • 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
  • F02M47/027—Electrically 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
  • 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
  • F02M61/18—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for
  • F02M61/1873—Valve seats or member ends having circumferential grooves or ridges, e.g. toroidal

Definitions

• the present invention is based on a fuel injection valve according to the preamble of patent claim 1.
• a fuel injection valve as is known for example from published patent application DE 198 18 200 AI, a bore is formed in a valve body, in which a piston-shaped valve needle is arranged.
• the valve needle interacts with a valve seat so that the opening of at least one injection opening is controlled by the longitudinal movement of the valve needle.
• a throttle collar is formed on the valve needle and is immersed in a corresponding throttle section when the valve needle rests on the valve seat. During the opening stroke movement of the valve needle, the throttle collar emerges from the throttle section, thereby opening up a flow cross section through which fuel is supplied to the injection openings.
• the flow cross section is designed as an annular channel which is formed between the valve needle and the wall of the bore.
• an injection profile can be achieved in which at the start of the opening stroke movement only a little fuel is supplied to the injection openings, while after the throttle collar has emerged from the throttle section, a large amount of fuel is supplied to the injection openings through the flow cross-section.
• the fuel injection valve has the disadvantage that not enough fuel can be supplied to the injection openings due to the flow cross section, in particular under full load of the corresponding internal combustion engine.
• the flow cross section which is opened between the valve needle and the wall of the bore by the throttle collar emerging from the throttle section still has a high flow resistance, so that the large amount of fuel, which is necessary in full load operation, can not be supplied in the time available.
• the fuel injection valve according to the invention with the characterizing features of claim 1 has the advantage that, after the throttle collar has emerged from the throttle section, a great deal of fuel flows into the injection openings at a high rate, so that a very large amount of fuel is injected in a very short time can.
• a fuel channel is formed in the valve needle, the inlet opening of which is arranged downstream of the throttle collar and which runs in the valve needle in such a way that additional fuel can be fed to the injection openings via the fuel channel, in addition to the annular channel which is formed between the valve needle and the wall of the bore is. This is particularly advantageous if the flow cross section of the ring channel cannot be increased arbitrarily, since the installation space in a fuel injection valve is very limited and this has to withstand ever higher pressures in the course of the development of diesel injection systems.
• the throttle section is formed by a central opening in an adjusting disc which is arranged in the bore of the valve body. The point in time at which the throttle collar exchanges from the throttle section can be set precisely via the thickness of the shim.
• the fuel channel opens at the end of the valve needle on the valve seat side. It is particularly advantageous here if the valve sealing surface, which is essentially conical, has two sealing areas. The two sealing areas seal the injection openings both upstream and downstream, so that when the valve needle rests on the valve seat there is no hydraulic connection between the fuel channel and the injection openings. This means that there can be no leakage and thus increased hydrocarbon emissions from the internal combustion engine.
• the fuel channel is formed by at least one transverse bore and a longitudinal bore intersecting the transverse bore. The longitudinal bore advantageously runs centrally in the axial direction of the valve needle. Bores designed in this way can be formed simply and at low cost in the valve needle.
• FIG. 1 shows a longitudinal section through a fuel injection valve
• FIG. 2 shows an enlarged illustration of the section of FIG. 1 labeled II.
• FIG. 1 an embodiment of the fuel injection valve according to the invention is shown in longitudinal section.
• the fuel injection valve has a valve body 1, in which a bore 3 is formed.
• the bore 3 is delimited at its combustion chamber end by an essentially conical valve seat 7, from which a plurality of injection openings 11 extend.
• the injection openings 11 open into the combustion chamber of the internal combustion engine in the installed position of the fuel injection valve.
• the bore 3 widens away from the valve seat 7 to form a spring chamber 8, a guide section 103 of the bore 3 being formed in a central section between the spring chamber 8 and the valve seat 7.
• a valve needle 5 is arranged to be longitudinally displaceable, which is essentially piston-shaped and has a longitudinal axis 6.
• the valve needle 5 is guided with a central section 30 in the guide section 103 of the bore 3 and has an essentially conical valve sealing surface 9 at its end on the valve seat side.
• a flow cross section 14 is formed, which has the shape of an annular channel between the central portion 30 and the valve seat 7.
• the flow cross section 14 continues towards the valve seat via recesses 32 which are formed on the central section 30 of the valve needle 5.
• a pressure shoulder 12, which faces away from the valve seat 7, is formed on the central section 30 facing the valve seat 7.
• the piston section 105 is guided in a sleeve 20 which is arranged in the spring chamber 8.
• Sleeve 20 and the end face of valve needle 5 facing the valve seat delimit a control chamber 17 which is filled with fuel and in which a variable pressure can be set.
• a closing spring 22 is arranged in the spring chamber 8 surrounding the piston section 105, said spring having a pressure prestress and thereby pressing the valve needle 5 in the direction of the valve seat 7.
• the sleeve 20 always remains stationary since it is pressed by the closing spring 22 against a further body of the fuel injector which is in contact with the valve body 1 and is not shown in the drawing.
• valve sealing surface 9 The interaction of the valve sealing surface 9 with the valve seat 7 is shown in more detail in FIG. 2 by an enlarged illustration of the section of FIG. 1 designated II.
• the valve sealing surface 9 has a first sealing region 109 and a second sealing region 209, which are separated from one another by an annular groove 50.
• first sealing region 109 When the valve sealing surface 9 is in contact with the valve seat 7, the first sealing region 109 is in contact with the valve seat 7 upstream of the injection openings 11, while the second sealing region 209 is in contact with the downstream side.
• the valve needle 5 rests on the valve seat 7, there is thus a sealing of the injection openings 11 both upstream and downstream.
• a throttle collar 34 is arranged on the valve needle.
• the throttle collar 34 plunges into a throttle section 36 which is formed by a central opening 28 in an adjusting disk 26.
• the shim 26 is arranged in the bore 3, and the central opening 28 is formed so that a gap remains between the throttle collar 34 and the throttle section 26 formed by the central opening 28, through which fuel can flow from the spring chamber 8 via the recesses 32 to the injection openings 11, but only throttled.
• an annular groove 38 is formed, in which a transverse bore 44 or a plurality of transverse bores 44 are formed, which intersect in the longitudinal axis 6 of the valve needle 5 in the case of a plurality of transverse bores 44.
• a longitudinal bore 46 is formed in the valve needle 5, which intersects the one or more transverse bores 44.
• a fuel channel 42 is formed via the transverse bore 44 and the longitudinal bore 46, the inlet opening 43 of which is formed by the transverse bore 44 and the outlet opening 48 is formed on the end of the valve needle 5 on the valve seat side.
• the fuel injection valve works as follows: There is always a high fuel pressure in the spring chamber 8 and thus also in the throttle cross section 14, the fuel being supplied to the end of the bore 3 facing away from the valve seat. If the valve needle 5 is to remain in its closed position, a high fuel pressure is provided in the control chamber 17, via its hydraulic force the valve needle
• valve needle 5 is held in contact with valve seat 7.
• the fuel pressure in the control chamber 17 is reduced, which also reduces the corresponding hydraulic force.
• the hydraulic force that is generated by acting on the pressure shoulder 12 on the valve needle 5 now results in a resultant force on the valve needle 5, which is directed away from the valve seat 7.
• valve needle 5 then lifts off the valve seat 7, so that the injection openings 11 are opened. Since the throttle collar 34 is still immersed in the throttle section 36 at the beginning of the opening stroke movement, fuel can flow to the injection openings 11 only via the narrow gap that remains between the throttle collar 34 and the throttle section 36. This makes the movement supply of the valve needle 5 relatively slow at the beginning and the injection rate correspondingly low. After the valve needle 5 has passed through the stroke h, the throttle collar 34 emerges from the throttle section 36. As a result, the flow cross section 14 is opened, so that a large amount of fuel can now flow through the recesses 32 and the flow cross section 14 to the injection openings 11.
• fuel flows through the fuel channel 42, that is to say through the transverse bore 44 and the longitudinal bore 46, and exits at the end on the valve seat side through the outlet opening 48 of the valve needle 5.
• the additional fuel channel allows more fuel to be supplied to the injection openings, since the flow cross section 14 can only be enlarged to a limited extent on account of the narrow dimensions and the limited installation space in the internal combustion engine.
• the pressure in the control chamber 17 is increased again, so that a resulting closing force directed onto the valve seat 7 results on the valve needle 5, which pushes it back into its closed position.
• the throttle section 36 in the adjusting disk 26, provision can also be made for the throttle section 36 to be formed directly in the bore 3.
• the shim 26 would be omitted in this case, but it is about
• Adjustment disk 26 and its thickness possible to set the stroke h very precisely, which the valve needle 5 traverses before the throttle collar 34 emerges from the throttle section 36.

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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 (2)

Publications (2)

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ID=34716562

Family Applications (1)

Country Status (4)

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• 2004
  • 2004-01-15 DE DE102004002084A patent/DE102004002084A1/de not_active Withdrawn
  • 2004-11-15 EP EP04798204A patent/EP1709321B1/fr not_active Not-in-force
  • 2004-11-15 DE DE502004009164T patent/DE502004009164D1/de active Active
  • 2004-11-15 WO PCT/EP2004/052959 patent/WO2005068824A1/fr active Application Filing
  • 2004-11-15 AT AT04798204T patent/ATE425355T1/de not_active IP Right Cessation

Non-Patent Citations (1)

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