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
  • F02M51/00—Fuel-injection apparatus characterised by being operated electrically
  • F02M51/06—Injectors peculiar thereto with means directly operating the valve needle
  • F02M51/0603—Injectors peculiar thereto with means directly operating the valve needle using piezoelectric or magnetostrictive operating means
• • 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
  • F02M61/08—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 the valves opening in direction of fuel flow
• • 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
  • F02M61/167—Means for compensating clearance or thermal expansion
• • 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
  • F02M2200/90—Selection of particular materials
  • F02M2200/9084—Rheological fluids

Definitions

• the invention relates to a fuel injection valve according to the preamble of the main claim.
• a displacement transformer for a piezoelectric actuator in which the actuator transmits a lifting force to a master cylinder, which is completed by a cylinder carrier.
• a slave piston is guided in this master cylinder, which also closes the master cylinder and thereby forms the hydraulic chamber.
• a spring is arranged in the hydraulic chamber, which presses the master cylinder and the slave piston apart.
• the slave piston mechanically transmits a stroke movement to, for example, a valve needle.
• the actuator transmits a stroke movement to the master cylinder
• this stroke movement is transmitted to the slave piston by the pressure of a hydraulic fluid in the hydraulic chamber, since the hydraulic fluid in the hydraulic chamber cannot be compressed and only a very small proportion of the hydraulic fluid can pass through the annular gap during the short Period of a stroke can escape.
• the spring pushes the slave piston out of the cylinder and the resulting one Vacuum penetrates the hydraulic fluid through the annular gap into the hydraulic space and fills it up again.
• the displacement transformer automatically adjusts to the length and pressure-related expansions of a fuel injection valve.
• a disadvantage of the coupler arrangement known from EP 0 477 400 AI is in particular the high cost due to the requirement for high manufacturing accuracy of the components. Furthermore, the coupler medium escapes from the coupler gap in the case of closely successive opening pulses and, due to the small width of the leakage gap, cannot flow in quickly enough, so that the switching dynamics of fuel injection valves with hydraulic couplers is limited.
• DE 197 35 232 A1 discloses the use of electrorheological fluid in a fuel injection valve, which has a damping element connected to the valve needle of the fuel injection valve for modeling the injection process or the amount of fuel injected, which damping element excites or de-excites the electromagnet a flow of electrorheological fluid in a steaming chamber via a capacitive component causes the viscosity of the electrorheological fluid can be changed by means of the capacitive component by means of an electronic control unit depending on the operating parameters of the internal combustion engine such that the course of movement of the damping element takes place in such a way that the ber the sprayed sprayed fuel takes a desired jet shape or is sprayed temporally in the desired manner.
• the use of the rheological fluid for a compensating element f r piezoelectric actuators or magnecost ⁇ ktive is not described there
• the fuel injector according to the invention with the characterizing features of the main claim has the advantage that a closed, filled with a rheological fluid compensation element is arranged downstream of the piezoelectric or magnetostrictive actuator, which on the one hand compensates for the slow thermal expansion of the different components of a fuel injector and on the other hand fast switching movements of the Actuator transmits as an opening impulse to the valve needle.
• the compensating element is advantageously formed from a pot and a lid, the pot being rigid and the lid being flexible.
• the lid is provided with beads that improve the elastic deformability of the lid.
• the pot of the compensating element is easy to manufacture by deep drawing. After filling, the lid can be hermetically connected to the pot, so that the filled compensating element can be assembled in a simple manner as an overall component in the fuel injector.
• FIG. 1 shows a schematic section through an embodiment of a fuel injector designed according to the invention
• FIG. 2 shows a schematic detail from the exemplary embodiment shown in FIG. 1 of the fuel injection valve according to the invention in the area II m
• FIG. 1 shows a schematic section through an embodiment of a fuel injector designed according to the invention
• FIG. 2 shows a schematic detail from the exemplary embodiment shown in FIG. 1 of the fuel injection valve according to the invention in the area II m
• FIG. 1 shows a schematic section through an embodiment of a fuel injector designed according to the invention
• FIG. 1 of a fuel injection valve 1 is designed in the form of a fuel injection valve 1 for fuel injection systems of mixture-compressing, externally ignited internal combustion engines.
• the fuel fine injection valve 1 is particularly suitable for the direct injection of fuel into a combustion chamber, not shown, of an internal combustion engine
• the fuel fine injection valve 1 comprises an actuator 2, which is constructed, for example, from piezoelectric layers 3.
• the actuator 2 is encapsulated in a housing 4, on which the actuator 2 is supported at the end
• an actuating element 5 is arranged, which is designed in the form of a stamp and rests on a compensating element 6
• a valve needle 7 Downstream of the compensating element 6, a valve needle 7 is arranged, with which a support disk 8 is non-positively connected Between the support disk 8 and a housing shoulder 9, a return spring 10 is arranged, which acts on the valve needle 7 so that the valve closing body 11 m connected to the valve needle 7 sealing system is held on a valve seat surface 12, which is formed on a valve seat body 17 integrated in the exemplary embodiment with the housing 4 of the fuel injection valve 1.
• valve needle 7 m operatively connected valve closing body 11 lifts off the valve seat surface 12, whereby fuel m is injected into the combustion chamber of the internal combustion engine, which is not shown in detail
• FIG. 2 shows an enlarged, schematic view of the detail designated II in the region of the compensating element 6
• the compensating element 6 has the task of compensating slow changes in length due to thermal influences, in particular of the actuator 2, so that the valve closing body 11 should not lift off the valve seat surface 12 due to the slow thermal expansion of the actuator 2. Fast changes in length of the actuator 2 by energizing to switch the fuel injection valve 1 are intended on the other hand, are transferred to the valve needle 7
• the compensating element 6 is constructed from a bowl-shaped pot 13, which can be produced, for example, by deep drawing, and a lid 1, which closes the pot 13 and can be connected to it by a circumferential weld seam the stamp-shaped actuating element 5, while the valve needle 7 rests on the cover 14.
• the Pot 13 is filled prior to sealing with a rheological fluid 15 before the cover '14 fitted and the pot 13 is closed hermetically.
• the thickness of the material of the pot 13 is preferably chosen so that the pot 13 is rigid, while the material of the lid 14 is chosen to be thinner and thus more flexible.
• beads 16 can be provided, which are attached to the lid 14, for example in a ring. Due to the flexibility of the cover 14, it is possible that this is reversibly elastically deformed when various components of the fuel injector 1 heat up due to the thermal load during operation of the internal combustion engine and thereby experience a change in length.
• the enclosed rheological fluid 15 'behaves like a fluid at a slow rate of stress, i. H. the cover 14 is pressed into the pot 13 by the opposing forces of the expanding actuator 2 and the return spring 10, so that the fuel injector 1 remains closed despite the thermal change in length.
• the rheological fluid 15 behaves like a solid at high actuation speed, that is to say when the actuator 2 is energized to open the fuel injector 1, so that the compensating element 6 reacts stiffly and transmits the stroke of the actuator 2 to the valve needle 7.
• Such an arrangement has the main advantage that the compensating element 6 is simple and inexpensive to manufacture.
• the compensating element 6 also has the advantage over a hydraulic coupler that the range of functions of the piezoelectric actuator 2 is not restricted. While in a hydraulic coupler the coupler medium escapes between the pistons in the case of two rapidly successive pulses and the time for backflow is too short, the compensating element 6 with the rheological fluid 15 can React successively opening impulses as quickly as possible.
• the invention is not limited to the exemplary embodiment shown and z. B. also suitable for magneto-st ⁇ active actuators 2 and for any other construction of fuel injection valves 1.

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

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=7713422

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (12)

Citations (8)

Family Cites Families (6)

• 2002
  • 2002-01-30 DE DE10203659A patent/DE10203659A1/de not_active Withdrawn
  • 2002-11-29 DE DE50211993T patent/DE50211993D1/de not_active Expired - Lifetime
  • 2002-11-29 EP EP02792621A patent/EP1472451B1/de not_active Expired - Lifetime
  • 2002-11-29 KR KR1020047011708A patent/KR100942670B1/ko not_active Expired - Fee Related
  • 2002-11-29 US US10/473,501 patent/US6932278B2/en not_active Expired - Fee Related
  • 2002-11-29 JP JP2003564420A patent/JP4456872B2/ja not_active Expired - Fee Related
  • 2002-11-29 WO PCT/DE2002/004386 patent/WO2003064846A1/de not_active Ceased

Patent Citations (8)

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