WO2009019247A1 - Module activateur piézoélectrique - Google Patents

Module activateur piézoélectrique Download PDF

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Publication number
WO2009019247A1
WO2009019247A1 PCT/EP2008/060220 EP2008060220W WO2009019247A1 WO 2009019247 A1 WO2009019247 A1 WO 2009019247A1 EP 2008060220 W EP2008060220 W EP 2008060220W WO 2009019247 A1 WO2009019247 A1 WO 2009019247A1
Authority
WO
WIPO (PCT)
Prior art keywords
actuator module
piezoelectric actuator
base layer
protective layer
fuel
Prior art date
Application number
PCT/EP2008/060220
Other languages
German (de)
English (en)
Inventor
Marco Holst
Peter Cromme
Helmut Sommariva
Ullrich Kraatz
Original Assignee
Robert Bosch Gmbh
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Robert Bosch Gmbh filed Critical Robert Bosch Gmbh
Priority to EP08786833A priority Critical patent/EP2186145A1/fr
Publication of WO2009019247A1 publication Critical patent/WO2009019247A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N30/00—Piezoelectric or electrostrictive devices
    • H10N30/80—Constructional details
    • H10N30/88—Mounts; Supports; Enclosures; Casings
    • H10N30/883—Additional insulation means preventing electrical, physical or chemical damage, e.g. protective coatings
    • 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
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N30/00—Piezoelectric or electrostrictive devices
    • H10N30/50—Piezoelectric or electrostrictive devices having a stacked or multilayer structure

Definitions

  • the invention relates to a piezoelectric actuator module for a fuel injection valve and a fuel injection valve with such a piezoelectric actuator module. Specifically, the invention relates to the field of injectors for fuel injection systems of air compressing, self-igniting internal combustion engines.
  • the known piezoelectric element comprises a ceramic lamination, which alternately stacked one above the other contains a plurality of ceramic layers of piezoelectric ceramic and a plurality of internal electrode layers.
  • an organic insulating layer of organic material is formed on a part of the surface of the ceramic lamination.
  • an inorganic insulating layer of inorganic material is formed on the organic insulating layer.
  • the organic insulating layer has enough elasticity to absorb the deflection of the piezoelectric element.
  • the organic insulation layer can not actively prevent the passage of moisture and allows moisture into it.
  • the inorganic insulating layer suppresses moisture passage, but the inorganic insulating layer has no elasticity.
  • the piezoelectric element known from DE 102 17 361 A1 and the injection nozzle provided with this piezoelectric element have the disadvantage that the design is relatively complicated. Furthermore, there is the problem that in the production or in the Operation occurring openings or cracks in the inorganic insulating layer allow penetration of fuel into the organic insulating layer, which leads to short circuits between the inner electrode layers.
  • the piezoelectric actuator module according to the invention with the features of claim 1 and the fuel injection valve according to the invention with the features of claim 11 have the advantage that a relatively inexpensive production is possible, with a reliable protection against media is ensured, and that in particular ensures high reliability and functionality is.
  • the protective layer is formed as a flexible or elastic protective layer.
  • the protective layer may consist of a flexible or elastic plastic.
  • the flexibility or elasticity of the protective layer has the advantage that the protective layer is not damaged by the resulting mechanical stresses in the formation of cracks on the actuator body and possibly the base layer, so that there is effective protection of the base layer to fuels.
  • the protective layer is also preferable to diesel fuel or others
  • the base layer is formed from a lacquer which can be applied directly to the actuator body.
  • the paint can advantageously be based on epoxides, which may be filled or unfilled, on the basis of inorganic-organic hybrid polymers, in particular with solvent-based polymer matrix and nanoparticles, or be prepared on the basis of organosilicon compounds.
  • organosilicon compounds are polysilazane-based paints which may also be chemically modified to improve media stability, for example in the form of a florid polysilazane which may be filled or unfilled, polycarbosilane-based paints which may be filled or unfilled , and paints based on
  • Polyfluoralkylether which may be filled or unfilled, in question.
  • the base layer is recessed at least in an outer electrode region of the outer side, in which an outer electrode of the actuator module is connected to the actuator body.
  • the application of the base layer is carried out selectively and may preferably be applied to the outside of the actuator body by means of a spraying, dipping, immersion coating, trickling or printing process.
  • At least one media-resistant film is provided, which surrounds the actuator body coated with the base layer and the protective layer.
  • a media-resistant film on the basis of at least one
  • Polypropylene sulfide or at least one polyimide is provided.
  • FIG. 1 is a fuel injection valve with a piezoelectric actuator module in a schematic sectional view according to a first embodiment of the Invention
  • Fig. 2 is a section along that designated in Fig. 1 with II
  • Fig. 3 shows the section shown in Fig. 2 according to a second embodiment of the invention.
  • Fig. 1 shows a fuel injection valve 1 with a piezoelectric actuator 2 according to a first embodiment of the invention.
  • the fuel injection valve 1 can serve in particular as an injector for fuel injection systems of air-compressing, self-igniting internal combustion engines.
  • a preferred use of the fuel injection valve 1 is for a fuel injection system with a common rail, the diesel fuel under high pressure to several
  • Fuel injection valves 1 leads.
  • the piezoelectric actuator 2 according to the invention is particularly suitable for such a fuel injection valve 1 and also for an inverse control of the piezoelectric actuator 2.
  • the fuel injection valve 1 according to the invention and the piezoelectric actuator 2 according to the invention are also suitable for other applications.
  • the fuel injection valve 1 has a valve housing 3 and a fuel inlet 4 connected to the valve housing 3.
  • a fuel line can be connected to connect the fuel injector 1 via a common rail or directly with a high-pressure pump.
  • Fuel can then be introduced into an actuator chamber 5 provided in the interior of the valve housing 3 via the fuel inlet stub 4, so that in the operation of the fuel injector 1, fuel is present in the actuator chamber 5, in which the piezoelectric actuator 2 is provided is located.
  • the actuator chamber 5 is separated by a housing part 6 from a fuel space 7 likewise provided in the interior of the valve housing 3. Passage openings 8, 9 are configured in the housing part 6 in order to guide the fuel guided into the actuator chamber 5 via the fuel inlet stub 4 into the fuel chamber 7.
  • the valve housing 3 is connected to a valve seat body 10, on which a valve seat surface 11 is formed.
  • the valve seat surface 11 cooperates with a valve closing body 12 to form a sealing seat.
  • the valve closing body 12 is integrally formed with a valve needle 15, via which the valve closing body 12 is connected to a pressure plate 16 provided in the actuator chamber 5.
  • the valve needle 15 is guided through the housing part 6 along an axis 17 of the fuel injection valve 1.
  • a spring element 18 which rests on the one hand on the housing part 6 and on the other hand on the pressure plate 16, acts on the piezoelectric actuator 2 with a biasing force, wherein the valve needle 15 is actuated by the pressure plate 16 by the application, so that between the valve closing body 12 and of the
  • Valve seat surface 11 formed sealing seat is closed.
  • valve housing 3 has a connecting element 20 in order to allow the connection of an electrical supply line to the fuel injection valve 1.
  • the electrical supply line can be connected by means of a plug to electrical lines 21, 22.
  • the electrical lines 21, 22 are guided by the housing 3 and an actuator body 23 attached to the actuator 2 actuator foot 24 to the actuator body 23.
  • an actuator head 25 is also attached, via which the actuator body 23 against the force of the spring element 18 acts on the pressure plate 16.
  • the piezoelectric actuator 2 has in the illustrated embodiment, the actuator body 23, the actuator base 24 and the actuator head 25, so that an actuator module 19 is formed.
  • the actuator module 19 can also consist of two or more actuator bodies 23 be constructed. In this case, 23 intermediate pieces may be provided between the individual actuator bodies or the individual actuator body 23 may also be glued together at their end faces.
  • the actuator body 23 of the piezoelectric actuator 2 has a
  • outer electrodes 36, 37 are provided, which are connected to the electrical lines 21, 22.
  • the outer electrodes 36, 37 are alternately connected to the electrode layers 28, 29 so that alternating positive and negative electrodes are provided between the ceramic layers 26, 27.
  • the piezoelectric actuator 2 can be charged via the electrical lines 21, 22, whereby it expands in the direction of the axis 17, so that the sealing seat formed between the valve closing body 12 and the valve seat surface 11 is opened. This results in the spraying of fuel from the fuel chamber 7 via an annular gap 30 and the open sealing seat. When discharging the piezoelectric actuator 2, this contracts again, so that the sealing seat formed between the valve-closing body 12 and the valve seat surface 11 is closed again.
  • the further embodiment of the actuator module 19 with the piezoelectric actuator 2 of the fuel injection valve 1 of the first embodiment is further described with reference to FIGS. 1 and 2 in detail.
  • a fuel-resistant base layer 38 is partially applied, which is recessed in the region of the outer electrodes 36, 37.
  • the base layer 38 and the outer electrodes 36, 37 are also surrounded by a fuel-resistant protective layer 39.
  • the base layer 38 and / or the Protective layer 39 may also consist of several individual layers. Furthermore, in addition to the two-layer structure shown in FIG. 2, a three- or multi-layered construction is possible in which further intermediate layers are applied to the actuator body 23 in addition to the base layer 38 and the protective layer 39.
  • the base layer 38 has, in particular, the task of ensuring sufficient electrical insulation and dielectric strength as well as protecting the outer surface 35 of the piezoelectric actuator 2 from the environment.
  • the base layer 38 in this case has a good adhesion to the piezoelectric actuator 2 and optionally the attachments, in particular the actuator base 24 and the actuator head 25, so that a detachment of the base layer 38 during operation of the fuel injection valve and / or during the polarity of the piezoelectric actuator. 2 is prevented.
  • the base layer 38 preferably ensures electrical insulation in direct contact with a fuel under the operating conditions of the injector where high pressure fuel is provided in the actuator chamber 5.
  • the base layer forms an interface between the actuator body 23 and further layers, in particular the protective layer 39.
  • the base layer 38 is preferably formed from a material which has good resistance to fuels, which has good thermal conductivity as well as sufficient chemical resistance and which serves to improve the
  • the base layer 38 may be formed of a lacquer.
  • a lacquer based on an epoxy which may be filled or unfilled, be formed.
  • a lacquer based on an inorganic-organic hybrid polymer in particular with solvent-based polymer matrix and nanoparticles
  • a lacquer based on at least one organosilicon compound in particular based on a polysilazane, which may also be chemically modified to improve the media stability, for example in the form of a fluorinated polysilazane, and which may be filled and unfilled.
  • a lacquer based on a filled or unfilled polycarbosilane is suitable.
  • Another example of the material of the base coat is a paint based on a polyfluoroalkyl ether which may be filled or unfilled.
  • the base layer 38 is preferably selectively by a spray, dip, dip coating, trickling or printing process on the actuator body 23 and optionally further intermediate or
  • Attachment parts in particular the actuator base 24 and the actuator head 25, applied.
  • the protective layer 39 is preferably formed of a flexible or elastic plastic.
  • a protection of the base layer 38 is ensured, so that, for example, in a case in which the base layer 38 due to brittleness or the like during operation of the fuel injection valve or during the poling process cracks, in particular poling cracks, forms, penetration of fuel in the base layer 38 is prevented.
  • the elasticity or flexibility of the protective layer 39 prevents mechanical damage by mechanical stresses in the formation of cracks on the actuator body 23 and / or on the base layer 38.
  • the protective layer 39 preferably has at least one material which is resistant to a fuel, in particular diesel fuel.
  • a perfluoropolyether with or without silicone side groups, a fluororubber or a fluorinated silicone can be used.
  • Fig. 3 shows the section shown in Fig. 2 by a piezoelectric actuator 2 of a fuel injection valve 1 according to a second embodiment of the invention.
  • the base layer 38 is selectively applied to the outer surface 35.
  • the protective layer 39 is applied to the base layer 38, which also includes the outer electrodes 36, 37 surrounds.
  • a media-resistant film 40 is provided, which is placed around the actuator body 23 coated with the base layer 38 and the protective layer 39.
  • the media-resistant film 40 offers mechanical protection against damage, such as may occur during storage or installation of the piezoelectric actuator 2.
  • the media-resistant film 40 offers further protection against fuels.
  • the media-resistant film 40 may be made of a polypropylene sulfide or a polyimide.
  • a further embodiment variant is that the protective layer 39 in the first embodiment shown in FIG. 2 or in the second embodiment shown in FIG. 3 is formed from a lacquer layer, wherein the lacquer layer of the same or a different material as the base layer 38 may exist.
  • the protective layer 39 in particular paints come into question, as listed above for the base layer 38.

Landscapes

  • Fuel-Injection Apparatus (AREA)

Abstract

Le module activateur piézoélectrique (19) selon l'invention pour une soupape d'injection de combustible (1) comporte un corps activateur (23) qui comporte une pluralité de couches céramiques (26, 27) et une pluralité de couches d'électrodes (28, 29) entre les couches céramiques (26, 27). Le dispositif comporte pour cela une couche de base (38) résistant au carburant qui est posée sur une surface extérieure du corps activateur (23). Le dispositif comporte de plus une couche de protection (39) résistant au carburant qui est posée sur la couche de base (38) résistant au carburant.
PCT/EP2008/060220 2007-08-09 2008-08-04 Module activateur piézoélectrique WO2009019247A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP08786833A EP2186145A1 (fr) 2007-08-09 2008-08-04 Module activateur piézoélectrique

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102007037553A DE102007037553A1 (de) 2007-08-09 2007-08-09 Piezoelektrisches Aktormodul
DE102007037553.2 2007-08-09

Publications (1)

Publication Number Publication Date
WO2009019247A1 true WO2009019247A1 (fr) 2009-02-12

Family

ID=40011299

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2008/060220 WO2009019247A1 (fr) 2007-08-09 2008-08-04 Module activateur piézoélectrique

Country Status (3)

Country Link
EP (1) EP2186145A1 (fr)
DE (1) DE102007037553A1 (fr)
WO (1) WO2009019247A1 (fr)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002089225A2 (fr) * 2001-04-30 2002-11-07 Epcos Ag Materiau de passivation pour composant electrique et composant piezo-electrique a structure multicouche
DE10217361A1 (de) 2001-04-19 2002-12-05 Denso Corp Piezoelektrisches Element und damit versehene Einspritzdüse
EP1683824A2 (fr) * 2005-01-21 2006-07-26 Aero Sekur S.p.A. Récipients a haute performance mécanique
DE102005024710A1 (de) * 2005-05-30 2006-12-07 Robert Bosch Gmbh Brennstoffeinspritzventil
WO2007093921A2 (fr) * 2006-02-14 2007-08-23 Delphi Technologies, Inc. Revêtements barriere destines a un dispositif piezoelectrique
WO2007122227A2 (fr) * 2006-04-26 2007-11-01 Siemens Aktiengesellschaft Piézo-actionneur comportant un encapsulage multicouche et procédé de fabrication
EP1981097A2 (fr) * 2007-04-10 2008-10-15 Robert Bosch Gmbh Actionneur piézoélectrique

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10217361A1 (de) 2001-04-19 2002-12-05 Denso Corp Piezoelektrisches Element und damit versehene Einspritzdüse
WO2002089225A2 (fr) * 2001-04-30 2002-11-07 Epcos Ag Materiau de passivation pour composant electrique et composant piezo-electrique a structure multicouche
EP1683824A2 (fr) * 2005-01-21 2006-07-26 Aero Sekur S.p.A. Récipients a haute performance mécanique
DE102005024710A1 (de) * 2005-05-30 2006-12-07 Robert Bosch Gmbh Brennstoffeinspritzventil
WO2007093921A2 (fr) * 2006-02-14 2007-08-23 Delphi Technologies, Inc. Revêtements barriere destines a un dispositif piezoelectrique
WO2007122227A2 (fr) * 2006-04-26 2007-11-01 Siemens Aktiengesellschaft Piézo-actionneur comportant un encapsulage multicouche et procédé de fabrication
EP1981097A2 (fr) * 2007-04-10 2008-10-15 Robert Bosch Gmbh Actionneur piézoélectrique

Also Published As

Publication number Publication date
DE102007037553A1 (de) 2009-02-12
EP2186145A1 (fr) 2010-05-19

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