WO2007107595A1 - Unité d'actionnement pour soupape d'injection haute pression - Google Patents

Unité d'actionnement pour soupape d'injection haute pression Download PDF

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Publication number
WO2007107595A1
WO2007107595A1 PCT/EP2007/052713 EP2007052713W WO2007107595A1 WO 2007107595 A1 WO2007107595 A1 WO 2007107595A1 EP 2007052713 W EP2007052713 W EP 2007052713W WO 2007107595 A1 WO2007107595 A1 WO 2007107595A1
Authority
WO
WIPO (PCT)
Prior art keywords
cylinder spring
actuator
actuator unit
unit according
fluid
Prior art date
Application number
PCT/EP2007/052713
Other languages
German (de)
English (en)
Inventor
Bernhard Gottlieb
Andreas Kappel
Tim Schwebel
Carsten Wallenhauer
Original Assignee
Siemens Aktiengesellschaft
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 Siemens Aktiengesellschaft filed Critical Siemens Aktiengesellschaft
Publication of WO2007107595A1 publication Critical patent/WO2007107595A1/fr

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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
    • 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
    • F02M63/0012—Valves
    • F02M63/0014—Valves characterised by the valve actuating means
    • F02M63/0015—Valves characterised by the valve actuating means electrical, e.g. using solenoid
    • F02M63/0026—Valves characterised by the valve actuating means electrical, e.g. using solenoid using piezoelectric or magnetostrictive actuators
    • 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
    • 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
    • H10N30/886—Additional mechanical prestressing means, e.g. springs

Definitions

  • the invention relates to an actuator unit for a high-pressure injection valve, consisting of a monolithic multi-layer actuator, which is encapsulated in a housing.
  • piezoelectric multilayer actuators abbreviated PMA (Piezoelectric Mutilayer Actuator)
  • PMA piezoelectric Mutilayer Actuator
  • the PMA is hermetically sealed or encapsulated.
  • the enclosure must - for about 5xlO 9 cycles - axially sufficiently flexible and permanently elastic to be.
  • a hollow cylindrical spring in which a piezoactuator can be introduced and prestressed. While previously known tubular and cylindrical springs had a slot-like structure to reduce the spring constant, the known cylinder spring has no recesses. This has the advantage that a separate sealing of the PMA against moisture and fuel in the injection valve is no longer required for the PMA, as with earlier actuator units.
  • the spring constant can be reduced in the known closed cylinder spring by reducing the wall thickness of the spring, but only to a certain extent, since otherwise the hollow cylindrical spring is no longer radially pressure-resistant.
  • a monolithic multi-layer actuator which - without bias - from a metallic see or ceramic housing is sealingly enclosed.
  • the housing In order to prevent the access of leakage steam causing water vapor to the actuator surface, the housing, more precisely: the space between actuator and housing, with a water-absorbing medium and a water-transporting, electrically insulating medium, such as a silicone oil filled.
  • the invention is based first of the idea to connect the functions of the biasing spring of the actuator and the encapsulation of the actuator. This creates a complex situation in which several, mutually linked effects of the pressure and temperature behavior of the actuator unit must be taken into account.
  • the encapsulation to avoid damaging tensile stresses in low pressure operation provide at least a small mechanical biasing force, so that the PMA is held between the end plates.
  • no fluid should get between the end plates and the ceramic end faces of the PMA. Otherwise, there is the risk that particles are carried along and introduced there, which produce the required destroy rigid mechanical coupling between PMA and the end plates of the enclosure, so that the actuator unit is unusable.
  • the possibly very high external pressure must be transmitted as efficiently as possible through the wall of the cylinder spring into the interior of the actuator unit so that harmful pressure differences across the wall are avoided.
  • the inner cavity is therefore completely filled with fluid.
  • the inner space of the encapsulation must have the lowest possible compressibility, ie a high compression modulus.
  • the ceramic of the PMA is almost incompressible.
  • the cavity between the PMA and the encapsulation must be kept small and filled with a little compressible, inert, electrically insulating, but preferably good thermally conductive medium.
  • the filling medium should also have a sufficiently low shear modulus, so that the longitudinal movement of the actuator is not appreciably hampered.
  • the encapsulation must be radially sufficiently flexible so that the wall of the encapsulation can follow thermal volume changes of the filling medium, and no thermally induced deformations destroy the encapsulation.
  • the actuator unit comprises a monolithic multilayer actuator and a thin-walled metal cylinder spring whose ends are connected to an upper end plate and with a lower end plate so that mounted within the cylinder spring, itself with its end faces on the end plates supporting actuator is under a compressive bias and is hermetically sealed relative to the outer space of the actuator unit, wherein a limited by the actuator unit cavity is completely filled with an inert, electrically insulating fluid.
  • the actuator - starting from a square ceramic cross section - is designed to minimize the cavity with a cross section in the form of a regular n-corner, to come close to the ideal round cross-section. This can be done in a conventional manner by grinding.
  • the cylinder spring is formed in several parts such that an outer cylinder spring tube is frictionally connected at a first end to the upper end plate and an inner cylinder spring tube at a first end to the lower end plate, wherein between the respective second ends of these two cylinder spring tubes at least one in space between the outer cylinder spring tube and the inner cylinder spring tube extending central cylinder spring tube is fixed so that there is a Z-fold in longitudinal section, sealed against external media cylinder spring.
  • the particular advantage of this embodiment is seen in the fact that the substantial increase in the radial and axial flexibility of the cylinder spring does not have to be paid for with a corresponding increase in the cavity enclosed in the spring.
  • the number of cylinders of such a multi-layer cylinder spring is not limited to three layers, but is generally an odd integer.
  • the middle cylinder spring tube has a greater wall thickness than the outer and / or inner cylinder spring tube.
  • the middle, pressure-loaded spring for mechanical stabilization may advantageously be formed with an increased wall thickness.
  • the middle cylinder spring tube is made from a different material relative to the outer and / or inner cylinder spring tube, wherein the existing of different materials cylinder spring tubes have different thermal expansion coefficients.
  • the cylinder spring tubes frictionally interconnect by welding, soldering or gluing, the cylinder spring tubes - for improved Verbind- availability and material stress reduction - each other at their junctions have a stiffening Umfalzung or a stiffening ring , Further, it is advantageous to produce the outer, inner and middle cylinder spring tube together by simultaneous, multi-layer forming to To achieve such a narrow diameter gradation of the springs and thus a space reduction.
  • the fluid provided for the cavity comes from the classes of silicone oils, hydraulic fluids or gels. Accordingly, this embodiment directly relies on minimizing the compression and / or thermal expansion of the fluid.
  • an embodiment is advantageous in which the fluid is added to reduce the compressibility and / or the thermal expansion of a solid filler. Particularly low values can be achieved by adding to the fluid about 50% by volume of a ceramic powder which reduces compressibility and thermal expansion.
  • FIG. 2 shows a cross section of the actuator unit shown in FIG. 1,
  • FIG. 3 shows a further variant of the actuator unit according to the invention in the representation according to FIG.
  • FIG. 4 shows a variant of the embodiment shown in FIG.
  • the inventive high-pressure actuator unit shown in Figure 1 consists of a lower end plate 1 and an upper end plate 5, between which a solid-state actuator 3 under a pressure biasing force in a thin-walled metal cylinder (liner cylinder spring) 4 is welded.
  • the thin-walled metal cylinder 4 serves as a tension spring.
  • the thin-walled metal cylinder 4 and the End plates 1, 5 limited cavity 2 is completely filled by an inert, electrically insulating, temperature-stable, incompressible as possible, shear-elastic medium with low thermal expansion but good thermal conductivity.
  • Suitable fluids for this purpose are, for example, silicone oil, hydraulic fluid or a gel, in each case with or without solid-body fillers.
  • the upper end plate 5 also contains high-pressure-stable bushings for the electrical connections 6.
  • Thin-walled metal cylinders with wall thicknesses> 20 ⁇ m can be inexpensively manufactured in multiple layers by means of drawing processes in a wide range of diameters. They serve e.g. as a semi-finished product for the metal bellows and metal tube production.
  • Fluids are up to about 100 times to 500 times higher
  • FIG. 2 shows how, for example, a fairly good approximation to the ideally circular ceramic cross section can already be achieved with the illustrated regular 8-corner with outer circle diameter di ⁇ .
  • the outer circle diameter For a regular n-corner of the same surface area, the following applies for the outer circle diameter:
  • hydraulic oil typical data of pure hydraulic oil:
  • the thin-walled cylinder spring 4 (sleeve) is sufficiently mechanically biased, so that under no circumstances a
  • An additional mechanical compressive bias of the solid state actuator 3 of e.g. F 500 N, which is from the sleeve 4 e.g. to ensure emergency running properties in the event of failure of the high-pressure pump of the motor and to avoid contact loss of the end surfaces of the actuator 3 with the end plates 1, 5, generates an additional axial tensile stress in the sleeve 4 of approx.
  • the idle elongation of a piezoelectric actuator 3 in operation amounts to a maximum of about ⁇ 0 - 0.13% of its initial length. If it is clamped in the sleeve 4, then the sleeve 4 must carry out the elongation, whereby it counteracts the elongation with its spring rate (spring constant).
  • spring rate spring constant
  • the worst case operating condition of the high pressure actuator unit is when the engine is turned off hot and the fuel pressure drops to about ambient level.
  • an overpressure AF 7 sets in which in no way leads to a lifting of the end plates 1, 5 from the solid-state actuator 3. ren, since then there is a risk that particles between the bearing surfaces of the solid state actuator 3 with the end plates 1, 5 can pass, prevent its stiff mechanical coupling during operation and make the actuator unusable. Lifting off with an increase in internal pressure counteracts only the mechanical preload force.
  • the change in volume of the metal cylinder 4 corresponds to the volume change of the fluid, so that the following applies:
  • the pressure in the interior 2 reaches a value of about 20 bar when the filler was filled at room temperature without pressure.
  • F (AT) F 0 -C 0 -I- (Z 11 -AT,
  • the mechanical biasing force of the sleeve 4 is reduced by the thermal elongation of the sleeve 4 to about 160 N.
  • Void volume: V 230 mm 3 .
  • the further requirement must be met simultaneously with the requirement of a small filling volume that the filling medium behave almost incompressibly.
  • the filling medium must have a very low thermal expansion.
  • FIGS. 3 and 4 show variants of a further embodiment of a high-pressure actuator unit according to the invention.
  • the most difficult to fulfill condition of the extremely small-scale and to be filled cavity volume 2 can be weakened.
  • the reason for this lies in the almost tripled radial flexibility of the arrangement (three radially flexible cylinder walls or cylinder spring tubes 7, 8, 9 instead of one, which mediate the external pressure inward and compensate thermal volume changes of the enclosed fluid), with comparatively much less increase of the enclosed in the spring 4 cavity 2.
  • the cylinder spring 4 consists of an outer cylinder spring tube 9, a central cylinder spring tube 8 and an inner cylinder spring tube 7.
  • the outer cylinder spring tube 9 is liquid-tight welded to the upper end plate 5 and the inner cylinder spring tube 7 is at his welded in this illustration lower end to the lower end plate 1.
  • Between the upper end plate 5 and the lower end plate 1 of the PMA 3 is arranged, which via electrical Supply lines 6 can be supplied with voltage.
  • the outer cylinder spring tube 9 is connected at its lower end via a weld 10 with the lower end of the central cylinder spring tube 8.
  • the upper end of the central cylinder spring tube 8 is connected via a further weld 10 with the upper end of the inner cylinder spring tube 7.
  • the multi-part cylinder spring 4 has, as can be seen from the longitudinal section of Figure 3, a compressed Z-fold, in the inner cylinder spring tube 7, middle cylinder spring tube 8 and outer cylinder spring tube 9 are parallel to each other in cross section.
  • the PMA When a voltage is applied to the PMA 3, the PMA expands, whereby a tension force is applied to the PMA 3 by the cylinder spring 4.
  • the spring rate of the loaded on train inner cylinder spring tube 7 and the outer cylinder spring tube 9 is substantially equal to the spring rate of the pressure-loaded central cylinder spring tube 8.
  • FIG. 4 shows a variant with a built-in multi-position cylinder spring, according to which the central cylinder spring tube 8 can be made of a stronger material or with a greater material thickness in order to achieve greater stability against kinking.
  • the middle cylinder spring tube 8 is stabilized and protected against buckling under a thrust.
  • the individual hollow cylinders 7, 8, 9 can be made of different, but connectable materials.
  • Advantageous is the selection of materials with different thermal Expansion coefficient, whereby, for example, a substantial temperature stability of the pressure biasing force can be achieved, or with which an effective thermal expansion of the actuator unit can be adjusted, which is tailored to the thermal expansion of the surrounding mechanical components.
  • the wall thicknesses (for example by crimping) can be increased for improved connectability and material tension reduction, or a suitably formed thin-walled joining ring can be used.
  • the cylinders 7, 8, 9 are formed in a narrow diameter graduation and interlocked or pulled together thinly as a multi-layer structure or hydraulically deformed.
  • the number of cylinders 7, 8, 9 of a multi-layer cylinder spring is not limited to three layers, but is generally an odd integer.
  • the electrical connections electrically insulating, hermetically sealed and high pressure resistant out of the enclosure out to the outside. This can e.g. by
  • Metallkeramik- or metal glass elements (ceramic or glass-coated contact pins), which are suitably used in a metal lid (end plate) guaranteed.

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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)

Abstract

L'invention a pour objet de permettre à une unité d'actionnement qui consiste en un ressort cylindrique (4) en métal et un actionneur (3) disposé de façon hermétique dans celui-ci, d'être exposée à du carburant sous une pression pouvant atteindre 2000 bar. A cet effet, la cavité (2) formée dans l'unité d'actionnement est remplie en intégralité d'un fluide inerte. En fonction d'une compressibilité - la plus petite possible - déterminée et d'une dilatation thermique déterminée du fluide, le volume de la cavité (2) est maintenu si petit que les contraintes qui interviennent dans la matière à l'intérieur du ressort cylindrique (4) ne dépassent pas les limites de contrainte malgré les exigences de pression et de température.
PCT/EP2007/052713 2006-03-23 2007-03-21 Unité d'actionnement pour soupape d'injection haute pression WO2007107595A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102006013511A DE102006013511A1 (de) 2006-03-23 2006-03-23 Aktoreinheit für ein Hochdruckeinspritzventil
DE102006013511.3 2006-03-23

Publications (1)

Publication Number Publication Date
WO2007107595A1 true WO2007107595A1 (fr) 2007-09-27

Family

ID=38197900

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2007/052713 WO2007107595A1 (fr) 2006-03-23 2007-03-21 Unité d'actionnement pour soupape d'injection haute pression

Country Status (2)

Country Link
DE (1) DE102006013511A1 (fr)
WO (1) WO2007107595A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008018342A1 (de) * 2008-04-11 2009-10-15 Robert Bosch Gmbh Piezoaktormodul für eine von einem Medium umströmte Anordnung

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0794799A (ja) * 1993-09-21 1995-04-07 Nikon Corp 積層型電気・歪変換素子およびその製造方法
EP0977285A1 (fr) * 1998-07-30 2000-02-02 Siemens Aktiengesellschaft Charge de pression pour actuateur piezoélectrique
DE19908471A1 (de) * 1999-02-26 2000-09-14 Siemens Ag Hohlzylindrische Feder
DE10211107A1 (de) * 2001-07-12 2003-02-13 Ceramtec Ag Monolithischer Vielschichtaktor in einem Gehäuse
DE102005046178B3 (de) * 2005-09-27 2006-11-16 Siemens Ag Zylinderfeder
DE102005029470B3 (de) * 2005-06-24 2006-12-14 Siemens Ag Verfahren zur Herstellung eines Piezo-Vielschicht-Aktors

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19941044A1 (de) * 1999-08-28 2001-03-22 Bosch Gmbh Robert Piezoelektrischer Keramikkörper
DE10048430A1 (de) * 2000-09-29 2002-04-25 Bosch Gmbh Robert Piezoelektrischer Aktor
DE10237587B4 (de) * 2002-08-16 2012-09-20 Robert Bosch Gmbh Verfahren zur Herstellung eines Piezoaktors
DE10245109A1 (de) * 2002-09-27 2004-04-08 Siemens Ag Injektor, insbesondere Kraftstoff-Einspritzventil, mit einem piezoelektrischen Aktor

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0794799A (ja) * 1993-09-21 1995-04-07 Nikon Corp 積層型電気・歪変換素子およびその製造方法
EP0977285A1 (fr) * 1998-07-30 2000-02-02 Siemens Aktiengesellschaft Charge de pression pour actuateur piezoélectrique
DE19908471A1 (de) * 1999-02-26 2000-09-14 Siemens Ag Hohlzylindrische Feder
DE10211107A1 (de) * 2001-07-12 2003-02-13 Ceramtec Ag Monolithischer Vielschichtaktor in einem Gehäuse
DE102005029470B3 (de) * 2005-06-24 2006-12-14 Siemens Ag Verfahren zur Herstellung eines Piezo-Vielschicht-Aktors
DE102005046178B3 (de) * 2005-09-27 2006-11-16 Siemens Ag Zylinderfeder

Also Published As

Publication number Publication date
DE102006013511A1 (de) 2007-09-27

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