EP1656499A1 - Einspritzventil mit kapazitivem ventilhubsensor - Google Patents
Einspritzventil mit kapazitivem ventilhubsensorInfo
- Publication number
- EP1656499A1 EP1656499A1 EP04742011A EP04742011A EP1656499A1 EP 1656499 A1 EP1656499 A1 EP 1656499A1 EP 04742011 A EP04742011 A EP 04742011A EP 04742011 A EP04742011 A EP 04742011A EP 1656499 A1 EP1656499 A1 EP 1656499A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- valve
- needle
- nozzle
- injector
- injection valve
- Prior art date
- Legal status (The legal status 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 status listed.)
- Withdrawn
Links
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
- F02M65/00—Testing fuel-injection apparatus, e.g. testing injection timing ; Cleaning of fuel-injection apparatus
- F02M65/005—Measuring or detecting injection-valve lift, e.g. to determine injection timing
Definitions
- the invention relates to an injection valve with a capacitive valve lift sensor for internal combustion engines.
- needle lift sensors For the purpose of detecting the actual movement of the valve needle, needle lift sensors have become known in recent years which are non-contact, for example on the
- a needle stroke sensor with limited monitoring options in the form of a needle tip / valve seat contact switch is known, the two switching positions tion are correlated with the times of closing or opening of the valve needle, so that the actual injection duration, but not the exact injection course or the actual injection quantity, can be measured.
- Seat contact switches also require good electrical contact between the tip of the valve needle and the valve seat in the closed position, i.e. when the valve needle hits the valve seat, while newer efforts tend to reduce the high impact stresses in operation.
- the invention is therefore based on the object of realizing a valve of the type specified at the outset as an injection valve, in particular as a piezo injector.
- an injection valve of the type mentioned at the outset that there is an electrically conductive injector body connected to the circuit, on which a nozzle body with a valve seat is formed, and that the closure member is designed as a valve needle, which on its side Valve seat opposite, valve-facing end surface is connected to the circuit.
- the invention is based on the premise of a valve needle which, apart from an electrical contact point at the end opposite the valve seat, is completely insulated from the nozzle body (housing).
- Valve needle and housing form a capacitor.
- the movement of the valve needle changes the distance between the tip of the valve needle and the valve seat, while the distance between the needle guide and the housing remains constant.
- the valve needle and nozzle body are both electrically conductive and in particular by an insulating de layer are separated from one another, they fulfill the characteristic of a capacitor with a variable capacitance value, the capacitance being indirectly proportional to the distance between the valve seat and valve needle tip.
- the voltage connection of the capacitor circuit is carried out via a conductor which is insulated in an axial bore in the injector body and which is connected to an electrically conductive contact spring which is arranged insulated in the injector body which is supported in a contact-making manner on the underside of the head of a conductive injector piston which is pressed in a contact-making manner against the end face of the valve needle facing away from the valve.
- the injector body is designed as an intermediate disk above the end face of the valve needle facing away from the valve, and that an electrically conductive contact part for the electrical connection between the conductor and the contact spring is provided on the side of the intermediate disk facing away from the valve is electrically insulated from the injector body and the washer and on which the contact spring is supported with its valve-side end. It is also advantageous to provide a seal at the beginning and end of the axial bore.
- a nozzle holding spring which is arranged in an electrically insulated manner in the injector body and which presses the valve needle against the valve seat, where the nozzle holding spring is supported with an end facing away from the valve on an adjusting disk, which is electrically connected to a further connection contact, and is supported on the valve side on a conductive injector piston which is pressed in a contacting manner against the end face of the valve needle facing away from the valve.
- the electrical insulation can be ensured or improved in a simple manner, in that in particular the valve needle and the injector piston have an insulating layer on at least part of the surfaces which are not used for contacting.
- the capacitive valve lift sensor can advantageously be integrated in that the injector body is designed as an intermediate disk above the end face of the valve needle facing away from the valve and that an axial annular shoulder is formed on the end face of the valve needle, which shoulder shoulder is formed on the underside of the intermediate disk Counter shoulder is assigned as a stop surface, wherein the underside of the washer can be provided with an insulating layer at least in the region of the stop surface.
- valve lift present in each case is ascertainable by measuring the voltage U- ⁇ dropping at the valve seat (R 2 + C va r), the operating voltage being voltage U B an AC voltage is applied.
- the change in the complex resistance R 2 + C var is measured in a predetermined time window in order to determine the position of the nozzle needle or the valve lift.
- the insulating layers can preferably be formed, at least in places, as diamond-like-carbon (DLC) or aluminum oxide or as a zirconium oxynitrite layer which, in addition to its insulating properties, is distinguished by high abrasion resistance and resistance to impact and does not move due to the movement of the corresponding parts Friction inhibits.
- DLC diamond-like-carbon
- aluminum oxide aluminum oxide
- zirconium oxynitrite layer which, in addition to its insulating properties, is distinguished by high abrasion resistance and resistance to impact and does not move due to the movement of the corresponding parts Friction inhibits.
- the valve stroke H of the nozzle needle present can be determined by measuring the voltage falling across the complex resistor R 2 + C var , an AC voltage being applied as the operating voltage U B and the complex resistor being essentially formed between the nozzle needle and the nozzle body.
- the axial position of the nozzle needle depends on the determined capacity and the resistance between the injector body and at least one valve part.
- the point in time at which the nozzle needle is lifted off the valve seat depends on the determined change in the capacity between the nozzle needle and the nozzle body and can be determined in particular by the determined reduction in capacity.
- the wear of the insulating layer between the nozzle needle and the nozzle body depends on the determined ohmic resistance between the nozzle needle and the nozzle body, a reduction in the resistance (R 2 ) preferably being associated with increased wear.
- FIG. 1 schematically shows a longitudinal section through the part of an injection valve on the nozzle side according to the invention
- FIG. 2 shows another embodiment of an injection valve according to the invention in the illustration according to FIG. 1,
- Figure 3 is an electrical equivalent circuit diagram of the capacitor circuit used for the capacitive determination of the valve lift.
- FIG. 1 shows in longitudinal section, for example, a piezoelectrically driven injection valve which, together with other piezo injectors, can be connected in a manner known per se to a central pressure accumulator (common rail) for diesel fuel, not shown, and its electrical actuation by means of an external one Control unit (ECU) takes place.
- the piezo actuator itself is usually located in the upper part of the injector body 14, which is not shown here.
- the lower part of the injection valve shown is mainly made of electrically conductive materials and is preferably rotationally symmetrical with respect to the valve axis 1. It has a nozzle body 2, at the nozzle opening 3 of which a valve seat 4 is formed, on which a valve needle 5 is seated.
- the upper section of valve needle 5, which is enlarged in cross-section, is guided closely in nozzle body 2, an insulating layer 22 r, however, providing abrasion-resistant and low-friction insulation between this section of valve needle 5 and nozzle body 2.
- a high-pressure fuel via an inlet, not shown
- Pressure chamber 13 is provided, from which the supply of fuel can take place along the valve needle 5, via the valve seat 4, to the nozzle opening 3.
- sufficient electrical insulation to the nozzle body 2 is normally already provided along the lower section of the valve needle 5.
- the upper end face of the valve needle 5 borders on an intermediate disk 6, which, together with the narrow guidance of the valve needle 5, in this embodiment separates a valve-side high-pressure region of the fuel injection valve from a low-pressure region located above it and the others with those arranged above and below it Areas of the nozzle body 2 and the injector body 14 is conductively connected.
- a spring space 7, which is open at the end and in which a nozzle holding spring 8 is arranged, is recessed in the injector body 14.
- the nozzle holding spring 8 is supported downwards on the upper side of an injector piston 9 designed as a T-piece, which is guided through a bore in the intermediate piece 6 and with it
- the nozzle holding spring 8 is supported on an adjusting disk 10 which is insulated from the injector body 14 and is electrically connected by a bore leading outwards to a connection contact 11 insulated from the injector body 14.
- a control piston 12 is guided axially through the nozzle holding spring 8 and presses with one end surface on the upper side of the injector piston 9 and extends with the opposite end into the upper part of the injection valve.
- the mode of operation of this construction is based on the fact that, as long as the injector is not actuated, the high fuel pressure is simultaneously applied to the tip of the valve needle 5 and in one to the upper end face of the control piston 12. orderly control room is present there, because of the larger area, but expresses itself with a greater effective pressure force and thus closes the valve. If the injector is actuated, the expanding piezo actuator opens a fuel return from the control chamber, as a result of which the pressure at the tip of the valve needle 5 becomes overweight, pushes the valve needle 5 upward and opens the nozzle valve. In principle, however, other designs are also possible according to the invention in which a piezo actuator or a solenoid valve is energized when the valve is closed.
- the cross section of the upper section of the valve needle 5 is somewhat larger than the cross section of the bore provided in the intermediate disk 6 for the injector piston 9.
- an axial ring shoulder is formed on the upper end surface of the valve needle 5, which is assigned a counter shoulder formed on the underside of the intermediate disk 6 as a stop surface.
- FIG. 2 shows an embodiment of the injection valve according to the invention which differs in contact from the embodiment shown in FIG. 1.
- the voltage connection takes place via a connection 15 and an axial bore 19 in the injector body 14, through which an insulated conductor (wire) 16 is guided.
- an electrically conductive contact part 18 is incorporated, which is electrically insulated from the intermediate disk 6 and the injector body 14, for example by an insulating insert, and has a fixed electrical connection to the conductor 16.
- An electrically conductive contact spring 17 is supported on the contact part 18, which is supported at its other end on the underside of the head of the injector piston 9 and thus transfers the voltage to the injector piston 9.
- the injector piston 9 is electrically decoupled and to reduce the parasitic capacitances with respect to the control piston 12 on the head surface and the side surfaces of the head with an electrically risch insulating layer 21 provided.
- the voltage is passed to the valve needle 5 (which is laterally insulated to the nozzle body 2) via the valve-side end of the stroke adjustment bolt 9.
- Advantages of this contacting variant are the simpler installation in the engine compartment and the possibility of continuing the connection 15 in the injection valve upwards and thus in particular creating an electrical connection to the plug of the piezo actuator.
- the bore 19 should, as shown, be sealed from the inside to the outside and from the outside to the inside by means of a seal 20 in order to avoid the penetration of foreign substances or a loss of pressure.
- the nozzle needle 5 and the injector body 14 (housing) of the described injection valve form a capacitor connected in a circuit, which acts as a capacitive valve lift sensor as follows:
- the nozzle body 2 is connected to ground potential and the connection contact 11 is connected via a series resistor R before to a voltage source U B.
- the drop in voltage U ⁇ nj at R 2 + C var is measured directly and for evaluation, z. B. used as part of a central control unit (ECU).
- the voltage U B is fed to the adjusting disk 10 of the nozzle holding spring 8 or the connection 15 and, depending on the contact variant, is passed on to the valve needle 5. It should be noted that all current-carrying parts apart from the contact points are sufficiently well insulated from the nozzle body 2.
- a sputtered diamond-like-carbon (DLC) - or an aluminum oxide or a zirconium oxynitrite layer which has a high abrasion resistance and a low electrical conductivity and is therefore also suitable as an insulation layer, even if leakage currents cannot be excluded .
- An insulating layer must in particular which are provided at the locations of the shim 10 and the stroke adjustment bolt 9, at which there is a narrow guide to the nozzle body 2. With this insulating layer, it is also advantageous if it also has a very low coefficient of friction, which guarantees good running properties of the moving parts.
- the electrical equivalent circuit diagram shown in FIG. 3 also makes the resistance conditions in the injector clear and shows the simple structure of the measuring circuit with the voltage source U B , the capacitor C var and the resistor R VOr -R 2 connected in series with C var is the ohmic resistance component, C var is the corresponding capacitive reactive component between the nozzle needle and the valve seat.
- R IS0 denotes the insulation resistance of the insulating layer and R FG the contact resistance between the guidance of the valve needle 5 and the nozzle body 2.
- R 2 «(Riso + R FG ) applies.
- C var and R 2 essentially represent the complex resistance between the Valve seat is represented by the nozzle needle tip 4 and the associated inside of the nozzle body 2.
- the operating voltage U B is designed as an alternating voltage.
- the total stroke of the valve needle 5 can be, for example, 100-250 ⁇ .
- the electrical evaluation can also be based on another electrical principle or also in
- Combination with a suitable coil can be realized by detuning the resonance frequency.
- the electrical evaluation must take into account the fact that the relatively small changes in capacitance to be measured are also due to capacitances connected in parallel, cf. C
- the position of the valve needle 5 can be detected in a direct manner with relatively simple means, in particular without major mechanical outlay.
- a control chain can also be built, which uses a few arithmetic steps to infer the actual injection quantity from the measured values, compares this with the setpoints predefined according to the operating mode, and adjusts the control parameters accordingly by evaluating the differences.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Fuel-Injection Apparatus (AREA)
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE10338489A DE10338489B3 (de) | 2003-08-21 | 2003-08-21 | Einspritzventil mit kapazitivem Ventilhubsensor |
PCT/EP2004/051658 WO2005021958A1 (de) | 2003-08-21 | 2004-07-29 | Einspritzventil mit kapazitivem ventilhubsensor |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1656499A1 true EP1656499A1 (de) | 2006-05-17 |
Family
ID=33441796
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP04742011A Withdrawn EP1656499A1 (de) | 2003-08-21 | 2004-07-29 | Einspritzventil mit kapazitivem ventilhubsensor |
Country Status (4)
Country | Link |
---|---|
US (1) | US7055762B2 (de) |
EP (1) | EP1656499A1 (de) |
DE (1) | DE10338489B3 (de) |
WO (1) | WO2005021958A1 (de) |
Families Citing this family (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2006008728A1 (en) * | 2004-07-20 | 2006-01-26 | Mazrek Ltd. | Needle-spring locking device for pump-injector (injector) for internal combustion engines |
DE102004052005A1 (de) * | 2004-10-25 | 2006-05-11 | Raziol Zibulla & Sohn Gmbh | Vorrichtung und Verfahren zum Aufbringen eines flüssigen bis pastösen Mediums auf eine Werkstückoberfläche |
DE102005049259B3 (de) * | 2005-10-14 | 2007-01-04 | Siemens Ag | Ventilvorrichtung |
KR100706555B1 (ko) * | 2006-04-20 | 2007-04-13 | 현대자동차주식회사 | 디젤엔진 인젝터 |
JP5472204B2 (ja) * | 2011-05-27 | 2014-04-16 | 株式会社日本自動車部品総合研究所 | インジェクタ状態検出装置 |
DE102012223149B4 (de) * | 2012-12-14 | 2017-09-14 | Continental Automotive Gmbh | Injektor sowie Verfahren zum Steuern oder Regeln eines Injektors |
ITMI20130835A1 (it) * | 2013-05-22 | 2014-11-23 | Metrel S P A | Attrezzatura modulare, particolarmente per il controllo delle sedi delle valvole ricavate nelle teste dei motori a combustione interna. |
DE102014202136B4 (de) | 2013-09-19 | 2019-03-07 | Continental Automotive Gmbh | Verfahren und Vorrichtung zur Detektion von Betriebszuständen eines elektromagnetisch angetriebenen Gerätes |
FR3013080A1 (fr) * | 2013-11-12 | 2015-05-15 | Delphi Technologies Holding | Injecteur de carburant |
FR3024183B1 (fr) * | 2014-07-22 | 2019-07-26 | Delphi Technologies Ip Limited | Injecteur de carburant |
GB201511007D0 (en) * | 2015-06-23 | 2015-08-05 | Delphi Int Operations Lux Srl | Nozzle assembly with adaptive closed signal |
FR3043144B1 (fr) * | 2015-10-29 | 2019-08-02 | Delphi Technologies Ip Limited | Injecteur de carburant |
DE102015225733A1 (de) * | 2015-12-17 | 2017-06-22 | Robert Bosch Gmbh | Kraftstoffeinspritzdüse |
DE102016203822B4 (de) * | 2016-03-09 | 2017-12-07 | Robert Bosch Gmbh | Kraftstoffeinspritzventil |
US20190120188A1 (en) | 2016-04-01 | 2019-04-25 | Delphi Technologies Ip Limited | Fuel injector |
GB2549095A (en) * | 2016-04-04 | 2017-10-11 | Delphi Int Operations Luxembourg Sarl | Fuel injector |
FR3050771B1 (fr) * | 2016-04-29 | 2018-06-01 | Delphi Technologies Ip Limited | Injecteur de carburant |
FR3092625B1 (fr) * | 2019-02-07 | 2021-04-16 | Delphi Tech Ip Ltd | Ensemble guide haut |
GB2585196B (en) * | 2019-07-01 | 2021-10-27 | Delphi Tech Ip Ltd | Method and system to determine the state of needle valve of a fuel injector |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2305114A1 (de) * | 1973-02-02 | 1974-08-08 | Bosch Gmbh Robert | Kraftstoffeinspritzduese fuer brennkraftmaschinen |
IT1050083B (it) * | 1974-12-21 | 1981-03-10 | Cav Ltd | Ugelli di iniezione di combustibile |
GB1586254A (en) * | 1977-06-22 | 1981-03-18 | Lucas Industries Ltd | Fuel injection nozzle unit for supplying fuel to an internal combustion engine |
US4397180A (en) * | 1979-10-25 | 1983-08-09 | Wolff George D | Valve position sensor for a poppet fuel injector valve |
US4359895A (en) * | 1979-10-25 | 1982-11-23 | Wolff George D | Needle position indicator for a fuel injector nozzle holder |
DE3117779A1 (de) * | 1981-05-06 | 1982-11-25 | Robert Bosch Gmbh, 7000 Stuttgart | "kraftstoff-einspritzduese fuer brennkraftmaschinen" |
JPS6085248A (ja) * | 1983-10-18 | 1985-05-14 | Diesel Kiki Co Ltd | 燃料噴射弁 |
US4573349A (en) * | 1984-06-28 | 1986-03-04 | International Harvester Company | Needle position indicator for a fuel injection nozzle holder |
DE19751661C2 (de) * | 1997-11-21 | 2000-08-03 | Daimler Chrysler Ag | Kapazitive Meßeinrichtung |
DE19830667C2 (de) * | 1998-07-09 | 2002-10-31 | Daimler Chrysler Ag | Vorrichtung zur Bestimmung der Öffnungs- und Schließzeitpunkte eines Gaswechselventiles |
DE19830674A1 (de) * | 1998-07-09 | 2000-01-13 | Beiersdorf Ag | Klebeband und seine Verwendung |
-
2003
- 2003-08-21 DE DE10338489A patent/DE10338489B3/de not_active Expired - Fee Related
-
2004
- 2004-07-29 EP EP04742011A patent/EP1656499A1/de not_active Withdrawn
- 2004-07-29 WO PCT/EP2004/051658 patent/WO2005021958A1/de not_active Application Discontinuation
- 2004-07-29 US US10/533,812 patent/US7055762B2/en not_active Expired - Fee Related
Non-Patent Citations (1)
Title |
---|
See references of WO2005021958A1 * |
Also Published As
Publication number | Publication date |
---|---|
WO2005021958A1 (de) | 2005-03-10 |
US7055762B2 (en) | 2006-06-06 |
US20050269422A1 (en) | 2005-12-08 |
DE10338489B3 (de) | 2004-12-16 |
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Designated state(s): DE FR GB IT |
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RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: WONESCH, JOERG Inventor name: NEUMAIER, MARTIN Inventor name: GERBER, WOLFGANG Inventor name: LEUTERITZ, UWE |
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