EP1167751A1 - Injecteur de combustible - Google Patents

Injecteur de combustible Download PDF

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Publication number
EP1167751A1
EP1167751A1 EP01112756A EP01112756A EP1167751A1 EP 1167751 A1 EP1167751 A1 EP 1167751A1 EP 01112756 A EP01112756 A EP 01112756A EP 01112756 A EP01112756 A EP 01112756A EP 1167751 A1 EP1167751 A1 EP 1167751A1
Authority
EP
European Patent Office
Prior art keywords
injector
fuel
retainer
nozzle
contact surface
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Withdrawn
Application number
EP01112756A
Other languages
German (de)
English (en)
Inventor
Jean-Francois Berlemont
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Delphi Technologies Inc
Original Assignee
Delphi Technologies Inc
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 Delphi Technologies Inc filed Critical Delphi Technologies Inc
Publication of EP1167751A1 publication Critical patent/EP1167751A1/fr
Withdrawn legal-status Critical Current

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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
    • F02M55/00—Fuel-injection apparatus characterised by their fuel conduits or their venting means; Arrangements of conduits between fuel tank and pump F02M37/00
    • F02M55/002—Arrangement of leakage or drain conduits in or from injectors

Definitions

  • the present invention relates to fuel injectors and particularly to fuel injectors for diesel engines.
  • Fuel injectors are well known in association with diesel engines. They are used to inject fuel into a combustion chamber of the engine. Such fuel injectors generally comprise a nozzle body, which is connected to an injector body by means of a retainer. A fuel delivery passage extends from a fuel pump through the injector body and nozzle body to a nozzle cavity arranged in the nozzle body. The tip of the nozzle body has at least one nozzle orifice so that fuel can be injected from the nozzle cavity into the combustion chamber.
  • a valve needle is slideably movable in an axial central bore arranged in the nozzle body. An axial central bore of the injector body houses an actuator for actuating the valve needle, so as to open or close the nozzle orifice to either allow or prohibit fuel flow into the combustion chamber.
  • the nozzle body has an upper contact surface, which is pressed against a lower contact surface of the injector body.
  • the two bodies are aligned such that the fuel delivery passage is formed by two channels, one arranged in each of the bodies. Due to the high pressure of the fuel flowing through the fuel delivery passage, the connection point of the two channels is a potential leakage point. Generally, leakage is prevented by means of a retainer, which maintains the lower contact surface of the injector body and the upper contact surface of the nozzle body in compressive butting relationship. As the injection pressure of the fuel is increased, the compression force on the contact surfaces between injector body and nozzle body also needs to be increased in order to prevent leakage.
  • the trend in the automobile industry is to use lighter and smaller components.
  • the smaller the diameter of the fuel injector the smaller the contact surfaces of injector body and nozzle body surrounding the fuel delivery passage, and hence the greater the risk of leakage.
  • the object of the present invention is to provide a fuel injector which does effectively prevent leakage of fuel out of the fuel injector, and which does not significantly increase the manufacturing costs.
  • the present invention provides a fuel injector comprising an injector body, a nozzle body and a retainer for connecting the nozzle body to the injector body.
  • the nozzle body comprises a fuel channel extending from an upper contact surface of the nozzle body to at least one nozzle orifice.
  • the injector body comprises a low-pressure drain and a fuel channel extending from an upper part of the injector body to a lower contact surface of the injector body.
  • the retainer holds the lower contact surface of the injector body and the upper contact surface of the nozzle body in compressive butting relationship in such a way that the fuel channel of the nozzle body and the fuel channel of the injector body form a fuel delivery passage.
  • At least one drain channel extends from the retainer to the low-pressure drain arranged in the injector body.
  • the drain channel leads the leaked fuel from between the inner walls of the retainer and the outer walls of the injector body and/or nozzle body to the low-pressure drain, from where it can easily be evacuated.
  • the low-pressure drain is present in state of the art injectors, for evacuating excess fuel being pushed up in between the nozzle body and a valve needle arranged therein.
  • a fuel return passage comprising the drain channel and the low-pressure drain is formed. As the leaked fuel can now easily evacuate through the fuel return passage, leakage of fuel out of the fuel injector is prevented. No fuel is leaked into the atmosphere or into the cylinder head oil. Furthermore, due to the fuel return passage, it is not necessary to provide the contact surfaces of injector body and nozzle body with a better and more complex surface finish. The fuel injector can hence be manufactured without any significant increase of manufacturing costs.
  • one or more intermediate bodies can be arranged between the injector body and the nozzle body, each intermediate body comprising a fuel channel extending from an upper contact surface of the intermediate body to a lower contact surface of the intermediate body.
  • the drain channel still leads the leaked fuel from between the inner walls of the retainer and the outer walls of the injector body and/or nozzle body and/or injector body to the low-pressure drain, from where it can easily be evacuated.
  • the nozzle body comprises a valve needle and the injector body e.g. comprises an axial bore therethrough for receiving an actuation means for actuating the valve needle.
  • the axial bore can have the low-pressure drain arranged therein, whereby no additional bore needs to be arranged in the injector body.
  • the at least one drain channel most advantageously comprises a groove arranged in the lower contact surface of the injector body and/or in the upper contact surface of the nozzle body. If applicable, a groove can be arranged in the lower and/or upper contact surface of the intermediate body.
  • the drain channel can in this way be most economically produced as it is not necessary to provide the drain channel with a high quality finish.
  • the at least one drain channel may comprise a bore arranged through the injector body and/or through the nozzle body and/or through the intermediate body, thereby linking any part of the inner wall of the retainer with the low-pressure drain in the injector body.
  • an upper part of the retainer forms with a lower part of the injector body a sealing connection. It is thereby ensured that no fuel can leak into the atmosphere or into the cylinder head oil.
  • the sealing connection is advantageously formed through a closely wound thread on the retainer and a corresponding thread on the injector body. Such a thread provides a self-sealing connection.
  • the sealing connection can also be formed through a sealant applied between the retainer and the injector body.
  • the sealant can e.g. comprise an adhesive, whereby the retainer is securely connected to the injector body while at the same time ensuring that no fuel can leak into the atmosphere or into the cylinder head oil.
  • Fig.1 shows a section through a fuel injector 10 according to the invention.
  • the fuel injector 10 comprises an injector body 12 having an axial bore 14 therethrough and a nozzle body 16 having an axial bore 18 therethrough.
  • the injector body 12 and the nozzle body 16 each comprise a fuel channel 20, 22 for delivering fuel from a fuel pump (not shown) to a nozzle cavity 24 arranged around the axial bore 18 in the nozzle body 16.
  • the fuel can then flow from the nozzle cavity 24 through the axial bore 18 and at least one nozzle orifice 26 arranged in the tip of the nozzle body 16 into a combustion chamber of an engine (not shown).
  • the nozzle orifice 26 can be blocked by means of a valve needle 28 which is slideably mounted in the axial bore 18 of the nozzle body 16.
  • the diameter of a lower part 30 of the valve needle 28 is smaller than the diameter of the axial bore 18.
  • the diameter of an upper part 32 of the valve needle 28 is essentially the same as the diameter of the axial bore 18.
  • the valve needle 28 is actuated by means of an actuator 34 arranged in the axial bore 14 of the injector body 12.
  • the diameter of the actuator 34 is smaller than the diameter of the axial bore 14 of the injector body 12 so as to form a low-pressure drain 36 in the axial bore 14.
  • the low-pressure drain 36 is present in state of the art injectors, for evacuating excess fuel being pushed up in between the nozzle body 16 and the valve needle 28.
  • the injector body 12 has a lower contact surface 38 which is held in compressive butting relationship with an upper contact surface 40 of the nozzle body 16 by means of a retainer 42.
  • the lower contact surface 38 of the injector body 12 comprises a groove therein, which extends from an inner wall of the retainer 42 to the axial bore 14, thereby forming a drain channel 44.
  • An upper part of an internal wall of the retainer 42 comprises an internal thread which engages a corresponding external thread on an outer wall of the injector body 12, whereby the nozzle body 16 and the injector body 12 can be held together by simple relative rotation of the retainer 42 with respect to the injector body 12.
  • the thread is closely wound, so that it provides a self-sealing connection 46 between the retainer 42 and the injector body 12.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fuel-Injection Apparatus (AREA)
EP01112756A 2000-06-20 2001-05-25 Injecteur de combustible Withdrawn EP1167751A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
LU90604 2000-06-20
LU90604A LU90604B1 (en) 2000-06-20 2000-06-20 Fuel injector

Publications (1)

Publication Number Publication Date
EP1167751A1 true EP1167751A1 (fr) 2002-01-02

Family

ID=19731914

Family Applications (1)

Application Number Title Priority Date Filing Date
EP01112756A Withdrawn EP1167751A1 (fr) 2000-06-20 2001-05-25 Injecteur de combustible

Country Status (2)

Country Link
EP (1) EP1167751A1 (fr)
LU (1) LU90604B1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1255039A3 (fr) * 2001-05-03 2004-05-26 Siemens Aktiengesellschaft Injecteur de combustible
EP1757802A3 (fr) * 2005-08-26 2007-03-28 Robert Bosch Gmbh Dispositif de carburant à haute pression
US10578083B2 (en) 2015-05-07 2020-03-03 Volvo Truck Corporation Fuel pump assembly

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995024551A1 (fr) * 1994-03-08 1995-09-14 Man B & W Diesel A/S Injecteur de carburant, et moteur a gaz haute pression muni dudit injecteur
DE19608575A1 (de) * 1996-03-06 1997-09-11 Bosch Gmbh Robert Kraftstoffeinspritzventil für Brennkraftmaschinen

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995024551A1 (fr) * 1994-03-08 1995-09-14 Man B & W Diesel A/S Injecteur de carburant, et moteur a gaz haute pression muni dudit injecteur
DE19608575A1 (de) * 1996-03-06 1997-09-11 Bosch Gmbh Robert Kraftstoffeinspritzventil für Brennkraftmaschinen

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1255039A3 (fr) * 2001-05-03 2004-05-26 Siemens Aktiengesellschaft Injecteur de combustible
EP1757802A3 (fr) * 2005-08-26 2007-03-28 Robert Bosch Gmbh Dispositif de carburant à haute pression
US10578083B2 (en) 2015-05-07 2020-03-03 Volvo Truck Corporation Fuel pump assembly

Also Published As

Publication number Publication date
LU90604B1 (en) 2001-12-21

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