DE19914714C2 - Injector for storage fuel injection systems - Google Patents

Injector for storage fuel injection systems

Info

Publication number
DE19914714C2
DE19914714C2 DE1999114714 DE19914714A DE19914714C2 DE 19914714 C2 DE19914714 C2 DE 19914714C2 DE 1999114714 DE1999114714 DE 1999114714 DE 19914714 A DE19914714 A DE 19914714A DE 19914714 C2 DE19914714 C2 DE 19914714C2
Authority
DE
Germany
Prior art keywords
injector
control module
welding
head
injector head
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.)
Expired - Fee Related
Application number
DE1999114714
Other languages
German (de)
Other versions
DE19914714A1 (en
Inventor
Wilhelm Frank
Claus Zumstrull
Karen Schorn
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.)
Continental Automotive GmbH
Original Assignee
Siemens AG
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 AG filed Critical Siemens AG
Priority to DE1999114714 priority Critical patent/DE19914714C2/en
Publication of DE19914714A1 publication Critical patent/DE19914714A1/en
Application granted granted Critical
Publication of DE19914714C2 publication Critical patent/DE19914714C2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M47/00Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure
    • F02M47/02Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure of accumulator-injector type, i.e. having fuel pressure of accumulator tending to open, and fuel pressure in other chamber tending to close, injection valves and having means for periodically releasing that closing pressure
    • F02M47/027Electrically actuated valves draining the chamber to release the closing pressure
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M61/00Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/16Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
    • F02M61/168Assembling; Disassembling; Manufacturing; Adjusting

Description

The invention relates to an injector for fuel Accumulator injection systems in the preamble of the patent pronoun 1 referred to. Such an arrangement is generally known.

For the fuel supply of internal combustion engines memory injection systems are increasingly used in de very high injection pressures are used. Such Injection systems are common rail systems (for diesel engines gates) and HPDI injection systems (for gasoline engines). With these injection systems, the fuel is supplied with a High pressure pump in a common to all cylinders of the engine men pressure accumulator, from which the so-called In ejectors on the individual cylinders. The In jector essentially consists of the three separate elements injector head, control module and injector body. The injek The door body contains an injection valve with an injection nozzle se, for example from conventional injection technology nik is known for diesel engines. The control module is a Control valve with a control piston that opens and Closing the injector controls. Is in the injector head a control unit for the control module, which an electric or allows electromagnetic control of the control module.

The three parts injector head, control module and injector bodies are consecutive in the axial direction of the injector arranged; they usually meet at flat interfaces together. All three parts contain functional ones  Units lines for the fuel passing through the border areas between the individual elements of one element lead to the other. To these through lines at the high fuel pressures prevailing in these areas The interfaces are to seal one another and to the outside between the elements of the injector as flat surfaces forms that are worked very precisely. The parts and thus the flat surfaces are used to ensure the sealing effect, compressed with a given force.

Holding the parts of the injector together and opening Up to now, the flat surfaces have usually been pressed together by screwing, e.g. B. with a union nut, the Ele elements of the injector and axially prestressed against each other, what z. B. is known from DE 195 19 191. Need screw connections However, there is a lot of space in the installation area of the However, injectors are extremely scarce.

DE 198 43 915 A1 shows a component connection for a high pressure transition, especially in injection valves, in which at least two cylindrical components of a zy lindrian hollow body are enclosed, the one under a certain tensile stress. The tensile stress is thereby applied that the hollow body initially with the first construction part is connected. Then the hollow body is under tension set and then connected to the second component the. DE 197 12 589 C1 is still a fuel injection valve and a method for producing a Valve needle of such a fuel injector is known. This document discloses a fixed connection of the housing share this valve by means of a sleeve-shaped Ventilman means and by means of a laser-generated weld.

The object of the invention is therefore to the aforementioned ten injector and the process for its manufacture design that the elements of the injector save space and can be safely connected to each other without adverse effects on the tightness of the flat surfaces surrender.

This object is achieved with the in the patent claim 1 or ge specified in claim 5 features solves. Advantageous refinements of the invention ejectors or the manufacturing method according to the invention are described in the respective subclaims.

The injector according to the invention is accordingly characterized records that the connection of injector head, control module and injector body by means of a welding sleeve to which Injector head and injector body are welded, and that the injector head on its forehead facing the injector body surface is provided with an annular groove into which one end of the  Welding sleeve is inserted, the welding between welding sleeve and injector head is designed in such a way that the melting of the material of the welding sleeve and the Injector head only on the outside of the welding sleeve and on the apron surrounding the ring groove on the outside.

In this way it is achieved that the constructive predetermined small distance from weld on Injector head and sealing flat surfaces the flat surface of the Injector head and the control module not by heat kung warps and leaks.

Without special measures, the axial minimum is stood between a sweat created by laser welding seams and the next sealing plane surfaces when the Ge if the plan areas are warped should be at least 15 millimeters for the injectors in question. This minimum distance of 15 millimeters can be set on the injector head, the overall length of all dimensions of the injector con structurally determined, are usually not adhered to. The inventive design of an annular groove in the injection gate head and the creation of the weld seam only on the outside However, the flat surface of the injector head becomes the side of the ring groove fes thermally decoupled from the welding process, so that the Flatness of the sealing flat surfaces is maintained, too if the axial distance between the weld seam and the flat surface for example goes to zero.

In the following the invention is based on the drawing ago explained. The figure of the drawing schematically shows egg NEN injector for a fuel storage injection system in the Cut.

The injector 10 shown in the drawing for a fuel accumulator injection system, such as the common rail system of a diesel engine, consists essentially of the three elements injector head 20 , control module 40 and injector body 60th

The three parts are manufactured separately for manufacturing reasons and then combined into one unit, the injector 10 . Between the injector head 20 and the control module 40 there is a flat interface 30 and between the control module 40 and the injector body 60 a flat interface 50 .

The injector head 20 includes a (not shown in detail) electrical or electromagnetic control unit, which controls the supply of the pressurized fuel from the fuel accumulator (called rail in the common rail system of the diesel engine) to the control module. In the drawing, schematically some of the fuel lines are, inter alia, at 22 and 24 are shown, which extend in the injector 20 and which lead in particular at the interface 30 between injector 20 and control module 40 to the control module 40th

The injector body 60 contains the actual, conventionally constructed injection nozzle (not shown), by means of which fuel is injected into the combustion chamber of the internal combustion engine during the combustion process. The control module 40 , which is functionally connected upstream of the injection nozzle, is arranged between the injector head 20 and the injector body 60 .

The injection nozzle in the injector body 60 comprises an axially movable nozzle body with a nozzle needle at its front end, which opens and closes an injection holes upon movement of the nozzle body, which lead to the combustion chamber of the internal combustion engine. The nozzle needle releases the injection holes when fuel is supplied to a nozzle chamber at the front end of the nozzle body under high pressure, so that the nozzle body moves axially away from the injection holes against the action of a compression spring.

The control module 40 includes a control piston (not shown) which is connected to the fuel accumulator (rail) via the injector head 20 and which can selectively establish a hydraulic connection to the injection nozzle.

The control module 40 serves to hydraulically cause the opening and closing of the injection nozzle, that is to say, in particular, to precisely determine the start and end of the injection process. It also enables the injection of very small amounts of fuel for pre-injection (pilot injection) before the actual injection, which can be used to optimize the combustion process.

The control module 40 includes as the injector 20 fuel lines on which 60 module for connection to the pre-circuit-th injector 20 and the downstream injector body at the interface 30 between injector 20 and control 40 and the interface 50 between control module 40 and the injector 60 open . In the drawing, line 44 is shown as an example of such a fuel line, which is a continuation of line 24 in injector head 20 and which in turn leads as line 64 in injector body 60 .

In order to seal the fuel lines passing through the interfaces 30 , 50 , which contain fuel under high pressure, from one another and to the outside, the abutting surfaces 30 of the injector head 20 and the control module 40 and the abutting surface 50 at the interface 50 are abutting surfaces of the control module 40 and the injector body 60 are designed as high-pressure sealing surfaces with a flatness of, for example, less than 1 μm. In addition, the three parts injector head 20 , control module 40 and injector body 60 are pressed together with a predetermined force and welded under this biasing force.

The mechanical connection between the three elements injector head 20 , control module 40 and injector body 60 is produced by a welding sleeve 12 in the form of an expansion sleeve. The welding sleeve 12 is plugged onto the injector body 60 so that it surrounds the upper end of the injector body 60 , and welded to it. The control module 40 is located in the welding sleeve 12 . Subsequent to the control module 40 , the injector head 20 is plugged onto the welding sleeve 12 and welded to it under a prestress.

During assembly of the injector 10, the sealing sleeve 12 is pushed a distance a far on the injector body 60 and welded at their this regard, the lower end, which then preferential example rests against a step-shaped shoulder 66 on the outside of the injector body 60 by means of laser welding with the injector 60 . The distance a is large enough, at least about 15 mm, so that when welding the welding sleeve 12 to the injector body 60, the high-pressure sealing surfaces at the interface 50 do not heat up to such an extent that there is a risk of permanent deformation and thus a leakage speed.

Then the control module 40 is inserted into the welding sleeve 12 . The outer diameter of the control module 40 corresponds essentially to the inner diameter of the welding sleeve 12 , so that the control module 40 fits exactly into the welding sleeve 12 and has no substantial radial clearance therein. The welding sleeve 12 protrudes by a length b beyond the control module 40 used .

The injector head 20 is then placed on the free, upper end of the welding sleeve 12 , which projects beyond the control module 40 . The outside diameter d of the injector head 20 is larger in the connection area than the outside diameter of the welding sleeve 12 . To accommodate the upper end of the welding sleeve 12 , starting from the abutting surface 30 of the injector head 20 , into the injector head 20 an axially extending annular groove 26 is inserted, which receives the upper end of the welding sleeve 12 . The radial dimensions of the annular groove 26 correspond exactly to those of the welding sleeve 12 . This means that, for example, the radial distance of the inner wall of the annular groove 26 from the central axis of the injector 10 is half the inner diameter of the welding sleeve 12 and the radial width of the annular groove 26 is equal to the radial thickness of the annular groove 26 . The annular groove 26 is deep enough in the axial direction to accommodate the upper end of the welding sleeve 12 under all circumstances without the upper end of the welding sleeve 12 coming to the bottom of the annular groove 26 .

Because of the limited installation space for the injector 10 in the cylinder head area of the engine, however, the axial dimensions of the injector head 20 are constructively fixed, so that the depth of the annular groove 26 cannot exceed a maximum value. This also limits the length b of the upper En of the welding sleeve 12 which projects beyond the control module 40 and plunges into the annular groove 26 .

The outer diameter d of the injector head 20 is, as he imagines that in the region of the annular groove 26 by a defined value greater than the outer diameter of the welding sleeve 12, so that the upper end of the welding sleeve 12 outwardly from a Außenab section of the injector 20 in the form of an apron 28 is surrounded with a defined wall thickness. This wall thickness is equal to half the outer diameter d of the injector head 20 minus half the outer diameter of the welding sleeve 12 .

The assembly of the injector 10 is thereby continued that the injector head 20 placed on the welding sleeve 12 is pressed with a predetermined force onto the control module 40 and the injector body 60 . In order to apply this force, a collar 14 is formed on the outside of the welded sleeve 12 on the injector body 60 . This force generates the required pretension with which the high-pressure sealing surfaces at the interface 30 and the interface 50 are pressed together in a sealing manner.

When pre-tension is present, the connection between welding sleeve 12 and injector head 20 then takes place. For this purpose, a laser welding beam is irradiated onto the injector head 20 in the region of the apron 28 such that the apron 28 is welded to the welding sleeve 12 .

It is important that the welding takes place only on the outside of the welding sleeve 12 . The wall of the annular groove 26 in the injector head 20 lying against the inside of the upper end of the welding sleeve 12 must in no way heat up to such an extent that the material of the injector head 20 melts at this point. It must therefore be welded in area c, it being irrelevant what distance remains from the high-pressure sealing surface.

As experiments have shown, however, the performance in laser welding can be readily adjusted so that the welding process, that is to say the melting of the materials involved, remains limited to the outside of the welding sleeve 12 and the apron 28 . Thus, the area of the injector head 20 within the welding sleeve 12 with the high pressure sealing surfaces remains thermally decoupled from the welding process and the flatness of the high pressure sealing surfaces is maintained, even with an axial distance of the weld seam from the high pressure sealing surfaces, which is substantially less than the 15 millimeters he mentioned . It can thus, as in the described arrangement, an axial distance of the weld seam from the interface 30 be selected in the area c, the distance having no influence on the flatness.

After the weld seam has cooled in the region of the apron 28 , the assembly of the injector 10 is complete. The three elements injector head 20 , control module 40 and injector body 60 are then permanently connected to one another by the welding sleeve 12 and the weld seams at the lower and upper ends of the welding sleeve 12 .

This advantageous way of connecting with a sweat sleeve, the two or more elements of the injector together that connects is not on the elements of the shown here Injector limited, but can for all elements of the In be applied.

Claims (4)

1. Injector for fuel storage injection systems, with the separate elements injector head ( 20 ), control module ( 40 ) and injector body ( 60 ), which are connected to each other under prestress, characterized in that
the connection of injector head ( 20 ), control module ( 40 ) and injector body ( 60 ) is provided by a welding sleeve ( 12 ), to which the injector head ( 20 ) and injector body ( 60 ) are welded, and that
the injector head ( 20 ) is provided with an annular groove ( 26 ) into which one end of the welding sleeve ( 12 ) is inserted, the welding between the welding sleeve ( 12 ) and injector head ( 20 ) being carried out in such a way that melting only occurs at the Outside of the welding sleeve ( 12 ) and on the ring groove ( 26 ) on the outside circumferential skirt ( 28 ) is done.
2. Injector according to claim 1, characterized in that the welding was done by laser welding.
3. Injector according to claim 1, characterized in that the axial distance of the weld seam on the injector head ( 20 ) from a flat interface ( 30 ) between the injector head ( 20 ) and control module ( 40 ) goes to zero.
4. Injector according to claim 1, characterized in that the axial distance of the weld seam on the injector body ( 60 ) from a flat interface ( 50 ) between the injector body ( 60 ) and control module ( 40 ) is approximately 15 millimeters.
DE1999114714 1999-03-31 1999-03-31 Injector for storage fuel injection systems Expired - Fee Related DE19914714C2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE1999114714 DE19914714C2 (en) 1999-03-31 1999-03-31 Injector for storage fuel injection systems

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE1999114714 DE19914714C2 (en) 1999-03-31 1999-03-31 Injector for storage fuel injection systems

Publications (2)

Publication Number Publication Date
DE19914714A1 DE19914714A1 (en) 2000-10-12
DE19914714C2 true DE19914714C2 (en) 2001-09-20

Family

ID=7903149

Family Applications (1)

Application Number Title Priority Date Filing Date
DE1999114714 Expired - Fee Related DE19914714C2 (en) 1999-03-31 1999-03-31 Injector for storage fuel injection systems

Country Status (1)

Country Link
DE (1) DE19914714C2 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1293664A3 (en) * 2001-09-18 2004-03-10 Siemens Aktiengesellschaft Fuel injection valve for an internal combustion engine
DE102012203621A1 (en) * 2012-03-07 2013-09-12 Man Diesel & Turbo Se Fuel injector

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19519191C2 (en) * 1995-05-24 1997-04-10 Siemens Ag Injector
DE19712589C1 (en) * 1997-03-26 1998-06-04 Bosch Gmbh Robert Valve needle for solenoid-operated fuel-injector of IC engine
DE19843915A1 (en) * 1998-09-24 2000-03-30 Siemens Ag Component connection for high pressure conduction

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19519191C2 (en) * 1995-05-24 1997-04-10 Siemens Ag Injector
DE19712589C1 (en) * 1997-03-26 1998-06-04 Bosch Gmbh Robert Valve needle for solenoid-operated fuel-injector of IC engine
DE19843915A1 (en) * 1998-09-24 2000-03-30 Siemens Ag Component connection for high pressure conduction

Also Published As

Publication number Publication date
DE19914714A1 (en) 2000-10-12

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Legal Events

Date Code Title Description
OP8 Request for examination as to paragraph 44 patent law
D2 Grant after examination
8364 No opposition during term of opposition
8327 Change in the person/name/address of the patent owner

Owner name: CONTINENTAL AUTOMOTIVE GMBH, 30165 HANNOVER, DE

8339 Ceased/non-payment of the annual fee