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
  • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
  • F02M61/04—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series
  • F02M61/08—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series the valves opening in direction of fuel flow
• • 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
  • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
  • F02M61/04—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series
  • F02M61/042—The valves being provided with fuel passages
  • F02M61/045—The valves being provided with fuel discharge orifices

Definitions

• the invention is based on a fuel injection valve for internal combustion engines according to the preamble of claim 1.
• a fuel injector known from the unpublished German patent application with the file number 1 96 34 716.5 has a valve body with an axial through-bore, in which a piston-shaped valve member is guided, which controls a
• Injection cross-section is displaceable outward by the high fuel pressure against the force of a valve spring.
• the valve member has at its combustion chamber end a projecting from the bore of the valve body closing head, which forms a valve closing member and at the
• a valve sealing surface is arranged on the side facing the valve body, with which the closing head interacts with a valve seat surface arranged on the end face of the valve body on the combustion chamber side. At least one injection opening on the valve member is still at the level of the
• Closing head provided, which starts from a pressure chamber formed between the valve member and the bore.
• the outlet opening of the injection opening is covered in the firing position of the valve member by the valve body and is only in the course of the outward opening stroke of the Valve member released by dipping out of the hole.
• the valve member With its end facing away from the closing head and away from the combustion chamber, the valve member projects into a spring chamber which is formed in a holding body axially braced with the valve body. The valve member points to its distant combustion chamber
• the maximum opening stroke movement of the valve member is limited by the contact of a contact surface formed by a collar on the valve member shaft on a stationary stroke stop ring, the size of which allows the maximum opening stroke to be set.
• the known fuel injection valve has the disadvantage that the entire supporting force of the valve spring is transmitted to the valve body only via the stroke stop ring. As a result of the small contact surface of the stroke stop ring, there is a so-called hammering into the valve body, as a result of which the opening stroke of the valve member can be adjusted. Furthermore, the setting of different opening stroke paths is carried out by means of stroke stop rings of different sizes, whereby the spring preload force of the valve spring also changes and thus again adjusts the opening characteristics of the fuel injection valve.
• the fuel injection valve for internal combustion engines according to the invention with the characterizing features of claim 1 has the advantage that the supporting force of the valve spring via the spacer ring on the support ring surrounding the split stroke stop ring is tested.
• This support ring is fixed in place with respect to the valve body, it being able to be supported directly on the valve body with its ring end face or by clamping the stroke stop ring. In this way, a large contact surface for the introduction of force into the valve body is achieved, which reliably prevents the components from hammering into the end face of the valve body.
• the stroke stop ring is preferably formed in two parts, but can alternatively be divided into more sub-segments.
• the preferably two half-shells of the axially divided stroke stop ring form in the assembled state in the fuel injection valve a completely closed stroke stop ring which has a conical stroke stop surface on its end face facing the spacer ring and which rests on the valve body with its opposite ring end face. Both the stroke stop surface on the stroke stop ring and the contact surface interacting with it on the valve member are conical.
• the preferably two half-shells of the axially divided stroke stop ring are preferably produced by targeted breaking (cracking).
• the stroke stop ring is made of a brittle material at least in the area of the predetermined breaking points, so that the half-shells are without
• the stroke stop ring is advantageously produced by a non-cutting process, preferably pressing, forging, sintering.
• the spacer ring and the support ring surrounding the divided stroke stop ring are designed as a one-piece component, preferably as a sleeve.
• This sleeve is guided with its outer circumference in a receiving bore in a valve holding body clamped axially with the valve body.
• the inner diameter of this sleeve is designed as a stepped bore, the smaller bore diameter forming the original spacer ring and the larger bore diameter forming the original support ring.
• the sleeve can rest axially on a flat end face region of the stroke stop ring, it being particularly advantageous to provide a conical ring collar on the stroke stop ring, on which the sleeve is braced with a conical end face.
• the cone angles on this contact surface are advantageously designed so that the clamping force of the valve spring on the sleeve is oriented radially inwards in the direction of the stroke stop ring, so that the holding force of the two stroke stop ring half-shells is caused by an inward action
• the fuel injection valve according to the invention is designed as an outward opening injection valve, the use of the stroke stop components described on a so-called vario-register nozzle with spray hole cross sections arranged one above the other being particularly advantageous.
• FIG. 1 shows the fuel injection valve according to the invention in a longitudinal section
• FIG. 2 shows a first exemplary embodiment in an enlarged detail from FIG. 1, in which the spacer ring and support ring are designed as two separate components
• FIG. 3 shows a second exemplary embodiment in an enlarged form Individual part representation, in which the spacer ring and support ring are designed as a common sleeve which is supported directly on the valve body
• FIG. 4 shows a third exemplary embodiment according to the illustration in FIG. 3, in which the sleeve is supported on a ring shoulder of the stroke stop ring
• FIG. 5 shows a fourth Exemplary embodiment analogous to the representation of Figures 3 and 4, in which the contact surfaces between the
• Sleeve and the stroke stop ring are conical and Figure 6 is a schematic representation of the manufacturing process of the stroke stop ring of the fuel injector according to the invention. Description of the embodiments
• the fuel injection valve according to the invention for internal combustion engines shown in FIG. 1 has a valve body 1 which is clamped axially against a valve holding body 5 by means of a union nut 3.
• the valve body 1 which projects into the combustion chamber of the internal combustion engine with its free end, has an axial guide bore 7, in which a piston-shaped valve member 8 is axially displaceably guided, and a valve closing head 9 is arranged on the combustion chamber-side end which projects from the guide bore 7.
• This valve closing head 9 has a conical valve sealing surface 11 which faces the valve body 1 and which interacts with a corresponding conical valve seat surface 13 on the end face of the valve body 1 on the combustion chamber side.
• the portion of the valve closing head 9 which projects into the guide bore 7 and is radially offset from the part which has the sealing surface 11 is designed as a piston slide valve which, with its annular end face 15 remote from the combustion chamber, forms a pressure chamber 17 within the
• the high-pressure fuel supply into the pressure chamber 17 takes place via a high-pressure channel 23, which axially penetrates the valve body 1 and the valve holding body 5 and to which an injection line leading away from a fuel injection pump, not shown, is connected.
• the valve member 8 With its valve member shaft facing away from the combustion chamber, the valve member 8 projects into a spring chamber 25 provided in the valve holding body 5, into which a valve spring 27 is applied, which acts on the valve member 8 in the closing direction towards the valve seat 13.
• a spring plate 29 is arranged on the end of the valve member 8 remote from the combustion chamber, between which and a housing-fixed spacer ring 31 the valve spring 27 is clamped.
• the spacer ring 31 shown in FIG. 2 in an enlarged detail from the first exemplary embodiment of FIG. 1 rests with its ring end face facing away from the valve spring 27 against a support ring 33, which with its ring end face facing away from the spacer ring 31 rests against the end face of the valve body 1 remote from the racing space supports.
• a stroke stop ring 35 is inserted radially within this support ring 33, the lower ring end face of which rests against the valve body 1 and has a conical stroke stop surface 37 at its end remote from the combustion chamber. This conical stroke stop surface is formed at the cross-sectional transition between a flat end face region 39 and the through hole in the stroke stop ring 35.
• this contact surface 41 is conical in accordance with the stroke stop surface 37, the two conical contact surfaces having the same cone angle, in order to provide the largest possible contact and force application surface.
• the stroke stop ring 35 is formed for mounting on the cross-sectional constriction of the valve member 8 from two half-shells which are produced by dividing a finished stroke stop ring 35 in a manner to be described later.
• the half-shells of the stroke stop ring 35 are inserted into the support ring 33 so that the spreading forces introduced on the half-shells are absorbed by the support ring 33.
• the axial height of the support ring 33 is, as shown in FIG. 2, greater than the axial height of the two-part stroke stop ring 35, so that the support forces F of the valve spring 27 are transmitted to the valve body 1 via the spacer ring 31 and the support ring 33.
• the stroke stop ring 35 only absorbs the valve member opening forces.
• the fuel injection valve for internal combustion engines works in the following manner.
• the valve spring 27 holds the valve member 8 with its sealing surface 11 in contact with the valve seat surface 13 on the valve body 1, the injection openings 21 being covered by the wall of the guide bore 7 are so that the injection valve is closed.
• the fuel delivered by the high-pressure injection pump (not shown in any more detail) reaches the pressure chamber 17 in a known manner via the high-pressure channel 23 and the annular gap between the guide bore 7 and the valve member 8.
• the high-pressure fuel engages the annular end face 15 of the valve closing head 9 in the opening direction of the valve member 8, and after reaching a certain opening pressure, the valve member 8 lifts outward against the restoring force of the valve spring 27 from the valve seat 13.
• the injection openings 21 emerge from the overlap with the wall of the guide bore 7, so that the fuel from the pressure chamber 17 passes through the inlet channel 19 and the injection openings 21 for injection into the combustion chamber of the internal combustion engine.
• the maximum opening stroke movement of the valve member 8 is limited by the contact of the valve member contact surface 41 on the fixed stroke stop surface 37 on the stroke stop ring 35, whereby the conical configuration of these two contact surfaces allows the supporting cross section on the valve member 8 to be increased such that fractures of the valve member 8 as a result of the hard impact on the stroke stop 37 can be safely avoided.
• FIGS. 3 to 5 differ from the first exemplary embodiment shown in FIGS. 1 and 2 in the design of the stroke stop area and the adjacent components.
• FIG. 3 shows a second embodiment in which the spacer ring 31 and the support ring 33 are designed as a common, one-piece component.
• This common component is in the form of a sleeve 45, which is guided with its outer circumference on the wall of the spring chamber 25 and whose inner through bore is designed as a stepped bore.
• a small inner bore Knife area 47 of the sleeve 45 functions as the original spacer ring 31.
• An area 49 of the sleeve 45 with a larger inner bore diameter takes over the function of the original support ring 33.
• the sleeve 45 lies with a ring shoulder 51 formed on the inner diameter transition on the flat end face area 39 of the stroke stop ring 35 radially outside the conical stroke stop surface 37.
• the sleeve 45 rests with its ring end face 53 facing the valve body 1 against an annular shoulder 55 formed on a cross-sectional widening on the outer circumference of the stroke stop ring 35.
• the force transmission from the valve spring 27 now takes place via the sleeve 45 and the entire end face of the stroke stop ring 35 on the valve body side.
• the end face 53 of the sleeve 45 and the ring shoulder 55 of the stroke stop ring 35 are conical, the cone angle of the contact surfaces being designed such that the axial clamping force on the sleeve 45 is directed radially inwards Direction stroke stop ring 35 is aligned.
• the axial clamping force of the sleeve 45 can support the inward-acting supporting force and thus ensure that the two half-shells of the stroke stop ring 35 are securely pressed together.
• the one-piece design of the spacer ring 31 and support ring 33 in FIGS. 3 to 5 has the advantage that the radial forces introduced by the stroke stop ring 35 into the relatively thin-walled support ring 33 are also absorbed by the considerably more stable spacer ring 31.
• FIG. 6 schematically shows the manufacturing steps of the preferably two-part lifting stop ring 35.
• the lifting stop ring 35 is first produced in a non-cutting process, the lifting stop ring 35 being made of a brittle material at least in the area of the predetermined breaking points of the later two half-shells. These predetermined breaking points are preferably along a central plane 57 of the stroke stop ring 35.
• the stroke stop ring 35 which is initially in one piece, is produced, it is divided into the two half-shells, this division of the ring profile by targeted breaking, e.g. done by a wedge or by cracking.
• the half-shells break in the brittle predetermined breaking area in such a way that they can be reassembled without any gaps when later inserted on the fuel injector, so that a completely closed round profile is created again.

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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)

Applications Claiming Priority (3)

Publications (1)

Family

ID=7850336

Family Applications (1)

Country Status (5)

Families Citing this family (8)

Family Cites Families (9)

• 1997
  • 1997-11-29 DE DE19753162A patent/DE19753162A1/de not_active Withdrawn
• 1998
  • 1998-06-26 EP EP98941233A patent/EP0977945A1/de not_active Withdrawn
  • 1998-06-26 JP JP52960399A patent/JP2001510530A/ja active Pending
  • 1998-06-26 US US09/355,501 patent/US6113011A/en not_active Expired - Fee Related
  • 1998-06-26 WO PCT/DE1998/001760 patent/WO1999028619A1/de not_active Application Discontinuation

Non-Patent Citations (1)

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