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
  • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
  • F02M61/18—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for
• • 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
  • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
  • F02M61/18—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for
  • F02M61/1866—Valve seats or member ends having multiple cones
• • 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
  • F02M61/047—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 being formed by deformable nozzle parts, e.g. flexible plates or discs with fuel discharge orifices
• • 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
  • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
  • F02M61/18—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for
  • F02M61/1873—Valve seats or member ends having circumferential grooves or ridges, e.g. toroidal
• • 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
  • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
  • F02M2200/30—Fuel-injection apparatus having mechanical parts, the movement of which is damped

Definitions

• the invention is based on a fuel injection valve for internal combustion engines according to the preamble of claim 1.
• a fuel injection valve is known from DE 196 34 933 AI.
• a valve member tip is arranged at the combustion chamber end of the valve member and two conical surfaces thereon.
• a first conical surface adjoins the valve member shaft and has an opening angle that is smaller than that of the conical valve seat.
• the first cone surface is followed by a second cone surface on the combustion chamber side, the opening angle of which is greater than that of the valve seat, so that a sealing edge is formed at the transition of the two cone surfaces, which comes into contact with the valve seat in the closed position of the valve member by a closing force acting on the valve member ,
• the opening stroke movement of the valve member is exerted by the hydraulic force of the fuel in the pressure chamber, which in the closed position inter alia acts on the first conical surface and thus causes a resultant force in the axial direction on the valve member.
• the sealing edge defines the hydraulically effective seat diameter of the valve member and thus, for a given closing force, the opening pressure of the fuel at which the valve member lifts off the valve seat against the closing force.
• the opening pressure of the fuel injection valve depends on the one hand on the closing force acting on the valve member and on the other hand on the hydraulically effective area of the Valve member.
• the closing force drops somewhat during operation due to relaxation processes in the valve holding body and in the device generating the closing force.
• the hydraulically effective area of the valve member must be reduced. This is achieved in that the difference in the cone angle of the valve seat and the first cone surface is smaller than the difference in the cone angle of the second cone surface and the valve seat.
• the sealing edge When the fuel injection valve is in operation, the sealing edge is pressed into the valve seat by plastic deformation, and the hydraulically effective sealing edge shifts from the original sealing edge to the valve member. This increases the hydraulically effective seat diameter and the associated reduction in the area acting in the opening direction at least partially compensates for the falling closing force, so that the opening pressure remains largely constant. If the closing force remains the same, the opening pressure increases accordingly.
• the fuel injection valve according to the invention with the characterizing features of claim 1 has the advantage that the resulting opening pressure of the Fuel injector does not change or changes only slightly during operation.
• a circumferential annular groove is formed on the first conical surface and limits the enlargement of the hydraulically effective seat diameter.
• the opening pressure of the fuel injector increases for a given closing force due to the increase in the effective hydraulic seat diameter, but only up to a value that can be easily determined by production. This compensates for the drop in the closing force that arises due to relaxation processes of the valve holding body and the mechanism that generates the closing force. Since the increase in the effective hydraulic seat diameter is precisely defined by the annular groove, the other components of the fuel injector can be optimally adapted to this increase in opening pressure.
• longitudinal grooves are arranged on the conical surface between the valve member shaft and the annular groove. This counteracts a cavitation effect in the ring groove and the associated wear problems. If the valve member lifts off the valve seat very quickly, it can happen at the beginning of the opening stroke movement that the fuel cannot flow into the annular groove quickly enough through the gap formed between the valve member tip and the valve seat.
• the longitudinal grooves improve the flow of fuel from the pressure chamber into the annular groove and cavitation cannot occur or can only occur to a significantly reduced extent.
• FIG. 1 shows a fuel injection valve in partial longitudinal section
• FIG. 2 shows an enlarged illustration of FIG. 1 in the region of the valve seat. Description of the embodiment
• a fuel injection valve for internal combustion engines is shown in partial longitudinal section.
• a valve body 5 is clamped by means of a tensioning element 3 against a valve holder body 1, which together form a nozzle holder combination, which in the installed position is arranged in a receiving bore of an internal combustion engine, not shown in the drawing.
• a bore 15 is formed, which is designed as a blind bore and the bottom surface of which is arranged towards the combustion chamber.
• a conical valve seat 23 is formed with a cone angle ⁇ and at least one injection opening 25, which connects the bore 15 to the combustion chamber.
• a piston-shaped valve member 7 Arranged in the bore 15 is a piston-shaped valve member 7 which has a longitudinal axis 19 and which is guided in the bore 15 with a guide section 207 facing away from the combustion chamber and is thus axially movable.
• the valve member 7 tapers towards the combustion chamber to form a pressure shoulder 9 and merges into a valve member shaft 107.
• a valve member tip 13 At the combustion chamber end of the valve member 7, a valve member tip 13 is arranged, which tapers towards the combustion chamber.
• the pressure shoulder 9 is arranged in a pressure chamber 11 formed in the valve body 5, which merges towards the combustion chamber into an annular channel surrounding the valve member shaft 107 and extends to the bottom surface of the bore 15.
• An inlet channel 17 is formed in the valve holding body 1 and in the valve body 5, which opens into the pressure chamber 11 and via which the pressure chamber 11 can be filled with fuel under high pressure.
• the valve member 7 is acted upon by a closing force in the direction of the combustion chamber.
• the device generating the closing force is arranged in the valve holding body 1, for example in the form of a prestressed spring. It can also be provided to generate the closing force by means of a plurality of springs which, depending on the stroke of the valve member 7, generate the closing force individually or together.
• an additional closing force can also be generated by building up a pressure in the spring chamber. This closing force presses the valve member 7 with the valve member tip 13 against the valve seat 23, as a result of which the pressure chamber 11 is closed against the injection openings 25.
• the opening stroke movement of the valve member 7 takes place in that the hydraulic force of the fuel in the pressure chamber 11 acts on the pressure shoulder 9 and at least on part of the valve member tip 13.
• valve member 7 is shown in the closed position in the region of the valve member tip 13 and the valve body 5 surrounding the valve member 7 in longitudinal section.
• a first conical surface 30 is formed on the valve member tip 13, which adjoins the valve member shaft 107 and has a conical angle ⁇ .
• the cone angle ⁇ is smaller than the cone angle ⁇ of the valve seat 23, so that a first difference angle ⁇ 2 is formed between the first cone surface 30 and the valve seat 23.
• a second cone surface 32 adjoins the first cone surface 30 on the valve member tip 13, the cone angle ⁇ of which is greater than the cone angle ⁇ of the valve seat 23.
• the second differential angle ⁇ 2 formed between the second conical surface 32 and the valve seat 23 is larger than the first differential angle ⁇ ⁇ . Due to the transition from the first 30 to the second cone surface 32, a circumferential sealing edge 40 is formed on the valve member tip 13, which is in a
• a circumferential annular groove 35 is arranged on the first cone surface 30 and runs in a radial plane to the longitudinal axis 19 of the valve member 7.
• Their cross-section can be in the form of an arc of a circle or also have another useful shape.
• the cross section can be formed by a polygon or be part of an ellipse.
• the width of the annular groove is preferably 0.15 to 0.5 mm.
• the longitudinal grooves 42 facilitate the inflow of fuel from the pressure chamber 11 into the annular groove 35 at the beginning of the opening stroke movement, so that cavitations cannot form or can be formed to a significantly reduced extent.
• the longitudinal grooves 42 preferably run parallel to the surface lines of the first conical surface 30 and, if more than one longitudinal groove 42 is provided, are preferably distributed uniformly over the circumference of the valve member 7.
• valve member tip 13 designed according to the invention is as follows: In the closed position of the valve tilliedes 7, the sealing edge 40 is pressed against the valve seat 23. This is in principle a line contact and there are high voltages both in the valve member 7 and in the valve seat 23, which lead to elastic and plastic deformation of the valve member 7 and valve seat 23, so that the sealing edge 40 in the valve seat during operation 23 presses in and there is surface contact. Since the first differential angle ⁇ is smaller than the second differential angle ⁇ 2 , the hydraulically effective sealing edge, i.e. the boundary line up to which the pressure of the fuel in the pressure chamber 11 acts in the closed position of the valve member 7, is displaced by the indentation of the sealing edge 40 Sealing edge 40 in the direction of the annular groove 35.
• valve member 7 and valve seat 23 can ensure that the valve member tip 13 is not pressed into the valve seat 23 to such an extent that the upper annular groove edge 37 facing away from the combustion chamber comes into contact with the valve seat 23.
• the cone angle of the valve seat is 55 to 65 degrees, preferably about 60 degrees.
• the cone angles of the first 30 and second cone surface 32 are designed such that the difference angles ⁇ l7 ⁇ 2 are each less than 1.5 degrees.
• the first differential angle ⁇ x is always smaller than the second differential angle ⁇ 2 .

Landscapes

• 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=7646964

Family Applications (1)

Country Status (9)

Families Citing this family (25)

Family Cites Families (11)

• 2000
  • 2000-06-27 DE DE10031265A patent/DE10031265A1/de not_active Withdrawn
• 2001
  • 2001-06-12 US US10/069,506 patent/US6827297B2/en not_active Expired - Fee Related
  • 2001-06-12 WO PCT/DE2001/002180 patent/WO2002001065A1/de active Application Filing
  • 2001-06-12 BR BR0106897-0A patent/BR0106897A/pt active Search and Examination
  • 2001-06-12 PL PL01352573A patent/PL352573A1/xx not_active Application Discontinuation
  • 2001-06-12 JP JP2002506361A patent/JP2004502074A/ja active Pending
  • 2001-06-12 CN CN01801776A patent/CN1383470A/zh active Pending
  • 2001-06-12 EP EP01947202A patent/EP1297252A1/de not_active Withdrawn
  • 2001-06-12 KR KR1020027002410A patent/KR20020027575A/ko not_active Application Discontinuation

Non-Patent Citations (2)

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