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
  • F02M61/047—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
  • 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 is based on a fuel injection valve for internal combustion engines according to the preamble of claim 1.
• a fuel injector known from the German patent application file number P 44 13 217.4
• the movable valve member executing the opening movement is formed by a membrane, the outer edge of which is clamped.
• the membrane interacts with a stationary, conical valve seat, this valve seat being arranged on a pin projecting axially from the valve body, which protrudes into a central bore in the membrane.
• the diaphragm bears under prestress with a sealing surface formed on the edge of the bore on the conical valve seat and thus delimits a pressure chamber which can be filled with high pressure from one into the combustion chamber of the one to be supplied
• the known fuel injection valve has the disadvantage that no sensor for detecting the
• the start of injection and the end of injection is provided so that no exact information can be ascertained about the injection duration and injection quantity.
• this information is necessary for an optimal adaptation of the fuel injection valve to the respective requirements of the internal combustion engine.
• these measurement data are used to control an optimal injection even during the operation of the
• sensors for detecting the stroke movement of the valve element are already known from the prior art of fuel injection valves, these sensors have so far been limited to injection valves with a piston-shaped valve element, on the piston end of which faces away from the combustion chamber, an electromagnetic Hall sensor is provided.
• this type of motion sensor cannot be used in the fuel injector of the generic type, so that the simplest possible sensor principle for detecting the opening movement of the valve membrane can be found.
• the fuel injection valve for internal combustion engines according to the invention with the characterizing features of claim 1 has the advantage that the start of injection and the end of injection at a so-called diaphragm nozzle can be detected in a structurally very simple and therefore inexpensive manner.
• This is advantageous due to the use of the adjustable wall as achieved electrical switching element of a motion sensor which cooperates with at least one fixed contact.
• This fixed contact is advantageously formed by the conical or alternatively spherical valve seat, to which a low reference potential, preferably earth potential, is applied.
• the adjustable wall membrane
• the adjustable wall is supplied with a supply voltage, so that a first circuit is closed when the injection valve is closed and the membrane is in contact with the valve seat.
• the current flow through this circuit is detected by means of a suitable evaluation circuit, so that at least one reliable statement can be gathered from this signal as to whether the injection cross section is open or closed, the injection time and the geometric injection cross section resulting from the duration of the current interruption in the first circuit derives the injection quantity. If, in addition, a statement is to be made about the opening duration with the maximum injection cross section, a stroke stop disk which limits the opening stroke movement of the valve membrane can also be provided with a
• the diaphragm and the stroke stop disc each have an electrical lead in the valve body.
• a spacer sleeve and an insulating disk made of non-conductive material preferably ceramic or temperature-resistant plastic, in which corresponding grooves and bores are provided for the passage of the electrical lines. If there is no need for signal detection with the injection cross-section fully open, the Stroke washer in one piece with the insulating washer receiving it and made of non-conductive material.
• Another essential advantage of the invention is achieved by the provision of an anti-rotation device between the clamping nut and the valve body used therein, which is necessary due to the axial cable routing of the electrical leads through the individual components.
• the axial clamping of the valve body in the clamping nut is now advantageously carried out by an additional hollow screw screwed into the clamping nut, which axially engages with its annular end face on a ring shoulder of the valve body and thus clamps the other components including the valve membrane against a stop on the combustion chamber side Clamping nut clamped.
• the Ventilk ⁇ rper also has a radial recess, preferably a pressed-in ball on its outer surface, which is guided in an axial longitudinal groove in the inner wall of the clamping nut.
• the construction according to the invention has the The advantage is that the membrane is clamped absolutely centrally to the pin. In this way it is ensured that the sealing force at the sealing seat between the valve member sealing surface on the membrane and the conical valve sealing surface on the pin is the same over the entire circumference and that when the opening pressure is reached, the valve membrane lifts up simultaneously over the entire seat circumference and releases a circular cross-section, which forms a rotationally symmetrical injection jet.
• FIG. 1 shows a first embodiment in a longitudinal section through the injection valve, in which both the closed position and the maximum opening stroke position of the valve membrane are detected
• FIG. 2 shows a second embodiment in an enlarged detail from FIG. 1, in which only the closed position of
• Figure 3 is a schematic diagram of the circuit arrangement of Figure 1.
• the fuel injection valve for internal combustion engines shown in FIG. 1 has a rotationally symmetrical valve body 1, which has at one end a connection 3 for a high-pressure line, not shown, to a
• a fixed valve needle 5 is screwed, which has a pin 7 projecting axially from the valve body 1.
• An axial leads from the high pressure connection 3 Pressure channel 9, which opens the valve body 1 and the valve needle 5 penetrating the pin 7 into a pressure chamber 11, a rod filter 10 being inserted into the pressure channel 9.
• This pressure chamber 11 is delimited radially inwards by the pin 7 and radially outwards by a spacer sleeve 13 which, with the interposition of a shim 15, lies sealingly against the end face of the valve body 1 on the combustion chamber side, delimiting the pressure chamber 11.
• a part of the pin 7 that tapers conically in the direction of the combustion chamber forms a conical valve seat 17, against which an adjustable wall 19, which delimits the pressure chamber 11 on the combustion chamber side and forms a valve member, comes into contact with a valve member sealing surface 21 formed on a central bore.
• This adjustable wall designed as a valve membrane 19 is disc-shaped and curved in the direction of the pressure chamber 11 and is made of a resilient, electrically conductive material, preferably metal.
• valve membrane 19 On its outer edge, the valve membrane 19 is clamped between the spacer sleeve 13 and an insulating disk 23 adjoining the combustion membrane on the combustion chamber side, the insulating disk 23 in turn being supported on a collar 25 of a clamping nut 27 covering the outer edge of the insulating disk 23.
• clamping nut 27 This, the valve body 1 axially receiving clamping nut 27 projects with its end face having the collar 25 in the
• an injection cross section being formed at its central opening 28 and extending through the insulating disk 23 to the sealing cross section formed between the valve sealing surface 21 and the valve seat surface 17 interacting with it.
• a clamping screw designed as a hollow screw 29 is screwed into the open end facing away from the combustion chamber, through which the connection 3 has the screw Extends through the stem end of the valve body 1 and which engages with its ring end face 31 which projects into the clamping nut 27 on a ring shoulder 33 on the outer surface of the valve body 1. It presses the valve body 1 and further the adjusting washer 15, the spacer sleeve 13, the valve membrane 19 and the insulating washer 23 axially against the collar 25 of the clamping nut 27, which forms a counterstop.
• a stroke stop disk 39 is also provided in the exemplary embodiment, which is inserted into a recess in the insulating disk 23 and has an axially projecting ring stop surface 41 which is formed on a passage opening through which the pin 7 protrudes.
• a voltage is applied to the outer edge of the valve membrane via a first electrical lead 43 and a contact point 45, the valve membrane 19 being insulated from the clamping nut 27 via the insulating washer 23 made of non-conductive material and the spacer sleeve 13 is.
• the electrical contact points interacting with the valve membrane 19 are shown in the first
• Embodiment formed by the pin 7 of the valve needle 5 and the stroke stop plate 39 which are made of electrically conductive material.
• the pin 7 is over the valve body 1 with a low Reference potential, preferably ground potential (ground) connected, which is present at a contact point 47 on the valve body 1.
• the stroke stop disk 39 is connected to a further voltage potential via a second electrical feed line 49 and a further contact point 51.
• the valve membrane 19 forms a movable switching element which, as shown in the circuit diagram in FIG. 3, alternately closes a first circuit or a second circuit.
• the electrical leads 43, 49 are guided through corresponding grooves and bores in the spacer sleeve 13, the shim 15 and the valve body 1 to the outside and connected in a manner not shown together with the contact point 47 to a suitable evaluation circuit that the current flow in one of the registered in both circuits.
• the fuel injection valve according to the invention works in the following way. Before the start of high pressure injection on
• the fuel injection valve has only a low fuel level pressure applied to the pressure chamber 11 via the pressure channel 9 and the high-pressure line (not shown).
• the force generated by the static pressure in the pressure chamber 11 on the valve diaphragm 19 is smaller than the pretensioning force of the valve diaphragm, so that it lies sealingly against the valve seat surface 17 and keeps the injection valve closed. If an injection is to take place, the high-pressure pump delivers fuel under high pressure via the
• the maximum opening stroke movement of the valve membrane 19 can be limited by the contact with the ring stop surface 41 of the stroke stop disk 39.
• the high-pressure supply to the pressure chamber 11 is interrupted, so that the high-pressure fuel there rapidly drops below the necessary opening pressure and the valve membrane 19 returns with its sealing surface 21 in contact with the valve seat 17.
• the opening stroke movement of the valve diaphragm 19 is now detected by the electrical contacts described above, the valve diaphragm 19 serving as an electrical switching element.
• a first circuit is closed, which emits a safe signal for the closed state of the injection valve to a corresponding evaluation circuit. If the valve membrane 19 lifts off the valve seat 17 of the pin 7 at the beginning of the opening stroke movement, this first circuit is interrupted, this electrical signal being registered by the evaluation circuit as the time of the start of injection.
• the second circuit When the maximum opening stroke position of the valve membrane 19 is reached, the second circuit is closed via its contact with the stroke stop disk 39, this electrical signal also being recorded by the evaluation circuit when the maximum opening cross section at the injection valve is reached.
• the end of injection is detected by the renewed contact of the valve membrane 19 on the pin 7 and the closing of the first circuit and from the evaluation circuit on Control unit communicates, in which an accurate statement about the actual injection duration and consequently the injection quantity can now be recorded, which can be used to control and continuously adjust the injection quantity, for which purpose the determined actual value is compared with a target value of a stored map.
• the second exemplary embodiment shown in FIG. 2 in an enlarged detail from FIG. 1 differs from the first exemplary embodiment only in that there was no detection of the maximum opening stroke lengths of the valve membrane 19.
• the insulating disc 23 and the stroke stop disc 39 are designed as a common, one-piece component 61 made of electrically non-conductive material.
• This one-piece insulating washer 61 has on a tubular extension the ring stop surface 41 that limits the opening movement of the valve membrane 19.
• the mode of operation of the second embodiment is the same as the mode of operation of the first embodiment, with no signal being detected at the injection valve when the maximum injection cross section is reached. Beginning of injection and end of injection can, however, analogously to FIG. 1, by the closed or interrupted first circuit, by means of the contact system of the valve membrane 19 on the pin 7, continue to be detected precisely, so that this very simple and therefore inexpensive embodiment provides reliable information about the injection duration and the injection quantity .

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=7776850

Family Applications (1)

Country Status (7)

Families Citing this family (17)

Family Cites Families (5)

• 1995
  • 1995-11-08 DE DE1995141508 patent/DE19541508A1/de not_active Withdrawn
• 1996
  • 1996-07-16 WO PCT/DE1996/001294 patent/WO1997017539A1/de not_active Application Discontinuation
  • 1996-07-16 KR KR1019970704600A patent/KR987001064A/ko not_active Application Discontinuation
  • 1996-07-16 JP JP9517726A patent/JPH10512648A/ja active Pending
  • 1996-07-16 RU RU97113055/06A patent/RU2161724C2/ru not_active IP Right Cessation
  • 1996-07-16 EP EP96923856A patent/EP0823959A1/de not_active Withdrawn
  • 1996-07-16 CN CN96191358A patent/CN1067745C/zh not_active Expired - Fee Related

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events