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
  • F02M17/00—Carburettors having pertinent characteristics not provided for in, or of interest apart from, the apparatus of preceding main groups F02M1/00 - F02M15/00
  • F02M17/16—Carburettors having continuously-rotating bodies, e.g. surface carburettors
• • 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
  • F02M69/00—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel
  • F02M69/06—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel characterised by the pressurisation of the fuel being caused by centrifugal force acting on the fuel

Definitions

• the invention relates to a central injection device for internal combustion engines, with a rotor having an impeller driven by the intake air flow, which in a hollow cylindrical housing around a fixed, connected to a fuel supply line and immersing in a central bore of the rotor without contact
• Fuel feed pin is rotatably arranged with a fuel outlet opening located within the rotor and has a lateral fuel outlet opening which is connected in the rotor to a connecting channel leading to the fuel outlet opening of the fuel feed pin, between the fuel feed pin and there is a narrow annular gap in the wall of the rotor bore, the opening of which, like the lateral fuel outflow opening, lies above a fuel level which is established in the rotor bore in the idle state of the rotor and which seals the rotor s absorbs the leakage fuel radially pushed away by centrifugal forces from the outlet opening of the fuel supply pin below the fuel level.
• Such a central injection device is known from DE-PS 25 36 996 with the title “carburetor for internal combustion engines”.
• carburetors or, better, central injection devices of this type generally emit an amount of atomized fuel that is directly proportional to the amount of air drawn into the intake manifold and produce a fuel-air mixture that is below the permissible limit values to guarantee Amounts of pollutants in the exhaust gases are properly processed.
• the pollutants in the exhaust gases can assume peak values in operation which are above the limit values and which essentially relate to a completely uncontrolled delivery of leakage fuel from the narrow annular gap Fuel feed pin and rotor are traced back into the intake manifold.
• the amount of fuel delivered by the rotor of the known central injection device mentioned above which is in a linear relationship to the amount of air drawn in over the entire operating range of the internal combustion engine, is regarded as unsatisfactory for internal combustion engines which require a fuel-air mixture enriched with fuel in the full-load range.
• the object is achieved in that a stowage space, which is peripherally limited by a concentric retaining ring and is acted upon directly by the intake air flow, is connected to the annular gap and an air overpressure which counteracts the leakage fuel pressure via the stowage space in the annular gap is generated.
• the air overpressure generated in it for all speeds of the intake air flow and thus for all speeds of the impeller is dependent on the opening width of the storage space directly affected by the intake air flow and on the geometry of the storage ring that peripherally limits it that these parameters can be used to set an air overpressure in the annular gap that balances or only slightly balances the leakage force pressure caused by centrifugal forces.
• Cl- ⁇ tl is larger than the leakage fuel pressure, which ensures that, on the one hand, the fuel transition from the fixed fuel supply pin to the connecting channel leading to the fuel outflow opening in the rotor is sealed by fuel against the ingress of air and, on the other hand, no leakage fuel from the The mouth of the annular gap flows out in an uncontrolled manner.
• the retaining ring has an inner wall that tapers conically in the direction of the intake air flow.
• the storage space can be connected to the mouth of the annular gap via the space between the outer and inner ring of the ball bearing located upstream in the intake air flow.
• an additional centrifugal seal can be provided, which consists of a suction pin at the bottom of the rotor bore, in the end face of which the inlet opening of the connecting channel leading to the lateral fuel outflow opening, and a hollow cylindrical end piece of the fuel supply pin, which surrounds the suction pin without contact, is formed.
• the end piece of the fuel supply pin is preferably tapered, so that the inner end section has a correspondingly larger gap width in the narrow annular gap.
• the lateral fuel outflow opening opens into a concentric annular space which extends along a central part of the rotor, which is sealed off at the end upstream in the intake air flow, is connected to the storage space by at least one ventilation duct opening on the inside of the annular space, and on the outer circumference by a direction in the direction of the intake air flow is conically widening wall and is open at the downstream end, in particular through a number of bores to a concentric atomizing ring extending in the flow direction of the intake air.
• the fuel released from the fuel outflow opening into the annular space when the rotor rotates then flows in the form of a thin film on the conical wall of the annular space downstream and through the bores to the atomizing ring, from the spray edge of which it atomizes into a mist of the finest droplets is, air being additionally introduced from the storage space into the annular space through the ventilation duct.
• Such a ventilation of the annular space ensures a uniform and unimpeded flow of the fuel emitted from the fuel outflow opening to the atomizing ring for all speeds of the rotor and thus prevents the occurrence of pollutant peaks in the exhaust gases caused by irregular fuel flow.
• the atomizing ring can be offset radially outward from the conical wall of the annular space and can have an inner wall which narrows conically in the direction of flow of the intake air, so that when the rotor rotates, some fuel can accumulate inside the atomizing ring.
• the formation of such, albeit small fuel is depleted promotes smooth running "of the internal combustion engine and is particularly advantageous when abrupt transitions from high to niedri ⁇ gen rotor speeds.
• the central injection device according to the invention can be used to enrich a fuel mixture with fuel a higher load range of the internal combustion engine can be used.
• Such a use is characterized according to the invention in that by adapting the opening width of the storage space exposed to the intake air flow to the flow velocity of the air drawn in in the higher load area in the annular gap, an air pressure which counteracts the leakage fuel pressure in the annular gap is generated, which is less than in the higher load area is the leak fuel and allows leakage fuel to flow out of the annular gap in a controlled manner.
• the leaked fuel flowing out of the annular gap enters the storage space and is then either atomized via the storage ring or, in the case of an annular space connected to the storage space by ventilation channels, passed through the ventilation channels and the annular space to the atomizing ring and atomized by the latter.
• the correct opening width of the storage space in each case can be determined by experiment without difficulty, material being preferably removed from the inner wall of the storage ring until the exhaust gases have the desired CO values. It was found that in this way a CO content of 0.1 vol.?6 upwards can be set as desired.
• FIG. 1 shows a longitudinal section of the central injection device and FIG. 2 shows this central injection device in a top view.
• a hollow cylindrical housing 1 has central bearing blocks 4, 5 held on its two end faces by radial struts 2, 3, in which the outer rings of ball bearings 6, 7 are fastened.
• the upper bearing block 5 has a central fuel feed pin 8 on the inside width, the coaxial feed pin 8 of which Guide bore 9 is connected via a radially through the bearing block 5, one of its struts 3 and an outer radial extension 10 outwardly leading supply channel 11 with the intake pipe 12 immersed in a float housing 13.
• the rotor 14, which has a central bore 15 for the contact-free reception of the fuel supply pin 8, is fastened at its two end faces to the inner rings of the ball bearings 6, 7 and rotates around the fuel supply pin 8 as the axis of rotation.
• a lateral fuel outflow opening 16 which is designed as a nozzle or orifice and to which a connecting channel 17 leading to the outlet opening 9a of the supply bore 9 in the fuel supply pin 8 is connected within the rotor .
• the inlet opening 17a of the connecting channel 17 lies in the end face of a cylindrical suction pin 18 projecting from the bottom of the rotor bore 15, and the connecting channel 17 u comprises an initial section 17b leading downward from the inlet opening 17a with the axis of rotation, and an adjoining section via a radial section 17c.
• the central section 17d which is preferably parallel to the axis of rotation, and an in turn radial end section 17e with the lateral fuel outflow opening 16, which is higher than the inlet opening 17a of the connecting channel 17, the fuel level N via the float in the idle state of the rotor between the fuel outflow opening 16 and inlet opening 17a is set.
• the suction pin 18 is one part of a "centrifugal seal", the other part of which consists of a hollow cylindrical end piece 19 of the fuel feed pin 8, which surrounds the suction pin 18 without contact, the end piece 19 being somewhat smaller in outer diameter than the fuel Is supply pin 8 and so that between the outer wall of the fuel supply pin 8 and the wall of the Ro-
• Door bore 15 existing narrow annular gap 20 around the hollow cylindrical end piece 19 has an enlarged inner end region 21 which, via the space between the suction pin 18 and the hollow cylindrical end piece 19 with the outlet opening 9a of the supply bore 9 in the fuel supply line 9 pin 8 and is connected to the inlet opening 17a of the connecting channel 17.
• the impeller 30 is fastened to the rotor 14 with its sleeve 31, the wall 32 of the sleeve, which widens conically downward, defines an outer circumferential surface as an annular space 33 which extends along the rotor central part 14a.
• the lateral fuel outflow opening 16 of the rotor 14 opens into the annular space 33 near the upper closed end thereof.
• the annular space 33 is defined at the lower end by a number, e.g. Eight, of holes 34 approximately parallel to the axis of rotation in the inner flange 31a of the impeller sleeve 31 opened downwards.
• the impeller sleeve 31 is designed as an atomizing ring 35, which preferably has a conical inner wall 36 narrowing downward with an atomizing edge 37 lying below the wings 38 of the impeller.
• the impeller sleeve 31 has a concentric retaining ring 39, the diameter of which is larger than the outer diameter of the upper bearing block 5 and forms the circumferential wall of an annular storage space 40 open at the top for sucked-in air.
• the retaining ring 39 preferably has an inner wall 39a which widens conically upwards and has an edge lying above the wings 38.
• the upper ball bearing 7 is arranged such that it is at a distance both from the inner end face of the pedestal 5 and from the bottom of the storage space 40, so that the storage space 40 via the opening between the outer and inner ring of the ball bearing 7 and the space between the ball bearing 7 and pedestal
• V -iL _ _ ... r ⁇ 7 Vr ' I ⁇ J Front side is connected to the mouth 20a of the narrow annular gap 20.
• the rotor middle part 14a also contains at least one ventilation duct 42 which leads away from the bottom of the storage space 40 to the annular space 33 and opens into it approximately halfway up the same.
• the hollow cylindrical housing 1 of the central injection device forms part of the intake pipe and is connected by a conical intermediate piece 43 to the section 44 of the intake pipe containing the throttle valve 45.
• the fuel level N is set when the rotor is at rest between the inlet opening 17a of the connecting duct 17 and the fuel outflow opening 16, and since the opening 20a of the annular gap is still above the fuel outflow opening 16, no fuel can flow out of the rotor .
• the rotor bore 15 is filled with fuel in the area of the transition from the fuel feed pin 8 to the inlet opening 17a.
• the air sucked in by the internal combustion engine drives the impeller and, via this, the rotor, the speed of rotation of the rotor being linearly related to the flow rate of the sucked-in air and thus to the amount of air sucked in.
• Due to the acting centrifugal acceleration fuel is conveyed through the connecting duct 17 to the fuel outflow opening 16, fuel accumulating in the radial end section 17e of the connecting duct and fuel present at the fuel outflow opening 16 with a pressure which increases with the square the speed changes.
• the fuel discharged from the outlet opening 16 into the annular space 33 flows downward along its conical wall 32 and through the bores 3 to atomize it. exercise ring 35, and its spray edge 37 atomizes it into a fine mist.
• the fuel reserve present in the enlarged inner end region 21 of the annular gap 20 holds the fuel at all speeds Intermediate space between the suction pin 18 rotating with the rotor and the end piece 19 of the fixed fuel supply pin 8 is filled with fuel, so that even when the air pressure in the annular gap is slightly greater than the leakage fuel pressure, no air enters the connecting channel 17 and through it to the fuel channel. Outflow opening 16 can reach.
• the ventilation channel 42 leading from the storage space 40 to the annular space 33 ensures that when the rotor rotates on the outlet side of the fuel outflow opening 16, there is no additional suction effect via the conical wall 32 of the annular space 33 and the intended fuel dose tion is not impaired by the outflow opening 16.
• the opening ratio of the storage space 40 is determined experimentally via the diameter ratio of the storage ring 39 to the ball bearing holder or bearing block 5, in which the air pressure in the annular gap 20 is lower Load range is slightly greater than the leakage fuel pressure, but in the higher load range it is somewhat less than the leakage fuel pressure, and leakage fuel is additionally released from the annular gap 20 for enrichment.
• the change from slightly higher to lower air pressure in the annular gap takes place here in a sufficiently precisely defined small speed range, so that this is a controlled release of leak fuel.
• the gap between the impeller and the housing was dimensioned so that the following rotor speeds resulted in a motor vehicle engine:

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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)

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• 1982
  • 1982-09-29 US US06/426,648 patent/US4474712A/en not_active Ceased
• 1983
  • 1983-03-28 WO PCT/CH1983/000040 patent/WO1983004282A1/de not_active Application Discontinuation
  • 1983-03-28 JP JP58501060A patent/JPS59500978A/ja active Pending
  • 1983-03-28 EP EP83900898A patent/EP0110891A1/de not_active Withdrawn
  • 1983-05-13 IT IT21085/83A patent/IT1163363B/it active

Non-Patent Citations (1)

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