EP4119782A1 - Dispositif d'alimentation en carburant et moteur à deux temps doté d'un dispositif d'alimentation en carburant - Google Patents

Dispositif d'alimentation en carburant et moteur à deux temps doté d'un dispositif d'alimentation en carburant Download PDF

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Publication number
EP4119782A1
EP4119782A1 EP21185729.7A EP21185729A EP4119782A1 EP 4119782 A1 EP4119782 A1 EP 4119782A1 EP 21185729 A EP21185729 A EP 21185729A EP 4119782 A1 EP4119782 A1 EP 4119782A1
Authority
EP
European Patent Office
Prior art keywords
section
supply device
fuel supply
throttle valve
lateral sections
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.)
Granted
Application number
EP21185729.7A
Other languages
German (de)
English (en)
Other versions
EP4119782B1 (fr
Inventor
Michael Grether
Johannes ALBER
Michael Raffenberg
Hannes Frank
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.)
Andreas Stihl AG and Co KG
Original Assignee
Andreas Stihl AG and Co KG
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 Andreas Stihl AG and Co KG filed Critical Andreas Stihl AG and Co KG
Priority to EP21185729.7A priority Critical patent/EP4119782B1/fr
Priority to US17/866,374 priority patent/US11713738B2/en
Priority to CN202210830023.XA priority patent/CN115614186A/zh
Publication of EP4119782A1 publication Critical patent/EP4119782A1/fr
Application granted granted Critical
Publication of EP4119782B1 publication Critical patent/EP4119782B1/fr
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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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
    • F02M9/00—Carburettors having air or fuel-air mixture passage throttling valves other than of butterfly type; Carburettors having fuel-air mixing chambers of variable shape or position
    • F02M9/08—Carburettors having air or fuel-air mixture passage throttling valves other than of butterfly type; Carburettors having fuel-air mixing chambers of variable shape or position having throttling valves rotatably mounted in the passage
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B25/00—Engines characterised by using fresh charge for scavenging cylinders
    • F02B25/14—Engines characterised by using fresh charge for scavenging cylinders using reverse-flow scavenging, e.g. with both outlet and inlet ports arranged near bottom of piston stroke
    • 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
    • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
    • F02M35/10—Air intakes; Induction systems
    • F02M35/1015—Air intakes; Induction systems characterised by the engine type
    • F02M35/1019—Two-stroke engines; Reverse-flow scavenged or cross scavenged engines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B25/00—Engines characterised by using fresh charge for scavenging cylinders
    • F02B25/20—Means for reducing the mixing of charge and combustion residues or for preventing escape of fresh charge through outlet ports not provided for in, or of interest apart from, subgroups F02B25/02 - F02B25/18
    • F02B25/22—Means for reducing the mixing of charge and combustion residues or for preventing escape of fresh charge through outlet ports not provided for in, or of interest apart from, subgroups F02B25/02 - F02B25/18 by forming air cushion between charge and combustion residues
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D9/00—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits
    • F02D9/08—Throttle valves specially adapted therefor; Arrangements of such valves in conduits
    • F02D9/10—Throttle valves specially adapted therefor; Arrangements of such valves in conduits having pivotally-mounted flaps
    • F02D9/1035—Details of the valve housing
    • F02D9/104—Shaping of the flow path in the vicinity of the flap, e.g. having inserts in the housing
    • 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
    • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
    • F02M35/10—Air intakes; Induction systems
    • F02M35/1015—Air intakes; Induction systems characterised by the engine type
    • F02M35/1017—Small engines, e.g. for handheld tools, or model engines; Single cylinder engines
    • 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
    • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
    • F02M35/10—Air intakes; Induction systems
    • F02M35/1015—Air intakes; Induction systems characterised by the engine type
    • F02M35/10196—Carburetted engines
    • 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
    • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
    • F02M35/10—Air intakes; Induction systems
    • F02M35/10242—Devices or means connected to or integrated into air intakes; Air intakes combined with other engine or vehicle parts
    • F02M35/10262—Flow guides, obstructions, deflectors or the like
    • 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
    • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
    • F02M35/10—Air intakes; Induction systems
    • F02M35/104—Intake manifolds
    • F02M35/108—Intake manifolds with primary and secondary intake passages
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B2710/00—Gas engines
    • F02B2710/03—Two stroke engines
    • F02B2710/034—Two stroke engines with measures for charging, increasing the power
    • 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
    • F02M1/00—Carburettors with means for facilitating engine's starting or its idling below operational temperatures
    • F02M1/02—Carburettors with means for facilitating engine's starting or its idling below operational temperatures the means to facilitate starting or idling being chokes for enriching fuel-air mixture
    • 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
    • F02M17/02—Floatless carburettors
    • F02M17/04—Floatless carburettors having fuel inlet valve controlled by diaphragm

Definitions

  • the invention relates to a fuel supply device of the type specified in the preamble of claim 1 and to a two-stroke engine with a fuel supply device.
  • a fuel supply device namely a carburetor, in which the intake duct in the carburetor is divided into a mixture duct and an air duct.
  • a partition section is provided in the carburetor.
  • means are provided for dethrottling the mixture duct and/or for throttling the air duct.
  • the dividing wall section can be slanted toward the throttle valve.
  • the invention is based on the object of creating a fuel supply device of the generic type which is easy to produce and achieves good separation of the mixture channel and air channel in the second end position of the throttle valve.
  • the intake duct section is usually machined in the region of the bearing points of the throttle shaft.
  • the machining area usually extends beyond the bearing area of the throttle shaft in order to prevent the throttle valve from jamming and tilting in the areas in which the throttle valve protrudes close to the intake port wall, even if the manufacturing tolerances are unfavorable.
  • a narrow connecting opening between the air duct and the mixture duct is formed in this area between the wall of the intake duct and the throttle valve.
  • the partition wall section protrudes into this area in order to close the connection opening, the partition wall section cannot be designed in one piece with the main body of the fuel supply device, since otherwise the machining of the intake port section in the area of the throttle shaft bearing is not possible as before.
  • the partition wall section projects as far as the throttle shaft and laterally up to the intake port wall, in order to enable good sealing and, on the other hand, that the movement of the throttle shaft is not impeded by the partition wall section will. This makes the production of the fuel supply device expensive.
  • the two areas of the fuel supply device result when the fuel supply device is mentally divided into two parts by a plane at the reference plane.
  • the throttle valve is arranged in the first area when it is in the end position is located.
  • the end position of the throttle valve in which the throttle valve lies at least partially in the recess, is the open end position of the throttle valve.
  • the throttle valve advantageously forms part of a partition that divides the intake channel into the mixture channel and the air channel.
  • the throttle valve advantageously largely frees up the flow cross section in the intake port.
  • the throttle valve advantageously has a further, closed end position in which the throttle valve largely closes the flow cross section in the intake port.
  • the middle section of the partition is hereinafter referred to as the middle section.
  • the lateral sections of the partition are referred to below as lateral sections.
  • the central section and the lateral sections are sections of a continuous mixture channel surface of the partition section facing the mixture channel and are located upstream of the recess.
  • the mixture channel area is therefore not interrupted. This allows fuel to flow freely from the center section to the side sections.
  • the lateral sections and the central section are sections of the surface of the partition section along which the mixture can flow in the second end position of the throttle valve, ie the mixture channel surface. Upstream of the throttle valve, the lateral sections form a separation edge for the flow in the mixture channel. This directs the flow from the middle Section to the lateral sections and from there via the connection openings formed in the partition section between the throttle valve, the intake port wall and the partition section.
  • connection openings extend between the throttle valve, the partition wall and the intake port wall.
  • the connection openings have a substantially triangular shape, with one side of the triangle being curved.
  • the flow flowing in the mixture channel is guided via the throttle valve and does not impinge on the end face of the throttle valve in the lateral sections.
  • the flow in the mixture channel can be guided well via the connection openings.
  • the mixture channel area in the lateral sections in the direction of flow does not decrease in relation to the reference area but runs parallel to the reference plane or increases in relation to the reference plane.
  • mixture flowing along the mixture channel surface in the lateral sections is conducted away via the connection openings.
  • the middle section lies at least partially in the first area.
  • the flow in the mixture channel in the second end position of the throttle valve flows at least partially against the end face of the throttle valve. If the throttle valve is pivoted out of the fully open position, the proportion of the end face of the throttle valve against which the mixture in the mixture channel flows increases continuously. Due to the fact that the end face is also subjected to flow in the second end position of the throttle valve, the change in flow when the throttle valve is opened is comparatively small, so that a disruption in mixture formation due to suddenly changing pressure conditions at the fuel opening, in particular at a main fuel opening, is avoided .
  • Mixture that flows onto the end face of the throttle valve is due to the curvature of the Front side of the throttle at least partially passed in the direction of the lateral sections and from there over the connecting openings.
  • the middle section at least immediately upstream of the recess, is at least in one area at a distance of at least 50% of the thickness of the throttle valve, in particular at least 80% of the thickness of the throttle valve, from the reference plane.
  • the central section is at a smaller distance from a partition plane of the partition immediately upstream of the cutout for the throttle valve over a length that corresponds to at least 30%, advantageously at least 50%, of the diameter of the throttle valve than the lateral sections.
  • the length of the middle section is measured parallel to the longitudinal center axis of the intake port section.
  • the flow in the mixture channel can be influenced in such a way that no mixture or only very small amounts of mixture can enter the air channel via the connecting openings and at the same time disturbances in mixture formation when the throttle valve is opened from the second end position are avoided.
  • the central section is at a smaller distance from the plane of the partition wall over its entire length than the lateral sections.
  • a comparatively large flow cross section can also be provided in the mixture channel.
  • the lateral sections advantageously have an overall width of at least 5 mm, in particular at least 7 mm.
  • the overall width of the lateral sections is the sum of the individual widths of the two lateral sections.
  • the overall width is measured perpendicularly to the longitudinal center axis of the intake port section.
  • the lateral sections have a total width of at least 50% of the smallest width of the mixture channel surface of the partition section, in particular at least 70% of the smallest width of the mixture channel surface of the partition section.
  • the overall width and the smallest width are measured perpendicularly to the longitudinal center axis.
  • the middle section advantageously has a width which is at least 30%, advantageously at least 50%, of the smallest width of the mixture channel surface of the partition section.
  • the width of the lateral sections and the middle section are measured perpendicularly to the longitudinal center axis and on the surface of the mixture channel.
  • the lateral sections preferably run at an angle to the reference plane, at least immediately upstream of the tear-off edge.
  • the lateral sections can run inclined in a sectional plane perpendicular to the longitudinal center axis to the reference plane.
  • the lateral sections are designed in particular in the form of ramps.
  • the tear-off edge extends over the entire width of the mixture channel surface of the partition section. In an alternative advantageous design, it can be provided that the mixture channel surface merges into the bottom of the recess for the throttle valve. A transition without a tear-off edge can be provided in this area.
  • the middle section is formed by a recess in the partition section.
  • the depression preferably runs concavely in a sectional plane perpendicular to the longitudinal center axis of the intake port section.
  • a different course of the depression can also be advantageous.
  • the bottom of the recess runs parallel to the longitudinal center axis of the intake port section.
  • the course parallel to the longitudinal center axis of the intake port section is provided in particular in a sectional plane perpendicular to the pivot axis of the throttle valve and parallel to the longitudinal center axis of the intake port section.
  • the indentation forms a section of the recess for the throttle valve.
  • the lateral sections run in a radius in a section perpendicular to the longitudinal center axis of the intake port section.
  • the radius connects to the intake port wall and is at least 2 mm, in particular at least 3 mm.
  • the radius with which the partition wall section merges into the intake port wall is significantly increased as a result. This increased radius is already sufficient to direct the flow away from the connection openings.
  • the lateral sections adjoin the middle section on both sides.
  • further sections which can be located in the first area or in the second area of the fuel supply device, extend between the lateral sections and the middle section.
  • a choke element is advantageously arranged upstream of the partition section.
  • the choke element is preferably a choke flap.
  • the choke flap, partition wall section and throttle flap advantageously form an approximately continuous partition wall between the mixture duct and the air duct.
  • the partition wall section is particularly advantageously designed in one piece with the base body of the fuel supply device.
  • an uninterrupted transition between the mixture channel surface of the partition wall section and the intake channel wall can be produced in a simple manner.
  • the molding of the partition wall section to the body also allows for easy manufacture. Due to the increased lateral sections of the mixture channel area, a mixture can largely be avoided from the mixture channel passing through the connecting openings formed between the intake channel wall, partition wall section and throttle valve into the air channel. At the same time, a sufficiently long surface can be made available for machining the area of the intake port section in which the throttle valve is mounted. This results in the fuel supply device being easy to manufacture and also in advantageous properties during operation.
  • the fuel supply device is preferably used with a two-stroke engine, in particular with a two-stroke engine working with a scavenging receiver.
  • the air duct section of the fuel supply device preferably forms part of an air duct of the two-stroke engine, which is used to supply fuel-free air for pre-storage in overflow ducts of the two-stroke engine.
  • the mixture channel section forms part of a mixture channel of the two-stroke engine, with which the mixture is advantageously fed into the crankcase interior of the two-stroke engine.
  • An independent inventive idea lies in the design of the middle section of the mixture channel area.
  • the middle section of the mixture channel surface is located at least directly upstream of the recess in the first region, the flow is directed against the end face of the throttle valve that is upstream in the direction of flow when the throttle valve is open.
  • the flow conditions change less strongly when the throttle valve is closed slightly from the fully open position on the front side of the throttle valve.
  • uncontrolled leaning of the mixture when closing the throttle valve can be avoided.
  • the lateral portions are in the reference plane or in the second region, mixture is directed across the connection openings and not towards the connection openings. As a result, the proportion of mixture that passes into the air duct when the throttle valve is closed and when the throttle valve is opened can be reduced compared to known designs.
  • the lateral sections are particularly preferably located at least directly upstream of the recess in the second area, so that the mixture flowing in the mixture channel is routed via the connection openings.
  • the fuel supply device is provided in particular in a two-stroke engine, preferably in the two-stroke engine in a hand-held, advantageously a hand-held working device.
  • the fuel supply device is in particular a carburetor.
  • the two-stroke engine 1 shows a two-stroke engine 1 schematically.
  • the two-stroke engine 1 can advantageously be provided as a drive motor in a working device, in particular in a hand-held working device, for example a chain saw, a cut-off grinder, a blower, a brush cutter, a lawnmower or the like.
  • the two-stroke engine 1 has a cylinder 2 in which a combustion chamber 3 is formed.
  • a piston 5 is mounted to go back and forth.
  • the piston 5 drives a crankshaft 7 , which is mounted rotatably about an axis of rotation 8 in a crankcase interior 9 .
  • the crankcase interior 9 is formed in a crankcase 4 and is separated from the combustion chamber 3 by the piston 5 .
  • An outlet opening 15 for exhaust gases leads out of the combustion chamber 3 .
  • a spark plug 32 protrudes into the combustion chamber 3.
  • a mixture channel 18 with a mixture inlet 10 opens on the cylinder 2 .
  • the mixture inlet 10 opens into the crankcase interior 9 and is fluidically connected to the crankcase interior 9 in the region of top dead center of the piston 5 .
  • the piston 5 preferably has at least one piston pocket 14 .
  • the two-stroke engine 1 has overflow channels 12 which fluidly connect the crankcase interior 9 to the combustion chamber 3 in the region of the bottom dead center of the piston 5 .
  • the overflow channels 12 open out with overflow windows 13 on the cylinder bore.
  • the two-stroke engine 1 comprises an air duct 19 which opens out with an air inlet 11 at the cylinder bore of the cylinder 2 .
  • the air inlet 11 is located in the area of the piston pocket 14 and connects the air duct 19 with the overflow windows 13 of the overflow ducts 12.
  • Four overflow ducts 12 are provided in the exemplary embodiment, of which the sectional view in FIG 1 two are visible. A different number and/or a different shape of overflow channels 12 can also be advantageous.
  • the overflow channels 12 connect the crankcase interior 9 in the area of bottom dead center 5 to the combustion chamber 3, so that the fuel/air mixture flows out of the crankcase interior 9 can flow into the combustion chamber 3 via the overflow channels 12 .
  • the overflow windows 13 are controlled by the piston 5 and open towards the combustion chamber 3 in the region of the bottom dead center of the piston 5 .
  • the combustion air is drawn in via an air filter 37 .
  • the air filter 37 has filter material 39 which separates a clean room 38 of the air filter 37 from the environment.
  • the mixture channel 18 and the air channel 19 are connected to the clean room 38 .
  • Air is sucked in via an intake duct 16 which opens out at the clean room 38 of the air filter 37 .
  • the intake channel 16 is divided into the air channel 19 and the mixture channel 18 by a partition wall 17 over at least part of its length.
  • a fuel supply device 20 is provided for supplying fuel.
  • the fuel supply device 20 has a base body 21. In the base body 21, an intake channel section 22 of the intake channel 16 is formed.
  • the fuel supply device 20 can be a carburetor, which supplies fuel as a function of the negative pressure prevailing in the intake channel section 22 .
  • the fuel supply device 20 is a membrane carburettor.
  • the fuel supply device 20 comprises a fuel valve which is opened and closed by a controller of the two-stroke engine 1 .
  • the fuel valve is in particular an electromagnetic valve, preferably a normally open valve or a normally closed valve. The fuel metered by the fuel valve is advantageously fed into the intake duct section 22 due to the negative pressure prevailing in the intake duct section 22 .
  • a throttle flap 25 is arranged in the intake duct section 22 .
  • the throttle flap 25 is advantageously pivoted with a throttle shaft 35 .
  • the throttle flap 25 has a diameter m.
  • the partition wall 17 has a partition wall section 27 upstream of the throttle shaft 35 and a partition wall section 28 downstream of the throttle shaft 35.
  • the intake channel section 22 has a longitudinal center axis 29 .
  • the longitudinal central axis 29 is the axis that connects the geometric centers of the intake channel section 22 to one another on the upstream and downstream end faces of the base body 21 .
  • the partition wall 17 divides the intake channel 16 into the mixture channel 18 and the air channel 19.
  • a main fuel opening 23 and several auxiliary fuel openings 24 open into the mixture channel 18 in the fuel supply device 20.
  • the main fuel opening 23 is arranged in the area of a venturi section 31.
  • FIG. 2 shows the fuel supply device 20 schematically in detail in longitudinal section.
  • the throttle valve 25 is pivoted about a pivot axis 45 with the throttle shaft 35 .
  • a choke valve 26 is arranged in the intake channel section 22 upstream of the throttle valve 25 in relation to the direction of flow 30 .
  • the choke flap 26 is pivoted about a pivot axis 46 with a choke shaft 36 .
  • the longitudinal center axis 29 of the intake duct section 22 intersects the pivot axes 45 and 46.
  • the pivot axes 45 and 46 are offset in the intake duct section 22 with respect to the longitudinal center axis 29 and do not intersect the longitudinal center axis 29.
  • the main fuel opening 23 is formed on a main fuel nozzle 40 shown in the sectional view in FIG 2 is shown partially cut.
  • the intake duct section 22 has a center plane 50 .
  • the center plane 50 contains the longitudinal center axis 29 of the intake port section 22 and runs parallel to the pivot axes 45 and 46.
  • the pivot axes 45 and 46 lie in the center plane 50.
  • the partition section 27 has a mixture channel surface 41.
  • the mixture channel surface 41 of the partition section 27 is the surface that delimits the mixture channel 18 in the illustrated end positions of the throttle valve 25 and choke valve 26 .
  • the partition section 27 has an air duct surface 42 which delimits the air duct 19 in the illustrated end positions of the throttle flap 25 and choke flap 26 .
  • the air duct surface 42 runs flat and approximately parallel to the center plane 50.
  • the choke flap 26 lies parallel to the center plane 50 in its fully open position.
  • the throttle flap 25 can be pivoted between a first end position 51, shown with a dashed line, and the second end position 52, shown with a solid line.
  • the throttle flap 25 In the first end position 21, the throttle flap 25 largely closes the flow cross section in the intake channel section 22.
  • the first end position 51 preferably corresponds to the position of the throttle valve 25 when idling.
  • the throttle flap 25 In the first end position 51, the throttle flap 25 is arranged completely downstream of the partition section 27 in the exemplary embodiment.
  • the throttle valve 25 In the second distortion 52, the throttle valve 25 largely frees the flow cross section in the intake channel section 22.
  • the throttle valve 25 In the second end position 52 , the throttle valve 25 encloses an angle ⁇ with the center plane 50 .
  • An upstream face 58 of the throttle flap 25 is on the side of the center plane 50 on which the mixture channel 18 runs.
  • the end face 62 of the throttle flap 25 lying downstream lies on the side of the central plane 50 on which the air duct 19 runs.
  • the angle ⁇ , which the throttle valve 25 forms with the center plane 50, can also be 0°.
  • a slight inclination of the throttle flap 25 in the opposite direction in its second end position 52 can also be provided.
  • the partition wall section 27 has a recess 48 on its side facing the mixture channel 18, into which the throttle flap 25 in its second end position 52 at least partially protrudes.
  • the partition section 27 and the throttle valve 25 overlap in the second end position 52, so that the partition section 27 is not arranged completely upstream of the throttle valve 25 in the second end position 52.
  • the partition wall portion 27 is located entirely upstream of the throttle shaft 35 .
  • the dividing wall section 27 has a depression 47 on its side facing the mixture channel 18 . Because of the depression 47 , the mixture flowing in the mixture channel section 18 flows against the end face 58 of the throttle valve 25 lying counter to the direction of flow 30 .
  • the recess 47 has a base 59 which runs parallel to the longitudinal center axis 29 in particular.
  • the bottom 59 of the depression 47 runs through the longitudinal center axis 29 closer to the air duct 19 than the end face 58 in the longitudinal section shown.
  • the throttle valve 25 protrudes with a peripheral region over its entire thickness d from the recess 48.
  • the end face 58 in the second end position 52 only extends over part of the thickness d of the throttle valve 25 from the recess 48 in the mixture channel 18 protrudes.
  • Throttle flap 25 advantageously protrudes in a peripheral region by at least 50%, in particular by at least 80% of its thickness d out of recess 48.
  • the throttle valve 25 has a side 57 facing the mixture channel 18 .
  • Side 57 is a flat side of throttle valve 25. Mixture flows along side 57 in second end position 52 of throttle valve 25 during operation. The side 57 delimits the mixture channel 18 in the second end position 52.
  • the side 57 of the throttle valve 25 forms an in 2 drawn reference plane 60. At the in 2 In the illustrated position of the fuel supply device 20, the reference plane 60, i.e. also the side 57 of the throttle valve 25 facing the mixture channel 18, is arranged horizontally, and the fuel opening 23 ( 1 ) is arranged above the partition wall section 27 . In this position of the fuel supply device 20 the middle section 53 of the mixture channel surface 41 runs below the reference plane 60.
  • the reference plane 60 divides the fuel supply device into two areas, namely a first area 71 and a second area 72.
  • the throttle flap 25 is arranged in its second end position 52.
  • the partition wall section 27 runs in the first area 71.
  • the main fuel nozzle 40 is arranged in the second area 72 in the exemplary embodiment.
  • the air duct 19 advantageously runs in the first area 71.
  • the middle section 53 has a distance e measured perpendicularly to the reference plane 60 at the edge of the recess 48 to the reference plane 60 .
  • the distance e is advantageously at least 50%, in particular at least 80%, of the thickness d of the throttle valve 25.
  • the distance e corresponds at least to the thickness d.
  • the distance e is greater than the thickness d.
  • the dividing wall 17 has a dividing wall plane 63 which runs in the middle of the dividing wall 17 .
  • the partition plane 63 advantageously runs parallel to the center plane 50.
  • the partition plane 63 coincides with the center plane 50.
  • the middle section 53 ( 3 ), which is shown in 2 runs through the sectional plane has a smallest distance f measured perpendicularly to the partition plane 63 to the partition plane 63 .
  • the distance f is over the entire length 1 of the middle section 53 (measured parallel to the longitudinal center axis 29 3 ) is less than a distance g between the lateral sections 54 and the partition plane 63.
  • the central section 53 has a distance f from the partition plane 63 over a length 1 immediately upstream of the recess 48 for the throttle valve 25, which is smaller than a distance g between the lateral Sections 54 to the partition plane 63 is.
  • the length 1 advantageously corresponds to at least 30%, in particular at least 50%, of the diameter m of the throttle valve 25.
  • the distance g of the lateral sections 54 to the partition plane 63 changes in the exemplary embodiment in the direction of flow 30, such as 2 indicates.
  • the lateral sections 54 accordingly do not run parallel to the partition plane 63.
  • the smallest distance f of the central section 53 from the partition plane 63 is constant in the flow direction 30 in the exemplary embodiment.
  • the smallest distance f is in each case the smallest distance between the middle section 53 and the partition plane 63 in each cross section perpendicular to the longitudinal center axis 29.
  • the recess 47 extends from the side of the partition wall section 27 facing the choke shaft 36 to the throttle valve 25 in its second end position 52.
  • the recess 47 has a width c on the side facing the throttle valve 25, which is measured perpendicularly to the longitudinal center axis 29.
  • the width c is measured at the mixture channel surface 41 .
  • the width c is advantageously at least 30%, in particular at least 50% of the smallest width b, measured in the same direction, of the mixture channel surface 41 of the partition section 27.
  • the smallest width b of the mixture channel surface is on the mixture channel surface 41 from one suction channel wall 56 to the opposite and perpendicular to the longitudinal center axis 29 measured.
  • the smallest width b runs in the region of the Venturi section 31.
  • the depression 47 has a length 1 which is advantageously at least 30%, in particular at least 50%, of the diameter m of the throttle flap 25. amounts to.
  • the length 1 is measured on the longitudinal center axis 29 in a plan view of the center plane 50 .
  • the recess 47 forms a central section 53 of the mixture channel surface 41.
  • lateral sections 54 extend on both sides of the central section 53.
  • the lateral sections 54 directly adjoin the central section 53.
  • further areas are arranged between the lateral sections 54 and the central section 53 .
  • the lateral sections 54 connect directly and without interruption to the intake port wall 54 .
  • the mixture channel surface 41 ends upstream of the recess 48 at a tear-off edge 43.
  • the tear-off edge 43 delimits the recess 48.
  • the recess 47 extends partially into the area of the throttle valve 25.
  • the length 1 of the recess 47 corresponds the length of the region of central section 53, which is lower than lateral sections 54 in relation to reference plane 60.
  • recess 47 extends to the upstream side of mixture channel surface 41, facing choke flap 26.
  • Mixture channel surface 41 is included the in the in 3
  • the sectional view shown shows a top view of the side of the partition wall 17 facing the mixture channel 18 when the throttle valve 25 and choke valve 26 are in the open end position 41 considered.
  • connection openings 55 are located downstream of the partition section 27 between the throttle valve 25 and the intake port wall 56. In the area of the connection openings 55, the intake port wall 56 is advantageously machined to prevent the throttle valve 25 from jamming when opening and closing.
  • the design of the connection openings 55 is also shown in the enlarged view in FIG Figure 3a shown.
  • the lateral sections 54 each end at a tear-off edge 43.
  • the middle section 53 extends over the width c, which is advantageously at least 30%, in particular at least 50%, of the smallest width b of the mixture channel surface 41.
  • the lateral sections 54 have a width a1 or a width a2.
  • the widths a 1 and a 2 of the two lateral sections 54 can be the same size or different sizes.
  • the lateral sections 54 have an overall width a which is the sum of the widths a 1 and a 2 .
  • the overall width a is advantageously at least 5 mm.
  • the overall width a is advantageously at least 50%, in particular at least 70%, of the smallest width b of the mixture channel surface 41.
  • the throttle valve 25 has a thickness d, which is advantageously 0.5 mm to 3 mm.
  • the lateral sections 54 are flat in the area arranged upstream of the throttle valve 25 .
  • the tear-off edge 43 is located approximately at the same height as the side 57 of the throttle valve 25 facing the mixture channel 18. The tear-off edge 43 is therefore advantageously located in the reference plane 60.
  • the lateral sections 54 run in the reference plane 60 (see Figures 6 to 8 ). 8 also shows the design of the tear-off edge 43 on the central section 53 at a distance from the longitudinal central axis 29.
  • a depression 47 is also provided on the partition wall section 27 .
  • the same reference symbols designate in all exemplary embodiments corresponding elements. Elements that are not described in detail for an exemplary embodiment are advantageously designed in accordance with one of the other exemplary embodiments.
  • the recess 47 is in the embodiment according to 9 formed less deep than in the previous embodiment.
  • the tear-off edge 43 extends continuously over the entire width of the mixture channel surface 41.
  • the lateral sections 54 extend, as in particular 11 12, upstream of the trailing edge 43 in the second region 72.
  • the main fuel nozzle 40 and the lateral sections 54 are advantageously arranged on the same side of the reference plane 60.
  • the main fuel nozzle 40 and the lateral sections 54 are advantageously arranged in the second region 72 .
  • the lateral sections 54 are designed as guide elements 44 .
  • the lateral sections 54 run in the direction of flow 30 inclined to the reference plane 60. As a result, the mixture of the in 3 shown connection openings 55 passed away.
  • the guide elements 44 are advantageously designed as ramps.
  • the lateral sections 54 run approximately parallel to the longitudinal central axis 29 and to the central plane 50.
  • the guide elements 44 run inclined at an angle ⁇ to the reference plane 60, which corresponds to the angle ⁇ .
  • the angle ⁇ between the guide elements 44 and the reference plane 60 is advantageously at least 5°, in particular at least 10°: It can also be provided that the guide elements 44 rise in the flow direction 30 .
  • a curved course of the guide elements 44 can also be advantageous.
  • the guide elements 44 advantageously extend over a length h in the first region 72, which is at least 3 mm, in particular at least 5 mm.
  • the guide elements 44 are also in 12 shown.
  • the partition wall section 27 is preferably formed in one piece with the base body 21 of the fuel supply device 20 .
  • the partition wall section 27 and the base body 21 are advantageously designed as a one-piece cast part.
  • the fuel supply device 20 is advantageously a carburetor, in particular a membrane carburetor. Metering fuel via an electromagnetic valve can also be advantageous.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Control Of Throttle Valves Provided In The Intake System Or In The Exhaust System (AREA)
EP21185729.7A 2021-07-15 2021-07-15 Dispositif d'alimentation en carburant et moteur à deux temps doté d'un dispositif d'alimentation en carburant Active EP4119782B1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
EP21185729.7A EP4119782B1 (fr) 2021-07-15 2021-07-15 Dispositif d'alimentation en carburant et moteur à deux temps doté d'un dispositif d'alimentation en carburant
US17/866,374 US11713738B2 (en) 2021-07-15 2022-07-15 Fuel feed unit and two-stroke engine having a fuel feed unit
CN202210830023.XA CN115614186A (zh) 2021-07-15 2022-07-15 燃料供应设备和具有燃料供应设备的二冲程马达

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP21185729.7A EP4119782B1 (fr) 2021-07-15 2021-07-15 Dispositif d'alimentation en carburant et moteur à deux temps doté d'un dispositif d'alimentation en carburant

Publications (2)

Publication Number Publication Date
EP4119782A1 true EP4119782A1 (fr) 2023-01-18
EP4119782B1 EP4119782B1 (fr) 2026-02-25

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EP21185729.7A Active EP4119782B1 (fr) 2021-07-15 2021-07-15 Dispositif d'alimentation en carburant et moteur à deux temps doté d'un dispositif d'alimentation en carburant

Country Status (3)

Country Link
US (1) US11713738B2 (fr)
EP (1) EP4119782B1 (fr)
CN (1) CN115614186A (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7813261B2 (ja) * 2023-05-29 2026-02-12 株式会社Willbe ガバナ装置

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102005003559A1 (de) 2005-01-26 2006-08-10 Andreas Stihl Ag & Co. Kg Vergaser
DE102006032475A1 (de) * 2006-07-13 2008-01-17 Andreas Stihl Ag & Co. Kg Vergaser
DE102010054838A1 (de) * 2010-12-16 2012-06-21 Andreas Stihl Ag & Co. Kg Zweitaktmotor
DE10362394B3 (de) * 2003-10-01 2017-03-02 Andreas Stihl Ag & Co. Kg Vergaseranordnung
US20210095619A1 (en) * 2019-09-30 2021-04-01 Andreas Stihl Ag & Co. Kg Fuel Supply Device

Family Cites Families (6)

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Publication number Priority date Publication date Assignee Title
JP2001295652A (ja) 2000-04-13 2001-10-26 Zama Japan Kk 層状掃気２サイクルエンジン
DE10345653B4 (de) 2003-10-01 2013-02-28 Andreas Stihl Ag & Co. Kg Vergaseranordnung
GB0407921D0 (en) 2004-04-07 2004-05-12 Ricardo Uk Ltd Carburettor
DE102010054840B4 (de) * 2010-12-16 2020-03-26 Andreas Stihl Ag & Co. Kg Zweitaktmotor
JP6411200B2 (ja) * 2014-12-10 2018-10-24 株式会社やまびこ 空気先導型２ストロークエンジン用の気化器
DE102019004063A1 (de) * 2019-06-08 2020-12-10 Andreas Stihl Ag & Co. Kg Gemischbildungseinheit und Zweitaktmotor mit einer Gemischbildungseinheit

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10362394B3 (de) * 2003-10-01 2017-03-02 Andreas Stihl Ag & Co. Kg Vergaseranordnung
DE102005003559A1 (de) 2005-01-26 2006-08-10 Andreas Stihl Ag & Co. Kg Vergaser
DE102006032475A1 (de) * 2006-07-13 2008-01-17 Andreas Stihl Ag & Co. Kg Vergaser
DE102010054838A1 (de) * 2010-12-16 2012-06-21 Andreas Stihl Ag & Co. Kg Zweitaktmotor
US20210095619A1 (en) * 2019-09-30 2021-04-01 Andreas Stihl Ag & Co. Kg Fuel Supply Device

Also Published As

Publication number Publication date
US20230013645A1 (en) 2023-01-19
EP4119782B1 (fr) 2026-02-25
US11713738B2 (en) 2023-08-01
CN115614186A (zh) 2023-01-17

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