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
  • F02M21/00—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form
  • F02M21/02—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form for gaseous fuels
  • F02M21/0218—Details on the gaseous fuel supply system, e.g. tanks, valves, pipes, pumps, rails, injectors or mixers
  • F02M21/023—Valves; Pressure or flow regulators in the fuel supply or return system
  • F02M21/0239—Pressure or flow regulators therefor
• • 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
  • F02M21/00—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form
  • F02M21/02—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form for gaseous fuels
  • F02M21/04—Gas-air mixing apparatus
  • F02M21/042—Mixer comprising a plurality of bores or flow passages
• • 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
  • F02M35/02—Air cleaners
  • F02M35/024—Air cleaners using filters, e.g. moistened
  • F02M35/02475—Air cleaners using filters, e.g. moistened characterised by the shape of the filter element
  • F02M35/02483—Cylindrical, conical, oval, spherical or the like filter elements; wounded filter elements
• • 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
  • F02M35/02—Air cleaners
  • F02M35/04—Air cleaners specially arranged with respect to engine, to intake system or specially adapted to vehicle; Mounting thereon ; Combinations with other devices
  • F02M35/042—Air cleaners specially arranged with respect to engine, to intake system or specially adapted to vehicle; Mounting thereon ; Combinations with other devices combined with other devices, e.g. heaters ; for use other than engine air intake cleaning, e.g. air intake filters arranged in the fuel vapour recovery system
• • 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
  • F02B43/00—Engines characterised by operating on gaseous fuels; Plants including such 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
  • F02M21/00—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form
  • F02M21/02—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form for gaseous fuels
  • F02M21/0203—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form for gaseous fuels characterised by the type of gaseous fuel
  • F02M21/0209—Hydrocarbon fuels, e.g. methane or acetylene
  • F02M21/0212—Hydrocarbon fuels, e.g. methane or acetylene comprising at least 3 C-Atoms, e.g. liquefied petroleum gas [LPG], propane or butane
• • 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
  • F02M21/00—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form
  • F02M21/02—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form for gaseous fuels
  • F02M21/0203—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form for gaseous fuels characterised by the type of gaseous fuel
  • F02M21/0215—Mixtures of gaseous fuels; Natural gas; Biogas; Mine gas; Landfill gas
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/10—Internal combustion engine [ICE] based vehicles
  • Y02T10/30—Use of alternative fuels, e.g. biofuels

Definitions

• This invention relates to air/fuel mixers for internal combustion (IC) engines.
• Air/fuel mixers for vehicles adapted to run on liquid petroleum gas (LPG) or compressed natural gas (CNG) and conventional motor spirit generally comprise a housing having an LPG or CNG fuel supply and including a manifold vacuum operated flexible rubber diaphragm for controlling dynamic air flow for variation of the fuel/air mixture ratio between that required for gas operation and that required for petrol operation.
• LPG liquid petroleum gas
• CNG compressed natural gas
• Such mixers are generally manufactured specifically for a particular engine.
• Such mixers are generally unique to type, mutually incompatible between types and non-adjustable.
• the rubber diaphragms used to control dynamic air flow in changing from LPG to motor spirit are easily deformed and deteriorate rapidly in the operating environment of the mixer and are of doubtful accuracy in controlling dynamic air flow. In general, no adjustments are available to accommodate different air/fuel ratios required for stoichiometric combustion.
• the present invention aims to substantially alleviate the above disadvantages and to provide dual fuel air/fuel mixers which will be reliable and efficient in use. Other objects and advantages of this invention will hereinafter become apparent.
• this invention in one aspect resides broadly in air/fuel mixer apparatus including:- a body member defining a flow path from an air inlet to an engine air intake; variable restriction means mounted in said air flow path; operating means for said restriction means and responsive to selection between a fuel gas supply means for supplying fuel gas to said air flow path downstream from said restriction means and a petrol supply means to the engine.
• the body member may take any suitable form and preferably takes the form of an assembly adapted to replace the conventional air filter assembly of a carburetted internal combustion engine or the inlet air manifold of an injected engine.
• the body member may comprise a pressed metal or moulded plastic assembly including a mounting portion adapted to mount to the air intake of a conventional carburetor.
• the body member may have defined therein a chamber adapted to be divided by conventional air filter element means into an air receiving chamber and a filtered air mixing chamber.
• the air receiving chamber is preferably provided with an air horn as an air intake, in common with conventional air cleaner assemblies.
• the body member is preferably circular in form to accept the standard annular air cleaner elements and may comprise a lower portion including the aforementioned mounting means and having a first sealing surface adapted to sealably engage the air cleaner element and an upper portion securable to the lower portion and being adapted to seal to the upper edge of the air cleaner element.
• the air horn is formed up to the cylindrical portion of the body member to form an air horn assembly which may be rotated relative to the upper and lower portions.
• variable restriction means may take any suitable form consistent with the function of variably restricting the flow of air through the flow path.
• the variable restriction means is preferably located downstream of the air filter.
• the variable restriction means preferably takes the form of a substantially circular plate mounted concentrically within the body member and adapted to vary the effective cross section of the flow path through the body member.
• the plate member is provided with movement limiting means adapted to provide a flow path cross section capable of meeting the air flow requirements of the IC engine running on gas and may be movable to provide a larger flow path cross section suited to the engine air requirements running on petrol.
• the operating means may take any suitable form consistent with the function of operating the variable restriction means in response to selection of fuel type.
• the operating means is mounted out of the air flow such that the operating means is not subject to the degradation caused by exposure to incoming air velocity and/or exposure to the gas fuel.
• the operating means may for example, comprise a diaphragm, piston or other means adapted to respond to selection of fuel type and may be mounted within or without the body member.
• the operating means comprise, in the case of the preferred round body member, vacuum powered operating means.
• the vacuum powered operating means may comprise a bellows member bonded to the aforementioned restrictor plate and secured to the body member such that application of vacuum depression to the interior of the bellows members alternately draws the restrictor plate towards and away from the attachment to the body member.
• the restrictor plate itself may comprise the working member, there being provided flexible skirt means or flexible portions of the restrictor plate to isolate the upper housing chamber above the plate from the air flow path.
• the restrictor plate and operating means assembly may be biased towards its gas operation position by means of biassing means which may comprise, for example, the inherent stiffness of the material of the bellows (if used), plate or skirt or separate biasing means such as a spring.
• connection between the bellow or upper chamber is made the vacuum source of the IC engine by means of a spigot providing fluid communication through the housing and into the bellows or upper chamber for connection of a vacuum line between the spigot and a suitable spigot provided on the vacuum source.
• the fuel gas supply means may take any form consistent with the function of providing suitable gas flow for mixing within the air to supply said IC engine.
• the fuel supply means may comprise a suitable gas regulator/vaporizer apparatus, delivering gas at a suitable line pressure and delivering same via control valve means to a fuel mixer assembly located downstream from the restriction means.
• the fuel gas supply assembly may comprise an annular array of fuel gas jets disposed about the air flow path downstream of the restriction means and preferably configured such that air flow draws gas into the carburetor intake.
• the annular array is preferably integrally formed with the body member.
• the fuel gas supply means may include an integrally formed annular manifold disposed about the mounting region of the body member and having an annular array of a plurality of gas supply jets disposed immediately about the mounting point and adjacent the air intake of the carburetor.
• the preferred manifold is preferably fed by means of a supply pipe mounted thereto, said supply pipe preferably mounting control means such as an economizer valve for control of gas supply whilst cruising and power valve and adjuster for providing increased gas flow under high load conditions.
• control means such as an economizer valve for control of gas supply whilst cruising and power valve and adjuster for providing increased gas flow under high load conditions.
• the apparatus is associated with fuel selector means adapted to allow the apparatus to function as an air filter assembly when the IC engine is being powered by motor spirit by closing off the fuel gas supply and adapted to close off the motor spirit supply where gas is supplied to the supply line.
• the vacuum source for operating the preferred vacuum powered operating means may be provided by any suitable means such as a vacuum pump, manifold vacuum (with or without an accumulator) or otherwise.
• the vacuum source may comprise a vacuum line connected to the vehicle manifold and the bellows or upper chamber, and controlled by valve means operable in concert with a fuel selector switch.
• valve means operable in concert with a fuel selector switch.
• closure of the valve may occur as a result of selection of gas fuel, allowing the plate restriction means to descend to its stops thereby configuring the apparatus for gas operation.
• Selection of petrol operation may open the valve, connecting the bellows or upper chamber to manifold vacuum, thereby raising the plate for petrol operation.
• the vacuum may be provided as a function of shutting off the supply of gas to the gas manifold by connection of a vacuum line between the aforementioned bellows or chamber spigot and a spigot provided in the gas supply line between the gas manifold and the gas supply closure means, whether it be at the gas vaporizer or in the line.
• Incoming air passing over the gas manifold openings when the gas is off causes a depression in the supply line downstream of the shut-off which causes the plate to be raised to its petrol operation position.
• FIGURE 1 is a cut away perspective view of apparatus in accordance with the present invention.
• FIG. 2 is a cut away perspective view of alternative apparatus in accordance with the present invention.
• FIG. 3 is a section through the apparatus of FIG. 2, and
• FIGS. 4 and 5 illustrate sections through power/economy valve suitable for use in the apparatus of FIGS. 1 to 3.
• FIGS. 1 and 2 there is illustrated respective fuel air mixer apparatus including a housing 10 of the form of a conventional air cleaner assembly and comprising a base portion 11, having a mounting flange 12 adapted to engage the air inlet of an engine carburetor.
• an annular seat 13 adapted to engage an air filter element 14 dividing the housing 10 into an air receiving chamber 15 and an air regulating and mixing chamber 16.
• the outer periphery of the housing 10 is provided with a side member 17 adapted to sealingly engage the base portion 11 and to sealingly receive a top portion 20.
• the top portion 20 is provided with an annular sealing portion 21 adapted to sealably engage an upper sealing surface of the air filter element 14.
• the top portion 20 secures the housing 10 to the carburetor by means of a centre bolt 22 adapted to engage a threaded stud mounte to the carburetor (not shown) .
• a regulator assembly 23 including a metal restrictor plate 24 mounted concentrically on a guide portion 25 of a centre bolt 22.
• the metal restrictor plate 24 has an annular restrictor portion 26 adapted to be moved relative to a corresponding base restrictor portion 27 integrally formed in the base portion 11 in the region of the mounting flange 12.
• the base restrictor portion 27 forms the upper and outer surface of a gas distribution manifold 30 adapted to receive gas from a gas supply line 31 and feed gas to the engine by means of a plurality of orifices 32 disposed about the air inlet to the carburetor.
• the annular restrictor portion 26 is provided with limit adjustor screws 33 defining the minimum opening of the gap between the annular restrictor portion 26 and the base restrictor portion 27.
• the upper surface of the metal restrictor plate 24 is isolated from the air regulating and mixing chamber 16 by means of flexible peripheral portion 37 adapted to be sealingly entrapped between the top of the air filter element 14 and the top portion 20.
• the air receiving chamber 15 receives air from atmosphere via an air horn 40.
• the gas supply line 31 receives gas from a vaporizer/regulator (not shown) and controls the delivery flow to the manifold 30 by means of an adjustable power/economy valve adapted to respond to demand of the IC engine and an economizer valve for control of cruise fuel mixture.
• the power/economy valve assembly has an adjustable power valve portion 42 and cruise adjuster screw 43.
• the power valve portion includes an occluding rod 50 movable into and out of the gas supply line 31, sealably and slidably mounted in a housing 51.
• the rod is constrained in the housing by a diaphragm (not shown for clarity) which bears on a piston 52 formed on the rod end.
• a spring 53 biases the rod 50 out of the gas supply line 31 in a "power" configuration.
• a spigot 54 is provided for connection of the interior of the housing 51 to the inlet manifold of th IC engine.
• manifold vacuum is high, such as at cruise and idle, the depression causes the rod 50 to occlude the supply line 31 against the spring 53 pressure.
• the spring 53 opens the supply line 31.
• the maximum power opening is controlled by adjuster screw assembly 55.
• the minimum passage allowable is controlled by the cruise adjuster screw 43.
• the restrictor plate 24 is biased towards the aforementioned minimum flow position by means of a spring 34 disposed about the centre bolt 22 and urging the restrictor plate 24 away from the top portion 20.
• Bonded to the upper surface of the restrictor plate 24 is an annular elastomeric bellows 35 which is similarly attached to the top portion 20, the interior of the bellows being placed in fluid communication with the intake manifold of the IC engine by means of a nipple 36, secured to and passing through the top portion 20 and into the bellows 35, for connection to the inlet manifold by means of vacuum line assembly (not shown), including control means comprising a valve adapted to shut off the vacuum in response to switching the fuel supply from petrol to gas.
• the restrictor plate is not controlled by a bellows or spring.
• the top portion 20 and plate 24 define an upper housing space 45 into which passes the spigot 36.
• a stub pipe 46 Located in the gas supply line downstream of the gas fuel cut off valve is a stub pipe 46 which is connected to the spigot 36 by a vacuum line 47.
• the upper housing space 45 tends to be isostatic with the gas supply line pressure at the stub pipe 46.
• air enters the air receiving chamber 15 by way of the air horn 40 and passes through the air filter element 14.
• the filtered air is drawn through the annular space between the restrictor portion 26 and base restrictor portion 27 by demand from the IC engine and thence into the original engine manufacturers carburetor.
• the limiting adjuster screws 33 which maintain a minimum separation between the respective restrictor portions 26, 27.
• Gas fuel from a regulator/vaporizer enters the gas supply line 31 by way of the power/economizer valve assembly to enter the gas distribution manifold 30 and then pass through the plurality of orifices 32, the air passing below the restrictor plate 24 creating a vacuum which draws the gas through the orifices 32 and hence into the original engine manufacturers carburetor.
• the present apparatus by virtue of the dimensional stability of the metal restrictor plate 24 maintains a more precisely controllable profile through the space defined between the annular restriction portion 26 and the base restrictor portion 27. This provides for more precise control of the air/fuel ratio in operation. Additionally, due to the greater stability over time of the metal restrictor plate 24 as opposed to a rubber diaphragm, the apparatus does not suffer from the problems of aging and deformity of the rubber diaphragm and hence provides accuracy of the mixing ratio of air to gas over an extended service life.
• the apparatus allows the use of existing original engine manufacturers carburetor, together with either LPG or CNG. Control of the air fuel ratio is infinitely adjustable allowing maximum flexibility though a wide range of engine types and sizes.
• the apparatus is suitable for use with engines using either leaded or unleaded petroleum motor spirit.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Output Control And Ontrol Of Special Type Engine (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=4971191

Family Applications (1)

Country Status (4)

Citations (9)

• 1992
  • 1992-08-10 CN CN92230160U patent/CN2129828Y/zh not_active Expired - Fee Related
• 1993
  • 1993-08-06 WO PCT/AU1993/000405 patent/WO1994003718A1/en active Application Filing
  • 1993-08-06 AU AU46906/93A patent/AU4690693A/en not_active Abandoned
  • 1993-10-01 TW TW082108060A patent/TW237510B/zh active

Patent Citations (9)

Also Published As

Similar Documents

Legal Events