WO2001083977A1 - In tank fuel pump - Google Patents
In tank fuel pump Download PDFInfo
- Publication number
- WO2001083977A1 WO2001083977A1 PCT/AU2001/000505 AU0100505W WO0183977A1 WO 2001083977 A1 WO2001083977 A1 WO 2001083977A1 AU 0100505 W AU0100505 W AU 0100505W WO 0183977 A1 WO0183977 A1 WO 0183977A1
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- WO
- WIPO (PCT)
- Prior art keywords
- fuel
- pump
- breather
- motor
- fuel pump
- Prior art date
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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
- F02M37/00—Apparatus or systems for feeding liquid fuel from storage containers to carburettors or fuel-injection apparatus; Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines
- F02M37/04—Feeding by means of driven pumps
- F02M37/08—Feeding by means of driven pumps electrically driven
- F02M37/10—Feeding by means of driven pumps electrically driven submerged in fuel, e.g. in reservoir
Definitions
- the present invention is generally directed to fuel pumps for supplying fuel to an internal combustion engine, and in particular to fuel pumps suitable for location within a fuel tank.
- fuel systems commonly used to supply fuel to an internal combustion engine of a vehicle such as automobiles, motorcycles, scooters, boats and aircraft.
- These fuel systems are carburetor based fuel systems and injector based fuel systems.
- Carburetor based fuel systems can provide an air/fuel mixture to an inlet manifold of an engine, with fuel being drawn by the carburetor from a fuel tank through a fuel conduit extending into the tank.
- the carburetor provides a vacuum within the conduit and as the conduit can be located with its end adjacent the bottom of the tank the fuel tank can commonly be almost fully emptied by a carburetor.
- Fuel pumps may be driven by an electric motor, and may be conveniently located within a fuel tank.
- the electric motor of the pump, and in particular the commutator and brush of the electric motor are arranged so as to be flooded by the fuel held within the tank as this helps to prevent sparks being generated between the commutator and brush of the motor while it is running.
- the Applicant has developed fuel injection systems for small engine applications.
- An example of a small engine application is a motor-scooter having an engine with a capacity in the range of about 50cc to 100cc. It is preferable under these circumstances to have a relatively inexpensive fuel pump with a small current draw while at the same time providing sufficient pressure for a fuel injection system, particularly direct injection fuel systems that require fuel to be supplied at higher pressures than manifold (or port) injection systems.
- Typical in-tank pumps do not however provide such a combination of features and typically draw too high a current (in the order of 1.5A or greater) and hence represent a significant parasitic loss to a small engine application employing a fuel injection system.
- pumps that have low power draw typically supply fuel at insufficient pressure for effective operation of a fuel injection system.
- One type of pump which provides such features incorporates an elongate piston driven in a reciprocal movement by a cam and follower arrangement or by a linear slider mechanism.
- a pump is described in the Applicant's International Application No. PCT/AU99/00601 , details of which are incorporated herein by reference.
- the described pump is however particularly adapted for use as an "in-line” pump and has a fully sealed housing for the electric motor.
- Such a pump cannot be located in use in a fuel tank because the electric motor is not housed sufficiently for it to be safely flooded by fuel.
- an fuel pump locatable within a fuel tank including: a fuel pump housing; a pumping mechanism located within the housing for pumping fuel; an electric motor for driving the pumping mechanism, the motor being accommodated within a motor cavity within the housing; a fuel inlet for the pumping arrangement; wherein the fuel pump housing includes a breather arrangement for allowing air and fuel vapour within the cavity to escape therefrom when displaced by fuel passing into the motor cavity.
- the breather operates as a filter.
- the breather provides impedance to air flow into and out of the motor cavity after priming of the pump.
- the provision of a breather arrangement enables the motor cavity to be flooded with fuel when the fuel pump is located in a tank and fuel is admitted to the tank so as to reach a level that submerges the motor cavity.
- the fuel may enter through a fuel inlet of the pump and pass or percolate through the pumping mechanism and the electric motor and thereby force air trapped in the pump housing / motor cavity through the breather.
- the fuel inlet is positioned below the breather when the pump is located for use within a fuel tank. This enables the breather to assist with priming the pump.
- the breather arrangement may be in the form of a sintered breather plate or disc.
- This sintered breather may be located above the motor in a position that is either co-extensive with or adjacent an aperture in the fuel pump housing or may be located in an end cap separable from the rest of the housing when the fuel pump is located into its "in use" orientation.
- the remainder of the housing is preferably sealed so that the breather forms the primary mechanism through which air is admitted to and expelled from the motor cavity.
- the sintered breather may also be of a sufficient thickness to be able to act as a flame arrestor for preventing a flame caused by a spark from the electric motor's commutator and / or brush from causing a fire or an explosion in the motor cavity or fuel tank. I.e.
- the breather is of sufficient thickness to quench any flame or hot gasses developing within the motor cavity from escaping into the fuel tank.
- the thickness of the sintered breather may therefore for example be in the range of 2 to 2.5mm.
- the breather presents a mesh of 100 microns ( ⁇ m) and preferably the sintered material is of grade 60 and preferably the breather has a diameter approximately 10.5mm and a thickness of approximately 2.5mm.
- the breather could be made of other materials.
- the breather could be made of synthetic reverse osmosis materials which encourage flow preferentially in one direction.
- the fuel pump may include a fuel outlet through which fuel pumped by the pumping mechanism may exit the pump to a fuel supply circuit of a fuel injected internal combustion engine.
- the fuel exiting the fuel outlet may pass through a bypass regulator of the fuel supply circuit that may typically return a significant portion of the fuel back to the fuel pump. Typically, at least 50% of the fuel can be expected to be returned to the fuel pump under normal operating conditions. Under idle conditions of the engine, the fuel return may be up to about 98%.
- the returned fuel may be directed to a void (or a space) located above the sintered breather so as to allow the returned fuel to wet the breather.
- a spigot may support a fuel return line which may direct the fuel to the space above the breather.
- the motor is intermediate the breather and the inlet so that an additional advantage of the motor having fuel flowing through it may also be achieved.
- the abovenoted fuel return arrangement maintains the sintered breather in a wet condition.
- the breather has been observed to assist with priming of the pump as it allows air trapped in the motor cavity to escape. And when the level of fuel in the tank falls below the level of the breather a wetted breather is believed to create a partial vacuum in the motor cavity that assists with pumping of fuel. In this sense the breather may operate to provide selective impedance to air flow through the pump housing.
- the fuel pump When the fuel pump, according to the present invention, is used in a small engine application, for example a scooter, it is preferable that the fuel pump has a small current draw, for example 0.5 Amps at 14V and preferably no greater than 0.8 Amps at 14V, while, at the same time, providing fuel at sufficient pressure for a small engine port injected fuel system or a direct fuel injection system. Accordingly it is preferable that the pump supply fuel at pressures exceeding 400Kpa (Kilo Pascal) for this level of current draw and more preferably in excess of 600Kpa.
- Kilo Pascal Kelten Pascal
- a typical dual fluid direct injection fuel system (also known as a low pressure direct injection fuel system) delivers fuel at a pressure of 750Kpa and the pump has been observed to supply fuel at this pressure with a current draw of less than 0.8 Amps and typically in the order of 0.6 Amps. The pump has also been observed supplying fuel at pressure in the order of 20 Bar.
- the pumping mechanism may include an elongate piston, the length of which is substantially greater than the cross-sectional diameter of the piston.
- the piston may be slidably accommodated within an elongate piston passage.
- the piston when accommodated within the piston passage defines a variable volume pump chamber which is in fluid communication with the fuel inlet and fuel outlet of the fuel pump.
- the piston may be actuated for reciprocal movement by means of a crank pin and slider mechanism or conrod mechanism.
- This mechanism may include a crank pin supported on, and extending from, a drive shaft of the motor.
- the crank pin may engage a slider mechanism attached to one end of the elongate piston.
- the piston may be actuated by means of a conrod supported at one end on the motor drive shaft and the other end on the piston.
- the above-noted drive arrangements for the piston mechanism may be located within a chamber located within the fuel pump and in communication with the cavity locating the motor.
- a vent line may connect this chamber with the fuel inlet to thereby allow for fluid flow into this chamber and, hence, into the motor. Where a partial vacuum is created within the motor cavity, this vent line assists with communicating fuel from the inlet valve area to the motor cavity. In this way the level of fuel in the motor cavity can be greater than the level of fuel in the tank. The fuel in the motor cavity is thereby believed to act as a secondary source of fuel for the inlet valve.
- a filter may be provided at the fuel inlet to filter the fuel entering the fuel pump from the fuel tank.
- the filter preferably has a mesh less than 100 /m, and preferably of a size comparable with any filter employed within a fuel injector of a fuel system supplied by the pump.
- a fuel pump according to the present invention is therefore particularly adapted for use within a fuel tank, with the electric motor being readily flooded with fuel to thereby prevent the generation of sparks between the commutator and brush. Furthermore, the breather arrangement also acts as a flame arrester if any such sparks are generated.
- the fuel pump also has the ability to substantially fully empty the fuel pump thereby helping to maximise the potential driving range of the vehicle in which the fuel pump is installed.
- a fuel pump of a fuel circuit for an internal combustion engine said fuel pump adapted for location in a fuel tank, said fuel circuit having an auxiliary fuel path and said fuel pump further adapted to receive said auxiliary path whereby in use a motor of said fuel pump is located in said auxiliary path.
- this aspect provides a fuel circuit for an internal combustion engine comprising a fuel pump and an auxiliary fuel path; said fuel pump adapted to receive said auxiliary fuel path whereby in use a motor of said pump is located in said auxiliary path.
- auxiliary fuel path is a fuel return circuit for in use returning excess fuel to said fuel tank.
- said pump comprises a filter intermediate said auxiliary path and said motor.
- said filter is a breather and preferably said motor is located in a motor cavity and said breather provides impedance to air flow into said motor cavity whereby in use said breather creates a partial vacuum in said motor cavity.
- said breather provides said impedance in use when wetted by fuel from said auxiliary path and preferably said breather provides minimal impedance when dry.
- said impedance is sufficient to create a partial vacuum capable of lifting fuel from an inlet filter to at least an inlet valve and more preferably to a motor cavity via a vent line communicating an area adjacent the inlet valve with the motor cavity.
- a fuel pump for an internal combustion engine comprising a fuel inlet located at a level below a breather in said pump; said breather providing impedance to air flow through said pump thereby creating at least a partial vacuum in said pump; said partial vacuum in cooperative association with said inlet so as to assist with drawing fuel through said fuel inlet.
- said breather is operatively located in association with a first cavity separate from an outlet side of said inlet valve; said first cavity in fluid communication with an area adjacent the inlet side of said inlet valve.
- said first cavity is a housing for a motor for said pump and a vent line provides fluid communication between said housing and said area adjacent the inlet side of said inlet valve.
- a fuel circuit for at least a dual fluid fuel injection system wherein fuel supplied by said fuel circuit comprises a first of said fluids and a propellant fluid comprises a second of said fluids; said fuel circuit comprising a fuel pump adapted to provided fuel under pressure and at intermittent pulses and a pressure regulator for supplying said fuel to a fuel metering device; said pressure regulator operating at a differential pressure that is differential to the fuel pressure and the pressure of said second fluid; said differential pressure being less than said pressure pulses whereby metering of said fuel by said fuel metering device is precise to within predetermined tolerances.
- said fuel pump is a single chamber pump.
- said pressure differential is less than one quarter of said pressure pulse and more preferably it is less than one fifth of said pressure pulse.
- said second fluid is air that is supplied at approximately 500
- said pump has a displacement of 0.041 CC (cubic centimeters) per stroke and said fuel circuit supplies fuel to a 50CC engine.
- said pump has a DC motor that draws current in the range of 600mA to 200mA at terminal voltage varying between 14V and 7V. However at 12V it is also preferred that the pump draws approximately 450mA. At 14V the DC motor preferably operates at approximately 3900 RPM (revs per minute) and at 12V approximately 3300 to
- the pump may operate outside these specified ranges, however the specified ranges are preferred operational parameters. In particular it has been observed that such a 0.041 CC per stroke pump typically draws less than
- Figure 1 is a representative fuel injected small engine scooter.
- Figure 2a and 2b are schematic representations of fuel injected engines and associated fuel supply circuits suitable for use in the scooter of Figure 1 and other small engine applications.
- FIG 3 is a perspective view of a fuel pump of the type employed in the fuel circuit of Figures 2a and 2b;
- Figure 4 is a cross-sectional view of the fuel pump of Figure 3.
- the present embodiments are particularly suited to application as "in- tank" fuel pumps for small engine vehicles such as motorscooters, that utilise port injected fuel systems, low pressure direct injection fuel systems and other direct injection fuel systems for internal combustion engines. Examples of a low pressure dual fluid direct injection fuel system for an internal combustion engine is detailed in the applicants patents US 4,693,224; & US 4,934,329 incorporated herein by reference. Small engine vehicles and other applications typically have capacity in the order of 50cc to 100cc and they typically have low battery capacity and so a low current motor for the pump, in the order of 0.5 amps is particularly suitable.
- FIG. 1 is a schematic illustration of a scooter 300 being a representative small engine application for an in-tank pump, will now be described.
- the scooter has a front wheel 305 and a rear wheel 310 which support a chassis and associated panel work 315 off of a road surface 320.
- the chassis and panel work 315 comprises a rider area 325 which typically consists of a seat that is capable of supporting two riders.
- the rider area 325 is located above the rear wheel 310.
- An engine and associated drive mechanism 330 is mounted intermediate the rider area 325 and the rear wheel 310.
- Handle bars 335 are rotationally mounted to the chassis and panel work 315 and further support shock absorbers 340 that located the front wheel 305 onto the scooter 300.
- a rider positions themselves onto the rider area and locate their feet on foot rests 345 located on a floor pan 350 of the chassis and associated panel work 315. These foot rests 345 are located intermediate the base of handle bars 335 and the rider area 325.
- the handle bars 335 contain a mechanical throttle actuation mechanism which may be actuated by the rider rotating their hand.
- the handle bars 335 also contain an ignition switch which activates an electrical circuit between a battery, located adjacent the engine and associated drive mechanism 330, and an electronic control unit and other electrical components, such as a fuel pump and headlights 355.
- the scooter has a single cylinder fuel injected engine with small capacity which may be in the range of 50CC to 100CC though utilisation of an increased capacity engine is also possible.
- a fuel tank supporting an in-tank pump may be located underneath the riders area 325. The in-tank pump supplies fuel to a fuel supply circuit that is in communication with a fuel injector of the engine.
- FIG. 2a and 2b each of which is a schematic representation of an engine and an associate fuel supply circuit suitable for use with the scooter of Figure 1 and other fuel injected applications and in particular small engine applications.
- the engine and associated fuel system of Figure 2a is a direct injected single cylinder two stroke engine 50 having a fuel tank 1 which communicates fuel to a fuel injector 5 by means of a fuel pump 3 located within fuel tank 1 as described in this specification.
- the fuel supply circuit also includes fuel pressure regulator 4 and fuel supply line 52 and fuel return line 53.
- the fuel injector 6 meters fuel to a fuel delivery injector 7 in accordance with metering signals received from engine control unit (ECU) 11.
- the fuel delivery injector 7 is in fluid communication with compressed air via air supply line 70 that receives compressed air from air compressor 13.
- the compressor 13 is driven by a roller follower that is activated by an eccentric cam 68 that is mounted to or that forms part of a flywheel 67.
- the fuel delivery injector 7 uses compressed air as a propellant to deliver fuel metered by the fuel injector 5 to combustion chamber 61 of engine 50. Further examples of fuel systems of this type may be found in the Applicant's United States Patents US 4,693, 224 and US 4,934,329 referred to previously.
- the fuel delivery injector 7 delivers a spray of fuel to the combustion chamber 61 in a manner so that the fuel passes across a spark gap of spark plug 8.
- the spark plug is controlled by ignition coil 10 which in turn is activated by ECU 11.
- the engine 50 operates by establishing a stratified charge of fuel in the combustion chamber which is ignited by spark plug 8.
- the spark plug ignites the fuel spray as it issues from the fuel delivery injector 7 so as to provide a spray guided combustion system.
- Airflow is provided to the combustion chamber 61 via air box 18 and air filter 19.
- the air box 18 is in fluid communication with an inlet manifold 65 intermediate throttle 16 and inlet reed valve 64.
- a combined manifold absolute pressure (MAP) sensor and temperature sensor 20 often referred to as a TMAP sensor is located in the inlet manifold.
- the TMAP sensor provides MAP signals to ECU 11 that indicate pressure in the inlet manifold 65 and that similarly provides temperature signals to the ECU 11 that indicate the temperature of air entering the engine 50.
- the TMAP sensor 20 is an analogue sensor whose signals may be sampled by ECU 11 through use of analogue to digital conversion techniques and digital sampling filtering techniques. Air flow to the engine is in part controlled by the position of throttle 16.
- This position is indicated to ECU 11 by throttle position sensor 15.
- Oil is supplied to the engine 50 by oil pump 17 which is controlled by ECU 11 and which receives oil from oil tank 12.
- Electrical power is supplied to the engine (including the fuel pump), at least at cranking, by battery 22 and ignition switch 21.
- the ECU 11 receives information as to the position of piston 60 within the combustion chamber 61 by crank shaft position sensor 14 and an encoder wheel 66 mounted on fly wheel 67.
- Encoder wheel 66 comprises a number of teeth, typically 24 (one of which may be missing so as to provide a reference tooth) which pass by position sensor 14.
- the teeth interact with position sensor 14 so as to generate a square wave signal as input to ECU 11. the square wave is commonly edge detected by the ECU 11 resulting in detection of each leading edge of the encoder wheel 66 as it passes position sensor 16.
- the information as to the position of the piston 60 within combustion chamber 61 is commonly referred to as the engine's crank angle.
- a two stroke engine cycle is said to have 360 s of crank angle whereas a four stroke engine cycle is said to have 720 s of crank angle.
- an engine's crank angle corresponds to the instantaneous position of the engine within its current engine cycle. This position is measured relative to the engines top dead center (TDC) position, which for a two stroke engine is the point of maximum compression on any engine revolution and for a four stroke engine is the point of maximum compression on an intake (i.e. compression) stroke and which is often referred to as TDC firing.
- TDC top dead center
- a 24 tooth encoder provides 15 Q of crank angle resolution for both a two stroke and a four stroke engine.
- FIG 2b is a schematic representation of a single cylinder four stroke port injected engine 150 similar to the two stroke engine 50 of Figure 4a.
- the four stroke engine 150 has a fuel tank 101 that communicates fuel to a fuel injector 111 under control of an ECU 116 via a fuel filter 102, an in tank fuel pump 103, and a fuel pressure regulator 104.
- a fuel pressure regulator 174 is formed integrally with the pump 103, or if not integrally with the pump at the point where the pump is mounted to the fuel tank 101. Accordingly, a single fuel supply line 172 extends from regulator 174 to fuel injector 172.
- a fuel return path 173 extends from the regulator 174 to the pump 103.
- Air is inlet to the combustion chamber 161 via air box 105 that houses air filter 106 and inlet manifold 165 that houses a throttle 109, a TMAP sensor 107, a throttle air bypass valve 108 and fuel injector 111.
- An air inlet valve 151 is actuated under operation of a cam (not shown) so as to communicate air in the inlet manifold with the combustion chamber.
- Fuel injector 111 sprays fuel into the inlet manifold which fuel is then transported into the combustion chamber 161 by the inlet air so that a homogenous charge of fuel is formed within combustion chamber 161.
- Spark plug 112 operates under the control of ignition coil 113 which is in turn controlled by ECU 116.
- An exhaust valve 152 is actuated under operation of a cam to permit egress of combustion gasses from the combustion chamber on an exhaust stroke.
- An engine temperature sensor 114 indicates engine temperature to the ECU 116.
- the engine 150 has an engine position sensor 115 and corresponding encoder wheel for indicating the engine's instantaneous crank angle when operational.
- the engine 150 (including fuel pump 103) is supplied electrical power, . at least at cranking, by means of a battery 118 and an ignition switch 117.
- the fuel pump includes a fuel pump housing 1 within which is located an electric motor 3 and pump arrangement 5. Located at one end of the fuel pump housing 1 is an intake filter 7 for filtering fuel entering the fuel inlet 9 of the fuel pump.
- the filter 7 is located at or near the bottom of the fuel tank and may be located within a depression in the bottom of the fuel tank. Fuel passing through the filter 7 into the fuel inlet 9 passes through an inlet valve assembly 11. This inlet valve assembly 11 is described in detail in the Applicant's International Application No.
- PCT/AU99/00601 PCT/AU99/00601 and will therefore not be described herein in any detail, however it should be noted that this arrangement does provide a pump that is efficient at high pressure, which allows for lower levels of current to be drawn by the pump motor compared with less efficient pumps of similar capacity (which capacity is in the order of 0.04 CC per stroke).
- a further feature of the pump is that it can be arranged to displace lower volumes of fuel at high pressures suitable for small engine fuel injection applications. By displacing lower volumes of fuel compared with typical fuel pumps (along with being relatively efficient), the pump has a lower current draw, which is advantageous for small engine applications where the parasitic losses to engine power of a high current fuel pump can be significant.
- the configuration of the pump arrangement 5 means that the output of the pump has a pulsating or intermittent characteristic. Further detail on the effect of this intermittent characteristic is provided herein.
- the intake filter 7 may be of a woven fabric such as a woven nylon, polyester or other suitable plastics and / or fabrics well known in the art and preferably has a mesh size less than 100 ⁇ m, although a smaller mesh size comparable to any mesh utilised as a filter in a fuel injector supplied with fuel by the fuel pump may also be used.
- the intake filter is of a type having an inlet tube extending to the base of the filter.
- the inlet tube has apertures adjacent the base of the filter so that fuel is drawn by the inlet valve assembly from adjacent the base of the filter. In operation fuel passes from the inlet valve assembly 11 into a pump chamber 13 of the pumping arrangement 5.
- the pumping arrangement 5 includes an elongate piston 15 located within a piston passage 17 which together define the variable volume pump chamber 13.
- the piston 15 is driven for reciprocal movement by a drive arrangement 19 which includes a crank pin 21 supported on, and extending from, a drive shaft 6 of the electric motor 3.
- the crank pin 21 co-operates with a one end of a conrod mechanism 23 which is supported at the other end by the piston 15.
- the conrod, its supporting structure and engagement mechanism with crank pin 21 are constructed from a self lubricating plastic suitable for high pressure velocity applications such as Polyetheretherketone (PEEK) as described in the Society of Automotive Engineers (SAE) paper 970244 "Lubriacted Thermoplastic Composites for High P-V Applications" Williams, E.H.
- PEEK Polyetheretherketone
- Other materials such as PPS(OBG) and PPA(BQU) which are also described in SAE 970244 Williams, E. H. may form suitable alternatives.
- the drive arrangement 19 is supported within a chamber 25 located under and open to the electric motor 3.
- An internal vent line 27 communicates this chamber 25 with the fuel inlet 9 at a location on the inlet side of fuel inlet valve assembly 11.
- the vent line 27 and the inlet side of the fuel inlet valve assembly 11 have a proximity such that the fuel inlet valve assembly 11 can draw fuel from or access fuel supplied from chamber 25 via vent line 27.
- Fuel pumped from the pumping chamber 13 passes through a fuel outlet valve 29 and through a fuel outlet passage 31 to a fuel outlet 33 of the fuel pump.
- the fuel inlet is at a level below the fuel outlet. This is advantageous in certain "in tank” applications, though it is not believed to be essential to the operation of the embodiment.
- a pressure relief valve 50 communicates fuel from the outlet passage 31 to chamber 25 when pressure within the outlet passage 31 exceeds a pre-determined minimum value.
- the relief valve 50 operates according to principles known in the art and accordingly is not further described.
- the electric motor 3 is supported within a motor cavity 10 in the fuel pump housing 1. This cavity 10 is closed off at the top thereof by an end cap 12. Supported within the end cap 12 is a sintered breather 2. This sintered breather 2 is positioned adjacent an aperture 8 passing through the end cap 12. The breather allows air to flow from the motor cavity to a point external of the pump.
- the fuel pump When the fuel pump is located within a fuel tank, the fuel pump can be totally submerged within the fuel. In these situations, fuel can pass through the fuel inlet 9, through the inner vent line 27 into the cavity 25 and hence through the motor cavity 10. The fuel passes or percolates through the electric motor 3 and any air or fuel vapour within that motor cavity 10 passes out through the sintered breather 2 and the aperture 8 out of the fuel pump. This allows fuel to rise within the motor cavity 10 to the level of the fuel in the tank which in turn allows the motor 3 to be flooded when the pump is submerged, or at least partially submerged, by fuel within a fuel tank. This flooding of the motor with fuel assists with preventing sparks being generated between the electric motor's commutator and brush (not shown). Flooding of the motor and the motor cavity means that in operation fuel is drawn by the inlet 9 and the variable volume chamber 13 from both the filter 7 and the motor cavity 10 via vent line 27. The primary draw however is believed to be through the inlet filter 7.
- a significant portion of fuel pumped through a fuel pump is returned to a fuel source such as a fuel tank.
- a fuel source such as a fuel tank.
- the fuel delivered from the fuel pump to a fuel circuit passes through a by-pass regulator (not shown) which ensures that fuel that is not delivered to the engine by the fuel circuit is returned via a return line to the fuel source.
- the return line is connected to a fuel return spigot 35 of the fuel pump. This allows returned fuel to enter a volume 37 above the sintered breather 2. This ensures that the breather 2 remains wetted with fuel when the fuel level in a fuel tank housing the pump drops below the level of the sintered breather 2.
- any flame that may arise within the motor chamber is believed to be quenched by use of a breather of sufficient thickness to prevent the flame escaping into the fuel tank generally and causing an explosion and to prevent hot gasses re-igniting once they have passed through the breather.
- the breather may be constructed of sintered metal. A thickness of between 2mm and 2.5mm is believed to be effective, however 2.3mm has been found to be sufficient for a small engine application fuel pump. A breather having a diameter of approximately 10.5mm and a thickness of approximately 2.5mm and that is constructed from grade 60 sintered material so as to present a mesh of approximately 100 ⁇ m has been found to be particularly effective, however a breather presenting a mesh in the range of 80 ⁇ m to 120 ⁇ m is also believed to be effective. It is also believed that other materials providing impedance to air flow may also provide effective alternatives to the sintered breather material detailed. For example metal woven mesh or alternate forms of flame arrestors may also be suitable.
- Alternate embodiments may not have a fuel return circuit or may not locate the fuel return path adjacent an aperture into a cavity housing the motor.
- an additional fuel path such as a branch line from a main supply line or a return line, that feeds fuel to the breather so as to maintain the breather in a wetted state or so as to maintain fuel flow over the motor is envisaged.
- breather Whilst it is often not necessary to provide a breather in a fuel circuit that returns fuel through an in-tank motor, in some applications it is preferable that such a circuit have such a breather or filter. Alternatively, it believed that acceptable operation may be derived from a pump having a breather and a fuel return circuit that bypasses the breather.
- the in-tank fuel pump mechanism of figures 4a and 4b is a single chamber arrangement that provides higher efficiency (in the order of 30%) at higher pressures and lower flow rates than standard fuel pumps (that are in the order of 15% efficient). This enables the pump to draw less than 800mA and typically 500mA when used in a small engine application, such as a motorscooter.
- the pump has an intermittent output, that is seen as pressure pulses of fuel within the fuel supply circuit.
- fuel is typically metered to an air assisted delivery injector via a fuel injector commonly used in port injected systems.
- the fuel injector needs to see a relatively stable fuel pressure at its fuel inlet.
- the fuel pressure seen by the fuel injector inlet it is common for the fuel pressure seen by the fuel injector inlet to be set relative to the pressure of the second fluid, typically compressed air.
- the delivery injector is in continuous communication with a pressurised source of the second fluid.
- the fuel supply circuit typically has a higher pressure than the second fluid so that it can be metered into the delivery injector against the pressure of the second fluid.
- a differential pressure control regulator is typically used to achieve this differential pressure between the fuel supply pressure and the pressure of the second fluid.
- the pressure differential between the fuel supply pressure and the pressure of the second fluid be exceeded by the level of the pressure pulses by an amount such that a generally constant pressure is seen at the inlet to the fuel injector that meters fuel into the fuel delivery injector. This generally constant pressure should be sufficient to allow metering of fuel into the fuel delivery injector within predetermined metering tolerances.
- a pump of the embodiments above having a 4mm diameter plunger that delivers 0.041 CC per stroke, at a pressure differential of 250Kpa between fuel pressure and compressed air was found to be sufficient.
- fuel pressure was approximately 750Kpa and the pressure of the compressed air was approximately 500Kpa.
- the pump operated off of a DC motor with a frequency of 3900 strokes per minute with a 14V supply across the terminals and at 12V the pump typically operates between 3300 and 3400 strokes per minute. Accordingly a typical pump in production can be expected to draw less than approximately 11.2 watts of electrical power (i.e.
- a pump having a 4mm plunger and a breather with a diameter of approximately 10.5mm, a thickness of approximately 2.5mm and presenting a mesh of approximately 100 ⁇ m was capable of lifting fuel through a negative suction head of between 20 and 25mm for terminal voltage in the range 8 - 14 Volts with a dry breather. It has also been observed that with a wet breather, as provided by locating the breather in a fuel return path, the negative suction head range increased to 55 - 65 mm for the same terminal voltages. This increased negative suction head is believed to arise as a result of a partial vacuum within the motor cavity created by surface tension effects when the breather is wet and when the fuel level in the tank is below the level of breather.
- the increased negative suction head is also believed to draw fuel along vent line 27 and into the motor cavity resulting in the level of fuel in the motor cavity often exceeding the level of fuel in the tank. It is believed that this negative suction head allows the pump to almost fully empty a fuel tank (i.e. allows the pump to draw fuel from below the level of the inlet valve assembly 11).
- Present embodiments provide a fuel pump that may be located within a fuel tank and submersed in fuel.
- the fuel pump provides fuel at sufficient pressure for a direct injection fuel system and at sufficiently low power consumption that it can be utilised in small engine applications.
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Abstract
Description
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Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP01927496A EP1278954A4 (en) | 2000-05-03 | 2001-05-03 | In tank fuel pump |
AU54525/01A AU5452501A (en) | 2000-05-03 | 2001-05-03 | In tank fuel pump |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AUPQ7269 | 2000-05-03 | ||
AUPQ7269A AUPQ726900A0 (en) | 2000-05-03 | 2000-05-03 | In tank fuel pump |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2001083977A1 true WO2001083977A1 (en) | 2001-11-08 |
Family
ID=3821350
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/AU2001/000505 WO2001083977A1 (en) | 2000-05-03 | 2001-05-03 | In tank fuel pump |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP1278954A4 (en) |
CN (1) | CN1309953C (en) |
AU (2) | AUPQ726900A0 (en) |
TW (1) | TWI228571B (en) |
WO (1) | WO2001083977A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2107233A1 (en) * | 2008-04-04 | 2009-10-07 | Kwang Yang Motor Co., Ltd. | Installation structure for fuel pump and pressure regulating valve of motorcycle |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4693809B2 (en) * | 2007-04-03 | 2011-06-01 | 三菱電機株式会社 | Fuel pump module |
IT1393176B1 (en) * | 2009-02-27 | 2012-04-11 | Icomet Spa | DEVICE FOR THE ACCOMMODATION OF AN LPG PUMP IN A TANK SUITABLE FOR ALLOWING THE PUMP WITHOUT EMPTYING THE LPG TANK PRESENT IN HIS PREVIOUSLY |
CN108119273B (en) * | 2016-11-28 | 2020-05-08 | 长城汽车股份有限公司 | Fuel pump and fuel supply system |
CN113550851B (en) * | 2021-08-27 | 2022-12-13 | 山东速力动力科技有限公司 | Starting exhaust device for engine fuel control system |
Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2157803A (en) * | 1984-04-25 | 1985-10-30 | Facet Enterprises | Vent-relief valve for a wet motor gerotor fuel pump |
US4619588A (en) * | 1984-04-25 | 1986-10-28 | Facet Enterprises, Incorporated | Wet motor gerotor fuel pump with vapor vent valve and improved flow through the armature |
DE3540260A1 (en) * | 1985-11-13 | 1987-05-14 | Bosch Gmbh Robert | Unit for feeding fuel from a storage tank to an internal combustion engine |
US4712524A (en) * | 1985-05-24 | 1987-12-15 | Orbital Engine Company Proprietary Limited | Fuel injection system |
DE4038875A1 (en) * | 1990-08-30 | 1992-03-12 | Vdo Schindling | Fuel pump with valve for motor vehicle IC engine - incorporates vent for airexpulsion from engine space into which fuel enters at commencement ofstroke |
US5146901A (en) * | 1992-02-03 | 1992-09-15 | General Motors Corporation | Vapor suppressing fuel handling system |
EP0536719B1 (en) * | 1991-10-07 | 1996-03-27 | Yamaha Hatsudoki Kabushiki Kaisha | Vehicle engine |
DE19519689A1 (en) * | 1995-05-30 | 1996-12-05 | Ruediger Ufermann | Pneumatic fuel injection for IC engine |
RU2099581C1 (en) * | 1995-01-10 | 1997-12-20 | 21 Научно-исследовательский испытательный институт (автомобильной техники) Минобороны Российской Федерации | Fuel nozzle |
JPH10252596A (en) * | 1997-03-11 | 1998-09-22 | Nissan Motor Co Ltd | Fuel tank for vehicle |
EP0903489A2 (en) * | 1997-09-23 | 1999-03-24 | Honda Giken Kogyo Kabushiki Kaisha | Fuel supply unit for vehicle |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11241659A (en) * | 1998-02-25 | 1999-09-07 | Mitsubishi Electric Corp | Fuel supply device |
-
2000
- 2000-05-03 AU AUPQ7269A patent/AUPQ726900A0/en not_active Abandoned
-
2001
- 2001-05-03 TW TW090110629A patent/TWI228571B/en not_active IP Right Cessation
- 2001-05-03 EP EP01927496A patent/EP1278954A4/en not_active Withdrawn
- 2001-05-03 WO PCT/AU2001/000505 patent/WO2001083977A1/en not_active Application Discontinuation
- 2001-05-03 AU AU54525/01A patent/AU5452501A/en not_active Abandoned
- 2001-05-03 CN CNB01811783XA patent/CN1309953C/en not_active Expired - Fee Related
Patent Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2157803A (en) * | 1984-04-25 | 1985-10-30 | Facet Enterprises | Vent-relief valve for a wet motor gerotor fuel pump |
US4619588A (en) * | 1984-04-25 | 1986-10-28 | Facet Enterprises, Incorporated | Wet motor gerotor fuel pump with vapor vent valve and improved flow through the armature |
US4712524A (en) * | 1985-05-24 | 1987-12-15 | Orbital Engine Company Proprietary Limited | Fuel injection system |
DE3540260A1 (en) * | 1985-11-13 | 1987-05-14 | Bosch Gmbh Robert | Unit for feeding fuel from a storage tank to an internal combustion engine |
DE4038875A1 (en) * | 1990-08-30 | 1992-03-12 | Vdo Schindling | Fuel pump with valve for motor vehicle IC engine - incorporates vent for airexpulsion from engine space into which fuel enters at commencement ofstroke |
EP0536719B1 (en) * | 1991-10-07 | 1996-03-27 | Yamaha Hatsudoki Kabushiki Kaisha | Vehicle engine |
US5146901A (en) * | 1992-02-03 | 1992-09-15 | General Motors Corporation | Vapor suppressing fuel handling system |
RU2099581C1 (en) * | 1995-01-10 | 1997-12-20 | 21 Научно-исследовательский испытательный институт (автомобильной техники) Минобороны Российской Федерации | Fuel nozzle |
DE19519689A1 (en) * | 1995-05-30 | 1996-12-05 | Ruediger Ufermann | Pneumatic fuel injection for IC engine |
JPH10252596A (en) * | 1997-03-11 | 1998-09-22 | Nissan Motor Co Ltd | Fuel tank for vehicle |
EP0903489A2 (en) * | 1997-09-23 | 1999-03-24 | Honda Giken Kogyo Kabushiki Kaisha | Fuel supply unit for vehicle |
Non-Patent Citations (3)
Title |
---|
DATABASE WPI Derwent World Patents Index; Class Q13, AN 1998-564325/48, XP002962003 * |
DATABASE WPI Derwent World Patents Index; Class Q53, AN 1998-375869/32, XP002962004 * |
See also references of EP1278954A4 * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2107233A1 (en) * | 2008-04-04 | 2009-10-07 | Kwang Yang Motor Co., Ltd. | Installation structure for fuel pump and pressure regulating valve of motorcycle |
Also Published As
Publication number | Publication date |
---|---|
EP1278954A1 (en) | 2003-01-29 |
AU5452501A (en) | 2001-11-12 |
AUPQ726900A0 (en) | 2000-05-25 |
CN1309953C (en) | 2007-04-11 |
EP1278954A4 (en) | 2005-08-03 |
TWI228571B (en) | 2005-03-01 |
CN1439076A (en) | 2003-08-27 |
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