Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02N—STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR
  • F02N3/00—Other muscle-operated starting apparatus
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/04—Introducing corrections for particular operating conditions
  • F02D41/06—Introducing corrections for particular operating conditions for engine starting or warming up
  • F02D41/062—Introducing corrections for particular operating conditions for engine starting or warming up for starting
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02N—STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR
  • F02N11/00—Starting of engines by means of electric motors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D2200/00—Input parameters for engine control
  • F02D2200/50—Input parameters for engine control said parameters being related to the vehicle or its components
  • F02D2200/503—Battery correction, i.e. corrections as a function of the state of the battery, its output or its type

Definitions

• the present invention is directed at the control of the fuelling rate to an internal combustion engine at start-up of the engine. More particularly, the present invention is directed at controlling the fueling rate at start-up as a function of the particular mode of starting that is used for the engine.
• a method of controlling the fuelling rate to an internal combustion engine during start-up of the engine including :-
• a method of determining the mode of starting for an internal combustion including :- (a) determining whether the engine is started by way of a manual arrangement or by way of an automated starting; means; and (b) providing an appropriate fuelling rate to the engine during start-up based on this determination.
• a "manual start” of the engine equates to the use of a “kick start” arrangement to start the engine.
• a “manual start” of the engine may also or alternatively equate to the use of a “pull-start” arrangement to start the engine.
• an "automated starting means” equates to an electrical means such as starter motor or like device.
• a starter motor needs to be provided with current from the battery at start-up leading to a drop in the battery voltage during engine starting.
• this battery current flow or voltage drain is one means of providing an indication that a starter motor is being used.
• the use of a kick or pull-start arrangement to start the engine typically does not require any current from the battery, and there is therefore no drop in the battery voltage when such a manual start is used.
• the battery voltage that is measured is typically the unfiltered battery voltage as could be read across the terminals of the battery by way of a sensor of a suitable engine management system.
• the engine is typically operatively arranged within a motor-scooter or other suitable vehicle or device which includes a key operated ignition switch.
• the vehicle or motor-scooter generally also includes a starter button or switch to actuate the starter motor and the operator must initially turn the ignition on before pressing the starter button.
• the engine management system measures the initial battery voltage once the ignition switch has been turned on and prior to starting of the engine.
• the engine management system becomes aware of the impending start-up of the engine when the starter button is activated or a manual start arrangement is used. Upon or subsequent to the commencement of engine rotation, the engine management system then measures the prevailing battery voltage. Preferably, the difference or delta between the initial battery voltage and the prevailing battery voltage subsequent to the commencement of engine rotation is compared against a predetermined threshold battery voltage value.
• the threshold value is conveniently selected so as to clearly provide an indication of the mode of starting that is being used for the engine. Where delta is less than the threshold value, the engine management system determines that a manual start arrangement is being used to start the engine and thus selects a first low fuelling level for the engine. Where delta is greater than the threshold value (ie. as a result of a drain or drop in the battery voltage), the engine management system determines that a starter motor is being used to start the engine and thus selects a second higher fuelling level for the engine.
• the engine management system may be initially set to provide an amount of fuel suitable for a manual or kick start of the engine. However, if a drop in the battery voltage is detected during start-up, then the engine management system may reset the amount of fuel to be provided to the engine such that the amount is suitable for a starter motor start-up of the engine. In this way, the minimum fuelling level at start-up is used unless it is determined a starter motor or like device is being used.
• the engine management system may typically include an electronic control unit (ECU) for controlling the fuelling rate to the engine and the timing of the ignition and fuel delivery to the engine.
• ECU electronice control unit
• One advantage of the method according to the present invention is that the ECU can detect the change in battery voltage at start-up, and hence there is no need to provide additional hardware on the engine to determine the mode of starting which is used. That is, the method is typically able to be implemented by way of code or software in the ECU.
• a further advantage of the present invention is that, to a certain extent, the same engine management system and/or ECU are able to be used across a range of vehicle applications where a first group of vehicles only incorporate one mode of starting for the engine and a second group of vehicles only incorporate the other mode of starting for the engine.
• Scooter engines and other vehicle engines typically include crankshaft position sensing means for determining engine speed and the crankangle of the engine.
• Such means typically include a toothed encoder disc or wheel arranged on the crankshaft and a corresponding sensor to provide encoder tooth signals to the ECU as the crankshaft rotates.
• the battery voltage may be timed to be measured at a predetermined tooth occurrence following start-up of the engine.
• the battery voltage may for example be measured at the occurrence of the first or second tooth after the start of engine rotation.
• the second tooth can be chosen to avoid any erroneous signals, due to rocking of the scooter'while stationary or other movement not associated with the engine operation. Otherwise, the first tooth can be used to help ensure that the correct amount of fuel for start-up is determined as soon as possible.
• the method according to the present invention therefore ensures that the engine management system of a scooter or other vehicle having both a kick start arrangement and an electrical starter motor is able to provide the correct fuelling level to the engine during engine start-up.
• the ECU of the engine management system programmed to achieve the method according to the present invention could be equally used on a scooter or other vehicle only having a kick start or only having a starter motor starting means. This, for example, means that it is not necessary to use different ECUs for differently set up scooters.
• the method of the present invention is employed on fuel injected engines and in particular direct fuel injected engines.
• the method is conveniently implemented on dual fluid or air-assist fuel injected engines wherein a compressed gas, typically air, is used to entrain and deliver a metered quantity of fuel into one or more combustion chambers of the engine.
• a compressed gas typically air
• it is known to assist in pressurising a gas chamber or rail of the fuel injection system during engine start-up by delivering pressurised gas from within a combustion chamber or cylinder into the gas rail.
• a delivery injector associated with the cylinder is opened at an appropriate time in the cylinder cycle so that compressed gas within the cylinder can flow through the open injector and into the gas rail to increase the gas pressure therein.
• Various "pump-up" methods of this type are disclosed in the Applicant's US Patent No's. 4936279 and 6164268, the contents of which are incorporated herein by way of reference.
• the method of the present invention is employed together with a pump-up strategy for pressurising a gas rail or chamber of a dual fluid fuel injection system at engine start-up.
• the pump-up strategy includes a predetermined plurality or sequence of pump-up events which are effected upon start-up of the engine.
• the sequence of pump-up events is re-initialised. That is, when a determination is made that an automated starting means is being used to start the engine, the complete sequence of pump-up events is used to ensure that sufficient gas pressure is developed in the gas rail to support the subsequent delivery of fuel.
• the sequence of pump-up events is continued from where it last finished. That is, when a determination is made that a manual staring arrangement is being used to start the engine, the sequence of pump-ups is not pre-initialised. This avoids the need to go through a full pump-up sequence upon every manual start attempt and hence avoids the situation where fuel may never be injected (ie. as only a finite number of engine revolutions typically result from a kick or pull-start event and some fuel needs to be delivered and combusted during these finite number of cylinder cycles to try and get the engine to fire).
• an electronic control unit for controlling the fuelling rate to an internal combustion engine during start-up of the engine, the ECU determining whether the engine is started by way of a manual starting arrangement or by way of an automated starting means and then selecting an appropriate fuelling rate for the engine based on this determination.
• an electronic control unit for determining the mode of starting for an internal combustion including the ECU determining whether the engine is started by way of a manual starting arrangement or by way of an automated starting means; such that an appropriate fuelling rate is then provided to the engine during start- up based on this determination.
• an electronic control unit for controlling the fuelling rate to an internal combustion engine during engine start-up based on a determination of the mode of starting used for the engine, the engine having a battery operatively associated therewith, and the ECU including:
• the drawing depicts a flow diagram showing the operational sequence followed by an ECU of an engine management system to determine the fuelling level required at start-up of the engine.
• the ECU initially detects when the ignition switch of the engine is turned to the "on" position (step 1 ). Knowing that the ignition is on, the ECU measures the initial battery voltage (V1) (step 2), this being the voltage read across the terminals of the battery prior to any rotational movement of the engine. By way of signals received from the crankshaft position sensor, the ECU is then able to determine that engine rotation has commended (step 3) and can hence proceed to make a determination of which mode of starting has been used.
• crankshaft position sensor forms part of the overall engine management system and typically includes a toothed encoder wheel arranged on the crankshaft and a corresponding sensor. Measurement of the crankshaft position can typically occur as soon as a first encoder tooth is detected by the sensor following commencement of engine rotation or movement.
• the ECU makes a further measurement of the battery voltage (V2) (step 4) in order to enable a comparison between the prevailing battery voltage (V2) and the initial battery voltage (V1 ).
• This comparison is effected by the ECU then determining whether the difference in measured battery voltages (V1-V2) (step 5) is greater than a predetermined or threshold value (step 6). In this way, the ECU is able to assess whether the battery has experienced a voltage drain or drop due to actuation of a starter motor.
• the predetermined or threshold value may simply be the battery voltage immediately prior to the start-up sequence of the engine (ie V1 ). Alternatively, the threshold value may be set at some other suitable level which would enable a clear distinction to be made between different modes of starting for the engine.
• step 7 If the difference in the battery voltages (ie. Delta) is less than the predetermined value, then the ECU determines that the fuelling level to be supplied to the engine during the start-up sequence is that required for a manual or kick start (step 7). However, if the difference in the battery voltages or the Delta is greater than the predetermined value, then the ECU determines that the fuelling level to be supplied to the engine during the start-up sequence is that required for start-up using a starter motor (step 8), this fuelling level being higher than that supplied in respect of a kick start. Depending upon the selection of the threshold value, it is also possible for the ECU to proceed to step 7 (ie. fuelling level to be supplied is that required for engine starting via a kick start) where the difference in the battery voltages (ie. Delta) is equal to the threshold value.
• an appropriate fuelling rate is able to be provided to the engine at start-up based on whether one mode of starting is used over a different mode of starting. This hence enables improved and more reliable starting.
• Monitoring battery voltage is one preferred way of distinguishing between different modes of starting for the engine, but it is to be appreciated that other methods may also be implemented.
• the provision of suitable sensors operatively arranged with respect to the kick start arrangement and starter motor where both are implemented on a scooter or vehicle is perhaps a different way by which the fuelling level at start-up can be determined based on the mode of starting that is used.
• the predetermined value could also relate to, for example, a range of values to take into account the change in battery voltage over the life of the battery.
• the predetermined value could be selected or adapted so as to offer a certain level of compensation for situations where the scooter or vehicle is operated at temperatures significantly colder than normal.
• the method of the present invention is particularly suited for use with fuel injected engines and in particular direct fuel injected engines.
• the invention is equally applicable to engines which are not fuel injected and regardless of whether the engines are of the 4-stroke or 2-stroke type.
• the method may be applicable to a wider spectrum of engine applications where there is a requirement to have pull-start or kick-start as an option for starting the engine.
• the method of the present invention may be used in conjunction with a suitable pump-up strategy as may be desirous for an engine equipped with a two fluid or air assisted fuel injection system.
• a suitable pump-up strategy as may be desirous for an engine equipped with a two fluid or air assisted fuel injection system. Examples of such a two fluid fuel injection system and different pump-up strategies are disclosed in the Applicant's US Patent No's. 4936279 and 6164268, the contents of which are included herein by way of reference.
• the main purpose of such a pump-up strategy is to ensure that, following engine start-up, fuel may be subsequently transported with sufficient air/gas pressure into the engine cylinders for combustion to occur when the first fuel injection event occurs.
• a prime pump-up event is one where the sole purpose is to increase the pressure in a gas or air rail and hence fuel is not injected into a cylinder during the cylinder cycle.
• the pump-up strategy would generally be one which includes a predetermined plurality or sequence of such pressure pump-up events. Hence, no fuel would typically be delivered to the engine until the full sequence of prime pump-up events has been completed and thus resulted in the attainment of a certain level of pressurisation of a gas or air rail of the two fluid fuel injection system.
• the ECU of the engine management system may be programmed to ensure that the pressure pump-up sequence, which is generally a one-way sequence, is only performed once per power up (ie. after ignition is switched "ON" as at step 1).
• the ECU may be programmed to ensure that the pressure pump-up sequence is re-initialised each time a start event occurs.
• the complete sequence of pump-up events will be re-initiated each time an electrical starter motor or like device is used to start the engine, regardless of how many start events are required to start the engine. In this way, it is ensured that there is sufficient pressure in the gas or air rail of the two fluid fuel injection system to effect subsequent fuel delivery and hence provide a better chance for the engine to fire.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)

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• 2001
  • 2001-02-20 AU AUPR3195A patent/AUPR319501A0/en not_active Abandoned
• 2002
  • 2002-02-20 TW TW091102979A patent/TW527472B/zh not_active IP Right Cessation
  • 2002-02-20 WO PCT/AU2002/000175 patent/WO2002066810A1/en not_active Application Discontinuation
  • 2002-02-20 CN CNB028052382A patent/CN1317499C/zh not_active Expired - Fee Related
  • 2002-02-20 EP EP02711655A patent/EP1362171A4/de not_active Withdrawn

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