Classifications

• • 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
  • F02D41/30—Controlling fuel injection
  • F02D41/3005—Details not otherwise provided for
• • 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
  • F02D2200/02—Input parameters for engine control the parameters being related to the engine
  • F02D2200/04—Engine intake system parameters
  • F02D2200/0402—Engine intake system parameters the parameter being determined by using a model of the engine intake or its components

Definitions

• the present invention relates to a fuel injection control device, and more particularly to a fuel injection control device capable of determining a fuel injection amount of a single-cylinder four-cycle engine based on an estimated intake air mass.
• a fuel injection amount corresponding to the operation state is determined according to the target air-fuel ratio based on the intake air mass.
• an air flow meter is used to measure the amount of intake air.
• Japanese Patent Laying-Open No. 58-173173 discloses an example of an air flow meter for detecting an intake air amount for determining a fuel injection amount.
• an intake air amount is estimated using an intake negative pressure-engine speed map based on the intake negative pressure and the engine speed. Further, the intake air amount can be estimated based on the throttle opening.
• FIG. 9 is a diagram showing a basic injection amount determination method in the conventional fuel injection control.
• the region determined by the throttle opening ⁇ ⁇ ⁇ ⁇ ⁇ and the engine speed Ne is divided into two regions.
• the basic injection amount is determined using a PB-NE map in which the basic injection amount is set as a function of the intake pipe negative pressure PB and the engine speed Ne.
• the throttle opening S TH and the engine The basic injection quantity is determined using a TH-NE map with the basic injection quantity as a function of the speed Ne. Further, the values of these maps are subjected to engine temperature correction, intake air temperature correction, atmospheric pressure correction, and the like, and the fuel injection amount is finally determined.
• PB sensor negative air pressure sensor
• An object of the present invention is to provide a fuel injection control device that can determine a fuel injection amount based on an accurate intake air mass even if the number of components such as sensors is reduced in view of the above problems. Disclosure of the invention
• the present invention for solving the above-mentioned problem is a fuel injection control device for a single-cylinder four-stroke engine, which calculates an intake air mass in an intake stroke using a function of energy loss generated in a compression stroke and energy loss generated in an exhaust stroke.
• a first feature is that there is provided intake air mass calculation means, and fuel injection amount calculation means for calculating a fuel injection amount corresponding to the intake air mass according to a target air-fuel ratio.
• the intake air mass is calculated based on the energy loss in the compression stroke and the exhaust stroke of the intake air mass.
• the present invention includes time calculating means for calculating an elapsed time in a range set at the beginning and end of the compression stroke and an elapsed time in a range set at the beginning and end of the exhaust stroke, respectively, wherein the intake air mass calculating means is provided.
• the intake air mass calculating means is provided.
• the energy loss is calculated as a function of the elapsed time and the difference between the elapsed time at the start and end of the exhaust stroke.
• the energy loss is represented by a function of the time difference required between the start and end of the compression stroke and the exhaust stroke, for example, normally provided in a 4-cycle engine, the time of the compression stroke and the exhaust stroke is detected.
• the energy loss can be calculated by determining the time required for the crank angle change in a predetermined range from the output of the crank angle sensor.
• the intake air mass calculating means uses the elapsed times T el, T c 2 at the start and end of the compression stroke and the elapsed times T e 1 and T e 2 at the start and end of the exhaust stroke, and
• the third feature is that the intake air mass is determined. Intake air mass ⁇ [ ⁇ (1 / T cl) 2 — (1 / T c 2) 2 ⁇ — ⁇ (l ZT e 1) 2- (1 / T e 2) "].
• the intake air mass is calculated using the equation.
• the present invention further comprises, in addition to the fuel injection amount calculating means, determining a basic fuel injection amount as a function of a throttle opening and an engine speed.
• a second injection amount calculating means for performing air density correction to determine a fuel injection amount; and selecting the first injection amount calculating means in a scheduled low load region, and calculating the second injection amount in other than the low load region.
• a fourth feature lies in that a control switching means for selecting a means is provided.
• a fifth feature of the present invention is that the present invention includes means for calculating the air density for correcting the air density based on the intake air mass and the standard air flow rate.
• the fuel injection amount is calculated using the intake air mass calculated based on the energy loss in the compression stroke and the exhaust stroke. Is calculated.
• the present invention is characterized in that the low load region is an idling operation region, and the control switching means includes means for discriminating between the idling operation region and the steady operation region based on an engine rotation fluctuation rate.
• the control switching means includes means for discriminating between the idling operation region and the steady operation region based on an engine rotation fluctuation rate.
• the clutch connection changes the moment of inertia of the engine system, causing a difference in the rotational fluctuation rate. According to the sixth feature, it can be determined from the difference in the rotation fluctuation rate that the clutch has been interrupted, that is, that the switching between the low load region and the other load regions has been performed.
• FIG. 1 is a block diagram showing a configuration of a fuel injection control device according to one embodiment of the present invention.
• FIG. 2 is a diagram showing the energy generated for each stroke in a four-stroke engine.
• FIG. 3 is a flowchart showing a procedure for calculating a fuel injection amount.
• FIG. 4 is a block diagram illustrating a main hardware configuration of a fuel injection control device according to a second embodiment.
• FIG. 5 is a diagram showing a division of an engine load area.
• FIG. 6 is a diagram showing a load range determination map based on clutch disconnection determination.
• FIG. 7 is a block diagram showing a configuration of a fuel injection control device according to a second embodiment of the present invention.
• FIG. 8 is a flowchart showing a procedure for calculating a fuel injection amount in a high load region.
• FIG. 9 is a diagram showing a division of a load area according to the prior art. BEST MODE FOR CARRYING OUT THE INVENTION
• FIG. 1 is a block diagram showing a configuration of a fuel injection control device according to a first embodiment of the present invention.
• a four-cycle single-cylinder engine 1 is provided with a crank angle sensor 2.
• the crank angle sensor 2 is a sensor that detects a plurality of detected objects (for example, a magnetic material such as iron) provided at equal angular intervals around a crankshaft or a shaft 1a coupled to the crankshaft. Generates a corresponding pulse signal.
• the output signal of the crank angle sensor 2 is input to the compression / exhaust time calculation unit 3.
• the compression / exhaust time calculation unit 3 sets in advance the time required for the change in the crank angle and the start and end of the exhaust stroke, which are preset at the beginning and end of the compression stroke, based on the cycle of the pulse signal from the crank angle sensor 2.
• the time required to change the crank angle is calculated.
• the preset crank angle is, for example, 30 °.
• the calculated start and end times of the compression stroke and the calculated start and end times of the exhaust stroke are input to the intake air mass calculation unit 4.
• the intake air mass calculation unit 4 calculates the intake air mass based on the time at the start and end of the compression stroke and the time at the start and end of the exhaust stroke using a calculation formula described later.
• the calculated intake air mass is input to the fuel injection amount calculation unit 5, and is multiplied by an excess ratio ⁇ determined based on the target air-fuel ratio, to calculate a fuel injection amount corresponding to the intake air mass.
• the excess rate is determined according to the target air-fuel ratio.
• the calculated fuel injection amount is further corrected by the correction unit 6 using a correction coefficient corresponding to the acceleration state (throttle opening degree change rate).
• the corrected fuel injection amount is input to a fuel injection valve driving unit 7 that drives the fuel injection valve 16.
• the fuel injection valve driving section 7 drives the fuel injection valve 16 with a valve opening duty corresponding to the fuel injection amount.
• the calculation units 3, 4, and 5 and the correction unit 6 can be configured by a microphone opening and closing unit.
• FIG. 2 is a diagram showing the generated energy for each stroke in a four-stroke engine. Large combustion energy is generated during the combustion process. On the other hand, in each of the exhaust, suction, and compression strokes, energy is absorbed by the exhaust resistance, the intake resistance, and the compression resistance. In other words, negative energy is generated. Negative energy includes mechanical frictional resistance, for example, frictional resistance generated between a piston and a cylinder.
• the compression resistance the energy loss required for the compression of the intake air
• the compression resistance is such that the energy loss is greater in the compression stroke than in the exhaust stroke.
• Most of the loss in the process is frictional resistance.
• the compression resistance increases as the intake air mass increases.
• the compression stroke loss is considered to be a function of the intake air mass.
• T c1 and T c2 are the expected crank angle change times at the start and end of the compression stroke
• Tel and Te 2 are the expected crank angle change times at the start and end of the exhaust stroke
• K is the compression energy. It is a correction coefficient for converting loss to intake air mass.
• FIG. 3 is a flowchart showing the procedure for calculating the fuel injection amount.
• step S1 the delta times T e1 and T e2 at the start and end of the exhaust stroke are calculated.
• step S2 the delta times Tc1 and Tc2 at the start and end of the compression stroke are calculated.
• step S3 the intake air mass is calculated by the intake air mass calculator 10 using the above (Equation 2).
• step S4 the fuel injection amount calculation unit 1 1 Variable by multiplying the excess air ratio ⁇ fuel injection is t excess air ratio ⁇ calculated, is determined by the target air-fuel ratio A / F to the intake air mass by.
• the valve opening time of the fuel injection valve 6, that is, the valve opening duty is determined so that the calculated fuel injection amount is obtained.
• FIG. 4 is a block diagram illustrating a configuration of a fuel injection control device according to a second embodiment of the present invention.
• ECU 11 which will be described in detail later, receives detection signals from a crank angle sensor 2, a throttle opening sensor 13, an atmospheric temperature ( ⁇ ) sensor 14, and an engine temperature ( ⁇ ) sensor 15.
• -Crank angle sensor 2 has been described with respect to FIG.
• the throttle opening sensor 13 is connected to a throttle valve in a throttle body provided in an intake pipe of the engine 1, and outputs a throttle opening 0TH.
• the sensor 15 is provided, for example, in an oil pan of the engine, and detects the oil temperature with a probe immersed in engine oil.
• Sensed oil temperature t ECU 1 1 to be input to the E CU 1 1 as a signal indicative of the engine temperature comprises a microcomputer and its peripheral parts, it takes in the output of the sensors 2, 13, 14, 1 5, will The processing is performed in accordance with the algorithm described in (1), and the resulting command is output to the injector (fuel injection valve) 16, the ignition coil 17, the fuel pump 18 and the like.
• FIG. 5 is a diagram showing the division of the load range where the engine speed is a parameter. As shown in this figure, the load range was divided into a low load range LLZ and a high load range HLZ according to the engine speed. In other words, irrespective of the throttle opening of 0TH, the idle operation region where the engine speed Ne is low is determined as the low load region LLZ, and the region where the engine speed Ne is high is determined as the high load region HLZ.
• the algorithm for calculating the fuel injection amount is switched for each load range as follows. For example, in an engine equipped with a centrifugal clutch, the determination can be made based on the result of determining whether the engine speed Ne exceeds the clutch speed. In other words, when the engine speed Ne exceeds the clutch-in speed, the engine shifts from idling to steady running, and the engine switches to the high load range. Therefore, the calculation algorithm of the fuel injection amount is also switched to the one for the high load range.
• the on / off state of the clutch can be detected based on the engine speed fluctuation rate when the clutch is engaged and when the clutch is disengaged. This is because the intermittent clutch changes the moment of inertia and changes the engine rotation fluctuation rate.
• the rotation fluctuation rate can be calculated based on, for example, the time required for the compression stroke and the exhaust stroke. Since the difference between the compression stroke time and the exhaust stroke time changes remarkably due to the on / off operation of the clutch, the rotation fluctuation rate is represented as a function of the ratio of this time difference to the time of one cycle (two rotations of the crankshaft). It is better to let them.
• FIG. 6 is a diagram showing a clutch connection / disconnection line in which the engine rotation fluctuation rate and the engine speed are used as parameters.
• the vertical axis is the engine speed variation TSRAT
• the horizontal axis is the engine speed
• the clutch is disengaged when the speed variation is greater than the clutch connection line CCL. That is, the engine is idle and the load on the engine is small.
• the clutch is engaged when the rotation fluctuation rate TSRAT is smaller than the clutch connection line CCL. That is, the engine is not idle In the high load area.
• the rotational variability TSRAT is, for example, a function of the difference between the compression stroke time and the exhaust stroke time. Therefore, the engine speed fluctuation TSRAT and the engine speed Ne are monitored, the load is determined based on whether the engine speed fluctuation TSRAT is above the clutch connection line CCL, and the algorithm for calculating the fuel injection amount is switched. be able to.
• the fuel injection amount in the low load range LLZ is calculated by the following equation (Equation 2).
• Fuel injection quantity intake air mass / target air-fuel ratio (Equation 2).
• the target air-fuel ratio AF is determined based on the stoichiometric air-fuel ratio, taking into account acceleration conditions and the like.
• the intake air mass is not detected using an air flow meter, but is rotated within a predetermined range (for example, a crank angle of 30 °) at the start and end of each of a compression stroke and an exhaust stroke as described later. Calculate based on the time required for
• FIG. 7 is a block diagram showing main functions of fuel injection control according to the second embodiment.
• the output signal of the crank angle sensor 2 provided in the 4-cycle single cylinder engine is input to the compression / exhaust time calculation unit 103.
• the compression / exhaust time calculation unit 103 receives the output signal from the crank angle sensor 2 Based on the cycle of the pulse signal, the expected crank angle change times Tc1, Tc2, Tel, and Te2 at the start and end of each of the compression stroke and the exhaust stroke are calculated. The calculated time is input to the intake air mass calculator 104. Intake air mass calculation The outlet 104 calculates the intake air mass using the calculation formula (Equation 1) based on the expected crank angle change time.
• the calculated intake air mass is input to the fuel injection amount calculation unit 105, and a fuel injection amount corresponding to the intake air mass is calculated in consideration of the target air-fuel ratio AF.
• the basic fuel injection amount is set as a map value as a function of the engine speed Ne and the throttle opening 0TH.
• the output of the crank angle sensor 2 representing the engine speed N e and the throttle opening 0 TH which is the output of the throttle opening sensor 13 are input to the fuel injection amount map 106, these inputs are obtained.
• the map is searched using as a key, and the basic fuel injection amount is output.
• the basic fuel injection amount is input to the correction unit 107, and the map value is multiplied by an engine temperature correction coefficient, an intake air temperature correction coefficient, and an atmospheric pressure correction (air density correction) coefficient to determine the fuel injection amount.
• the correction unit 107 has correction coefficients corresponding to the engine temperature, the intake air temperature, and the air density as tables, respectively, and when the engine temperature TE, the intake air temperature TA, and the air density AD are provided.
• the basic fuel injection amount is corrected by a coefficient corresponding to the coefficient.
• the air density can be obtained by dividing the mass of intake air by the standard air flow rate in the air density calculation unit 108.
• the standard air flow rate can be obtained from the map value of the standard air flow rate measured under one atmosphere. That is, the standard air flow is mapped as a function of the throttle opening and the engine speed Ne, and the standard air flow can be obtained by searching this map.
• the switching unit 109 selects the output of the fuel injection calculation unit 105 when the load is in the low load region, based on the judgment of the low load region or the high load region in the load region judgment unit 110, and In the load range, the output of the correction unit 107 is selected.
• the load area determination unit 110 searches the above-mentioned Fig. 6 based on the engine Determine the area.
• the fuel injection amount output from the side selected by the switching unit 109 is input to the fuel injection valve driving unit 7 that drives the fuel injection valve 16.
• the fuel injection valve driving section 7 drives the fuel injection valve 16 with a valve opening duty corresponding to the fuel injection amount.
• the calculation procedure of the fuel injection amount for the low load region can use the processing of the flowchart described with reference to FIG.
• FIG. 8 is a flowchart of a fuel injection amount calculation procedure for a high load region.
• the engine speed Ne is read.
• the throttle opening 0TH is read.
• the basic fuel injection amount is obtained by searching the fuel injection amount map 12 using the engine speed Ne and the throttle opening as keys.
• the fuel injection amount is calculated by multiplying the basic fuel injection amount by the engine temperature correction coefficient, the intake air temperature correction coefficient, and the atmospheric pressure correction coefficient.
• the intake air mass is calculated from the energy loss of the engine cycle.
• the intake air mass can be calculated.
• the intake air mass is calculated from the energy loss of the engine cycle, and the fuel injection amount in the low load region is calculated based on the intake air mass.
• the air density correction in the region is also calculated based on the calculated intake air mass. According to the invention of claim 6, it is possible to accurately determine the low load region and the other region based on the engine rotation fluctuation rate, and switch the injection amount calculation means.

Landscapes

• 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)

Priority Applications (4)

Applications Claiming Priority (4)

Publications (1)

Family

ID=32032874

Family Applications (1)

Country Status (7)

Cited By (1)

Families Citing this family (3)

Citations (3)

Family Cites Families (2)

• 2003
  • 2003-09-05 MX MXPA05001895A patent/MXPA05001895A/es active IP Right Grant
  • 2003-09-05 BR BRPI0306681A patent/BRPI0306681B1/pt not_active IP Right Cessation
  • 2003-09-05 CN CNB038016613A patent/CN1328496C/zh not_active Expired - Fee Related
  • 2003-09-05 WO PCT/JP2003/011382 patent/WO2004027241A1/ja active Application Filing
  • 2003-09-09 MY MYPI20033387 patent/MY139881A/en unknown
  • 2003-09-17 AR ARP030103364 patent/AR041279A1/es active IP Right Grant
• 2005
  • 2005-06-28 HK HK05105359A patent/HK1072626A1/xx not_active IP Right Cessation

Patent Citations (3)

Also Published As

Similar Documents

Legal Events