JP6138551B2 - Engine fuel injection control device - Google Patents

Description

  The present invention relates to a fuel injection control device for an engine that performs O2 feedback control.

  In Patent Document 1 below, KO2 that is a variable is obtained from an O2 sensor that detects the oxygen concentration in the exhaust gas, and KBUK (KBU) that is a variable obtained by multiplying the fluctuation of KO2 is obtained, and the obtained KO2 and KBUK are obtained. The basic fuel injection amount is corrected to calculate the final fuel injection amount. Here, it is described that KBUK is stored for each of a plurality of learning areas divided by throttle opening and engine speed, and uses KBUK according to the current operating state.

  Further, Patent Document 2 below discloses that an idle screw is provided in an idle air control passage connecting the upstream and the downstream of a throttle valve in order to adjust the idle rotation speed.

JP 2009-202973 A JP 2006-70788 A

  As described in the above-mentioned Patent Document 1, by executing O2 feedback control, KO2 and KBUK are sequentially updated to ensure the accuracy of fuel adjustment. However, in the O2 feedback control using only the O2 sensor, KO2 can be calculated only when the air-fuel ratio is close to the ideal air-fuel ratio.

  Therefore, for example, if the engine is operated at an air / fuel ratio richer than the ideal air / fuel ratio in order to accelerate, the O2 feedback control is temporarily stopped. Here, when the air screw is adjusted by the driver during the operation of the engine and the acceleration operation is performed, the KBUK may be shifted. For this reason, if the air screw is adjusted while the acceleration operation frequently occurs, a fuel injection amount that is larger or smaller than the actually required fuel injection amount is calculated.

  Since the adjustment of the air screw is manually performed by the driver, in order to calculate an appropriate fuel injection amount even when the O2 feedback control such as the acceleration operation is stopped, first, whether or not the air screw has been adjusted. There is a problem that I want to detect.

  Therefore, an object of the present invention is to provide a fuel injection control device for an engine that can detect that the adjustment of the air screw has been performed.

  The fuel injection control device (12) of the engine (10) according to the present invention has the following features.

  First feature: a bypass passage (36) connecting the upstream side and the downstream side of the throttle valve (34) of the intake pipe (22) of the engine (10), and an air screw (opening and closing the bypass passage (36)) 38), an oxygen sensor (50) for detecting the oxygen concentration in the exhaust gas of the engine (10), and a feedback correction amount (KO2) which is a correction coefficient based on the oxygen concentration detected by the oxygen sensor (50). And a learning value (KBU), which is a correction coefficient learned according to the feedback correction amount (KO2), is divided into a plurality of feedbacks classified according to the throttle opening (TH) of the throttle valve (34). A coefficient calculation unit (84) that calculates and updates for each region, the basic injection amount (TIMB), the feedback correction amount (KO2), and the learning value (KB) ), And a fuel injection amount calculation unit (68) that calculates a fuel injection amount (TOUT). In the fuel injection control device (12) of the engine (10), the throttle opening (TH) is When the absolute value of the difference between the learned value (KBU) in the feedback region on the low opening side and the learned value (KBU) in the feedback region on the high opening side exceeds the threshold value Includes an adjustment detection unit (70) for detecting that the air screw (38) has been adjusted.

  Second feature: The feedback region on the low opening side is a first feedback region (A1) that is an idling region of the engine (10), and the feedback region on the high opening side is the throttle opening ( TH) is a feedback region (A4 to A6) that is greater than or equal to the medium opening.

  Third feature: The plurality of feedback regions include a first feedback region (A1) and a second feedback region (A2) adjacent to the first feedback region (A1) on the high rotation side of the engine speed (NE). ), A third feedback region (A3) adjacent to the first feedback region (A1) and the second feedback region (A2) on the high opening side of the throttle opening (TH), and the third feedback region A fourth feedback region (A4) adjacent to (A3) on the high opening side of the throttle opening (TH), and a fourth feedback region (A4) on the high opening side of the throttle opening (TH). An adjacent fifth feedback region (A5) and a sixth feedback region (A5) adjacent to the fifth feedback region (A5) on the high opening side of the throttle opening (TH). Fed back made from the area (A6), the feedback area of the high angle side is a fourth feedback region (A4) or the fifth feedback area (A5).

  4th characteristic; The said adjustment detection part (70) is an average value (KBUave) of the said learning value (KBUave) for the past predetermined frequency | count of the said feedback area of the said low opening side, and the feedback area | region of the said high opening degree It is detected whether the air screw (38) has been adjusted using a difference from an average value (KBUave) of the learning values (KBU) for the past predetermined number of times.

  Since the intake air passing through the bypass passage adjusted by the air screw flows through the bypass passage as the throttle opening is lower, the learning value shifts by the adjustment of the air screw as the learning value is lower. Prone to occur. As a result of research, the applicant has found that when the throttle opening becomes a high opening side, the intake air passes through the intake pipe without passing through the bypass passage, so the learning value on the high opening side is affected by the adjustment of the air screw. I found it difficult to receive. Therefore, according to the first feature of the present invention, which takes advantage of this property, the learning value in the feedback region where the throttle opening is on the low opening side and the learning value in the feedback region where the throttle opening is on the high opening side When the absolute value of the difference exceeds the threshold value, it is detected that the air screw has been adjusted, so that adjustment of the air screw can be detected with high accuracy.

  During idling, the throttle opening is fully closed, so the deviation of the learning value due to adjustment of the air screw is significant. In addition, the adjustment of the air screw is often performed during idling. According to the second feature of the present invention, the feedback region on the low opening side is a first feedback region that is an idling region of the engine, and the feedback region on the high opening side has a throttle opening that is greater than or equal to the middle opening. Therefore, the adjustment of the air screw can be easily detected, and the adjustment of the air screw can be detected with higher accuracy.

  The second and third feedback regions are driving regions that pass from the stop until the vehicle starts steady running. On the other hand, the fourth and fifth feedback regions are operating regions that are likely to be in steady running, and the throttle opening is higher than the first to third feedback regions. This is a region where the influence of displacement is less likely to occur. According to a third aspect of the present invention, the plurality of feedback regions include a first feedback region, a second feedback region adjacent to the first feedback region on the high engine speed side, a first feedback region, 2 The third feedback region adjacent to the feedback region on the high opening side of the throttle opening, the fourth feedback region adjacent to the third feedback region on the high opening side of the throttle opening, and the throttle opening to the fourth feedback region A fifth feedback region adjacent on the high opening side and a sixth feedback region adjacent to the fifth feedback region on the high opening side of the throttle opening. The feedback region on the high opening side is the fourth feedback region. Since this is the region or the fifth feedback region, it is easy to update the learning value frequently. By using the learned value of the region can be detected more accurately adjust the air screw.

  According to the fourth feature of the present invention, an average value of learning values for the past predetermined number of times in the feedback region on the low opening side, and an average value of learning values for the past predetermined number of times in the feedback region on the high opening side, Therefore, it is possible to detect whether the air screw has been adjusted by suppressing variation in the learning value, and to improve the detection accuracy of the adjustment of the air screw. it can.

It is a block diagram which shows the structure of the fuel-injection control apparatus of the engine of embodiment. It is a map for searching an engine operating region. It is a map which shows the feedback area | region of an air fuel ratio. FIG. 4 is a KBU map showing feedback regions of the O2F / B region divided into six by overlapping the regions defined in FIG. 2 and FIG. 3. It is a schematic diagram of the KBU map shown in FIG. It is a block diagram which shows the structure of the control part of FIG. It is a figure which shows an example of the injection quantity map of FIG. It is a block diagram which shows the structure of the volatile memory of FIG. It is a figure which shows the relationship between a base value and the learning value when an air screw has shifted | deviated from the initial position so that the air quantity which passes a bypass channel may be decreased. It is a figure which shows the relationship between the base value when the air screw has shifted to the closing side from the initial position so as to reduce the amount of air passing through the bypass passage, and the learning value of the second feedback region updated by the O2 feedback control. It is a figure which shows the relationship between the base value in open loop control, and the learning value of a 2nd feedback area | region when an air screw shifts to the closing side from an initial position so that the air quantity which passes a bypass channel may be decreased. It is a figure which shows the relationship between a base value and the learning value when environmental changes, such as external temperature and atmospheric pressure, arise. It is a figure which shows the adjustment amount map of FIG. It is a figure which shows the correction value table of FIG. It is a figure which shows the relationship between a learning value and a base value at the time of correcting a throttle opening during open loop control when an air screw has shifted from the initial position to the closing side so as to reduce the amount of air passing through a bypass passage. . It is a flowchart which shows the calculation operation | movement of a throttle opening correction value. It is a flowchart which shows calculation operation | movement of a basic injection amount. It is a flowchart which shows the main operation | movement of a control part.

  DESCRIPTION OF EMBODIMENTS A fuel injection control device for an engine according to the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments.

  FIG. 1 is a block diagram illustrating a configuration of a fuel injection control device 12 of an engine 10 according to an embodiment. A piston 16 is slidably fitted to a cylinder bore 14 of the engine 10 mounted on a vehicle such as a motorcycle. An intake pipe 22 that supplies an air-fuel mixture to the combustion chamber 20 and an exhaust pipe 24 that discharges exhaust gas from the combustion chamber 20 are connected to the cylinder head 18 of the engine 10. A catalytic converter 26 is attached to the exhaust pipe 24. A spark plug 28, an intake valve 30, and an exhaust valve 32 whose front ends protrude into the combustion chamber 20 are attached to the cylinder head 18.

  The intake pipe 22 is provided with a throttle valve 34 that controls the amount of intake air so that it can be opened and closed, and a bypass passage 36 that connects the upstream side and the downstream side of the throttle valve 34. The bypass passage 36 is provided with an air screw 38 that adjusts the amount of air passing through the bypass passage 36 by opening and closing the bypass passage 36. The driver adjusts the air screw 38 to adjust the idling (idle) rotation speed. A fuel injection valve 40 for injecting fuel is provided on the downstream side of the throttle valve 34.

  The control unit 42 controls the ignition timing of the spark plug 28, the fuel injection amount injected from the fuel injection valve 40, and the like. The fuel injection control device 12 of the engine 10 further includes a throttle opening sensor 44 that detects the opening (hereinafter referred to as throttle opening) TH of the throttle valve 34 and the rotation of the crankshaft 10 a of the engine 10 connected to the piston 16. An engine speed sensor 46 for detecting the number (hereinafter referred to as engine speed) NE, a water temperature sensor 48 for detecting the coolant temperature TW of the engine 10, and oxygen remaining in the exhaust gas provided upstream of the catalytic converter 26. An oxygen sensor 50 for detecting the concentration and an intake air temperature sensor 52 for detecting the intake air temperature TA taken into the combustion chamber 20 are provided. Output signals of the throttle opening sensor 44, the engine speed sensor 46, the water temperature sensor 48, the oxygen sensor 50, and the intake air temperature sensor 52 are input to the control unit 42.

  FIG. 2 is a map for searching for an operation region of the engine 10. Based on the engine speed NE and the throttle opening TH, the control unit 42 searches for which region the operation region is in. In this map, the lower limit throttle opening THO2L and the upper limit throttle opening THO2H, and the plurality of throttle openings THFB0, THFB1, THFB2, and THFB3 between the two throttle openings increase as the engine speed NE increases. . These throttle openings are set in advance so that the relationship THO2L <THFB0 <THF1 <THB2 <THB3 <THO2H is satisfied.

  The solid lines indicating the set throttle openings THO2L, THFB0, THFB1, THFB2, THFB3, and THO2H are boundary values applied when increasing the throttle opening TH, and the broken lines adjacent to the solid lines are respectively This is a boundary value applied when the throttle opening is decreased, and is set with hysteresis.

  FIG. 3 is a map showing an air-fuel ratio feedback region. The hatched air-fuel ratio feedback (O2 feedback, O2F / B) region includes a lower limit rotational speed NLOP, an idle region upper limit rotational speed NTHO2L, an upper limit rotational speed NHOP, a lower limit throttle opening THO2L, and an upper limit throttle opening THO2H. This is a fixed area. The lower limit rotational speed NLOP, the idle region upper limit rotational speed NTHO2L, and the upper limit rotational speed NHOP are indicated by a solid line on the increasing side of the engine rotational speed NE and indicated by a broken line on the decreasing side of the engine rotational speed NE. Hysteresis is set. Hysteresis is set for the lower limit throttle opening THO2L and the upper limit throttle opening THO2H, in which the value on the increase side of the throttle opening TH is indicated by a solid line and the value on the decrease side of the throttle opening TH is indicated by a broken line. ing.

  FIG. 4 is a KBU map 64 showing each feedback area A of the O2 feedback area divided into six by overlapping the areas defined in FIGS. 2 and 3, and FIG. 5 is a KBU map 64 shown in FIG. FIG. The plurality of feedback regions A are obtained by dividing the O2 feedback region into six according to the operation region (throttle opening TH and engine speed NE) in FIG. In FIG. 4, a plurality of operation regions including a plurality of feedback regions A are set based on the engine speed NE and the throttle opening TH. In the present embodiment, the operation areas of the six feedback areas A are indicated by numbers “1” to “6”, and the operation areas other than the feedback area are “0” and “7” to “11”. Shown with a number.

In FIG. 5, a feedback area A of “1” (hereinafter referred to as a first feedback area A1) is an idling area of the engine 10. In FIG. 5, a feedback area A of “2” (hereinafter referred to as a second feedback area A2) is a feedback area A where the engine speed NE is adjacent to the first feedback area A1 on the high speed side. In FIG. 5, a feedback area A of “3” (hereinafter, third feedback area A3) is a feedback area A adjacent to the first feedback area A1 and the second feedback area A2 on the high opening side of the throttle opening TH. is there. In FIG. 5, a feedback area A of “4” (hereinafter referred to as a fourth feedback area A4) is a feedback area A adjacent to the third feedback area A3 on the high opening side of the throttle opening TH. In FIG. 5, a feedback area A of “5” (hereinafter, fifth feedback area A5) is a feedback area A adjacent to the fourth feedback area A4 on the high opening side of the throttle opening TH. In FIG. 5, a feedback area A of “6” (hereinafter referred to as a sixth feedback area A6) is a feedback area A adjacent to the fifth feedback area A5 on the high opening side of the throttle opening TH. The second feedback area A2 and the third feedback area A3 are feedback areas in which the throttle opening TH is low, and the fourth feedback area A4 to the sixth feedback area A6 have a throttle opening TH that is greater than or equal to the intermediate opening. This is the feedback area.

  FIG. 6 is a block diagram illustrating a configuration of the control unit 42. The control unit 42 includes a basic injection amount calculation unit 60, an O2 feedback unit 62, a KBU map 64, a volatile memory 66, a non-volatile memory 67, a fuel injection amount calculation unit 68, an adjustment detection unit 70, shown in FIGS. And a correction value calculation unit 72.

  The basic injection amount calculation unit 60 has an injection amount map 80. The injection amount map 80 is a three-dimensional map in which the basic injection amount TIMB corresponding to the throttle opening degree TH and the engine speed NE is stored. This basic injection amount TIMB is set in advance by simulation or experiment so that the ideal air-fuel ratio can be obtained.

  FIG. 7 is a diagram illustrating an example of the injection amount map 80. FIG. 7 shows the basic injection amount TIMB when the engine speed NE is a predetermined number of times. As shown in FIG. 7, the basic injection amount TIMB increases as the throttle opening TH increases.

  The basic injection amount calculation unit 60 acquires, from the injection amount map 80, a basic injection amount TIMB corresponding to the throttle opening TH detected by the throttle opening sensor 44 and the engine speed NE detected by the engine speed sensor 46. The basic injection amount TIMB is calculated. This basic injection amount TIMB can be expressed by the time during which the fuel injection valve 40 is open.

  The O2 feedback unit 62 calculates a correction coefficient that brings the air-fuel ratio closer to the ideal air-fuel ratio (stoichiometric). The O2 feedback unit 62 includes a rich lean determination unit 82 and a coefficient calculation unit 84. The rich / lean determination unit 82 determines exhaust gas rich or lean based on the output signal of the oxygen sensor 50.

  The coefficient calculation unit 84 includes a feedback correction amount calculation unit 84a and a learning value calculation unit 84b. The feedback correction amount calculation unit 84a calculates the feedback correction amount KO2 and its average value KO2ave based on the determination result of the rich lean determination unit 82. The learning value calculation unit 84b calculates the learning value KBU learned according to the feedback correction amount KO2, and calculates the average value KBUave. In the present embodiment, the learning value calculation unit 84b calculates a learning value KBU that is obtained by multiplying the variation of the average value KO2ave with respect to the reference value. The calculated feedback correction amount KO2 and its average value KO2ave, the learned value KBU and its average value KBUave, and a throttle opening correction value ΔTHAS described later are stored in the volatile memory 66. The nonvolatile memory 67 stores learned values KBU1 to KBU6 after the engine 10 is warmed up and a throttle opening correction value ΔTHAS when the engine is stopped.

  The feedback correction amount KO2 and the learning value KBU are correction coefficients used when O2 feedback control is performed, and are for bringing the air-fuel ratio closer to the ideal air-fuel ratio (stoichiometric). The learning value calculation unit 84b calculates a learning value KBU for each of the plurality of feedback regions A based on the throttle opening TH and the engine speed NE.

  As shown in FIG. 8, the volatile memory 66 includes a KO2 storage unit 90 that stores the feedback correction amount KO2, and a KO2 average value storage unit 92 that stores the average value KO2ave of the feedback correction amount KO2. Further, the volatile memory 66 includes a KBU1 storage unit 94, a KBU2 storage unit 96, a KBU3 storage unit 98, which store learning values KBU (hereinafter, learning values KBU1 to KBU6) of the first feedback region A1 to the sixth feedback region A6. It has a KBU4 storage unit 100, a KBU5 storage unit 102, and a KBU6 storage unit 104.

  Further, the volatile memory 66 stores an average value KBUave (average value KBUave1 to KBUave6) of learning values KBU in the first feedback area A1 to the sixth feedback area A6, and a KBU2 average value storage section 108. , A KBU3 average value storage unit 110, a KBU4 average value storage unit 112, a KBU5 average value storage unit 114, and a KBU6 average value storage unit 116. Only the latest values are stored in the storage units (90 to 116).

  The feedback correction amount calculation unit 84a calculates the feedback correction amount KO2 when the determination result of the rich lean determination unit 82 is switched (for example, when the rich / lean state is changed to lean / rich state). The feedback correction amount calculation unit 84a updates the feedback correction amount KO2 by overwriting and storing the calculated feedback correction amount KO2 in the KO2 storage unit 90 of the volatile memory 66.

  Further, the feedback correction amount calculation unit 84a calculates the feedback correction amount KO2 calculated up to a predetermined number of times in the calculation cycle of each feedback correction amount KO2 (for example, the feedback correction amount KO2 for the past three times in the past, last time and previous time). The average value KO2ave of is calculated. The feedback correction amount calculation unit 84a overwrites and stores the calculated average value KO2ave in the KO2 average value storage unit 92 of the volatile memory 66, thereby updating the average value KO2ave every time the feedback correction amount KO2 is calculated.

  The learning value calculation unit 84b uses the KBU map 64 when the determination result of the rich lean determination unit 82 is switched, and uses the operation region (the throttle opening TH and the throttle opening TH detected by the throttle opening sensor 44 and the engine speed sensor 46). The feedback region A at that time according to the engine speed NE) is referred to, and the learning value KBU (any one of the learning values KBU1 to KBU6) of the referred feedback region A is calculated and updated.

  The learning value KBU is calculated by calculating the fluctuation amount (average value KO2ave / reference value) with respect to the reference value of the average value KO2ave stored in the KO2 average value storage unit 92 and the current value in the feedback region A corresponding to the current operation region. A new learning value KBU is calculated by multiplying the learning value KBU. The learning value calculation unit 84b stores the calculated learning value KBU in the volatile memory 66, so that each time the feedback correction amount KO2 is calculated, the learning value KBU of the feedback region A corresponding to the driving region at that time is calculated. Update.

  For example, when the feedback region A corresponding to the current operation region is the first feedback region A1, the learning value calculation unit 84b is a change amount with respect to the reference value of the average value KO2ave stored in the KO2 average value storage unit 92 ( The average value KO2ave / reference value) and the learning value KBU1 stored in the KBU1 storage unit 94 are multiplied to calculate a new learning value KBU1, and the new value is overwritten and stored in the KBU1 storage unit 94.

  Further, when the learning value calculation unit 84b calculates the learning value KBU of the feedback region A corresponding to the current driving region, the learning value calculating unit 84b newly calculates the average value KBUave of the learning value KBU of the feedback region A corresponding to the current driving region. . This average value KBUave can be obtained by calculating the average value of the learning values KBU calculated up to a predetermined number of times before (for example, the learning values for the past and the previous five times before four times). The learning value calculation unit 84b stores the calculated average value KBUave in the volatile memory 66, thereby updating the average value KBUave of the feedback region A corresponding to the driving region at that time every time the learning value KBU is calculated. .

  For example, when the feedback region A corresponding to the current operation region is the first feedback region A1, the learning value calculation unit 84b calculates the average value KBUave1 of the learning values KBU1 for the past predetermined number of times in the first feedback region A1. The calculated average value KBUave1 is stored in the KBU1 average value storage unit 106.

  The fuel injection amount calculation unit 68 calculates a fuel injection amount TOUT injected from the fuel injection valve 40. Specifically, when the O2 feedback control is performed, the fuel injection amount calculation unit 68 calculates the fuel injection amount TOUT by the equation (1) of TOUT = TIMB × KO2 × KBU × KTA.

  Here, TIMB in the equation (1) is the basic injection amount TIMB calculated by the basic injection amount calculation unit 60 according to the current throttle opening TH and the engine speed NE, and KO2 is stored in the KO2 storage unit 90. This is the feedback correction amount KO2. Further, the KBU in the equation (1) is a learning value KBU in the feedback region A corresponding to the current throttle opening TH and the engine speed NE, and is stored in the volatile memory 66. For example, when the feedback region A corresponding to the current operation region is the third feedback region A3, the learning value KBU3 is stored in the KBU3 storage unit 98. KTA in equation (1) is an intake air temperature correction coefficient KTA corresponding to the intake air temperature TA detected by the intake air temperature sensor 52. The intake air temperature correction coefficient KTA is acquired from a table or map (not shown).

  In the case of acceleration operation in which O2 feedback control cannot be performed (in the case of open loop control), the fuel injection amount calculation unit 68 calculates the fuel injection amount according to the equation (2) of TOUT = TIMB × KBUave × KTA + TACC × KTACC. TOUT is calculated. The TIMB and KTA in the equation (2) are the same as those in the equation (1), and the KBUave in the equation (2) is the average value KBUave of the learning value KBU in the feedback region A corresponding to the current current operation region. The TACC in the equation (2) is an additional injection amount TACC with acceleration correction according to the current throttle opening TH and the engine speed NE. This additional injection amount TACC is acquired from a map (not shown). Further, KTACC in the equation (2) is an acceleration correction coefficient KTACC. Equation (2) is a formula for calculating the fuel injection amount TOUT during acceleration operation as a kind of open loop control.

  In the case of open loop control in which O2 feedback control cannot be performed, the feedback correction amount KO2 and its average value KO2ave, and the learning value KBU and its average value KBUave are not sequentially updated, so that KBUave immediately before entering the open loop control is It will be used as it is.

  This fuel injection amount TOUT can be expressed by the time during which the fuel injection valve 40 is open. During the calculated fuel injection amount TOUT, the fuel injection valve 40 is opened so that fuel is injected from the fuel injection valve 40.

  FIG. 9 is a diagram showing the relationship between the base value E and the learned value KBU when the air screw 38 is displaced from the initial position so as to reduce the amount of air passing through the bypass passage 36 (close the bypass passage 36). . The base value E is a learning value KBU when the air screw 38 is in the initial position as a reference. As shown in FIG. 9, when the driver adjusts the air screw 38 from the initial position to the closing side, the learning values KBU4 to KBU6 in the fourth feedback region A4 to the sixth feedback region A6 having a large throttle opening TH are A difference from the value E does not occur so much.

  However, in the learning values KBU1 to KBU3 in the first feedback region A1 to the third feedback region A3 where the throttle opening TH is small, the difference from the base value E increases as the throttle opening TH decreases. In particular, the influence is greatest when the throttle opening TH is fully closed or a learning value KBU1 close to full closing. The reason for this is considered that as the throttle valve 34 is closed, the flow path resistance in the intake pipe 22 increases, and the flow path resistance of the bypass passage 36 relatively decreases. When the throttle valve 34 is opened more than the middle opening degree, the flow resistance of the intake pipe 22 decreases and the flow resistance of the bypass passage 36 becomes relatively large, so that the learning value KBU becomes substantially the same value as the base value E. is there.

  FIG. 10 is a diagram showing the relationship between the base value E and the learning value KBU2 updated by the O2 feedback control when the air screw 38 is shifted from the initial position to the closing side so as to reduce the amount of air passing through the bypass passage 36. It is. As shown in FIG. 10, even if the learning value KBU2 is in the same second feedback region, the throttle opening TH is a learning value KBU2 on the low opening side and the learning value KBU2 is on the high opening side. There will be a big difference. Along with this, there is a large difference between the average value KBUave2 calculated on the low opening side and the average value KBUave2 calculated on the high opening side.

  However, while the O2 feedback control is being performed, the feedback correction amount KO2 and its average value KO2ave, and the learning value KBU and its average value KBUave are sequentially updated each time the feedback correction amount KO2 is calculated as described above. Therefore, even if a difference occurs in the learning value KBU in the same second feedback region A2 due to the adjustment of the air screw 38, the influence on the fuel injection amount TOUT calculated by the above equation (1) is small.

  On the other hand, in the case of open loop control, the feedback correction amount KO2 and its average value KO2ave, and the learning value KBU and its average value KBUave are not updated. The influence on the fuel injection amount TOUT is increased.

  FIG. 11 is a diagram showing the relationship between the base value E and the learning value KBU2 during the open loop control when the air screw 38 is shifted from the initial position to the closing side so as to reduce the amount of air passing through the bypass passage 36. . In the case of the open loop control, the average value KBUave of the learning value KBU updated in the volatile memory 66 immediately before entering the open loop control is used as in the above equation (2). Therefore, for example, when the average value KBUave2 stored in the KBU2 average value storage unit 108 is calculated on the low opening side (black circle in FIG. 11), the current throttle opening TH is determined as the second feedback. When the opening becomes higher in the region (the white circle in FIG. 11), the deviation from the average value KBUave2 stored in the KBU2 average value storage unit 108 increases. Therefore, there is a case where fuel cannot be injected with an appropriate fuel injection amount TOUT. This also causes the same problem with respect to the learning value KBU3 and its average value KBUave3.

  Therefore, in the present embodiment, it is detected that the air screw 38 is adjusted, and when the air screw is adjusted, the throttle opening TH is corrected according to the adjustment amount.

  The adjustment detection unit 70 in FIG. 6 detects whether or not the air screw 38 is adjusted and deviated from the initial position. Specifically, the absolute value of the difference between the average value KBUave1 stored in the KBU1 average value storage unit 106 of the volatile memory 66 and the average value KBUave4 stored in the KBU4 average value storage unit 112 (KBUave1-KBUave4) is a threshold value. Is exceeded, it is detected that the air screw 38 has been adjusted and shifted from the initial position. The adjustment detection unit 70 detects whether or not the air screw 38 has been adjusted when the feedback region A corresponding to the current throttle opening TH and the engine speed NE is the first feedback region A1.

  The adjustment detection unit 70 sets the adjustment flag to 1 when detecting that the air screw 38 is adjusted, and sets the adjustment flag to 0 when detecting that the air screw 38 is not adjusted. This adjustment flag is stored in the adjustment flag storage unit 118 of the volatile memory 66. The adjustment detection unit 70 may detect that the air screw 38 has been adjusted when the absolute value of the difference between the average value KBUave1 and the average value KBUave5 (KBUave1-KBUave5) exceeds a threshold value.

  Here, the reason for taking the difference between the average value KBUave1 and the average value KBUave4 or the average value KBUave5 will be described. Since the average value KBUave1 varies greatly depending on the adjustment of the air screw 38, it is also possible to detect that the air screw 38 has been adjusted by taking the difference between the average value KBUave1 calculated last time and the average value KBUave1 calculated this time. It is possible. However, this technique cannot accurately detect whether or not the air screw 38 has been adjusted accurately. This is because the learning value KBU fluctuates even in response to environmental changes such as outside air temperature and atmospheric pressure, and as a result, the average value KBUave also fluctuates. For example, as shown in FIG. 12, when the atmospheric pressure decreases by going up to a high altitude, the learning value KBU decreases, and the average value KBUave also decreases accordingly.

  Here, when the applicant adjusts the air screw 38 as a result of the research, the learning value KBU changes in the feedback region A on the lower opening side, but the same learning value KBU in the entire feedback region A when the environment changes. It was discovered that changes occur. And the method of detecting the adjustment of the air screw 38 with high accuracy by inspecting the average value KBUave1-average value KBUave4 (or average value KBUave5) was invented. That is, if the environment changes due to changes in atmospheric pressure or the like, the average values KBUave1, KBUave4, and KBUave5 all change in the same way, so the average value KBUave1-average value KBUave4 (or average value KBUave5) It won't be big. On the other hand, when the air screw 38 is adjusted, the average value KBUave1 changes greatly, but since the average values KBUave4 and KBUave5 hardly change, KBUave1-average value KBUave4 (or average value KBUave5) takes a large value.

  Therefore, by taking the difference between the average value KBUave1 that varies due to environmental changes and adjustment of the air screw 38, and the average value KBUave4 or average value KBUave5 that varies due to environmental changes and does not vary much by adjustment of the air screw 38, the air screw 38 It is possible to accurately detect whether or not is adjusted.

  When the adjustment detection unit 70 detects that the air screw 38 has been adjusted and shifted from the initial position, the adjustment detection unit 70 detects the adjustment amount of the air screw 38 (hereinafter referred to as the idle intake amount change rate). The adjustment detection unit 70 has an adjustment amount map 70a as shown in FIG. In the adjustment amount map 70a, (KBUave1-KBUave4) and the idle intake amount change rate are stored in association with each other, as indicated by the solid line in FIG. The adjustment detection unit 70 detects the idle intake air amount change rate according to the difference between the calculated average value KBUave1 and average value KBUave4 using the adjustment amount map 70a. The idle intake amount change rate is a change rate with respect to the intake amount passing through the bypass passage 36 when the air screw 38 is in the initial position.

  The adjustment amount map 70a may be one in which (KBUave1-KBUave5) and the idle intake amount change rate are stored in association with each other, as shown by a broken line in FIG. In this case, the adjustment detection unit 70 detects the idle intake air amount change rate according to the difference between the calculated average value KBUave1 and average value KBUave5.

  Further, even when the air screw 38 is adjusted as described above, the difference between the learned value KBU6 and the base value E does not occur so much, so that the difference between the average value KBUave1 and the average value KBUave6 is taken and the air screw 38 is adjusted. Detection of whether or not the adjustment has been made and detection of the adjustment amount of the air screw 38 may be performed. However, the learned value KBU6 and its average value KBUave6 are considered to be unlikely to open the throttle valve 34 to the throttle opening TH that becomes the sixth feedback region A6 because the throttle opening TH is relatively high. . Then, the frequency with which the learning value KBU6 and its average value KBUave6 are updated is reduced. For this reason, in the present embodiment, the average value KBUave4 or the average value KBUave5 that is likely to be updated relatively frequently is used.

  The correction value calculation unit 72 has a correction value table 72a in which an idle intake amount change rate and a throttle opening correction value ΔTHAS are stored in association with each other as shown in FIG. The correction value calculation unit 72 calculates the throttle opening correction value ΔTHAS by acquiring the throttle opening correction value ΔTHAS corresponding to the idle intake amount change rate detected by the adjustment detection unit 70 from the correction value table 72a. The correction value calculation unit 72 overwrites and stores the calculated throttle opening correction value ΔTHAS in the correction value storage unit 120 of the volatile memory 66. When the adjustment detection unit 70 detects that the air screw 38 is not adjusted, the correction value calculation unit 72 sets the throttle opening correction value ΔTHAS stored in the correction value storage unit 120 to zero. .

  The basic injection amount calculation unit 60 determines that the adjustment flag is 1, and that the feedback region A corresponding to the current throttle opening TH and the engine speed NE is the second feedback region A2 or the third feedback region A3. Then, the throttle opening TH is corrected using the throttle opening correction value ΔTHAS. Specifically, the throttle opening TH is corrected by adding the throttle opening correction value ΔTHAS to the throttle opening TH detected by the throttle opening sensor 44. Then, the basic injection amount calculation unit 60 uses the injection amount map 80 to calculate a basic injection amount TIMB corresponding to the corrected throttle opening TH (hereinafter, THM) and the engine speed NE.

  Thus, when the air screw 38 is adjusted, the throttle opening TH is corrected, and the basic injection amount TIMB is calculated using the corrected throttle opening THM. Therefore, the learning value KBU2 updated by the O2 feedback control and The difference between the learning value KBU3 and the base value E is smaller than when the throttle opening TH is not corrected.

  FIG. 15 shows the learned value KBU2 and the base value when the throttle opening TH is corrected during the open loop control when the air screw 38 is shifted from the initial position to the closing side so as to reduce the amount of air passing through the bypass passage 36. It is a figure which shows the relationship with E. As shown in FIG. 15, even if the learned value KBU2 stored in the KBU2 storage unit 96 is calculated by the throttle opening TH on the low opening side (black circle in FIG. 15), it is stored in the KBU2 storage unit 96. The difference between the learned value KBU2 and the learned value KBU2 at which the throttle opening is higher is smaller than that when the throttle opening TH is not corrected (compared to FIG. 11). Therefore, even if the average value KBUave2 stored in the KBU2 average value storage unit 108 is calculated with the throttle opening TH on the low opening side, the average value stored in the KBU2 average value storage unit 108 is thereby obtained. The difference between KBUave2 and the average value KBUave2 on the high opening side can be reduced, and fuel can be injected with a more appropriate fuel injection amount TOUT.

  The operation of calculating the throttle opening correction value ΔTHAS will be described with reference to the flowchart of FIG. The operation shown in FIG. 16 is executed during the calculation cycle of each feedback correction amount KO2. The adjustment detection unit 70 determines whether or not the feedback area A corresponding to the current throttle opening TH and engine speed NE detected by the throttle opening sensor 44 and the engine speed sensor 46 is the first feedback area A1. (Step S1).

  If it is determined in step S1 that the feedback area A corresponding to the current throttle opening TH and engine speed NE is not the first feedback area A1, the process is terminated. On the other hand, if it is determined in step S1 that the feedback area A corresponding to the current throttle opening TH and the engine speed NE is the first feedback area A1, the adjustment detection unit 70 is stored in the KBU1 average value storage unit 106. It is determined whether or not the absolute value of the difference between the average value KBUave1 being stored and the average value KBUave4 stored in the KBU4 average value storage unit 112 exceeds a threshold value (step S2).

  If it is determined in step S2 that the absolute value of the difference between the average value KBUave1 and the average value KBUave4 exceeds the threshold value, the adjustment detection unit 70 detects that the air screw 38 has been adjusted, and sets the adjustment flag to 1. (Step S3). That is, 1 is stored in the adjustment flag storage unit 118.

  Next, the correction value calculation unit 72 calculates the throttle opening correction value ΔTHAS, and stores the calculated throttle opening correction value ΔTHAS in the correction value storage unit 120 of the volatile memory 66 (step S4). Specifically, the adjustment detection unit 70 detects an idle intake air amount change rate that is an adjustment amount according to a difference between the average value KBUave1 and the average value KBUave4 using the adjustment amount map 70a. Then, the correction value calculation unit 72 calculates a throttle opening correction value ΔTHAS according to the idle intake amount change rate detected using the correction value table 72a.

  On the other hand, if it is determined in step S2 that the absolute value of the difference between the average value KBUave1 and the average value KBUave4 does not exceed the threshold value, the adjustment detection unit 70 detects that the air screw 38 is not adjusted, and the adjustment flag Is set to 0 (step S5). That is, 0 is stored in the adjustment flag storage unit 118. Next, the correction value calculation unit 72 sets the throttle opening correction value ΔTHAS to 0 and stores it in the correction value storage unit 120 of the volatile memory 66 (step S6).

  The basic injection amount TIMB calculation operation of the basic injection amount calculation unit 60 will be described with reference to the flowchart of FIG. When the basic injection amount calculation unit 60 calculates the basic injection amount, first, a feedback region corresponding to the current throttle opening TH and engine speed NE detected by the throttle opening sensor 44 and the engine speed sensor 46 is used. It is determined whether A is the second feedback area A2 or the third feedback area A3 (step S11).

  If it is determined in step S11 that the feedback region A corresponding to the current throttle opening TH and the engine speed NE is the second feedback region A2 or the third feedback region A3, the basic injection amount calculation unit 60 sets the adjustment flag. It is determined whether or not 1 (step S12). This determination is made based on the value stored in the adjustment flag storage unit 118.

  If it is determined in step S12 that the adjustment flag is 1, the basic injection amount calculation unit 60 corrects the throttle opening TH detected by the throttle opening sensor 44 (step S13). Specifically, the throttle opening TH is corrected by adding the throttle opening correction value ΔTHAS stored in the correction value storage unit 120 to the detected throttle opening TH.

  Next, the basic injection amount calculation unit 60 uses the injection amount map 80 to calculate the basic injection amount TIMB according to the corrected throttle opening THM and the current engine speed NE detected by the engine speed sensor 46 ( Step S14).

  On the other hand, if it is determined in step S11 that the feedback area A corresponding to the current throttle opening TH and engine speed NE is not the second feedback area A2 or the third feedback area A3, or the adjustment flag is set in step S12. If it is determined that it is not 1, the process proceeds to step S15.

  In step S15, the basic injection amount calculation unit 60 uses the injection amount map 80 to determine the basic value corresponding to the current throttle opening TH and engine speed NE detected by the throttle opening sensor 44 and the engine speed sensor 46. An injection amount TIMB is calculated.

  Next, the main operation of the control unit 42 will be described with reference to the flowchart of FIG. First, the control unit 42 determines whether or not the angular velocity dTH / dt of the throttle opening TH detected by the throttle opening sensor 44 is larger than a predetermined value (step S21). That is, in step S21, it is determined whether or not the amount of change per unit time of the throttle opening TH is greater than a predetermined value.

  The angular velocity dTH / dt may be obtained by differentiating the throttle opening TH with time t, or may be obtained by a calculation formula of (TH1-TH0) / (t1-t0). TH1 represents the throttle opening TH detected this time, and TH0 represents the throttle opening TH detected last time. t1 represents the timing at which the throttle opening TH1 is detected, and t0 represents the timing at which the throttle opening TH0 is detected.

  If it is determined in step S21 that the angular velocity dTH / dt of the throttle opening TH is not greater than a predetermined value, the control unit 42 calculates the fuel injection amount TOUT by executing O2F / B control (step S22). The fuel injection valve 40 injects fuel with the calculated fuel injection amount TOUT.

Specifically, the fuel injection amount calculation unit 68 learns the feedback region A according to the current operation region (throttle opening TH and engine speed NE) detected by the throttle opening sensor 44 and the engine speed sensor 46. The value KBU and the feedback correction amount KO2 are acquired from the volatile memory 66. The fuel injection amount calculation unit 68 multiplies the basic injection amount TIMB the basic injection amount calculation unit 60 is calculated according to the operation of FIG. 1 7, a feedback correction amount KO2 and the learning value KBU acquired, the detected intake air temperature sensor 52 The fuel injection amount TOUT is calculated by multiplying the intake air temperature correction coefficient KTA according to the intake air temperature TA. That is, the calculation is performed using the above-described equation (1).

  The coefficient calculation unit 84 sequentially updates the feedback correction amount KO2 and its average value KO2ave, and the learning value KBU and its average value KBUave during the O2F / B control, and stores them in the volatile memory 66. The coefficient calculation unit 84 updates the learning value KBU (KBU1 to KBU6) and the average value KBUave of the feedback region A (A1 to A6) according to the current throttle opening TH and the engine speed NE.

  During the O2 feedback control with the air screw 38 adjusted, when the current operation region is in the second feedback region A2 or the third feedback region A3, the throttle opening TH is corrected. Accordingly, the learning values KBU2 and KBU3, and the average values KBUave2 and KBUave3, which have a small difference between the throttle opening TH and the low opening side, are updated.

  On the other hand, if it is determined in step S21 that the angular velocity dTH / dt of the throttle opening TH is larger than a predetermined value, acceleration correction injection control is performed to calculate the fuel injection amount TOUT (step S23).

Specifically, the fuel injection amount calculation unit 68 volatilizes the average value KBUave in the feedback region A according to the current throttle opening TH and engine speed NE detected by the throttle opening sensor 44 and the engine speed sensor 46. From the memory 66. The fuel injection amount calculation unit 68 multiplies the basic injection amount TIMB the basic injection amount calculation unit 60 is calculated according to the operation of FIG. 1 7, the average value KBUave obtained, according to the intake air temperature TA to the intake temperature sensor 52 detects The intake air temperature correction coefficient KTA is multiplied. Then, a value obtained by multiplying the value obtained by multiplication by the additional injection amount TACC and the acceleration correction coefficient KTACC in the acceleration correction according to the current throttle opening TH and the engine speed NE is added. An injection amount TOUT is calculated. That is, the calculation is performed using the above-described equation (2).

  The average values KBUave2 and KBUave3 stored in the volatile memory 66 have a small difference between the throttle opening TH on the low opening side and the high opening side, so that the O2 feedback control is not executed. Even in the case of control, an appropriate fuel injection amount TOUT can be calculated. Further, when the operation region is in the second feedback region A2 or the third feedback region A3, the basic injection amount TIMB is calculated by correcting the throttle opening TH, so that a more appropriate fuel injection amount TOUT is calculated. Can do.

  In the above embodiment, the learning value KBU is calculated by multiplying the fluctuation amount with respect to the reference value of the average value KO2ave of the feedback correction amount KO2, but the learning value KBU is multiplied by the fluctuation amount with respect to the reference value of the feedback correction amount KO2. The value KBU may be calculated.

  In the above embodiment, the air screw 38 is based on the absolute value of the difference between the average value KBUave1 of the first feedback region A1 and the average value KBUave4 of the fourth feedback region A4 or the average value KBUave5 of the fifth feedback region A5. The absolute value of the difference between the learning value KBU1 in the first feedback region A1 and the learning value KBU4 in the fourth feedback region A4 or the learning value KBU5 in the fifth feedback region A5 is detected. Whether or not the air screw 38 has been adjusted may be detected based on the above.

  Further, in the above embodiment, the idle intake amount change rate is set according to the difference between the average value KBUave1 in the first feedback region A1 and the average value KBUave4 in the fourth feedback region A4 or the average value KBUave5 in the fifth feedback region A5. Although detected, the idle intake amount change rate is detected according to the difference between the learning value KBU1 in the first feedback area A1 and the learning value KBU4 in the fourth feedback area A4 or the learning value KBU5 in the fifth feedback area A5. May be.

  That is, in the above embodiment, the average values KO2ave and KBUave are calculated and used, but the average values KO2ave and KBUave are used. Instead of calculating the average values KO2ave and KBUave, instead of the average values KO2ave and KBUave, Alternatively, the feedback correction amount KO2 and the learning value KBU may be used.

  Since the intake air passing through the bypass passage 36 adjusted by the air screw 38 flows through the bypass passage 36 as the throttle opening TH is lower, the air screw 38 is adjusted as the learning value KBU is lower. The learning value KBU is likely to shift due to As a result of the research, the applicant has found that when the throttle opening TH becomes a high opening side, the intake air passes through the intake pipe 22 without passing through the bypass passage 36. I found that it was not easily affected by 38 adjustments. Therefore, in this embodiment, taking advantage of this property, the learning value KBU of the feedback region A where the throttle opening TH is the low opening side and the learning value KBU of the feedback region A where the throttle opening TH is the high opening side When the absolute value of the difference exceeds the threshold value, it is detected that the air screw 38 has been adjusted. Therefore, the adjustment of the air screw 38 can be detected with high accuracy and a simple structure.

  During idling, the throttle opening TH is fully closed, so that the deviation of the learned value KBU due to adjustment of the air screw 38 is significant. In addition, the adjustment of the air screw 38 is often performed during idling. Therefore, in the present embodiment, the feedback region A on the low opening side is the first feedback region A1 that is the idling region of the engine 10, and the feedback region A on the high opening side is learned by adjusting the air screw 38. The value KBU is not affected, that is, the throttle opening TH is in the feedback region (any one of A4 to A5) that is greater than or equal to the middle opening, so that the adjustment of the air screw 38 can be easily detected, and the air Adjustment of the screw 38 can be detected with higher accuracy.

  2nd and 3rd feedback area | regions A2 and A3 are driving | running | working area | regions which it passes by starting from a stop and becoming a steady run. On the other hand, the fourth and fifth feedback regions A4 and A5 are operation regions that are likely to be in steady running, and the throttle opening TH is higher than the first to third feedback regions A1 to A3. This is a region where the influence of the deviation of the learning value KBU due to the adjustment of the screw 38 is difficult to occur. Therefore, in the present embodiment, the plurality of feedback areas A include the first feedback area A1, the second feedback area A2 adjacent to the first feedback area A1 on the high speed side of the engine speed NE, and the first feedback area. A third feedback region A3 adjacent to A1 and the second feedback region A2 on the high opening side of the throttle opening TH, and a fourth feedback region A4 adjacent to the third feedback region A3 on the high opening side of the throttle opening TH. A fifth feedback region A5 adjacent to the fourth feedback region A4 on the high opening side of the throttle opening TH, and a sixth feedback region A6 adjacent to the fifth feedback region A5 on the high opening side of the throttle opening TH. The feedback area A on the high opening side is the fourth feedback area A4 or Since the fifth feedback region A5, frequently learned value KBU By the use of the learned value KBU for easy feedback area A is updated, it is possible to detect more accurately the adjustment of the air screw 38.

  Using the difference between the average value KBUave of the learning value KBU for the past predetermined number of times in the feedback region A on the low opening side and the average value KBUave of the learning value KBU for the past predetermined number of times in the feedback region A on the high opening side Since it is detected whether the air screw 38 has been adjusted, it is possible to detect whether the air screw 38 has been adjusted while suppressing variations in the learning value KBU, and the detection accuracy of adjustment of the air screw 38 can be further improved. .

  The adjustment amount of the air screw 38 is detected, a throttle opening correction value ΔTHAS is calculated according to the adjustment amount of the air screw 38, and the throttle opening detected by the throttle opening sensor 44 using the throttle opening correction value ΔTHAS. Since the basic injection amount TIMB is calculated by correcting TH, the throttle opening TH closely related to the intake amount can be corrected in accordance with the amount of increase / decrease in the intake amount by adjusting the air screw 38, and this corrected throttle The basic injection amount TIMB can be calculated using the opening degree THM. Therefore, the increase / decrease in the intake air amount due to the adjustment of the air screw 38 can be corrected easily and accurately, the calculation accuracy of the basic injection amount TIMB can be improved, and as a result, the calculation accuracy of the fuel injection amount TOUT is improved. be able to.

  When the adjustment of the air screw 38 is performed, the learning value KBU on the low opening side of the throttle opening TH is easily influenced, and the learning value KBU on the high opening side is relatively insensitive to the low opening side. The amount of adjustment of the air screw 38 can be estimated from the difference between the learned value KBU and the learned value KBU on the high opening side. Therefore, the adjustment amount is detected based on the difference between the learning value KBU of the feedback region A where the throttle opening TH is the low opening side and the learning value KBU of the feedback region A where the throttle opening TH is the high opening side. Therefore, the adjustment amount of the air screw 38 can be obtained with high accuracy with a simple structure, and as a result, the calculation accuracy of the fuel injection amount TOUT can be improved.

  A feedback region that is larger than the throttle opening TH of the feedback region A on the low opening side and less than or equal to the throttle opening TH of the feedback region A on the high opening side, and affects the learning value KBU by adjusting the air screw 38. Since the basic injection amount TIMB is calculated by correcting the throttle opening TH detected by the throttle opening sensor 44 only within the feedback region A, the calculation accuracy of the basic injection amount TIMB can be improved. It is possible to improve the calculation accuracy of the fuel injection amount TOUT in the low throttle opening range which is easily affected by the adjustment of the air screw 38.

  The plurality of feedback regions A include a first feedback region A1 that is an idling region of the engine 10, a second feedback region A2 in which the engine speed NE is adjacent to the first feedback region A1 on the high speed side, and a first feedback region A1. And a third feedback region A3 adjacent to the second feedback region A2 on the high opening side of the throttle opening TH, and a fourth feedback region A4 adjacent to the third feedback region A3 on the high opening side of the throttle opening TH. From the fifth feedback region A5 adjacent to the fourth feedback region A4 on the high opening side of the throttle opening TH, and from the sixth feedback region A6 adjacent to the fifth feedback region A5 on the high opening side of the throttle opening TH. The learning value KBU is affected by adjusting the air screw 38. Since the feedback region A is the second feedback region A2 and the third feedback region A3, it is possible to improve the calculation accuracy of the basic injection amount TIMB. As a result, in the region of the total throttle opening TH, the fuel injection amount The calculation accuracy of TOUT can be improved.

  The calculated throttle opening correction value ΔTHAS is stored in the volatile memory 66. When the engine 10 is stopped, the throttle opening correction value ΔTHAS stored in the volatile memory 66 at that time is stored in the nonvolatile memory 67. The Therefore, an appropriate fuel injection amount TOUT can be calculated from the next engine start.

  As described above, the present invention has been described using the preferred embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above embodiment. It is apparent from the description of the scope of claims that embodiments with such changes or improvements can be included in the technical scope of the present invention. In addition, the reference numerals in parentheses described in the claims are appended to the reference numerals in the accompanying drawings for easy understanding of the present invention. It is not construed as limiting.

DESCRIPTION OF SYMBOLS 10 ... Engine 12 ... Fuel injection control apparatus 22 ... Intake pipe 24 ... Exhaust pipe 30 ... Intake valve 32 ... Exhaust valve 34 ... Throttle valve 36 ... Bypass passage 38 ... Air screw 40 ... Fuel injection valve 42 ... Control part 44 ... Throttle opening Degree sensor 46 ... Engine speed sensor 50 ... Oxygen sensor 60 ... Basic injection amount calculation unit 62 ... Feedback unit 64 ... KBU map 66 ... Volatile memory 68 ... Fuel injection amount calculation unit 70 ... Adjustment detection unit 70a ... Adjustment amount map 72 ... correction value calculation unit 72a ... correction value table 80 ... injection amount map 82 ... rich lean determination unit 84 ... coefficient calculation unit 84a ... feedback correction amount calculation unit 84b ... learning value calculation unit

Claims (4)

A bypass passage (36) connecting the upstream side and the downstream side of the throttle valve (34) of the intake pipe (22) of the engine (10);
An air screw (38) for opening and closing the bypass passage (36);
An oxygen sensor (50) for detecting the oxygen concentration in the exhaust gas of the engine (10);
A feedback correction amount (KO2) that is a correction coefficient is calculated based on the oxygen concentration detected by the oxygen sensor (50), and a learning value (KBU) that is a correction coefficient learned according to the feedback correction amount (KO2). A coefficient calculation unit (84) for calculating and updating the value for each of a plurality of feedback regions divided according to the throttle opening (TH) of the throttle valve (34),
A fuel injection amount calculation unit (68) that calculates a fuel injection amount (TOUT) by correcting a basic injection amount (TIMB) using the feedback correction amount (KO2) and the learning value (KBU);
In a fuel injection control device (12) of an engine (10) comprising:
The difference between the learned value of the throttle opening (TH) is a low opening side feedback region and (KBU), wherein the throttle opening degree (TH) is a high opening degree side of the learning value of the feedback control region and (KBU) A fuel injection control device (12) for an engine (10), comprising an adjustment detection unit (70) for detecting an adjustment amount of the air screw (38) based on the adjustment amount . In the fuel injection control device (12) of the engine (10) according to claim 1,
The feedback region on the low opening side is a first feedback region (A1) that is an idling region of the engine (10), and the feedback region on the high opening side is that the throttle opening (TH) is in the middle open state. The fuel injection control device (12) for the engine (10), characterized in that the feedback region (A4 to A6) is at least 20 degrees. In the fuel injection control device (12) of the engine (10) according to claim 2,
The plurality of feedback regions include the first feedback region (A1), the second feedback region (A2) adjacent to the first feedback region (A1) on the high rotation side of the engine speed (NE), and the first feedback region (A1). A third feedback region (A3) adjacent to the first feedback region (A1) and the second feedback region (A2) on the high opening side of the throttle opening (TH); and the third feedback region (A3) A fourth feedback region (A4) adjacent on the high opening side of the throttle opening (TH) and a fifth feedback adjacent on the high opening side of the throttle opening (TH) to the fourth feedback region (A4). The sixth feedback area adjacent to the area (A5) and the fifth feedback area (A5) on the high opening side of the throttle opening (TH). Made from the area (A6),
The fuel injection control device (12) of the engine (10), wherein the feedback region on the high opening side is the fourth feedback region (A4) or the fifth feedback region (A5). In the fuel injection control device (12) of the engine (10) according to any one of claims 1 to 3,
The adjustment detection unit (70) includes an average value (KBUave) of the learning value (KBUave) for the past predetermined number of times in the feedback region on the low opening side and the past predetermined number of times on the feedback region on the high opening side. The fuel injection control device (12) of the engine (10) is characterized by detecting whether the air screw (38) has been adjusted by using a difference from an average value (KBUave) of the learning value (KBU) of minutes. ).

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