JP6587977B2 - Engine control device - Google Patents

Description

  The present invention relates to an engine control device, and more particularly to an engine control device that controls an intake air amount during automatic stop and restart of the engine.

Conventionally, for the purpose of reducing energy consumption and reducing CO ₂ emissions during idling, when the driver stops the vehicle, the engine is automatically stopped by fuel cut (fuel injection is stopped in the cylinder). When an attempt is made to drive the vehicle by an accelerator operation or the like, for example, a vehicle equipped with an idle stop function that restarts by cranking the engine with a starter is known.

  In recent years, this idle stop function has been applied not only when the vehicle is stopped, but also a coast stop function that automatically stops the engine when the driver steps on the brake in the low vehicle speed range, and the driver applies torque in the high vehicle speed range. It has been proposed that the engine and clutch be disconnected when not required (for example, when the accelerator is off and the brake is off for a predetermined time or more) and the engine is automatically extended to a sailing stop function (for example, the following) Patent Document 1).

  In the idling stop function described above, when a driver's start operation (for example, accelerator operation or steering wheel operation) is performed and an engine restart request is generated, high restartability is required. The restartability here is the time required for the engine to enter the autonomous operation state after the restart request is generated. In particular, when the above-described sailing stop function is restarted, the vehicle is running and restartability is required in units of 100 ms.

  Such engine restart is performed by combustion (combustion recovery) by restarting fuel injection in a region where the engine speed is relatively high immediately after fuel cut is performed by an automatic stop request, while The starter cranking is performed in a region where the engine speed is low where starting is impossible or a region after engine stabilization (complete stop). In any case, at the time of restarting, sufficient air is required so that combustion can be performed quickly in order to ensure the above-described high restartability. That is, in order to ensure restartability during automatic stop, a high cylinder pressure is required.

  On the other hand, in the compression process immediately after the engine is stopped after the fuel cut is performed due to the automatic stop request, the inertial rotational force of the engine is defeated by the pressure in the cylinder, and the engine rotates backward. It is known that this phenomenon occurs. If a restart request occurs when this swingback occurs, from the viewpoint of protecting the starter durability, the starter cannot be bitten into the reversely rotated engine (specifically, the starter biting is automatically stopped). Therefore, there was a problem that the restart was delayed until the swingback converged.

  In addition, when cranking by a jump-in starter is performed in a region where the engine speed is low (for example, 200 rpm or less) after a fuel cut is performed by an automatic stop request, inertial rotation occurs when the cylinder pressure is high. There was a problem that engine rotation fluctuations became large, and the restart was delayed due to the failure to synchronize the rotation with the starter.

  In order to solve the above-mentioned problem, it is effective to close the intake throttle valve while the engine is automatically stopped to reduce the pressure in the cylinder. There is a contradictory problem that the air necessary for combustion is insufficient and the restartability deteriorates.

  Therefore, in Patent Document 2, if the filtered intake pipe pressure is equal to or lower than a predetermined pressure required for restarting the engine after it is determined that the engine is automatically stopped, a throttle valve provided in the intake pipe is opened. A technique has been proposed in which the throttle opening is closed to a predetermined degree of opening so that the pressure is maintained after the intake pipe pressure reaches a predetermined pressure required for restarting.

JP 2006-200370 A JP 2012-225289 A

  However, the conventional technique described in Patent Document 2 requires an intake pipe pressure sensor, and cannot be controlled when the intake pipe pressure sensor is absent or fails. Further, the main purpose of the prior art described in Patent Document 2 is to maintain the intake pipe pressure capable of ensuring restartability by suppressing fluctuations in the engine rotation speed, and the situation where the above-described shaking back occurs. Is not considered.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to appropriately control the in-cylinder pressure during automatic stop and restart of the engine even when the intake pipe pressure sensor is absent or has failed. Another object of the present invention is to provide an engine control device that can ensure restartability.

  In order to solve the above-described problem, an engine control apparatus according to the present invention includes an automatic stop determination unit that determines whether or not a preset automatic stop condition is satisfied in order to stop fuel injection into a cylinder of the engine. A restart determination unit that determines whether a preset restart condition is satisfied, an air amount adjustment unit that adjusts an intake air amount sucked into the cylinder, and an operating state of the engine. Intake pipe pressure estimating means for estimating the pressure in the intake pipe connected to the cylinder, and when the automatic stop condition is determined to be satisfied by the automatic stop determining means, the intake pipe pressure estimating means estimates the The intake air amount is adjusted by the air amount adjusting means based on the pressure of the intake pipe.

  According to the present invention, in a vehicle that does not have an intake pipe pressure sensor or has a malfunction in the intake pipe pressure sensor, the intake pipe pressure estimation means determines whether the engine is in an operating state between the automatic stop and the complete stop. Based on the estimated intake pipe pressure, it is possible to maintain the intake pipe pressure (and cylinder pressure) that can be restarted by the air amount adjusting means, and to reduce the possibility of engine reversal (swing back). Therefore, restartability can be ensured.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

1 is an overall configuration diagram showing an example of an overall configuration of an engine on which an engine control device according to the present invention is mounted. The internal block diagram which shows an example of the internal structure of the control apparatus of the engine which concerns on this invention. The block block diagram which shows an example of the control block structure of the control apparatus of the engine which concerns on this invention. The figure which shows an example of the physical model of an engine intake system. The figure explaining an example of the calculation process which calculates | requires an intake pipe pressure in the intake pipe pressure estimation means shown in FIG. The flowchart explaining an example of the process flow which calculates | requires the throttle opening degree in the engine control apparatus which concerns on this invention during an engine automatic stop or restart. The time chart which shows an example of the driving | running state of the engine by which the engine control apparatus which concerns on this invention is mounted in time series.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an example of the overall configuration of a control system for an engine 100 equipped with an engine control unit (ECU: Engine Control Unit) according to the present invention.

  The present control system includes an ignition switch 116 that is a main switch for operating and stopping the engine 100. An air cleaner (not shown) is provided in the uppermost stream of the intake pipe 104 connected to the cylinder 125 (for sending air into the cylinder 125), and an air flow sensor as intake air amount measuring means is provided downstream of the air cleaner. 101 (also referred to as an intake air amount sensor) is provided. The airflow sensor 101 measures the amount of air (intake) that passes through the throttle valve 102 downstream of the airflow sensor 101. The opening of the throttle valve 102 is controlled by a throttle valve drive motor 221 (see FIG. 2), and a throttle valve opening sensor 122 that detects the throttle valve opening is integrated. Further, an idle speed control valve 103 that controls the flow area of the flow path that bypasses the throttle valve 102 and is connected to the intake pipe 104 is provided. The throttle valve 102 and the idle speed control are controlled according to a command value from the ECU 119. The valve 103 is operated to control the amount of intake air drawn from the intake pipe 104 into the cylinder 125. The airflow sensor 101 is integrated with an intake air temperature sensor 123 that measures the temperature of the intake air.

  Further, engine 100 includes a fuel injection device (also referred to as an injector) 105 that injects fuel based on an injection command pulse from ECU 119, and an ignition module 107 that supplies ignition energy based on an ignition signal from ECU 119. ing. By opening the intake valve 114 with the cam 106, the ignition module 107 converts the air taken from the intake pipe 104 into the cylinder 125 (combustion chamber 115) and the fuel injected from the fuel injection device 105 into the mixed air. By igniting, an explosion occurs in the cylinder 125 (combustion chamber 115), and torque is output to the crankshaft 120 as a driving force of the vehicle.

  The exhaust gas after the explosion (combustion) passes from the exhaust valve 108 through the exhaust pipe 111, removes harmful gas in the exhaust gas with a catalyst (not shown) such as a three-way catalyst, and then is exhausted outside the vehicle. At this time, the oxygen concentration sensor 110 attached to the exhaust pipe 111 detects the air-fuel ratio or the rich / lean side of the exhaust gas.

  Further, the engine 100 is provided with an engine water temperature sensor 109 for detecting the cooling water temperature, a crank angle sensor 112 for detecting the rotation speed of the crankshaft 120 (engine rotation speed), and a reverse rotation of the crankshaft 120. The reverse rotation detection crank angle sensor 113 and the cam angle sensor 121 for detecting the angle of the cam 106 are provided. The ECU 119 determines that the engine 100 is reversely rotated from the output signals of the crank angle sensor 112 and the reverse rotation detection crank angle sensor 113, and determines the current cylinder position from the output signals of the crank angle sensor 112 and the cam angle sensor 121.

  The engine 100 further includes an accelerator pedal sensor (also referred to as an accelerator opening sensor) 117 that determines a driver's operation request, and a brake pedal sensor (also referred to as a brake switch) 118 that determines a stop request from the driver. A vehicle speed sensor 124 for detecting the vehicle speed is provided, and the ECU 119 controls the engine 100 in accordance with these operation amounts and the like.

  FIG. 2 shows an example of the internal configuration of an engine control unit (ECU) according to the present invention.

  The ECU 119 is basically composed of a CPU (Central Processing Unit) 201 and a driver 225. Inside the CPU 201, electrical signals from sensors installed in the engine are used as control signals for digital arithmetic processing. An I / O (Input / Output) unit 202 that converts control signals for conversion and digital computation into actual actuator drive signals is set. The I / O unit 202 includes an intake air temperature sensor 123, an engine water temperature sensor 109, a crank angle sensor 112, a cam angle sensor 121, an oxygen concentration sensor 110, an air flow sensor 101, a throttle valve opening sensor 122, an accelerator opening sensor 117, Electrical signals obtained from the ignition switch 116, the vehicle speed sensor 124, the brake switch 118, the reverse rotation detection crank angle sensor 113, and the like are input. Output signals (driving signals) from the CPU 201 are supplied via a driver 225 to fuel injection devices (here, fuel injection devices for three cylinders) 105a to 105c, and ignition modules (here, ignition modules for three cylinders) 107a. ˜107c, sent to the throttle valve drive motor 221 that drives the throttle valve 102, and sent to the starter drive solenoid 223 and the starter drive motor 224 via the battery relay switch 222.

  FIG. 3 shows an example of a control block configuration of an engine control unit (ECU) according to the present invention.

  In block 301 (engine automatic stop determination means), the output of the ignition switch 116, the output of the brake switch 118, the output of the accelerator opening sensor 117 (accelerator opening), the output of the vehicle speed sensor 124 (vehicle speed), Based on the determined engine restart request determination value and the clutch disengagement request determination value determined in block 304, which will be described later, the engine is automatically stopped by the fuel cut (stopping of fuel injection into the cylinder) (the engine automatic stop condition is satisfied / not satisfied). ). In block 302 (system restart request determination means), a system restart request is determined. In this block 302, when the engine is automatically stopped, when performance degradation or abnormality detection occurs for parts or functions of the vehicle system, when an air conditioner operation request occurs, when a power generation request occurs, external recognition information If an increase in vehicle deceleration is requested to avoid a collision with an object in front of the vehicle, whether or not it is necessary to start the engine other than the driver's accelerator operation, including at least one of them. judge. In block 303 (engine restart determination means), the output of the accelerator opening sensor 117 (accelerator opening), the engine reverse rotation determination value determined in block 305 to be described later, and the crank angle in block 306 (engine speed calculation means) From the engine speed calculated from the output of the sensor 112, the engine automatic stop determination value determined in block 301, and the system restart request determination value determined in block 302, an engine restart request (whether the engine restart condition is satisfied / not satisfied). Is established). In block 304 (clutch disengagement request determination means), the engine automatic stop determination value determined in block 301, the engine restart request determination value determined in block 303, the output (vehicle speed) of the vehicle speed sensor 124, and the calculation in block 306 A clutch disconnection request is determined from the engine speed and the clutch disconnection permission determination value from the transmission side. In this block 304, it is determined whether or not there is a request for coasting the vehicle by disengaging the clutch between the engine 100 and the wheel, and the transmission side control device ( Unit). The transmission-side unit performs optimum gear ratio control based on information on the engine side (engine speed, vehicle speed, throttle valve opening, etc.) including this determination result and information on the transmission side.

  In block 305 (reverse rotation detection determination means), the reverse rotation determination value of the engine 100 is output from the phase of the output of the reverse rotation detection crank angle sensor 113 and the output of the crank angle sensor 112. In block 307 (engine complete stop determination means), complete stop of engine 100 is determined from the output of crank angle sensor 112 or the engine speed calculated in block 306.

  In addition, since the processing content in the above-mentioned blocks 301-307 is substantially the same as what was known conventionally, the detailed description is omitted here (for example, refer also to patent document 2).

  On the other hand, in block 308 (intake pipe pressure estimating means), the output of the air flow sensor 101, the output of the intake air temperature sensor 123, the output of the throttle valve opening sensor 122, the output of the engine water temperature sensor 109, the engine speed calculated in the block 306 From this, an estimated intake pipe pressure value is output (detailed later). In block 309 (throttle opening calculating means that is an air amount adjusting means), an engine automatic stop determination value determined in block 301, an engine restart request determination value determined in block 303, and a reverse rotation determination determined in block 305 The engine complete stop determination value determined in block 307, the engine speed calculated in block 306, and the intake pipe pressure estimated value calculated in block 308 are used to determine whether the engine is being automatically stopped or The throttle opening during start-up is calculated, and based on the calculated throttle opening, the throttle valve drive motor 221 that drives the throttle valve 102 and manipulates the opening is controlled.

  The calculation method of the intake pipe pressure estimated value (absolute pressure) by the block 308 (intake pipe pressure estimating means) will be described in detail.

  FIG. 4 shows an example of a physical model of the intake system of the engine.

  An airflow sensor 401 is set at the inlet of the intake pipe 404 of the intake system, and an air amount (intake air amount) QA00402 that is sucked into the engine (in the cylinder), which fluctuates by opening / closing operation of the throttle valve 403, is set. To detect. The cylinder inflow air amount QAR 406 is determined by the non-linear intake efficiency determined by the pressure in the intake pipe 404 (intake pipe pressure) PMMHG 405, the engine speed, the engine exhaust amount, the intake temperature, and the engine region.

  FIG. 5 illustrates an example of a calculation process for obtaining the intake pipe pressure in the intake pipe pressure estimating means (block 308) shown in FIG.

  A block 501 is a block for calculating (estimating) the intake pipe pressure PMMHG. In block 501, the current intake pipe pressure PMMHG is calculated using the air quantity QA00 taken into the engine, the intake air temperature THA, the previously calculated cylinder inflow air quantity QAR, and the previously calculated intake pipe pressure PMMHG. In block 502, the intake efficiency η, which is a non-linear element, is obtained from a map search from the engine speed Ne and the intake pipe pressure PMMHG. The intake efficiency η corrects a deviation from the theoretical value of the cylinder inflow air amount QAR obtained based on the intake pipe pressure PMMHG. Further, in block 503, the cylinder inflow air amount QAR is calculated from the intake efficiency η obtained in block 502, the intake pipe pressure PMMHG, intake air temperature THA, and engine speed Ne obtained in block 501. The cylinder inflow air amount QAR is used to calculate basic fuel and the like, and is used to estimate the intake pipe pressure PMMHG. If the intake air temperature sensor is not set in engine 100, the error does not cause a problem even if the intake air temperature THA is fixed to a predetermined value (for example, 27 ° C.).

  Equation 1 below shows a theoretical formula for obtaining the intake pipe pressure PMMHG and the cylinder inflow air amount QAR in FIG.

(Equation 1)

  Equation (1) above shows the theoretical formula in the continuous region, and the inflow / outflow of air into the intake pipe (between the throttle valve and the intake valve) in a very short time becomes the pressure gradient in the intake pipe. Is shown. Equation (2) is a discretization of Equation (1), and the intake pipe pressure PMMHG is obtained by executing this equation. Equation (3) represents an equation for obtaining the cylinder inflow air amount QAR from the intake pipe pressure PMMHG obtained in Equation (2), and the basic equation is a state equation of an ideal gas. Therefore, the intake air efficiency η and the intake air efficiency correction coefficient VVTCRG are multiplied as nonlinear elements. Further, as described above, the intake air temperature THA may be fixed to a predetermined value.

  As a result of this calculation, even in a vehicle that does not have an intake pipe pressure sensor or has a malfunction in the intake pipe pressure sensor, the operation state of the engine 100, specifically, the intake air amount, is detected by the block 308 (intake pipe pressure estimation means). The intake pipe pressure (absolute pressure) PMMHG can be calculated (estimated) from QA00, the engine speed Ne, the gas constant R, the engine displacement KSV, and the nonlinear intake efficiency η determined by the engine region. In (throttle opening calculation means), the cylinder inflow air amount QAR for calculating the throttle opening for controlling the throttle valve drive motor 221 can be calculated.

  FIG. 6 illustrates an example of a processing flow of throttle opening calculation during engine automatic stop or restart of the engine control device (ECU) according to the present invention. In this processing flow, the opening degree (value) of the throttle valve 102 during the automatic stop of the engine 100 is mainly calculated.

  In step S601, it is determined whether or not restart determination is established (engine restart determination means 303). If it is determined that the restart determination is not established, the process proceeds to step S602. In step S602, it is determined whether engine complete stop determination is established (engine complete stop determination means 307). When it is determined that the engine complete stop determination is not established, the process proceeds to step S603 described later. If it is determined in step S601 that the restart determination is satisfied and if it is determined in step S602 that the engine complete stop determination is satisfied, the process proceeds to step S611, and the throttle opening of the throttle valve 102 is set to K1. (Throttle opening calculation means 309). Here, it is preferable that the value of K1 is a value that is almost fully open. This is because, when it is determined that the restart determination is satisfied or when the engine complete stop determination is determined to be satisfied, it is not necessary to consider the reduction of the swing back, and in order to improve the startability, as much air amount as possible (Specifically, the estimated intake pipe pressure PMMHG calculated by the above equation 1 is set to be equal to or higher than a predetermined pressure required for restarting the engine 100).

  In step S603, it is determined whether automatic stop determination is established (engine automatic stop determination means 301). If it is determined that the automatic stop determination is established, the process proceeds to step S604 described later. If it is determined that the automatic stop determination is not established, it is determined that the automatic stop or restart is not being performed, and the process proceeds to step S608, where the throttle opening during the automatic stop or restart is cleared (throttle opening calculating means 309). ).

  In step S604, it is determined whether the engine speed Ne is near 0 during engine inertia rotation during automatic fuel cut stop, based on whether the engine speed Ne is lower than a predetermined engine speed NE2. If it is determined that Ne is not lower than NE2, the process proceeds to step S605 described later. If it is determined that Ne is lower than NE2 (smaller than NE2), the process proceeds to step S611, and the throttle opening is set to K1 (throttle opening calculating means 309). This is because, in a region where the engine speed Ne is low (region close to 0), there is less fear of swinging back and the restartability after the engine is settled (completely stopped) is improved. At this time, a delay occurs until the air flows into the cylinder 125 due to a change in the air manifold pressure after the throttle valve 102 is opened. However, if the time is short, the amount of air in the cylinder 125 (shakeback occurrence) is reduced. There is little influence. Even if the swingback occurs, air flows from the exhaust valve 108 side to the intake valve 114 side during the swingback because the manifold has a negative pressure. If the throttle valve 102 is opened at this time, the negative pressure in the manifold is eliminated, so that the magnitude (period) of the swingback is not affected. In view of the above, NE2 may set the engine speed to a value slightly higher than zero.

  In step S605, it is determined whether the intake pipe pressure PMMHG is greater than a predetermined pressure BT1 using the estimated intake pipe pressure PMMHG calculated in the above equation 1. When it is determined that the intake pipe pressure PMMHG is equal to or lower than BT1, the process proceeds to step S606 described later. If it is determined that the intake pipe pressure PMMHG is greater than BT1, the process proceeds to step S609, where the throttle opening is set to a small value K3 (throttle opening calculating means 309). BT1 should have an intake pipe pressure (for example, -75mmHg) that can secure the required air volume when there is a restart request during automatic stop, which reduces backlash and improves restartability. For the purpose of improving, it is preferable to set a value obtained by adding a margin to the minimum necessary intake pipe pressure during engine inertia rotation. Thus, by using the estimated intake pipe pressure PMMHG, the intake air amount can be adjusted without using the intake pipe pressure sensor. Here, the value of K3 is equivalent to the fully closed opening of the throttle valve 102, so that fluctuations in the engine rotation (number) can be reduced and the engine can be prevented from reversely rotating (swinging back).

  In step S606, it is determined whether the estimated intake pipe pressure PMMHG is smaller than a predetermined pressure BT2 (<BT1). If it is determined that the intake pipe pressure PMMHG is greater than or equal to BT2, the process proceeds to step S607 described later. If it is determined that the intake pipe pressure PMMHG is smaller than BT2, the process proceeds to step S610, and the throttle opening is set to a large value K2 (K1 <K2 <K3) (throttle opening calculating means 309). BT2 may be set to the minimum required intake pipe pressure (for example, -80 mmHg) when a restart request is made during automatic stop. Here, the value of K2 is set to an opening degree at which the rotational fluctuation of the engine 100 does not increase, so that a necessary amount of air can be secured while suppressing a sudden fluctuation in the engine speed (number).

  In step S607 (that is, Ne ≧ NE2 and BT1 ≧ PMMHG ≧ BT2 during engine inertia rotation during automatic stop), it is determined whether or not the previous value of the throttle opening is K2. If the previous value of the throttle opening is K2, the process proceeds to step S610, where the throttle opening is again set to K2 (throttle opening calculating means 309). If the previous value of the throttle opening is not K2, the process proceeds to step S609 to reduce the swingback and ensure restartability, and the throttle opening is set to K3 (throttle opening calculating means 309).

  By executing the processing shown in FIG. 6, in the vehicle that does not have the intake pipe pressure sensor or the intake pipe pressure sensor has failed, the intake pipe is not changed until the engine 100 is automatically stopped until it completely stops. Based on the pressure PMMHG in the intake pipe 104 estimated from the operating state of the engine 100 by the pressure estimation means 308, the intake pipe pressure (and cylinder pressure) that can be restarted by the throttle opening calculation means 309 that controls the throttle operation is determined. In addition to being able to maintain, it is possible to reduce the possibility that the engine 100 will reverse (shake back), so it is possible to ensure restartability.

  FIG. 7 shows an example of the operating state of an engine equipped with an engine control device (ECU) according to the present invention. In the figure, a solid line indicates that the present invention is applied, and a dotted line indicates that the present invention is not applied.

  In the case where the present invention is not applied (dotted line), the throttle opening 705 is made constant at the idle opening before and after the engine automatic stop determination flag 706 is established and fuel injection is stopped at time t1. By sucking a certain amount of air after stopping the fuel injection, the intake pipe pressure 703 gradually increases and the amount of air in the cylinder increases, so that the rotational fluctuation of the engine speed 701 increases. The inertial rotational force of the engine is defeated by the air pressure in the cylinder and finally reverses.

  On the other hand, in the case where the present invention is applied (solid line), after the automatic engine stop determination flag 706 is established at time t1, the throttle opening 704 is set to K3 (idle) over time t2 (since intake pipe pressure PMMHG is larger than BT1). If the intake pipe pressure PMMHG is smaller than BT2 (<BT1) at time t2, the throttle opening 704 is opened to K2 (greater than the idle opening). After determining that the intake pipe pressure PMMHG has exceeded BT1 at time t3, it is determined that the necessary minimum air (amount) has been secured at the time of restart until the engine is completely stopped, and the throttle opening 704 is again set to K3. close. As a result, the fluctuation of the engine speed 700 is reduced and the possibility that the engine reverses is eliminated. Next, at the time t4, when it is determined that the engine speed 700 has fallen below NE2, it is determined that there is no effect on reverse rotation (shakeback), and the throttle opening 704 is opened to K1. Thereby, the air quantity at the time of the restart request | requirement after engine stabilization is secured early. The process at time t4 may be performed after the engine complete stop determination flag 707 is established at time t5. Therefore, in comparison with the engine speed 701 when the present invention is not applied, the engine speed 700 when the present invention is applied can suppress reverse rotation (shakeback) and quickly increase the amount of air necessary for combustion. It can be secured.

  In addition, this invention is not limited to above-described embodiment, Various deformation | transformation forms are included. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described.

  Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files that realize each function can be stored in a storage device such as a memory, a hard disk, or an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.

  Further, the control lines and information lines indicate what is considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

100 Engine 101 Airflow sensor 102 Throttle valve 104 Intake pipe 105 Fuel injection device 107 Ignition module 108 Exhaust valve 111 Exhaust pipe 112 Crank angle sensor 113 Reverse rotation detection crank angle sensor 114 Intake valve 115 Combustion chamber 116 Ignition switch 117 Accelerator pedal sensor 118 Brake pedal Sensor 119 ECU (Engine Control Unit) (engine control unit)
120 Crankshaft 125 Cylinder 301 Engine automatic stop determination means 302 System restart request determination means 303 Engine restart determination means 304 Clutch disengagement request determination means 305 Reverse rotation detection determination means 306 Engine rotation speed calculation means 307 Engine complete stop determination means 308 Intake pipe Pressure estimating means 309 Throttle opening degree calculating means (air amount adjusting means)

Claims (6)

Automatic stop determination means for determining whether or not a predetermined automatic stop condition is satisfied in order to stop fuel injection into the cylinder of the engine;
Restart determination means for determining whether a preset restart condition is satisfied or not;
An air amount adjusting means for adjusting the amount of intake air taken into the cylinder by controlling the throttle opening of the throttle valve during the automatic stop or restart of the engine ;
An intake pipe pressure estimating means for estimating the pressure in the intake pipe connected to the cylinder based on the operating state of the engine;
After the automatic stop determining means determines that the automatic stop condition is satisfied , the restart determining means determines that the restart condition is satisfied, or the complete stop determining means determines that the engine is in the complete stop state. In this case, the throttle opening is first set by the air amount adjusting means so that the pressure of the intake pipe estimated by the intake pipe pressure estimating means is equal to or higher than a predetermined pressure required for restarting the engine. To the value of
If it is determined that the automatic stop condition is satisfied by the automatic stop determination means and the engine is in inertial rotation and the engine speed is determined to be smaller than a predetermined engine speed, the intake pipe pressure The throttle opening is set to the first value by the air amount adjusting means so that the pressure of the intake pipe estimated by the estimating means is equal to or higher than a predetermined pressure required for restarting the engine. An engine control device characterized by increasing an intake air amount . Automatic stop determination means for determining whether or not a predetermined automatic stop condition is satisfied in order to stop fuel injection into the cylinder of the engine;
Restart determination means for determining whether a preset restart condition is satisfied or not;
An air amount adjusting means for adjusting the amount of intake air taken into the cylinder by controlling the throttle opening of the throttle valve during the automatic stop or restart of the engine ;
An intake pipe pressure estimating means for estimating the pressure in the intake pipe connected to the cylinder based on the operating state of the engine;
If it is determined that the automatic stop condition is satisfied by the automatic stop determination means and the engine is in inertial rotation and the engine speed is determined to be smaller than a predetermined engine speed, the intake pipe pressure The throttle opening is set to a first value by the air amount adjusting means so that the pressure of the intake pipe estimated by the estimating means is equal to or higher than a predetermined pressure required for restarting the engine, and the intake Increase the air volume,
After it is determined that the automatic stop condition is satisfied by the automatic stop determination unit, the engine is in inertial rotation, and it is determined that the engine speed is equal to or higher than a predetermined speed.
If it is determined that the pressure of the intake pipe estimated by the intake pipe pressure estimating means is larger than a first predetermined pressure, the throttle opening is set to a third value by the air amount adjusting means. Then, the intake air amount is reduced, and it is determined that the pressure of the intake pipe estimated by the intake pipe pressure estimating means is smaller than the predetermined second pressure smaller than the predetermined first pressure. The throttle opening is set to a second value by the air amount adjusting means to increase the intake air amount,
Said first value, the second value, and said third value, engine control apparatus wherein that you have been set larger in this order. Automatic stop determination means for determining whether or not a predetermined automatic stop condition is satisfied in order to stop fuel injection into the cylinder of the engine;
Restart determination means for determining whether a preset restart condition is satisfied or not;
An air amount adjusting means for adjusting the amount of intake air taken into the cylinder by controlling the throttle opening of the throttle valve during the automatic stop or restart of the engine ;
An intake pipe pressure estimating means for estimating the pressure in the intake pipe connected to the cylinder based on the operating state of the engine;
After the automatic stop determining means determines that the automatic stop condition is satisfied , the restart determining means determines that the restart condition is satisfied, or the complete stop determining means determines that the engine is in the complete stop state. In this case, the throttle opening is first set by the air amount adjusting means so that the pressure of the intake pipe estimated by the intake pipe pressure estimating means is equal to or higher than a predetermined pressure required for restarting the engine. To the value of
If it is determined that the automatic stop condition is satisfied by the automatic stop determination means and the engine is in inertial rotation and the engine speed is determined to be smaller than a predetermined engine speed, the intake pipe pressure The throttle opening is set to the first value by the air amount adjusting means so that the pressure of the intake pipe estimated by the estimating means is equal to or higher than a predetermined pressure required for restarting the engine. Increase the intake air volume,
After it is determined that the automatic stop condition is satisfied by the automatic stop determination unit, the engine is in inertial rotation, and it is determined that the engine speed is equal to or higher than a predetermined speed.
If it is determined that the pressure of the intake pipe estimated by the intake pipe pressure estimating means is larger than a first predetermined pressure, the throttle opening is set to a third value by the air amount adjusting means. Then, the intake air amount is reduced, and it is determined that the pressure of the intake pipe estimated by the intake pipe pressure estimating means is smaller than the predetermined second pressure smaller than the predetermined first pressure. The throttle opening is set to a second value by the air amount adjusting means to increase the intake air amount,
Said first value, the second value, and said third value, engine control apparatus wherein that you have been set larger in this order. In the case where it is determined that the pressure of the intake pipe estimated by the intake pipe pressure estimating means is equal to or lower than the predetermined first pressure and equal to or higher than the predetermined second pressure,
When the previous value of the throttle opening is the second value, the throttle opening is again set to the second value by the air amount adjusting means, and the previous value of the throttle opening is the second value. 4. The engine control device according to claim 2, wherein the throttle opening is set to the third value by the air amount adjusting means when the value is not equal to the value. 5. 5. The throttle opening degree during the automatic stop or restart of the engine is cleared when the automatic stop determination unit determines that the automatic stop condition is not satisfied. 5. The engine control device according to one item. The intake pipe pressure estimating means estimates the pressure in the intake pipe from the intake air amount, the engine speed, the gas constant, the engine exhaust amount, and the nonlinear intake efficiency determined by the engine region. The engine control device according to any one of claims 1 to 5, wherein

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