JP7345965B2 - Internal combustion engine control device - Google Patents

Description

The present invention relates to a control device for controlling an internal combustion engine installed in a vehicle or the like.

As is well known, when starting a stopped internal combustion engine, the crankshaft, which is the output shaft of the internal combustion engine, is rotated by an electric motor, and fuel is injected from the injector and combusted in the cylinder. Perform cranking to accelerate rotation. Cranking is when an internal combustion engine goes from the first explosion to a series of explosions, and a complete explosion occurs when the rotational speed of the crankshaft, that is, the engine rotational speed, exceeds a judgment value determined according to the temperature of the internal combustion engine's cooling water, etc. and terminates.

If the internal combustion engine stops rotating in a valve overlap state in which the intake valve and exhaust valve of any cylinder are both open, exhaust gas will flow from the exhaust passage to the intake passage through that cylinder during that stop period. Backflow may occur. This causes a decrease in the oxygen concentration within the intake passage. Nevertheless, when starting an internal combustion engine, if the opening degree of the throttle valve and the amount of fuel injection are set as usual, the amount of oxygen supplied to the combustion chamber of the cylinder will be insufficient, resulting in unstable fuel combustion or misfire. As a result, the rotation of the internal combustion engine does not accelerate, and there is a concern that this may lead to a delay in starting or a starting failure.

Therefore, when starting an internal combustion engine that has stopped in a valve overlap state, the throttle valve, which is an intake throttle valve, is expanded to a predetermined opening and then cranking is performed to scavenge the exhaust gas remaining in the intake passage. (For example, see the following patent documents).

Japanese Patent Application Publication No. 2015-183522

However, it is thought that the opening degree of the intake throttle valve that is necessary and sufficient for scavenging the intake passage is not always constant. If the opening degree of the intake throttle valve during cranking is small, the intake passage will not be sufficiently scavenged, resulting in a delay in starting the internal combustion engine. On the other hand, if the opening of the intake throttle valve during cranking is excessively large, the engine speed will increase after complete combustion, resulting in unnecessary fuel consumption.

The cause of delayed or poor starting of an internal combustion engine is not limited to backflow of exhaust gas during a period when the internal combustion engine is stopped. To give a specific example, in a port injection type internal combustion engine, fuel injected from an injector becomes liquid and adheres to the inner wall of an intake port, the valve body of an intake valve, etc., resulting in port wet. If the internal combustion engine is stopped before it has finished warming up, a large amount of fuel remains in the port wet state, which evaporates during the stop period, causing a relative decrease in the oxygen concentration in the intake passage. The air-fuel ratio becomes rich.

During periods when the internal combustion engine is stopped, an oil-tight leak may occur in which a small amount of fuel leaks from the injector. This oil leak also causes the air-fuel ratio at startup to become richer.

In addition, if deposits of fuel, lubricating oil, or their incomplete combustion products get caught between the valve body and valve seat of a cylinder's intake or exhaust valve, it may cause the air to leak from the cylinder during the cylinder's compression stroke. Air-fuel mixture leaks. As a result, combustion instability or misfire during starting or a decrease in engine torque may occur, leading to delayed or poor starting of the internal combustion engine.

An objective of the present invention is to appropriately deal with the causes of delayed or poor starting of an internal combustion engine and to improve startability.

In order to solve the above-mentioned problems, in the present invention, when starting a stopped internal combustion engine, the internal combustion engine is A control device for an internal combustion engine that further expands the opening of an intake throttle valve during cranking to start the engine, so that the intake pressure in the intake passage connected to the cylinder during cranking is at or near atmospheric pressure. was configured. Specifically, when the operation of the internal combustion engine is stopped before the cooling water temperature rises above a predetermined value after the previous start of the internal combustion engine, and/or before a predetermined period of time has elapsed after the previous start of the internal combustion engine. It is assumed that the specific condition is satisfied when the operation of the internal combustion engine is stopped. In addition, if the above-mentioned specific conditions are met, the amount of fuel injection during cranking for starting the internal combustion engine and/or immediately after cranking may be reduced compared to when the conditions are not met. . Furthermore, when the above-mentioned specific conditions are met, the ignition timing during cranking for starting the internal combustion engine and/or immediately after cranking can be further advanced than when the specific conditions are not met. be. The correction control when the specific conditions are satisfied ends when the engine speed increases to a predetermined value or more, or when a predetermined time has elapsed from the start or end of cranking. Here, when the driver operates the shift lever from the non-driving range to the driving range immediately after cranking to connect the internal combustion engine and the axle, the engine rotational speed is The predetermined value to be compared with is further reduced, or the predetermined time to be compared with the elapsed time from the start or end of the cranking is further shortened.

According to the present invention, the startability of an internal combustion engine can be further improved.

1 is a diagram showing a schematic configuration of a vehicle internal combustion engine and its control device in an embodiment of the present invention. The figure which shows the structure of the drive system of the vehicle in the same embodiment. FIG. 3 is a flow diagram showing an example of a procedure of processing executed by the control device according to the embodiment according to a program. FIG. 3 is a timing diagram illustrating the content of control performed by the control device of the embodiment.

An embodiment of the present invention will be described with reference to the drawings. Figure 1 shows an overview of a vehicle internal combustion engine. The internal combustion engine in this embodiment is a port injection type four-stroke spark ignition engine, and includes a plurality of cylinders 1 (for example, three cylinders, one of which is shown in FIG. 1). An injector 11 that injects fuel toward the intake port of each cylinder 1 is provided near the intake port of each cylinder 1 . Further, a spark plug 12 is attached to the ceiling of the combustion chamber of each cylinder 1, respectively. The spark plug 12 receives an induced voltage generated in the ignition coil and causes a spark discharge between the center electrode and the ground electrode.

The intake passage 3 for supplying intake air takes in air from the outside and guides it to the intake port of each cylinder 1. On the intake passage 3, an air cleaner 31, an electronic throttle valve 32 which is an intake throttle valve, a surge tank 33, and an intake manifold 34 are arranged in this order from upstream.

The exhaust passage 4 for discharging exhaust gas guides the exhaust gas generated as a result of burning fuel in the cylinders 1 from the exhaust port of each cylinder 1 to the outside. An exhaust manifold 42 and a three-way catalyst 41 for exhaust purification are arranged on the exhaust passage 4.

The external EGR (Exhaust Gas Recirculation) device 2 realizes external EGR in which a part of the exhaust gas flowing through the exhaust passage 4 is recirculated to the intake passage 3 and mixed with intake air. This EGR device 2 includes an external EGR passage 21 that communicates between the upstream side of the catalyst 41 in the exhaust passage 4 and the downstream side of the throttle valve 32 in the intake passage 3, an EGR cooler 22 provided on the EGR passage 21, and an EGR passage. 21 and an EGR valve 23 that opens and closes the EGR passage 21 to control the flow rate of EGR gas flowing through the EGR passage 21. The entrance of the EGR passage 21 is connected to the exhaust manifold 42 in the exhaust passage 4 or a predetermined location downstream thereof. The outlet of the EGR passage 21 is connected to a predetermined location downstream of the throttle valve 32 in the intake passage 3, particularly to a surge tank 33.

The internal combustion engine is sometimes equipped with a VVT (Variable Valve Timing) mechanism 5 that can variably control the opening and closing timing of at least the intake valve of each cylinder 1. The VVT mechanism 5 for adjusting the intake valve timing is, for example, a vane type mechanism that changes the rotational phase of the camshaft relative to the crankshaft that drives the intake valves of each cylinder 1 using hydraulic pressure (lubricating oil pressure), or an electric motor mechanism. It is an electric type (motor drive VVT) that changes the temperature. As is well known, the camshaft receives rotational driving force from the crankshaft, which is the output shaft of the internal combustion engine, and rotates as a result of the crankshaft. A wrap transmission (not shown) for transmitting rotational driving force is interposed between the crankshaft and the camshaft. A wrap transmission device consists of a crank sprocket (or pulley) installed on the crankshaft side, a cam sprocket (or pulley) installed on the camshaft side, and a timing chain (or pulley) that is wrapped around these sprockets (or pulleys). , timing belt). The VVT mechanism 5 changes the rotational phase of the camshaft with respect to the crankshaft by rotating the camshaft relative to the cam sprocket, thereby changing the opening/closing timing of the intake valve.

The VVT mechanism for adjusting the opening/closing timing of exhaust valves changes, for example, the rotational phase of a camshaft that drives the exhaust valves of each cylinder 1 with respect to a crankshaft using hydraulic pressure or an electric motor. Note that this VVT mechanism may not exist, in which case the exhaust valve timing remains unchanged.

FIG. 2 shows an example of a drive system included in a vehicle. This transmission includes a torque converter 7 and automatic transmissions 8 and 9. In this embodiment, as components of the automatic transmissions 8 and 9, a forward/reverse switching device 8 including a planetary gear mechanism and a belt type CVT 9 are employed.

Engine torque output by the internal combustion engine is input from a crankshaft, which is an output shaft of the internal combustion engine, to a pump impeller 71 on the input side of the torque converter 7, and is transmitted to a turbine runner 72 on the output side. The rotation of the turbine runner 72 is transmitted to the drive shaft 94 of the CVT 9 via the forward/reverse switching device 8, and rotates the driven shaft 95 through a speed change in the CVT 9. Rotation of driven shaft 95 is transmitted to output gear 101 . The output gear 101 meshes with a ring gear 102 of a differential device, and rotates an axle (drive shaft) 103 and a drive wheel attached to the axle 103 via the differential device.

Torque converter 7 includes a lockup mechanism. The lock-up mechanism includes a lock-up clutch 73 that engages the input side and output side of the torque converter 7 so that they cannot rotate relative to each other, and a lock that controls hydraulic pressure (hydraulic pressure) for switching and driving the lock-up clutch 73. and an up solenoid valve (not shown).

The forward/reverse switching device 8 has a sun gear 81 communicating with the turbine runner 72 and a ring gear 82 communicating with the drive shaft 94 . A forward brake 84, which is a hydraulic clutch that can be switched on and off, is interposed between the planetary carrier 83 that supports the planetary gear 831 and the transmission case. Further, a reverse clutch 85, which is a hydraulic clutch that can be switched on and off, is also interposed between the planetary carrier 83 and the sun gear 81 (or the output side of the torque converter 7).

In the D range of the driving ranges, the forward brake 84 is engaged and the reverse clutch 85 is disengaged. As a result, the rotation of the output shaft of the torque converter 7 is reversed, decelerated, and transmitted to the drive shaft 94, resulting in forward travel. On the other hand, in the R range, the reverse clutch 85 is engaged and the forward brake 84 is disengaged. As a result, the sun gear 81 and the planetary carrier 83 rotate integrally, and the output shaft of the torque converter 7 and the drive shaft 94 are directly connected, resulting in reverse travel.

In the N range of the non-driving ranges, both the forward brake 84 and reverse clutch 85 are disconnected. In the P range, the axle 103 is mechanically locked so that it does not move.

The CVT 9 is known in this field, and includes a drive pulley 91 supported non-rotatably on a drive shaft 94, and a driven pulley 92 non-rotatably supported on a driven shaft 95 disposed parallel to the drive shaft 94. and a belt 93 wound around a driving pulley 91 and a driven pulley 92.

The drive pulley 91 has a fixed sheave 911 fixed to the drive shaft 94 and a movable sheave 912 arranged opposite to the fixed sheave 911 so as to sandwich the belt 93 therebetween. The movable sheave 912 is supported on the drive shaft 94 via a roller spline so that it can be displaced in its axial direction and cannot rotate relative to it. Behind the movable sheave 912 and on the opposite side from the fixed sheave 911, a cylinder fixed to the drive shaft 94 is provided, and a hydraulic chamber 913 is formed between the cylinder and the movable sheave 912.

The driven pulley 91 has a fixed sheave 921 fixed to the driven shaft 95 and a movable sheave 922 arranged opposite to the fixed sheave 921 so as to sandwich the belt 93 therebetween. The movable sheave 922 is supported on the driven shaft 95 via a roller spline so that it can be displaced in its axial direction and cannot rotate relative to it. Behind the movable sheave 922 and on the opposite side from the fixed sheave 921, a cylinder fixed to the driven shaft 95 is provided, and a hydraulic chamber 923 is formed between the cylinder and the movable sheave 922.

In the belt-type CVT 9, the hydraulic pressure (operating oil pressure) supplied to each hydraulic pressure chamber 913, 923 of the driving pulley 91 and driven pulley 92 is controlled, and the width of the groove sandwiching the belt 93 in each pulley 91, 92 is changed. As a result, the pulley ratio between the driving pulley 91 and the driven pulley 92, in other words, the gear ratio realized by the CVT 9 is continuously and steplessly changed.

An ECU (Electronic Control Unit) 0, which is a control device for an internal combustion engine in this embodiment, is a microcomputer system including a processor, a memory, an input interface, an output interface, and the like. The ECU0 may include a plurality of ECUs or controllers connected to each other so as to be communicable via a telecommunication line such as a CAN (Controller Area Network).

The input interface of ECU0 includes a vehicle speed signal a output from a vehicle speed sensor that detects the actual vehicle speed, and a crank angle sensor (engine rotation sensor) that detects the rotation angle and engine rotation speed of the crankshaft of the internal combustion engine. a crank angle signal b, an accelerator opening signal c output from a sensor that detects the amount of depression of the accelerator pedal or the opening of the throttle valve 32 as the accelerator opening (in other words, the required engine load factor or engine torque); 1, an intake temperature/intake pressure signal d output from a temperature/pressure sensor that detects the intake air temperature and intake pressure in the intake passage 3 (in particular, the surge tank 33 or the intake manifold 34), and the temperature of the cooling water of the internal combustion engine. A cooling water temperature signal e output from a water temperature sensor that detects the temperature of the internal combustion engine (which indicates the temperature of the internal combustion engine), a shift position signal f output from a sensor or switch that detects the shift position, that is, the position of the shift lever (selector lever), and the vehicle Atmospheric pressure signal g output from an atmospheric pressure sensor that detects the atmospheric pressure at the location where the engine is located A compartment temperature signal h etc. are input.

From the output interface of the ECU 0, an ignition signal i is sent to the igniter of the spark plug 12, a fuel injection signal j is sent to the injector 11, an opening operation signal k is sent to the throttle valve 32, and an opening operation signal is sent to the EGR valve 23. A signal l, a control signal m for the opening/closing timing of the intake valve and/or exhaust valve for the VVT mechanism 5, an opening operation signal t for the lock-up solenoid valve for switching on/off the lock-up clutch 73, and a forward brake 84. Alternatively, it outputs an opening operation signal u to a solenoid valve for switching on and off of the reverse clutch 85, a control signal v to a shift control valve for operating the hydraulic servos 913 and 923 of the CVT 9, and the like.

The processor of ECU0 interprets and executes programs stored in memory in advance, calculates operating parameters, and controls the operation of the internal combustion engine. ECU 0 acquires various information a, b, c, d, e, f, g, and h necessary for operational control of the internal combustion engine through the input interface, learns the engine rotation speed, and inhales the information into cylinder 1. Estimate the amount of air. Then, the required fuel injection amount commensurate with the intake air amount, fuel injection timing (including the number of fuel injections for one combustion), fuel injection pressure, ignition timing, required EGR rate (or EGR gas amount), and intake valve timing. and/or exhaust valve timing, whether or not to lock up the torque converter 7, and connection/connection between the internal combustion engine and the axle 103 (the output shaft of the torque converter 7 and the drive shaft 94 of the CVT 9) by the forward/reverse switching device 8. , various operating parameters such as the gear ratio realized by the CVT 9 are determined. ECU0 applies various control signals i, j, k, l, m, t, u, v corresponding to operating parameters via an output interface.

In addition, when starting a stopped internal combustion engine (sometimes by cold start, sometimes by restarting from idling stop), ECU0 operates an electric motor (starter motor or ISG (Integrated Starter Generator), not shown). ) and executes cranking in which fuel injection and spark ignition are performed while the crankshaft is rotationally driven by the electric motor. Cranking is a process in which the internal combustion engine is considered to have completely exploded when the internal combustion engine goes from the first explosion to successive explosions and the engine speed exceeds the complete explosion judgment value determined according to the internal combustion engine's cooling water temperature, etc. finish. Normally, the complete explosion determination value is set higher as the cooling water temperature of the internal combustion engine at the time of starting is lower.

The following can be considered as specific factors that delay the acceleration of the rotation of the crankshaft during cranking for starting the internal combustion engine, that is, lead to delayed or poor starting of the internal combustion engine:
(i) The rotation of the internal combustion engine is stopped in a valve overlap state in which the intake valve and exhaust valve of any cylinder 1 are both open, and during the stop period, intake air is drawn from the exhaust passage 4 side via the cylinder 1. Exhaust flows backward into the passage 3 side (due to the chimney effect or the influence of wind blowing from the outside into the muffler at the end of the exhaust passage 4), and at the time cranking starts, it flows into the surge tank 33 or intake manifold 34 connected to the cylinder 1. If that exhaust remains. The oxygen concentration in the surge tank 33 or the intake manifold 34 decreases, and such intake air is sucked into the cylinder 1 at the beginning of cranking. (ii) The fuel injected from the injector 11 before the internal combustion engine stops is in liquid form. This causes port wetness to adhere to the inner wall of the intake port, the valve body of the intake valve, etc., and a large amount of fuel from the port wetness remains when the internal combustion engine is stopped. This vaporizes during the period when the internal combustion engine is stopped, and the oxygen concentration in the surge tank 33 or intake manifold 34 decreases (the air-fuel ratio becomes rich), and such intake air is sucked into cylinder 1 at the beginning of cranking. (iii) When an oil-tight leak in which fuel leaks from the injector 11 occurs while the internal combustion engine is stopped. This oil leak also causes the oxygen concentration in the surge tank 33 or the intake manifold 34 to decrease (the air-fuel ratio becomes richer), and such intake air is sucked into the cylinder 1 at the beginning of cranking.
(iv) If a deposit gets caught between the valve body and valve seat of the intake valve or exhaust valve of any cylinder 1 immediately before stopping, during stopping, or during cranking of the internal combustion engine. During the compression stroke of cylinder 1 during cranking, the air-fuel mixture leaks from cylinder 1. In order to deal with these factors, as shown in FIG. If a specific condition that is considered to be disadvantageous to the start is satisfied (step S1), the opening degree of the throttle valve 32 during cranking is expanded more than when this is not the case, and the surge during cranking is The intake pressure in the tank 33 or the intake manifold 34 is brought close to atmospheric pressure (step S2).

In step S1, ECU0 performs at least one of the following determination processes:
・When the operation of the internal combustion engine is stopped before the cooling water temperature rises above a predetermined value after the previous start of the internal combustion engine, and/or when the operation of the internal combustion engine is stopped before the predetermined time has elapsed after the previous start of the internal combustion engine. It is determined that certain conditions (in particular, (ii)) are met when operation is stopped (in other words, the internal combustion engine is stopped before it has been sufficiently warmed up). By knowing the angles of the crankshaft and camshaft with reference to the output signal b of a crank angle sensor (preferably an MRE (MagnetoResistive Effect) sensor), a specific condition (in particular, (i)) is satisfied.・The cooling water temperature at the time of the previous stop of the internal combustion engine and/or the start of cranking for starting the current internal combustion engine is within the specified range, and the temperature is within the specified range. It is determined that a specific condition (particularly (ii) or (iii)) is satisfied when the elapsed time until the start of cranking for starting the internal combustion engine is within a predetermined range. The length of the period during which the operation of the internal combustion engine is stopped cannot be measured by the ECU 0 itself if the ignition switch is turned off and the power supply to the ECU 0 is cut off during the stop period. Therefore, based on the size of the difference between the cooling water temperature when the internal combustion engine was stopped last time and the cooling water temperature at the start of cranking for starting the internal combustion engine, Estimate the amount of time that has elapsed since the start of . Basically, the larger the difference between the two, the longer the elapsed time. - The temperature inside the engine compartment when the internal combustion engine stopped was higher than a predetermined value, and/or the current internal combustion If the elapsed time until the start of cranking for starting the engine is shorter than a predetermined value, it is determined that a specific condition (particularly (iii)) is satisfied. When the temperature inside the engine compartment is high when the internal combustion engine is stopped, the temperature of the fuel system that supplies fuel to the injector 11 is difficult to decrease, and the fuel pressure remains high, making it easy for oil leakage to occur. The temperature in the engine compartment may be estimated with reference to the output signal d of an intake temperature sensor that detects the intake temperature in the surge tank 33 or the intake manifold 34. That is, the intake air temperature when the internal combustion engine was last stopped and/or when cranking for the current start was started is considered to be the temperature inside the engine compartment at that time. Also, based on the difference between the intake temperature at the previous stop and the intake temperature at the start of cranking for the current start, the elapsed time from the previous stop to the start of the current cranking is determined. It is also possible to estimate the length of time. The larger the difference between the two, the longer the elapsed time. Figure 4 shows the control that the ECU 0 of this embodiment performs during cranking to start the internal combustion engine and immediately after the end of cranking (completion of starting). It shows the content. In FIG. 4, the solid line represents normal control when the specific condition of step S1 is not satisfied, and the broken line represents the control when the specific condition of step S1 is satisfied. Time t0 is the start of cranking, and time t1 is the end of cranking (complete explosion). Time t2 is the time when the engine speed increases to a predetermined value or more, or the time when a predetermined time has elapsed from the start or end of cranking.

When a specific condition is met, the opening degree of the throttle valve 32 is enlarged compared to when the specific condition is not met, thereby increasing the flow rate of air flowing through the intake passage 3 during cranking and connecting it to the cylinder 1. The surge tank 33 and the intake manifold 34 are scavenged, and the amount of oxygen filled into the cylinder 1 is increased. In step S2 carried out during cranking, the throttle valve 32 is adjusted so that the difference between the intake pressure in the surge tank 33 or the intake manifold 34 and the atmospheric pressure at the location where the vehicle is currently located falls below a predetermined value. Set the opening degree. At this time, feedback control is executed to manipulate the opening degree of the throttle valve 32 so as to reduce the deviation between the intake pressure obtained by referring to the intake pressure signal d and the atmospheric pressure obtained by referring to the atmospheric pressure signal g. You may.

Further, in step S2, even if compression leakage occurs due to deposits being caught, the amount of air-fuel mixture filled into the cylinder 1 can be increased and the compression pressure can be increased. Overall, combustion can be stabilized during cranking and immediately after cranking, and the rotational speed of the crankshaft can be rapidly accelerated.

If the specific condition is met, the fuel injection amount during cranking and/or immediately after cranking is reduced compared to the case where this is not the case (step S3). Furthermore, if a specific condition is met, the ignition timing during cranking and/or immediately after the end of cranking is further advanced than if the specific condition is not met (step S4).

The correction control in steps S2 to S4 ends at time t2 when the engine speed increases to a predetermined value or more or a predetermined time has elapsed from the start or end of cranking (step S5), and thereafter the normal operation is performed. The process moves to control (step S6).

Immediately after cranking is completed, the driver operates the shift lever from the non-driving range to the driving range to connect the internal combustion engine and the axle 103 (the forward/reverse switching device 8 connects the output shaft of the torque converter 7 and the CVT 9 drive shaft 94). In that case, the predetermined value compared with the engine rotation speed in step S5 is further reduced, or the predetermined time compared with the elapsed time is further shortened, compared to the case where this is not the case. As a result, the correction control is terminated early, and the acceleration of the vehicle is prevented or suppressed.

Note that the present invention is not limited to the embodiments detailed above. For example, if an idle speed control valve is installed in the intake passage 3 of the internal combustion engine as an intake throttle valve together with the throttle valve 32, the idle speed control valve is By expanding the opening of the control valve, the flow rate of intake air flowing from the intake passage 3 toward the cylinder 1 is increased, and the intake pressure in the surge tank 33 or intake manifold 34 connected to the cylinder 1 is reduced to atmospheric pressure. can be approached. As is well known, the idle speed control valve is a flow control valve that opens and closes a bypass that communicates the upstream and downstream sides of the throttle valve 32 in the intake passage 3.

In addition, the specific configuration of each part, processing procedure, etc. can be variously modified without departing from the spirit of the present invention.

INDUSTRIAL APPLICATION This invention is applicable to the control of the internal combustion engine mounted in a vehicle etc.

0...Control unit (ECU)
1...Cylinder 3...Intake passage 32...Throttle valve (intake throttle valve)
4...Exhaust passage b...Crank angle signal c...Accelerator opening signal d...Intake temperature/intake pressure signal e...Voltage/current signal f...Cooling water temperature signal i...Ignition signal l...EGR valve opening operation signal

Claims (2)

When starting a stopped internal combustion engine, if certain conditions that are considered to be disadvantageous to starting the engine are met, the intake throttle during cranking for starting the internal combustion engine will be A control device for an internal combustion engine that further expands the opening of a valve and brings the intake pressure in an intake passage connected to a cylinder closer to atmospheric pressure during cranking,
When the operation of the internal combustion engine is stopped before the cooling water temperature rises above a predetermined value after the previous start of the internal combustion engine, or when the operation of the internal combustion engine is stopped before the predetermined time has elapsed after the previous start of the internal combustion engine. When the above specified conditions are met,
When the specific conditions are met, the fuel injection amount during cranking for starting the internal combustion engine or immediately after cranking is reduced compared to when the specific conditions are not met;
When the above-mentioned specific conditions are met, the expansion of the opening of the intake throttle valve during cranking and the reduction of the fuel injection amount during cranking or immediately after the end of cranking are performed when the engine speed exceeds a predetermined value. or when a predetermined period of time has elapsed from the start or end of cranking,
If the driver operates the shift lever from the non-driving range to the driving range immediately after completing cranking to connect the internal combustion engine and the axle, the engine rotation speed is compared with the case where this is not the case. A control device for an internal combustion engine that further reduces a predetermined value or further shortens a predetermined time compared with the elapsed time from the start or end of cranking. When starting a stopped internal combustion engine, if certain conditions that are considered to be disadvantageous to starting the engine are met, the intake throttle during cranking for starting the internal combustion engine will be A control device for an internal combustion engine that further expands the opening of a valve and brings the intake pressure in an intake passage connected to a cylinder closer to atmospheric pressure during cranking,
When the operation of the internal combustion engine is stopped before the cooling water temperature rises above a predetermined value after the previous start of the internal combustion engine, or when the operation of the internal combustion engine is stopped before the predetermined time has elapsed after the previous start of the internal combustion engine. When the above specified conditions are met,
When the specific condition is satisfied, the ignition timing during cranking for starting the internal combustion engine or immediately after the end of cranking is advanced more than when the specific condition is not met ,
When the above-mentioned specific conditions are met, the expansion of the opening of the intake throttle valve during cranking and the advance of the ignition timing during cranking or immediately after cranking are performed until the engine speed exceeds a predetermined value. or when a predetermined period of time has elapsed from the start or end of cranking,
If the driver operates the shift lever from the non-driving range to the driving range immediately after completing cranking to connect the internal combustion engine and the axle, the engine rotation speed is compared with the case where this is not the case. A control device for an internal combustion engine that further reduces a predetermined value or further shortens a predetermined time compared with the elapsed time from the start or end of cranking.

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