JP5418788B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine, for example, a control device for an internal combustion engine having a function of maintaining the temperature of exhaust gas at a predetermined temperature in order to maintain the performance of the exhaust purification device.

  Exhaust gas emitted from internal combustion engines (engines) mounted on automobiles, particularly diesel engines, includes carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), and particulate matter ( PM: Particulate Matter) is included. For this reason, an exhaust passage through which exhaust gas passes through an exhaust purification device such as an oxidation catalyst and NOx trap catalyst for decomposing (oxidizing, reducing, etc.) pollutants and a diesel particulate filter (DPF) for capturing PM The exhaust gas is purified by an exhaust gas purification device and released into the atmosphere.

  The exhaust purification device needs to be maintained at a predetermined high temperature state in order to perform a process of decomposing pollutants or to burn the trapped PM and perform a regeneration process. For this reason, the operating state of the engine is controlled, the temperature of the exhaust gas is maintained in a desired state, and the purification performance of the exhaust purification device is maintained.

  By the way, when the vehicle is decelerated, there is known a control in which the fuel supply is temporarily stopped based on the accelerator opening, the engine speed, and the like. With this control, fuel consumption can be improved by stopping the supply of fuel during deceleration. In addition, in vehicles equipped with an automatic transmission, there are also vehicles that include a control that engages a lock-up clutch to directly connect the drive side and the engine side in order to effectively apply the engine brake during deceleration. is there. In this case, the decrease in the engine speed is slow, the time during which the fuel supply is stopped is lengthened, and the fuel consumption can be further improved.

  When it is necessary to maintain the temperature of the exhaust gas at a predetermined high temperature state, for example, when it is necessary to perform regeneration processing of the DPF that is the exhaust purification device, the lockup clutch is engaged and the drive side and the engine side are connected. If the state is directly connected, there is a concern that the time during which the fuel supply is stopped becomes long, the return of the fuel supply is delayed, and the temperature of the exhaust gas decreases. For this reason, when it is necessary to perform the regeneration process of the DPF, it is desirable to speed up the return of the fuel supply.

  On the other hand, as a technique for maintaining the activation temperature of the exhaust purification device, when the vehicle is in a deceleration state, the engagement state of the lock-up clutch of the automatic transmission is controlled according to the catalyst temperature, and the engine output is kept constant. A technique for maintaining the temperature of the exhaust emission control device is known (see, for example, Patent Document 1). For example, when the catalyst temperature is low, the lockup clutch is disengaged to suppress the output fluctuation and maintain the catalyst temperature at the activation temperature. Further, when the catalyst temperature is high, the lockup clutch is engaged to suppress output fluctuation and maintain the catalyst temperature at the activation temperature.

  With the conventionally proposed technology, the fuel injection timing is appropriately controlled by controlling the lock-up clutch based on the catalyst temperature, and the output fluctuation is suppressed when the vehicle is decelerated, so that the exhaust purification device is brought into the active temperature range. Can be maintained.

  However, since the output fluctuation is suppressed by controlling the lockup clutch based on the catalyst temperature, that is, the fuel injection timing is appropriately controlled based on the catalyst temperature. The fuel is supplied regardless of the control for maintaining the temperature of the exhaust gas to be maintained at a predetermined temperature. For this reason, control is performed to maintain the temperature of the exhaust gas flowing through the exhaust purification device at a predetermined temperature, for example, fuel is supplied even in a situation where there is no need to regenerate the DPF and the supply of fuel may be stopped, The current situation is that the improvement of fuel consumption is hindered.

Japanese Patent No. 3678282

  The present invention has been made in view of the above situation, and even when operating conditions in which the supply of fuel is stopped to improve fuel efficiency, the fuel supply is performed when it is necessary to maintain the exhaust gas temperature at a predetermined temperature. An object of the present invention is to provide a control device for an internal combustion engine that can quickly maintain the exhaust gas temperature at a predetermined temperature without impeding the improvement of fuel consumption.

In order to achieve the above object, a control apparatus for an internal combustion engine according to a first aspect of the present invention includes an internal combustion engine in which fuel supply is temporarily stopped during traveling in accordance with a driving condition of the vehicle, and fuel supply. A fuel stop means for stopping the supply of fuel when the operation condition to be stopped is satisfied, a temperature maintenance operation means for performing an operation for maintaining the temperature of the exhaust gas of the internal combustion engine at a predetermined temperature, and the fuel stop means. When the stop condition for stopping the fuel supply is satisfied, the exhaust temperature is maintained at a predetermined temperature by the adjusting means for adjusting the internal combustion engine so that the stop condition is not satisfied and the temperature maintaining operation means. when it is implemented operation to be, when the supply of fuel by the fuel stop means becomes the operating state the supply is stopped once the fuel is established operating condition is stopped, the by the adjusting means Wherein the stopping condition and control means for adjusting the internal combustion engine so that the operating conditions to be satisfied.

  In the present invention according to claim 1, during the operation in which the temperature of the exhaust gas is maintained at a predetermined temperature, the supply of the fuel is temporarily stopped when the operation condition for temporarily stopping the supply of the fuel is satisfied, Thereafter, the internal combustion engine is adjusted to an operating condition in which the stop condition is not satisfied (an operating condition in which the stop condition in which fuel is not stopped is not satisfied), and the fuel supply is restored. For this reason, even if the operating condition in which the fuel supply is temporarily stopped is satisfied, the operation of returning the fuel supply at an early stage and maintaining the exhaust gas temperature at a predetermined temperature can be continued.

  As a result, even under operating conditions in which the fuel supply is stopped to improve fuel efficiency, the fuel supply is quickly returned only when it is necessary to maintain the exhaust gas temperature at a predetermined temperature. The exhaust gas temperature can be accurately maintained at a predetermined temperature without hindering improvement.

  The control apparatus for an internal combustion engine according to a second aspect of the present invention is the control apparatus for an internal combustion engine according to the first aspect, wherein the stop condition is that at least the rotational speed of the internal combustion engine is equal to or higher than a predetermined rotational speed. The adjusting means makes the stop condition unsatisfied by advancing a decrease in the rotational speed of the internal combustion engine.

  In the present invention according to claim 2, when it is necessary to maintain the temperature of the exhaust gas at a predetermined temperature, the amount of low-temperature exhaust gas that is not accompanied by combustion is suppressed and the fuel supply is quickly returned by reducing the rotational speed. Thus, the temperature of the exhaust gas can be accurately maintained at a predetermined temperature without hindering improvement in fuel consumption.

According to a third aspect of the present invention, there is provided a control device for an internal combustion engine according to the first or second aspect, wherein the internal combustion engine transmits an output depending on an engagement state of a lock-up clutch. An automatic transmission that controls the situation, and the adjusting means increases the speed ratio of the automatic transmission and releases the engagement of the lock-up clutch to accelerate the decrease in the rotational speed of the internal combustion engine. The stop condition is not satisfied.

  In the present invention according to claim 3, by releasing the engagement of the lock-up clutch, the reduction in the rotational speed of the internal combustion engine is accelerated, and the stop condition is not satisfied (the operating condition for stopping the fuel supply is not satisfied). Return the fuel supply.

  A control device for an internal combustion engine according to a fourth aspect of the present invention is the control device for an internal combustion engine according to any one of the first to third aspects, wherein an exhaust gas is disposed in an exhaust path of the internal combustion engine. An exhaust gas purification device that performs purification is provided, and the temperature reduction of the exhaust gas purification device is suppressed by maintaining the exhaust gas temperature at a predetermined temperature by the temperature maintaining operation means.

  In the present invention according to claim 4, when the exhaust gas temperature is maintained at a predetermined temperature, the temperature reduction of the exhaust gas purification device is suppressed, and the activation temperature of the catalyst is maintained, or the regeneration processing temperature of the catalyst and filters is maintained. be able to.

  According to a fifth aspect of the present invention, there is provided the control device for an internal combustion engine according to the fourth aspect, wherein the internal combustion engine is a diesel engine and the exhaust purification device is in the form of particles in the exhaust gas. A diesel particulate filter that traps the substance, and the exhaust gas temperature is maintained at a predetermined temperature by the temperature maintenance operation means, whereby the particulate matter burns and the diesel particulate filter is regenerated. To do.

  In the present invention according to claim 5, for example, when the fuel supply is stopped during deceleration of the vehicle, the stop condition is not satisfied even if the regeneration process of the diesel particulate filter (DPF) is performed. (The operating condition for stopping the supply of fuel is not satisfied), the supply of fuel is restored early, and the regeneration process is accurately continued without lowering the temperature of the DPF.

  The control device for an internal combustion engine according to the present invention is capable of supplying fuel only when it is necessary to maintain the temperature of the exhaust gas at a predetermined temperature even under operating conditions in which the supply of fuel is stopped to improve fuel efficiency. It is possible to speed up the return and accurately maintain the exhaust gas temperature at a predetermined temperature without hindering improvement in fuel consumption.

1 is a schematic configuration diagram illustrating an entire internal combustion engine including a control device according to an embodiment of the present invention. It is the schematic showing the output system of the internal combustion engine in FIG. It is a time chart showing the time-dependent change of the driving | running state of a vehicle. It is a time chart showing the time-dependent change of the driving | running state of a vehicle. It is a situation explanatory view of control of vehicles.

  FIG. 1 shows an outline of the overall configuration of an internal combustion engine provided with a control device according to an embodiment of the present invention, FIG. 2 shows an outline of the relationship between the internal combustion engine and an automatic transmission, and FIG. Changes in exhaust gas temperature, engine speed, vehicle speed, and fuel injection amount over time when the engine is not implemented. FIG. 4 shows changes over time in exhaust gas temperature, engine speed, vehicle speed, and fuel injection amount when this embodiment is implemented. FIG. 5 shows time-dependent changes in exhaust gas temperature increase control, fuel injection amount, fuel supply stop command, and lockup clutch status.

  A schematic configuration of the internal combustion engine will be described with reference to FIG.

  An internal combustion engine (engine) 1 is a multi-cylinder diesel engine. A piston 3 is accommodated in a cylinder block 2 of the engine 1 so as to be capable of reciprocating. The piston 3 is connected to the crankshaft 5 via the connecting rod 4, and the crankshaft 5 is rotated by the reciprocating motion of the piston 3.

  An intake port 7 is formed in the cylinder head 6 of the engine 1, and an intake pipe 9 including an intake manifold 8 is connected to the intake port 7. An intake valve 11 is provided in the intake port 7, and the intake port 7 is opened and closed by the intake valve 11. An exhaust port 12 is formed in the cylinder head 6, and an exhaust pipe 14 including an exhaust manifold 13 is connected to the exhaust port 12. The exhaust port 12 is provided with an exhaust valve 15 that opens and closes the exhaust port 12.

  A throttle valve 17 is provided on the upstream side of the intake pipe 9, and the throttle valve 17 opens and closes the intake pipe 9 by driving means (not shown) to control the intake flow rate. The throttle valve 17 is driven to open and close in response to depression of the accelerator pedal 18, the depression state of the accelerator pedal 18 is detected by an accelerator position sensor 19, and, for example, a deceleration state of the vehicle is detected based on a signal from the accelerator position sensor 19. The

  The cylinder head 6 is provided with a fuel injection valve 22 that directly injects fuel into the combustion chamber 21 of each cylinder, and fuel is supplied to the fuel injection valve 22 from a common rail 23. A fuel having a predetermined pressure is supplied to the common rail 23 by a supply pump 24 in accordance with the rotational speed of the engine 1. In the common rail 23, the fuel is adjusted to a predetermined pressure, and high-pressure fuel adjusted to the predetermined pressure is supplied from the common rail 23 to the fuel injection valve 22.

  In the exhaust pipe 14, a diesel oxidation catalyst (oxidation catalyst) 31, a NOx trap catalyst 32, and a diesel particulate filter (DPF) 33, which are exhaust purification devices, are sequentially arranged from the upstream side.

In the oxidation catalyst 31, nitrogen monoxide (NO) in the exhaust gas is oxidized by an oxidation reaction in an atmosphere at a predetermined temperature or higher, and nitrogen dioxide (NO ₂ ) is generated. The NOx trap catalyst 32 occludes NOx (NO ₂ generated by the oxidation catalyst 31, remaining NO) in a lean atmosphere, and reduces and releases it to nitrogen (N ₂ ) or the like in a rich atmosphere. The NOx trap catalyst 32 also stores sulfur oxides (SOx) like NOx, and releases sulfur components in a high temperature and rich atmosphere.

The DPF 33 is a filter having a honeycomb structure, for example, and traps particulate matter (PM) in the exhaust gas. The trapped PM is oxidized (combusted) by NO ₂ in the exhaust gas under a predetermined temperature atmosphere and discharged, and the remaining NO ₂ is decomposed into N ₂ and discharged. By maintaining the temperature of the exhaust gas at a predetermined temperature and making the DPF 33 into a high temperature atmosphere, the PM is burned and regenerated.

  An exhaust gas temperature sensor 34 is provided upstream of the oxidation catalyst 31 and the NOx trap catalyst 32 and downstream of the DPF 33, and the exhaust gas temperature sensor 34 detects the temperature of the exhaust gas flowing through the oxidation catalyst 31, the NOx trap catalyst 32 and the DPF 33. .

  The vehicle includes an electronic control unit (ECU) 36, and the ECU 36 includes an input device, a storage device, a central processing unit, a timer, and counters. In addition to the information of the accelerator position sensor 19 and the exhaust gas temperature sensor 34 described above, the ECU 36 receives information on sensors for detecting the state of the vehicle and the engine 1, such as information on the rotational speed of the engine 1 and information on the vehicle speed. Entered.

  The ECU 36 performs control such as air-fuel ratio control of the engine 1, intake air amount control (throttle valve 17 opening / closing control), fuel injection amount control, temperature control of exhaust gas flowing through the exhaust purification device, etc., based on sensor input information. Command information for performing comprehensive control is calculated. Further, shift command information of a hydraulic controller of the automatic transmission described later is calculated.

  A schematic configuration of the automatic transmission will be described with reference to FIG.

  The automatic transmission 41 includes a transmission main body 42 and a torque converter 50. The transmission main body 42 is connected to an output shaft 43 (crankshaft 5: see FIG. 1) of the engine 1, and a drive shaft 44 is not shown. Connected to the drive wheel side. The transmission main body 42 includes a plurality of sets of planetary gears and friction engagement elements. The casing 45 of the torque converter 50 is connected to the output shaft 43, and the turbine 46 is connected to the input shaft 47 of the transmission main body 42. The casing 45 is filled with hydraulic oil, and the hydraulic oil is discharged by a pump 48 that rotates together with the output shaft 43 to rotate the turbine 46.

  A lock-up clutch 51 is provided between the casing 45 and the turbine 46, and the engagement state of the lock-up clutch 51 is switched, whereby the direct connection state between the output shaft 43 and the input shaft 47 is switched. The torque converter 50 is connected to a hydraulic controller 52, and the hydraulic controller 52 is connected to a hydraulic source (not shown). The hydraulic oil from the hydraulic source is circulated and supplied to the torque converter 50 via the hydraulic controller 52, and the circulation direction is switched according to the output signal of the ECU 36.

  When the hydraulic oil is circulated and supplied in a state where the pressure of the hydraulic oil between the turbine 46 and the lockup clutch 51 becomes high, the lockup clutch 51 is engaged. Further, when the hydraulic oil is circulated and supplied in a state where the pressure of the hydraulic oil between the casing 45 and the lockup clutch 51 becomes high, the engagement of the lockup clutch 51 is released. When the lock-up clutch 51 is engaged, the output shaft 43 and the input shaft 47 are directly connected, and when the lock-up clutch 51 is disengaged, the output shaft 43 and the input shaft 47 are not engaged. Directly connected.

  When the vehicle decelerates, the automatic transmission 41 is controlled so as to increase the gear ratio, and in some cases, the driver performs an operation of fixing the gear ratio in a state where the gear ratio is large. When the output shaft 43 and the input shaft 47 are directly connected in this state, the decrease in the rotational speed of the engine 1 (see FIG. 1) becomes moderate, and when the output shaft 43 and the input shaft 47 are not directly connected. The rotational speed of the engine 1 (see FIG. 1) decreases early.

  In the engine 1 having the above-described configuration, when it is detected that the vehicle is in a decelerating state (below a predetermined number of revolutions), the fuel supply is stopped (fuel stop means), and fuel consumption is improved. Further, for example, in the DPF 33 in which particulate matter (PM) in the exhaust gas is captured, the temperature of the exhaust gas is maintained at a predetermined temperature (temperature maintaining operation means) and oxidized (combusted) under a predetermined temperature atmosphere. At the same time, the PM is burned and regenerated by the high temperature atmosphere.

  When the vehicle is decelerated during the regeneration process of the DPF 33, that is, when an operating condition is established in which the fuel supply is stopped, the fuel supply is temporarily stopped, and then the lockup clutch 51 of the automatic transmission 41 is stopped. Is disengaged. When the engagement of the lockup clutch 51 is released, the output shaft 43 and the input shaft 47 are brought into a non-directly connected state, and the rotational speed of the engine 1 is rapidly reduced. As a result, the engine 1 is adjusted to an operating state in which the stop condition for stopping the fuel supply is not satisfied (adjustment means).

  If the engagement of the lockup clutch 51 is continued during the regeneration process of the DPF 33, the decrease in the rotational speed of the engine 1 becomes gentle, and the operating condition in which the fuel supply is stopped continues and the fuel is not supplied. Becomes longer. For this reason, the temperature of the exhaust gas decreases, the temperature of the exhaust gas cannot be maintained at a predetermined temperature, and the regeneration process of the DPF 33 is hindered.

  That is, if the vehicle is decelerated while the lockup clutch 51 is engaged during the regeneration process of the DPF 33, the vehicle speed decreases as shown by the thick dashed line in FIG. At the same time, as indicated by thick dotted lines in FIG. 3B, the engine speed gradually decreases at time t1 and time t3. In this state, as shown by a thin solid line in FIG. 3D, the fuel supply is stopped and the fuel supply continues to be stopped until the engine speed decreases to a predetermined speed (until time t2 and time t4). Is done.

  For this reason, as shown by a thick solid line in FIG. 3A, the exhaust gas temperature decreases between time t1 and time t2 and between time t3 and time t4. Therefore, the temperature of the exhaust gas cannot be maintained at a predetermined temperature, which hinders the regeneration process of the DPF 33.

  On the other hand, in the present embodiment, the lockup clutch 51 is disengaged to bring the output shaft 43 and the input shaft 47 into a non-directly connected state, and the rotational speed of the engine 1 is reduced early. For this reason, the fuel supply can be returned early, the temperature of the exhaust gas does not decrease, and the regeneration process of the DPF 33 can be performed without any trouble while maintaining the temperature of the exhaust gas at a predetermined temperature. .

  Based on FIGS. 4 and 5, a specific situation when the vehicle is decelerated during the regeneration process of the DPF 33 will be described, and the control situation of the present embodiment will be specifically described. The following operations are performed based on commands from the ECU 36 that is a control means.

  When the vehicle is decelerated, the vehicle speed decreases as shown by the thick dotted line in FIG. 4C, and the engine rotates at time t1 and time t3 as shown by the thick dotted line in FIG. The number starts to decrease, and the fuel supply is temporarily stopped as shown by a thin solid line in FIG. 4D (see FIGS. 5B and 5C). As shown in FIG. 5 (a), when the flag for executing the control for raising the temperature of the exhaust gas is on and the regeneration process of the DPF 33 is in progress, the lock-up is performed as shown in FIG. 5 (d). The engagement of the clutch 51 is released.

  When the lock-up clutch 51 is disengaged, the engine speed decreases early as shown by a thick dotted line in FIG. 4 (b), and the fuel is supplied as shown in FIG. 4 (d). As shown in FIG. 5B, the fuel injection amount is increased. As the engine speed is reduced early and the fuel supply is restored, the exhaust gas temperature does not drop after time t1 and time t4, as shown by the thick solid line in FIG. Therefore, the temperature of the exhaust gas can be maintained at a predetermined temperature, and the regeneration process of the DPF 33 is not hindered.

  In addition, once the fuel supply is stopped when the vehicle is decelerated, the air-fuel ratio can be made lean (oxygen excess), and the fuel can be burned effectively when the fuel supply is restored. become.

  In the control apparatus for an internal combustion engine described above, an operating condition is established in which the fuel supply is stopped due to a deceleration state during the operation in which the exhaust gas temperature is maintained at a predetermined temperature (during the regeneration process of the DPF 33). When the supply of fuel is temporarily stopped, the engagement of the lock-up clutch 51 is released, so that the engine speed is reduced early (the internal combustion engine is adjusted to an operating condition where the stop condition is not satisfied), and the fuel is supplied. Is restored.

  For this reason, even if the operating condition in which the fuel supply is stopped when the vehicle is decelerated is satisfied, the operation of returning the fuel supply at an early stage and maintaining the exhaust gas temperature at the predetermined temperature can be continued. When the regeneration process is performed, the temperature of the DPF 33 is not lowered and the regeneration is not hindered.

  Therefore, even if the operating conditions are such that the fuel supply is stopped during the deceleration operation to improve the fuel efficiency, when the exhaust gas temperature needs to be maintained at a predetermined temperature during the regeneration process of the DPF 33, the fuel supply It is possible to quickly maintain the exhaust gas temperature at a predetermined temperature without impeding improvement in fuel consumption by speeding up the return.

  In the above-described embodiment, as the adjusting means for adjusting the engine 1 to an operating state where the stop condition for stopping the fuel supply is not satisfied, the rotation speed of the engine 1 is released by releasing the engagement of the lockup clutch 51. However, the adjusting means is not limited to the means for releasing the engagement of the lock-up clutch 51. For example, a means for reducing the rotational speed of the engine 1 by generating power by operating the alternator, or a means for reducing the rotational speed of the engine 1 by changing the lift timing or lift amount of the intake valve / exhaust valve is applied. Is possible.

  In the above-described embodiments, the operation when the regeneration process of the DPF 33 is performed as an operation for maintaining the temperature of the exhaust gas at a predetermined temperature has been described as an example. However, nitrogen monoxide (NO) in the exhaust gas is described. It is also possible to apply to the operation at the time of treatment with the oxidation catalyst 31 that maintains the temperature of the exhaust gas at a predetermined temperature in order to oxidize the gas.

  Further, the present invention can be applied to the operation during the occlusion process by the NOx trap catalyst 32 that maintains the temperature of the exhaust gas at a predetermined temperature in order to maintain the oxidizing atmosphere when storing NOx. In this case, as the internal combustion engine, a direct injection gasoline engine that directly injects fuel into the combustion chamber or a gasoline engine that performs lean combustion can be applied.

  The present invention can be used in the industrial field of control devices for internal combustion engines.

DESCRIPTION OF SYMBOLS 1 Engine 2 Cylinder block 3 Piston 4 Connecting rod 5 Crankshaft 6 Cylinder head 7 Intake port 8 Intake manifold 9 Intake pipe 11 Intake valve 12 Exhaust port 13 Exhaust manifold 14 Exhaust pipe 15 Exhaust valve 17 Throttle valve 18 Accelerator pedal 19 Accelerator position sensor 21 Combustion chamber 22 Fuel injection valve 23 Common rail 24 Supply pump 31 Diesel oxidation catalyst (oxidation catalyst)
32 NOx trap catalyst 33 Diesel particulate filter (DPF)
34 Exhaust temperature sensor 36 Electronic control unit (ECU)
DESCRIPTION OF SYMBOLS 41 Automatic transmission 42 Transmission main body 43 Output shaft 44 Drive shaft 45 Casing 46 Turbine 47 Input shaft 48 Pump 50 Torque converter 51 Lockup clutch 52 Hydraulic controller

Claims (5)

An internal combustion engine in which the supply of fuel is temporarily stopped during traveling according to the driving conditions of the vehicle;
Fuel stopping means for stopping the supply of fuel when an operating condition for stopping the supply of fuel is satisfied;
Temperature maintaining operation means for performing an operation of maintaining the temperature of the exhaust gas of the internal combustion engine at a predetermined temperature;
Adjusting means for adjusting the internal combustion engine so that the stop condition is not satisfied when the stop condition for stopping the fuel supply by the fuel stop means is satisfied;
When the operation for maintaining the exhaust temperature at a predetermined temperature is being performed by the temperature maintaining operation means, the operation condition for stopping the fuel supply by the fuel stop means is established and the fuel supply is temporarily stopped. A control device for an internal combustion engine , comprising: control means for adjusting the internal combustion engine such that the stop condition is not satisfied by the adjusting means when the operating state is reached. The control apparatus for an internal combustion engine according to claim 1,
The stop condition is
At least the rotational speed of the internal combustion engine is equal to or higher than a predetermined rotational speed,
The adjusting means includes
A control device for an internal combustion engine, characterized by prematurely lowering the rotational speed of the internal combustion engine and disabling the stop condition. The control apparatus for an internal combustion engine according to claim 1 or 2,
The internal combustion engine
An automatic transmission that controls the output transmission state according to the engagement state of the lockup clutch;
The adjusting means includes
The speed change ratio of the automatic transmission device is increased and the engagement of the lock-up clutch is released to accelerate the decrease in the rotational speed of the internal combustion engine, and the stop condition is not satisfied. Control device. The control apparatus for an internal combustion engine according to any one of claims 1 to 3,
The exhaust path of the internal combustion engine is provided with an exhaust purification device that purifies exhaust gas,
A control device for an internal combustion engine, characterized in that the exhaust gas temperature is maintained at a predetermined temperature by the temperature maintenance operation means, whereby a temperature drop of the exhaust gas purification device is suppressed. The control apparatus for an internal combustion engine according to claim 4,
The internal combustion engine is a diesel engine;
The exhaust purification device includes a diesel particulate filter that captures particulate matter in the exhaust gas,
The control apparatus for an internal combustion engine, wherein the exhaust gas temperature is maintained at a predetermined temperature by the temperature maintaining operation means, whereby the particulate matter is combusted and the diesel particulate filter is regenerated.

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