JP2016003576A - Internal combustion engine control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to suppress the degradation of exhaust emissions at a time of cylinder return for increasing the number of cylinders for combustion from a reduced-cylinder operation for stopping combustion of part of the cylinders of an engine.SOLUTION: At time t1 at which a reduced-cylinder operation request is generated during an engine operation, an all-cylinder operation is switched over to a reduced-cylinder operation. During this reduced-cylinder operation, processing is repeated for estimating or detecting a cylinder internal temperature of each combustion-stopped cylinder and calculating fuel injection conditions (fuel pressure, injection timing, and the number of times of injection) at a time of cylinder return in response to the cylinder internal temperature of the combustion-stopped cylinder. Subsequently, at time t2 at which a cylinder return request (an all-cylinder operation request, for example) is generated, the cylinder-reduced operation is switched over to the all-cylinder operation. At this time, fuel injection conditions are changed to the fuel injection conditions at the time of the cylinder return and a fuel injection control is executed. The fuel injection conditions are thereby changed to reduce a cylinder internal wet amount and an increase in the cylinder internal wet amount is suppressed so as to correspond to the fact that the cylinder internal wet amount tends to increase if the cylinder internal temperature of the combustion-stopped cylinder is lower.

Description

  The present invention relates to a control device for an internal combustion engine having a function of performing a reduced-cylinder operation in which the combustion of some cylinders of the internal combustion engine is stopped to operate the internal combustion engine.

  In an internal combustion engine mounted on a vehicle, for the purpose of improving fuel efficiency, for example, as described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-346875), all cylinders are used in accordance with the operating state of the internal combustion engine. There is one that switches between all-cylinder operation (all-cylinder mode) in which combustion is performed and reduced-cylinder operation (in-cylinder mode) in which combustion of some cylinders is stopped. In Patent Document 1, when switching from reduced-cylinder operation (cylinderless operation mode) to full-cylinder operation (all-cylinder operation mode), prior to the switching, the intake air amount is switched to the value corresponding to the all-cylinder mode, and compression stroke injection is performed. The torque shock is reduced by switching to the injection mode including

JP 2004-346875 A

  By the way, during the reduced-cylinder operation in which the combustion of some cylinders is stopped, the in-cylinder temperature of the combustion stopped cylinders decreases. For this reason, when performing cylinder recovery from reduced cylinder operation to switch to full cylinder operation and switching to full cylinder operation, in the cylinder inactive cylinder with reduced cylinder operation, when the fuel injection is resumed, the in-cylinder wet amount (piston) There is a possibility that the amount of fuel adhering to the upper surface or the cylinder inner wall surface will increase. When the in-cylinder wet amount increases, there is a problem that the amount of PM (particulate matter) generated increases and the exhaust emission deteriorates. However, in the above-described prior art, exhaust emission at the time of cylinder return from the reduced-cylinder operation is not considered at all, and the above-described problem cannot be solved.

  Therefore, the problem to be solved by the present invention is to provide a control device for an internal combustion engine that can suppress deterioration of exhaust emission when performing cylinder return from reduced-cylinder operation.

  In order to solve the above-mentioned problem, the invention according to claim 1 has a function of performing a reduced-cylinder operation in which the combustion of some cylinders of the internal combustion engine (11) is stopped and the internal combustion engine (11) is operated. In a control device for an internal combustion engine, when performing cylinder return from the reduced cylinder operation to increase the number of cylinders that perform combustion, the in-cylinder temperature of the combustion paused cylinder in the reduced cylinder operation or information correlated therewith (hereinafter referred to as “cylinder”). The cylinder return control means (30) for changing the fuel injection condition according to the "internal temperature information") is provided.

  When the cylinder is returned from the reduced cylinder operation, the in-cylinder wet amount is more likely to increase as the in-cylinder temperature is lower in the combustion paused cylinder in the reduced cylinder operation. Therefore, when the cylinder is returned from the reduced cylinder operation, the fuel injection condition is changed according to the in-cylinder temperature information of the combustion stopped cylinder in the reduced cylinder operation. Corresponding to the fact that the amount tends to increase, the fuel injection condition can be changed in the decreasing direction of the in-cylinder wet amount to suppress the increase in the in-cylinder wet amount. As a result, when returning to the cylinder from the reduced cylinder operation, an increase in the in-cylinder wet amount due to a decrease in the in-cylinder temperature can be suppressed, and an increase in the amount of PM generated can be suppressed, thereby suppressing deterioration in exhaust emission. can do.

FIG. 1 is a diagram showing a schematic configuration of an engine control system in Embodiment 1 of the present invention. FIG. 2 is a flowchart showing the flow of processing of a cylinder return control routine according to the first embodiment. FIG. 3 is a diagram conceptually illustrating an example of a fuel pressure map at the time of cylinder return. FIG. 4 is a diagram conceptually showing an example of a map of injection timing at the time of cylinder return. FIG. 5 is a diagram conceptually illustrating an example of a map of the number of injections when returning to the cylinder. FIG. 6 is a time chart showing an execution example of the cylinder return control of the first embodiment. FIG. 7 is a flowchart showing the flow of processing of a cylinder return control routine according to the second embodiment. FIG. 8 is a time chart illustrating an execution example of the cylinder return control of the second embodiment.

  Hereinafter, some embodiments embodying the mode for carrying out the present invention will be described.

A first embodiment of the present invention will be described with reference to FIGS.
First, a schematic configuration of the engine control system will be described with reference to FIG.
An air cleaner 13 is provided at the most upstream portion of the intake pipe 12 of the direct injection engine 11 which is an internal combustion engine of the direct injection type. Is provided. A throttle valve 16 whose opening is adjusted by a motor 15 and a throttle opening sensor 17 for detecting the opening (throttle opening) of the throttle valve 16 are provided on the downstream side of the air flow meter 14.

  Further, a surge tank 18 is provided on the downstream side of the throttle valve 16, and an intake pipe pressure sensor 19 for detecting the intake pipe pressure is provided in the surge tank 18. The surge tank 18 is provided with an intake manifold 20 that introduces air into each cylinder of the engine 11, and each cylinder of the engine 11 is provided with a fuel injection valve 21 that directly injects fuel into the cylinder. Yes. An ignition plug 22 is attached to the cylinder head of the engine 11 for each cylinder, and the air-fuel mixture in each cylinder is ignited by spark discharge of the ignition plug 22 of each cylinder.

  On the other hand, the exhaust pipe 23 of the engine 11 is provided with an exhaust gas sensor 24 (such as an air-fuel ratio sensor or an oxygen sensor) that detects the air-fuel ratio or rich / lean of the exhaust gas. A catalyst 25 such as a three-way catalyst for purifying gas is provided.

  A cooling water temperature sensor 26 that detects the cooling water temperature and a knock sensor 27 that detects knocking are attached to the cylinder block of the engine 11. A crank angle sensor 29 that outputs a pulse signal every time the crankshaft 28 rotates by a predetermined crank angle is attached to the outer peripheral side of the crankshaft 28, and the crank angle and the engine are determined based on the output signal of the crank angle sensor 29. The rotation speed is detected.

  Outputs of these various sensors are input to an electronic control unit (hereinafter referred to as “ECU”) 30. The ECU 30 is mainly composed of a microcomputer, and executes various engine control programs stored in a built-in ROM (storage medium), so that the fuel injection amount and the ignition timing are determined according to the engine operating state. The throttle opening (intake air amount) and the like are controlled.

  Further, the ECU 30 switches between all-cylinder operation and reduced-cylinder operation in accordance with the engine operation state in order to improve the fuel consumption of the engine 11. In all-cylinder operation, combustion is performed in all cylinders and the engine 11 is operated. In reduced-cylinder operation, combustion of some cylinders is stopped and combustion is performed in the remaining cylinders, and the engine 11 is operated.

  By the way, during the reduced-cylinder operation in which the combustion of some cylinders is stopped, the in-cylinder temperature of the combustion stopped cylinders decreases. For this reason, when performing cylinder recovery from reduced cylinder operation to switch to full cylinder operation and switching to full cylinder operation, in the cylinder inactive cylinder with reduced cylinder operation, when the fuel injection is resumed, the in-cylinder wet amount (piston) There is a possibility that the amount of fuel adhering to the upper surface or the cylinder inner wall surface will increase. When the in-cylinder wet amount increases, there is a problem that the amount of PM (particulate matter) generated increases and the exhaust emission deteriorates.

  As a countermeasure, in the first embodiment, the ECU 30 executes a cylinder return control routine shown in FIG. 2 to be described later, thereby performing cylinder return to increase the number of cylinders for combustion from the reduced cylinder operation to switch to all cylinder operation. In addition, the fuel injection condition is changed in accordance with the in-cylinder temperature information (in-cylinder temperature or information having a correlation with the in-cylinder temperature) of the combustion paused cylinder in the reduced cylinder operation.

  When the cylinder is returned from the reduced cylinder operation, the in-cylinder wet amount is more likely to increase as the in-cylinder temperature is lower in the combustion paused cylinder in the reduced cylinder operation. Therefore, when the cylinder is returned from the reduced cylinder operation, the fuel injection condition is changed according to the in-cylinder temperature information of the combustion stopped cylinder in the reduced cylinder operation. Corresponding to the fact that the amount tends to increase, the fuel injection condition can be changed in the decreasing direction of the in-cylinder wet amount to suppress the increase in the in-cylinder wet amount.

In the first embodiment, the in-cylinder temperature is estimated or detected as in-cylinder temperature information of the combustion paused cylinder, and the fuel pressure, the injection timing, and the number of injections are changed as the fuel injection conditions.
Since the atomization of the injected fuel can be promoted by increasing the fuel pressure, the in-cylinder wet amount can be reduced. In addition, by retarding the injection timing of the intake stroke, it is possible to reduce the amount of fuel adhering to the upper surface of the piston by bringing the injection timing closer to the bottom dead center of the piston. . Moreover, since the atomization of the injected fuel can be promoted by increasing the number of injections, the in-cylinder wet amount can be reduced (in addition, when the number of injections is two or more, the fuel is divided into a plurality of times). Means the number of times of divided injection to be injected). Therefore, if the fuel pressure, the injection timing, and the number of injections are changed, an increase in the in-cylinder wet amount due to a decrease in the in-cylinder temperature can be suppressed.

Hereinafter, the processing contents of the cylinder return-time control routine of FIG. 2 executed by the ECU 30 in the first embodiment will be described.
The cylinder return control routine shown in FIG. 2 is repeatedly executed at a predetermined cycle during the power-on period of the ECU 30, and serves as cylinder return control means in the claims. When this routine is started, first, at step 101, it is determined whether or not a reduced cylinder operation is being performed. If it is determined that the reduced cylinder operation is not being performed (for example, all cylinders are being operated), This routine is finished as it is.

  On the other hand, if it is determined in step 101 that the reduced-cylinder operation is being performed, the process proceeds to step 102 to estimate (calculate) the in-cylinder temperature of the combustion paused cylinder in the reduced-cylinder operation. In this case, for example, the in-cylinder temperature is calculated by a map or a mathematical formula based on the elapsed time from the start of the reduced cylinder operation and the coolant temperature (or oil temperature). The in-cylinder temperature map or mathematical expression is created in advance based on test data, design data, and the like, and stored in the ROM of the ECU 30. Alternatively, a temperature sensor that detects the in-cylinder temperature may be provided to detect the in-cylinder temperature.

Thereafter, in steps 103 to 105, fuel injection conditions (fuel pressure, injection timing, and number of injections) at the time of returning to the cylinder are calculated according to the in-cylinder temperature of the current non-combustion cylinder.
First, in step 103, the fuel pressure at the time of returning to the cylinder is calculated by a map or a mathematical formula according to the in-cylinder temperature of the current non-combustion cylinder. For example, as shown in FIG. 3, the fuel pressure map or mathematical expression at the time of cylinder return is set so that the fuel pressure at the time of cylinder return increases as the in-cylinder temperature decreases. The fuel pressure map or numerical formula, etc. at the time of cylinder return is created in advance based on test data, design data, etc., and stored in the ROM of the ECU 30.

  Thereafter, the routine proceeds to step 104, where the injection timing at the time of returning to the cylinder (injection timing of the intake stroke) is calculated by a map or a mathematical formula or the like in accordance with the current in-cylinder temperature of the combustion non-combustion cylinder. For example, as shown in FIG. 4, the injection timing map or mathematical expression at the time of cylinder return is set so that the injection timing at the time of cylinder return is retarded as the in-cylinder temperature is lower. The map or mathematical expression of the injection timing at the time of cylinder return is created in advance based on test data, design data, etc., and stored in the ROM of the ECU 30.

  Thereafter, the routine proceeds to step 105, where the number of injections at the time of returning to the cylinder is calculated by a map or a mathematical formula or the like according to the current in-cylinder temperature of the cylinder with the combustion stopped. For example, as shown in FIG. 5, the map or formula of the number of injections when returning to the cylinder is set such that the number of injections increases as the in-cylinder temperature decreases. The map or mathematical expression of the number of injections when returning to the cylinder is created in advance based on test data, design data, and the like, and is stored in the ROM of the ECU 30. The number of injections of 2 or more means the number of injections of divided injection in which the fuel is divided into a plurality of injections.

  In this way, after calculating the fuel injection conditions (fuel pressure, injection timing, and number of injections) at the time of cylinder return, the routine proceeds to step 106, where it is determined whether a cylinder return request (for example, all cylinder operation request) has occurred. To do.

  If it is determined in step 106 that a cylinder return request has not occurred, this routine is terminated. In this case, the process of calculating the fuel injection condition when returning to the cylinder according to the in-cylinder temperature of the combustion stopped cylinder during the reduced-cylinder operation (the processes of steps 101 to 105) is repeated.

  Thereafter, when it is determined in step 106 that a cylinder return request has occurred, the routine proceeds to step 107, where the fuel injection conditions are changed to the fuel injection conditions (fuel pressure, injection timing, and number of injections) at the time of cylinder return. Then, the fuel injection control is executed.

  At this time, the fuel injection conditions may be changed to return the cylinders to all cylinders that perform combustion. Alternatively, the fuel injection conditions (for example, fuel pressure) that cannot be changed for each cylinder are changed to the fuel injection conditions at the time of cylinder return in all cylinders, and the fuel injection conditions (for example, the injection timing and the number of injections) that can be changed for each cylinder are the combustion return cylinders. It may be changed to the fuel injection condition at the time of returning to the cylinder only with the cylinder (the cylinder that has been stopped until then). Further, in the case of a system in which all the fuel injection conditions (fuel pressure, injection timing, and number of injections) can be changed for each cylinder, the fuel injection conditions may be changed to the fuel injection condition at the time of cylinder return only by the combustion return cylinder.

Next, an execution example of the cylinder return control according to the first embodiment will be described with reference to the time chart of FIG.
At the time t1 when the reduced cylinder operation request occurs during engine operation, the entire cylinder operation is switched to the reduced cylinder operation. During this reduced-cylinder operation, the in-cylinder temperature of the non-combustion cylinder is estimated or detected, and the fuel injection conditions (fuel pressure, injection timing, and number of injections) when returning to the cylinder are calculated according to the in-cylinder temperature of the non-combustion cylinder. Repeat the process.

  Thereafter, at the time t2 when the cylinder return request (for example, all cylinder operation request) is generated, the reduced cylinder operation is switched to the all cylinder operation. At that time, the fuel injection condition is changed to the fuel injection condition (fuel pressure, injection timing, and number of injections) at the time of cylinder return, and fuel injection control is executed.

  In the first embodiment described above, when the cylinder return operation is performed from the reduced cylinder operation to the full cylinder operation, the fuel injection condition (the fuel pressure and the injection timing is determined according to the in-cylinder temperature of the combustion paused cylinder in the reduced cylinder operation). The number of injections) is changed. Accordingly, in response to the fact that the in-cylinder wet amount is likely to increase as the in-cylinder temperature of the cylinder with the combustion stopped is lower, the fuel injection condition is changed in the decreasing direction of the in-cylinder wet amount to increase the in-cylinder wet amount. Can be suppressed. As a result, when returning to the cylinder from the reduced cylinder operation, an increase in the in-cylinder wet amount due to a decrease in the in-cylinder temperature can be suppressed, and an increase in the amount of PM generated can be suppressed, thereby suppressing deterioration in exhaust emission. can do.

  In the first embodiment, the fuel pressure, the injection timing, and the number of injections are changed as the fuel injection conditions. Since the atomization of the injected fuel can be promoted by increasing the fuel pressure, the in-cylinder wet amount can be reduced. In addition, by retarding the injection timing of the intake stroke, it is possible to reduce the amount of fuel adhering to the upper surface of the piston by bringing the injection timing closer to the bottom dead center of the piston. . Moreover, since the atomization of the injected fuel can be promoted by increasing the number of injections, the in-cylinder wet amount can be reduced. Therefore, if the fuel pressure, the injection timing, and the number of injections are changed, an increase in the in-cylinder wet amount due to a decrease in the in-cylinder temperature can be suppressed.

  At this time, in the first embodiment, the lower the in-cylinder temperature of the non-combustion cylinder, the higher the fuel pressure when returning to the cylinder. In this way, in response to the fact that the in-cylinder wet amount is more likely to increase as the in-cylinder temperature is lower, it is possible to increase the fuel pressure and enhance the increase in the in-cylinder wet amount.

  In the first embodiment, the lower the in-cylinder temperature of the combustion paused cylinder, the more retarded the injection timing when returning to the cylinder. In this way, in response to the fact that the in-cylinder wet amount is more likely to increase as the in-cylinder temperature is lower, it is possible to retard the injection timing and enhance the increase in the in-cylinder wet amount.

  Furthermore, in the first embodiment, the number of injections is increased as the in-cylinder temperature of the combustion pause cylinder is lower. In this way, in response to the fact that the in-cylinder wet amount is more likely to increase as the in-cylinder temperature is lower, the increase in the in-cylinder wet amount can be increased by increasing the number of injections.

  In the first embodiment, the in-cylinder temperature is estimated or detected as the in-cylinder temperature information of the combustion paused cylinder. In this way, it is possible to appropriately change the fuel injection conditions (fuel pressure, injection timing, and number of injections) according to the estimated or detected in-cylinder temperature.

  Next, Embodiment 2 of the present invention will be described with reference to FIGS. However, description of substantially the same parts as those in the first embodiment will be omitted or simplified, and different parts from the first embodiment will be mainly described.

  In the second embodiment, the ECU 30 executes a cylinder return control routine shown in FIG. 7 to be described later, thereby reducing the cylinder operation time (the elapsed time from the start of the cylinder reduction operation) as the in-cylinder temperature information of the combustion paused cylinder in the cylinder reduction operation. ) Is calculated, and the fuel injection condition is changed according to the reduced-cylinder operation time when switching from the reduced-cylinder operation to the all-cylinder operation. Since the in-cylinder temperature tends to decrease as the reduced-cylinder operation time (elapsed time from the start of reduced-cylinder operation) becomes longer, the reduced-cylinder operation time can be used as in-cylinder temperature information.

  In the cylinder return control routine of FIG. 7, first, in step 201, it is determined whether or not the reduced cylinder operation is being performed. If it is determined that the reduced cylinder operation is being performed, the process proceeds to step 202 and the reduced cylinder operation is performed. Calculate the operation time (elapsed time from the start of reduced-cylinder operation). In this case, for example, the reduced cylinder operation time is calculated based on the count value of a timer that measures the elapsed time from the start of the reduced cylinder operation.

Thereafter, in steps 203 to 205, fuel injection conditions (fuel pressure, injection timing, and number of injections) at the time of cylinder return are calculated according to the current reduced cylinder operation time.
First, in step 203, the fuel pressure at the time of cylinder return is calculated by a map or a mathematical formula according to the current reduced cylinder operating time. The fuel pressure map or mathematical expression at the time of cylinder return is set such that the fuel pressure at the time of cylinder return is increased as the reduced-cylinder operation time is longer (the in-cylinder temperature is lower). The fuel pressure map or numerical formula, etc. at the time of cylinder return is created in advance based on test data, design data, etc., and stored in the ROM of the ECU 30.

  Thereafter, the routine proceeds to step 204, where the injection timing at the time of returning to the cylinder (injection timing of the intake stroke) is calculated according to the current reduced cylinder operating time by using a map or a mathematical expression. The map or numerical formula of the injection timing at the time of cylinder return is set so that the injection timing at the time of cylinder return is retarded as the reduced-cylinder operation time is longer (the in-cylinder temperature is lower). The map or mathematical expression of the injection timing at the time of cylinder return is created in advance based on test data, design data, etc., and stored in the ROM of the ECU 30.

  Thereafter, the routine proceeds to step 205, where the number of injections at the time of cylinder return is calculated by a map or a mathematical formula according to the current reduced cylinder operating time. The map or mathematical expression of the number of injections at the time of cylinder return is set so that the number of injections is increased as the reduced-cylinder operation time is longer (the in-cylinder temperature is lower). The map or mathematical expression of the number of injections when returning to the cylinder is created in advance based on test data, design data, and the like, and is stored in the ROM of the ECU 30.

  After calculating the fuel injection conditions (fuel pressure, injection timing, and number of injections) at the time of cylinder return in this way, the process proceeds to step 206 to determine whether or not a cylinder return request (for example, all cylinder operation request) has occurred. To do.

  If it is determined in step 206 that no cylinder return request has occurred, this routine is terminated. In this case, during the reduced-cylinder operation, the process of calculating the fuel injection conditions when returning to the cylinder according to the reduced-cylinder operation time (the processes of steps 201 to 205) is repeated.

  Thereafter, when it is determined in step 206 that a cylinder return request has occurred, the process proceeds to step 207, where the fuel injection conditions are changed to the fuel injection conditions (fuel pressure, injection timing, and number of injections) at the time of cylinder return. Then, the fuel injection control is executed.

Next, an execution example of cylinder return control according to the second embodiment will be described with reference to the time chart of FIG.
At the time t1 when the reduced cylinder operation request occurs during engine operation, the entire cylinder operation is switched to the reduced cylinder operation. During this reduced-cylinder operation, the reduced-cylinder operation time (elapsed time from the start of reduced-cylinder operation) is calculated, and the fuel injection conditions (fuel pressure, injection timing, and number of injections) when returning to the cylinder according to the reduced-cylinder operation time The process of calculating is repeated.

  Thereafter, at the time t2 when the cylinder return request (for example, all cylinder operation request) is generated, the reduced cylinder operation is switched to the all cylinder operation. At that time, the fuel injection condition is changed to the fuel injection condition (fuel pressure, injection timing, and number of injections) at the time of cylinder return, and fuel injection control is executed.

  In the second embodiment described above, the reduced cylinder operation time (elapsed time from the start of the reduced cylinder operation) is calculated as the in-cylinder temperature information of the combustion stopped cylinder. In this way, it is not necessary to estimate (calculate) the in-cylinder temperature, the calculation load on the ECU 30 can be reduced, and it is not necessary to newly provide a temperature sensor or the like for detecting the in-cylinder temperature. Can meet the demand for

  In the second embodiment, the reduced-cylinder operation time (elapsed time from the start of reduced-cylinder operation) is used as the in-cylinder temperature information of the combustion stopped cylinder. However, the present invention is not limited to this. An injection number integrated value from the start, an ignition number integrated value, an intake air amount integrated value, a fuel injection amount integrated value, and the like may be used.

  Further, in each of the first and second embodiments, the process of calculating the fuel injection condition at the time of returning to the cylinder is repeated according to the in-cylinder temperature information of the combustion stopped cylinder during the reduced cylinder operation. However, the present invention is not limited to this. For example, when a cylinder return request is generated, the fuel injection condition at the time of cylinder return may be calculated according to the in-cylinder temperature information of the combustion paused cylinder.

  Further, in each of the first and second embodiments, the fuel pressure, the injection timing, and the number of injections are all changed according to the in-cylinder temperature information of the combustion paused cylinder. However, the present invention is not limited to this. One or two of the timing and the number of injections may be changed.

  Further, in each of the first and second embodiments, the present invention is applied when switching to full cylinder operation by performing cylinder return to increase the number of cylinders that perform combustion from reduced cylinder operation, but the present invention is not limited to this. The present invention may be applied when switching from the reduced-cylinder operation to the second reduced-cylinder operation by performing cylinder return that increases the number of cylinders that perform combustion.

  In addition, the present invention is not limited to the in-cylinder injection engine as shown in FIG. 1, but includes an intake port injection engine, and both an intake port injection fuel injection valve and an in-cylinder injection fuel injection valve. It can also be applied to dual-injection engines.

  DESCRIPTION OF SYMBOLS 11 ... Engine (internal combustion engine), 12 ... Intake pipe, 16 ... Throttle valve, 21 ... Fuel injection valve, 22 ... Spark plug, 23 ... Exhaust pipe, 30 ... ECU (control means at the time of cylinder return)

Claims (7)

In a control device for an internal combustion engine having a function of performing a reduced-cylinder operation in which the combustion of some cylinders of the internal combustion engine (11) is stopped and the internal combustion engine (11) is operated,
When performing cylinder return from the reduced-cylinder operation to increase the number of cylinders that perform combustion, the in-cylinder temperature of the combustion-canceled cylinder in the reduced-cylinder operation or information correlated therewith (hereinafter referred to as “in-cylinder temperature information”) A control apparatus for an internal combustion engine, comprising: a cylinder return-time control means (30) for changing a fuel injection condition in accordance with a generic name).   The control apparatus for an internal combustion engine according to claim 1, wherein the cylinder return control means (30) changes at least one of fuel pressure, injection timing, and number of injections as the fuel injection condition.   The control apparatus for an internal combustion engine according to claim 2, wherein the cylinder return time control means (30) increases the fuel pressure as the in-cylinder temperature information becomes a lower temperature side of the in-cylinder temperature.   The internal combustion engine control according to claim 2 or 3, wherein the cylinder return control means (30) retards the injection timing as the in-cylinder temperature information becomes a lower temperature side of the in-cylinder temperature. apparatus.   The internal combustion engine according to any one of claims 2 to 4, wherein the cylinder return control means (30) increases the number of injections as the in-cylinder temperature information becomes a lower temperature side of the in-cylinder temperature. Control device.   The control device for an internal combustion engine according to any one of claims 1 to 5, wherein the cylinder return control means (30) uses the in-cylinder temperature as the in-cylinder temperature information.   The control apparatus for an internal combustion engine according to any one of claims 1 to 5, wherein the cylinder return control means (30) uses an elapsed time from the start of the reduced cylinder operation as the in-cylinder temperature information.

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