DE112008000359T5 - Control device for a multi-cylinder internal combustion engine - Google Patents

Abstract

A control apparatus for a multi-cylinder internal combustion engine that automatically stops the engine by interrupting the fuel injection when an automatic stop command is issued, characterized by comprising:
a remaining torque calculating section (51) which, when a start command is issued in a period after the cutoff of the fuel injection due to the automatic stop command until the engine is stopped completely, calculates the remaining torque (TR) of the engine based on a then current engine operating condition;
a cylinder state determining section (52) that determines whether the first cylinder to start an intake stroke after the start command has been issued is to be able to complete a compression stroke before the engine is fully completed, based on the remaining torque (TR) stops; and
a fuel injection control section (53) which, only when it has been determined that the cylinder will be able to complete the compression stroke, starts the fuel injection from the intake stroke of that cylinder.

Description

BACKGROUND OF THE INVENTION

Field of the invention

The The invention relates to a control device for a multi-cylinder internal combustion engine, the fuel is injected to keep the engine in a self-sustaining or to return autonomous operating state, if the Engine speed drops to or below a predetermined speed, the is lower than the idle speed.

The Japanese Patent Application Publication No. 2004-232489 ( JP-A-2004-232489 ), for example, describes such a control device for a multi-cylinder internal combustion engine. A typical related control device for a multi-cylinder internal combustion engine, including the in JP-A-2004-232489 described control device, performs a so-called idling stop control, in which it automatically stops the engine by interrupting the fuel injection when an automatic stop command (hereinafter also referred to as "automatic stop command") is present when Vehicle is idling (ie with the engine running), for example, at an intersection. Then, when a command to start the engine (hereinafter also referred to as "start command") comes, the control device restarts the engine by operating a starter motor such as a starter motor to turn the engine while injecting fuel, and by it increases the engine speed to a predetermined speed.

With This type of relevant control device will be the Motor, after being completely stopped by the engine Actuation of the starter device and the injection restarted from fuel. Even if between the time to the fuel injection due to the automatic stop command was interrupted, and the time at which the engine is complete is stopped, a start command is issued, thus the Engine does not restart before not fully stopped was causing a delay between the output of the Start command and the restart of the engine leads.

Around This delay can thus be reduced in Be considered, the engine regardless of whether the engine was completely stopped by injecting of fuel immediately after issuing the start command in the return self-sufficient operating state. Even if fuel is immediate is injected after issuing the start command, but may be dependent from the time the start command was issued, and From the operating condition of the engine at this time, the combustion energy from the injected fuel is insufficient to increase the engine speed to bring the given speed, and thus it may be that the engine is unable to resume self-sufficient operation. In this case, the injected fuel is simply wasted.

there This type of problem is not following a startup control afterwards limited to an idling stop control. The same Problem occurs when the engine is in a vehicle with a manual For example, due to a too abrupt insertion of the transmission Clutch dies. That is, when the engine dies, The engine speed drops below a specified speed, the lower is the idle speed. Also at this time will be according to a Operation command continues to inject fuel. If the engine is unable to resume self-contained operation, In this case, the injected fuel is wasted as in the start control described above. Therefore, the described Problem common in control devices in multi-cylinder internal combustion engines, inject the fuel to the engine in a self-sufficient operating condition bring back when the engine speed is up or down a given speed has dropped, which is lower than that Idle speed.

SUMMARY OF THE INVENTION

The Invention thus provides a control device for a Multi-cylinder internal combustion engine, which is able to drive the engine in to return a self-sufficient operation while it avoids wasted fuel injection.

A first aspect of the invention relates to a control apparatus for a multi-cylinder internal combustion engine that automatically stops the engine by interrupting the fuel injection when an automatic stop command is issued. This control apparatus includes: a residual torque calculating section that, when outputting a start command in a period from an interruption of fuel injection due to the automatic stop command until the engine is stopped completely, a remaining torque of the engine based on then current Engine operating condition calculated; a cylinder state determining section that determines, based on the remaining torque, whether the first cylinder to start an intake stroke after the start command is issued will be able to complete a compression stroke before the engine stops completely; and a fuel injection control section that only when determined has been that the cylinder will be able to complete the compression stroke that starts fuel injection from the intake stroke of the cylinder.

According to the the above-described control device calculates the remaining torque calculating section, if during the period from the interruption of the fuel injection due to an automatic stop command until complete Stopping the engine a start command was issued, the rest Torque of the engine due to the then current engine operating condition. In this case, the residual torque of the engine is the moment of inertia, which is determined according to the engine speed, minus the working resistance, such as the compression resistance and the sliding resistance the cylinder. Only when the cylinder state determination section due to the residual torque determines that the first cylinder, which is to control the intake stroke after the start command has been issued, in will be able to complete this compression stroke before the Engine stops completely, d. H. that the piston the cylinder will be able to cover the distance from the UT (lower Dead center) of the compression stroke to TDC (top dead center) of the compression stroke then the fuel injection control section starts with the fuel injection from the intake stroke of this cylinder. When a start command is issued, therefore, fuel is injected when increases the engine speed to a predetermined speed so that the engine can only self-sustain using energy that is injected by burning Fuel is received, can resume. Thus, the Engine to return to the self-sufficient operating state while an uneconomical fuel injection is avoided.

If was determined that the cylinder will not be able to Compression stroke can be completed with this control device the fuel injection control section also includes a starter device Press and inject fuel.

According to this Control device is injected with fuel when the engine is not is able to do so only by using the energy provided by the Combustion of injected fuel is getting self-sufficient Resume operation while the engine speed is below Use of the starter device is increased. thats why the engine will be able to resume the self-sufficient operation while an uneconomical fuel injection is avoided.

In This control device may be the fuel injection control section also prevent fuel from being injected, if it has been determined that the cylinder will not be able to to complete the compression stroke.

If the engine is unable to do so, using only the obtained by the combustion of the injected fuel Energy to resume self-sufficient operation, according to this Control device an uneconomical fuel injection prevented. Therefore, an uneconomical fuel injection be avoided.

One Another aspect of the invention relates to a control device for a multi-cylinder internal combustion engine equipped with a fuel injection valve equipped, the fuel during a compression stroke injected directly into a cylinder, and the engine automatically stops by interrupting the fuel injection, when an automatic stop command is issued. This control device includes: a remaining torque calculating section, if in a period of time from the interruption of the fuel injection due to the automatic stop command until complete Stopping the engine a start command was issued, the rest Torque of the motor due to a then current operating state calculated; a compression stroke cylinder determination section that due to the residual torque determines whether the first cylinder, the after the start command is issued, start a compression stroke, will be able to complete this compression stroke; and a fuel injection control section that controls the fuel injection from the compression stroke of this cylinder starts when the cylinder will be able to complete the compression stroke.

According to the above-described control device, the residual torque calculating section calculates the residual torque of the engine. Then, based on the remaining torque, the compression stroke cylinder determination section determines whether the first cylinder to start the compression stroke after the start command is issued will be able to complete this compression stroke, that is, the piston of the first cylinder to start the compression stroke , will be able to cover the distance from the UT of the compression stroke to the OT of the compression stroke. If this cylinder will be able to complete the compression stroke, the fuel injection control portion will start fuel injection from the compression stroke of that cylinder. Thus, when a start command is issued, fuel is injected if the engine speed can be increased to the predetermined speed, so that the engine is able to autonomously recover only by using the energy obtained by the combustion of the injected fuel Resume operation. Therefore, the engine can resume autonomous operation while avoiding wasteful fuel injection.

In This control device may be the fuel injection control section also operate a starter and Inject fuel if the cylinder will not be able to is going to complete the compression stroke.

According to the The control device described above becomes the starter device pressed and fuel is injected when the cylinder is unable to complete the compression stroke. If the Engine is not capable, only by using the energy, obtained from the combustion of the injected fuel is to resume the self-sufficient operation, thus becomes fuel injected while the engine speed using the starting device is increased. Therefore, the engine can to resume self-sufficient operation, while an uneconomical Fuel injection is avoided.

In This control device may be the fuel injection control section also prevent fuel from being injected, if this cylinder is unable to increase the compression stroke accomplish.

According to the The control device described above becomes uneconomical Fuel injection prevents when the engine is unable to is just by using the energy that comes from the combustion of the injected fuel, the self-sufficient operation to resume. Therefore, uneconomical fuel injection can be avoided become.

If the fuel injection is interrupted, the force decreases acts on the crankshaft so that it rotates, d. H. the remaining torque, over time. Therefore, the remaining torque continues to increase the more time between the interruption of the fuel injection until the start command is issued, and as a result becomes make it harder to get the engine back into self-sufficient operation.

Therefore can lower the value of the remaining torque be calculated, the more time from the interruption of the fuel injection until passes to the output of the start command.

According to the The control device described above is for the rest Torque a smaller value, the more time from the calculated Interruption of fuel injection until the start command is issued passes. Thus, the remaining torque can be calculated exactly such that the cylinder state determination section determines the cylinder state can determine exactly or the compression stroke cylinder determination section can determine the compression cylinder exactly. Therefore, the engine can to resume self-sufficient operation, while an uneconomical Fuel injection appropriately suppressed becomes.

One Another aspect of the invention relates to a control device for a multi-cylinder internal combustion engine that automatically powers the engine stops by interrupting the fuel injection, when an automatic stop command is issued. This control device includes: a remaining torque calculating section, when the fuel injection due to the automatic stop command was interrupted, the remaining torque of the engine due the then current engine operating condition is calculated; a cylinder state determination section, which, due to the residual torque, determines whether the last cylinder, the one immediately before the engine stops completely to start a compression stroke, will be able to do this Complete compression stroke; and a fuel injection control section, which, if this cylinder will be able, the compression stroke to complete fuel injection starting with this cylinder, if a start command before this compression stroke of this cylinder in a period after interruption of the fuel injection was issued until the engine stopped completely.

According to the above-described control device, when a fuel injection is interrupted due to an automatic stop command, the remaining torque calculating section calculates the remaining torque of the engine based on the then current engine operating state, regardless of whether a start command is issued thereafter. Then, the final compression cylinder determination section determines whether the last cylinder to start a compression stroke immediately before the engine stops completely will be able to complete this compression stroke, ie, whether the piston of the cylinder will be able to travel the distance from the UT of the compression stroke to the TDC of the compression stroke. If this cylinder will be able to complete the compression stroke, the fuel injection control section will commence fuel injection with that cylinder if a start command prior to that compression stroke of that cylinder was issued in the period after the fuel injection stop until the engine is stopped completely , Here, for example, in an internal combustion engine capable of injecting fuel during the intake stroke, the fuel injection from the intake stroke immediately precedes this compression stroke. In a burn Engine equipped with a fuel injection valve capable of injecting fuel directly into the cylinder during a compression stroke, the fuel injection begins either from the intake stroke or from the compression stroke of this cylinder. Thus, when a start command has been issued, fuel is injected if the engine speed can be increased to the predetermined speed, so that the engine is able to operate autonomously using only the energy obtained from the combustion of the injected fuel to resume. Therefore, the engine can resume self-sustaining operation while avoiding wasteful fuel injection.

In This control device may be the fuel injection control section also press the starter and Inject fuel when the start command after an injection period was issued, which corresponds to the compression stroke.

If the engine is unable, only using the energy, obtained from the combustion of the injected fuel is to take up the self-sufficient operation like that will according to the above described control device fuel injected while increases the engine speed using the starter motor becomes. Therefore, the engine can be returned to the self-sustaining state while avoiding wasteful fuel injection becomes.

In This control device may be the fuel injection control section also prevent fuel injection when the Start command was issued after an injection period, the corresponds to the compression stroke.

According to the The control device described above becomes the fuel injection prevents if a start command after an injection period, which corresponds to the compression stroke is output. Accordingly, becomes prevents uneconomical fuel injection if the engine is unable to do so, using only the Energy resulting from the combustion of the injected fuel is obtained to resume the self-sufficient operation. Therefore, will an uneconomical fuel injection avoided.

Further The control device may also have an opening degree control section having an opening degree of a throttle valve, which is provided in an intake passage and the intake air quantity is greater after issuing the automatic stop command makes than before issuing the automatic stop command.

According to the The control device described above becomes the opening degree the throttle is made larger after issuing an automatic stop command as before the issue of the automatic stop command. As a result, one can Pumping loss of the engine over that which is present if the throttle opening degree is at most is as large as the opening degree before output of the automatic stop command, be reduced so that the rest Torque can gradually decrease. Even if a start command is spent at a time that is relatively far behind the Interruption of the fuel injection, the engine can thus the resume self-sufficient operation. In addition, the throttle opening degree greater than before the automatic stop command was issued, which means that a correspondingly larger intake air can be ensured. As a result, if fuel can is injected to the engine in the self-sufficient operating condition bring back the engine power to be increased, so that the engine can quickly resume self-sufficient operation can.

If the degree of opening of the throttle after issuing an automatic stop command is made larger than before the automatic stop command was issued, the remaining torque is gradually lowered. If however, no start command is issued after the fuel injection is interrupted was, the time at which the engine can complete stops, too much delayed.

In the control device can thus the opening degree control section after issuing the automatic stop command and until the output of the Start command make the opening degree of the throttle just as large such as the opening degree before the automatic stop command is issued, and after issuance of the start command, the opening degree control section may set the opening degree make the throttle larger than the opening degree before the automatic stop command is issued.

According to the above-described control device, after issuing an automatic stop command until the issuance of a start command, the opening degree of the throttle valve is made the same as before the issue of the automatic stop command. Thus, if no start command is issued after an automatic stop command has been issued, the remaining torque may decrease rapidly, so that the engine can be stopped completely quickly. On the other hand, when a start command has been issued, the throttle opening degree is made larger thereafter than before the automatic stop command is issued, so that a pumping loss can be reduced. In addition, by increasing the amount of intake air before starting the fuel injection, the engine output after the start of the fuel injection can be increased rapidly, whereby the engine self-sufficient operation can resume quickly.

One Another aspect of the present invention relates to a control device for a multi-cylinder internal combustion engine that during injecting fuel into a suction stroke. This control device includes: a remaining torque calculating section, when an engine speed drops to a predetermined speed, which is lower than an idle speed, and an operation command is output, the remaining torque of the engine due to a then calculated current engine operating condition; a cylinder state determination section, determined based on the remaining torque, whether the first cylinder, which is to start a suction stroke after the engine speed the has reached predetermined speed, will be able to one Completing the compression stroke before the engine completes stops; and a fuel injection control section, the fuel injection continues if the cylinder state determination section has determined that the cylinder will be able to the compression stroke to complete.

According to the the above-described control device calculates the residual torque calculating section, when an output command is issued and the engine speed is up the predetermined speed decreases, which is lower than the idling speed, the remaining torque due to the then current engine operating condition. In this case, the remaining torque of the engine is the moment of inertia, the is determined according to the engine speed, minus the Working resistance, such as the compression resistance and the sliding resistance the cylinder. When the cylinder state determining section is due to of the remaining torque determines that the first cylinder, the to start the intake stroke after the engine speed has reached the preset speed Speed has reached, will be able to the compression stroke to complete before the engine stops completely, d. H. that the piston of the cylinder will be able to track the distance from the UT of the compression stroke to the OT of the compression stroke, before the engine stops completely, then the Fuel injection control section the fuel injection continued. Therefore, the engine can resume self-sufficient operation, while avoiding uneconomical fuel injection becomes.

In The control device may further include the fuel injection control section operate a starter and inject fuel, if it has been determined that the cylinder will not be able to to complete the compression stroke.

If due to the residual torque was determined that the cylinder will not be able to complete the compression stroke, is in accordance with the As described above, the starting device is operated and fuel is injected. If the engine is unable is just by using the energy that comes from the combustion of the injected fuel, the self-sufficient operation Thus, fuel is injected while the starter device is actuated to the engine speed to increase. Therefore, the engine is capable of self-sufficient operation resume while uneconomical fuel injection is avoided.

In The control device may be the fuel injection control section also prevent fuel injection when determined was that the cylinder will not be able to the compression stroke to complete.

If due to the residual torque was determined that the cylinder is unable to complete the compression stroke, is in accordance with the Control device described above, the fuel injection prevented. That is, an uneconomical fuel injection is prevented when the engine is unable, only using energy injected by the combustion of the Fuel is resumed the self-sufficient operation. Thus, an uneconomical fuel injection can be avoided.

One Another aspect of the invention relates to a control device for a multi-cylinder internal combustion engine equipped with a fuel injection valve equipped, the fuel during a compression stroke injected directly into a cylinder, and during the Compression strokes inject fuel from the fuel injector. This control apparatus includes: a remaining torque calculating section, when an engine speed drops to a predetermined speed, which is lower than an idle speed, and an operation command is output, the remaining torque of the engine due to a then calculated current engine operating condition; a cylinder state determination section, determined based on the residual torque, whether the first cylinder, which should start the compression stroke after the engine speed has reached the predetermined speed, will be able to do this Complete compression stroke; and a fuel injection control section, the fuel injection continues when this cylinder in will be able to complete the compression stroke.

According to this control apparatus, when an operation command is issued and the engine speed decreases to the predetermined speed lower than the idling speed, the remaining torque calculating section calculates the remaining one Torque of the engine due to the then current engine operating condition. Then, based on the remaining torque, the cylinder state determining section determines whether the first cylinder to start the compression stroke after the engine rotational speed has reached the predetermined rotational speed will be able to complete the compression stroke, ie, whether the piston of the cylinder in the Will be able to cover the distance from the UT of the compression stroke to the OT of the compression stroke. If the cylinder will be able to complete the compression stroke, the fuel injection control section will continue fuel injection. Therefore, the engine can resume the autonomous operating state, while an uneconomical fuel injection can be avoided.

In The control device may be the fuel injection control section also operate a starter and Inject fuel if the cylinder will not be able to is going to complete the compression stroke.

According to this Control device, the starter device is actuated and fuel is injected when the cylinder is not in the Able to complete the compression stroke. If the engine is not is able to, just by using the energy that comes from the combustion of the injected fuel is obtained, the self-sustaining operation, therefore, fuel is injected while increases the engine speed using the starter device becomes. Therefore, the engine can be returned to the self-sustaining state, while avoiding uneconomical fuel injection becomes.

In The control device may be the fuel injection control section also prevent fuel from being injected, if this cylinder is unable to increase the compression stroke accomplish.

According to this Control device is prevented from fuel injection when This cylinder will not be able to the compression stroke to complete. Therefore, an uneconomical fuel injection prevented when the engine is unable, only under Use of energy resulting from the combustion of the injected fuel is obtained to resume the self-sufficient operation. Thus, can an uneconomical fuel injection can be avoided.

With increasing intake air amount that is introduced into the cylinder will also increase the compression resistance that is generated when the intake air is compressed, resulting in a lower residual motor torque leads. On the other hand leads a larger opening degree of the throttle valve too a lower pumping loss of the engine, resulting in an increased residual motor torque leads. That is, that remaining torque of the engine changes depending on the degree of opening the throttle, which determines the intake air quantity.

Therefore can in the control device, the remaining torque according to an opening degree of Throttle, which determines an intake air amount to be calculated.

According to the The control device described above becomes the remaining torque according to the opening degree of the throttle valve, which adjusts the intake air amount, calculated so that the remaining torque of the engine can be calculated exactly. Therefore, the engine is in the Able to resume self-sufficient operation while an uneconomical fuel injection in an appropriate manner is avoided.

ever higher the temperature of the sucked air becomes, d. H. ever the more the density of the sucked air decreases, the more it sinks Compression resistance generated when the intake air is compressed so that the remaining torque of the engine increases. Therefore can be larger in the control device Value for the remaining torque can be calculated, depending higher the temperature of a sucked air becomes.

According to the The control device described above may have the remaining torque of the engine can be calculated exactly. Therefore, the engine can be self-sufficient Resume operation while an uneconomical Fuel injection appropriately suppressed can be.

BRIEF DESCRIPTION OF THE DRAWING

The Features and advantages as well as the technical and industrial significance The invention will be more apparent from the following detailed description Embodiments of the invention in conjunction with the accompanying drawing better understandable, wherein:

1 the overall structure of a control device for a multi-cylinder internal combustion engine according to a first embodiment of the invention;

2 Fig. 13 is a flowchart showing the first part of a special routine for automatically stopping and restarting the engine, which is performed by the control apparatus according to the first embodiment;

3 a flowchart is the second Shows part of a special routine for automatically stopping and restarting the engine, which is performed by the control device according to the first embodiment;

4 Fig. 10 is a flowchart showing another special routine for automatically stopping and restarting the engine, which is performed by the control apparatus according to the first embodiment;

5 Fig. 12 is a graph showing the relationship between an inertia torque, the time period after interruption of the fuel injection due to an automatic stop command and the issuance of a start command and the throttle opening degree;

6 FIG. 12 is a graph showing the relationship between an inertia torque, the time period after fuel cut due to an automatic stop command and the issuance of a start command and an engine speed; FIG.

7 Fig. 12 is a graph showing the relationship between a compression resistance force, a throttle opening degree and a temperature of the intake air;

8th Fig. 12 is a graph showing the relationship between a sliding resistance force and a coolant temperature;

9 Fig. 11 is a timing chart showing the manner in which the engine automatic stop and restart control routine executed by the control apparatus according to the first embodiment is performed;

10 FIG. 7 is a timing chart showing the relationship between the timing at which a start command is issued, the cylinder to be injected with fuel, and the timing at which fuel injection starts; FIG.

11 Fig. 12 is a block diagram of the structure of a control apparatus for a multi-cylinder internal combustion engine according to a second embodiment of the invention;

12 Fig. 10 is a flowchart showing a specific routine for automatically stopping and restarting the engine executed by the control apparatus according to the second embodiment;

13 Fig. 10 is a flowchart showing another special routine for automatically stopping and restarting the engine executed by the control apparatus according to the second embodiment;

14 Fig. 12 is a graph showing the relationship between an inertia torque and an engine speed when the fuel injection is interrupted;

15 FIG. 12 is a block diagram showing a structure of a control apparatus for a multi-cylinder internal combustion engine according to a third embodiment of the present invention; FIG.

16 Fig. 10 is a flowchart showing a specific routine for automatically stopping and restarting the engine executed by the control apparatus according to the third embodiment;

17 Fig. 10 is a flowchart showing another specific routine for automatically stopping and restarting the engine executed by the control apparatus according to the third embodiment; and

18 FIG. 10 is a flowchart showing the manner in which the engine returning control routine is performed in the autonomous operating state executed by the control apparatus according to the third embodiment.

DETAILED DESCRIPTION THE EMBODIMENTS

In the following description and the accompanying drawings is the present invention described in more detail with reference to embodiments.

A first embodiment in which a control apparatus for a multi-cylinder internal combustion engine according to the present invention has been applied to a control apparatus that automatically stops and restarts a vehicle-mounted internal combustion engine will now be described in detail with reference to FIG 1 to 9 described. In this example, the internal combustion engine is a four-cylinder in-line engine.

1 FIG. 12 is an illustration of a frame format of the overall structure of the internal combustion engine and its control apparatus according to this embodiment. FIG. As shown in the drawing, are a suction pipe 2 and an exhaust pipe 3 with a cylinder head 12 connected to the internal combustion engine. Likewise, an up and down movable piston 13 in each of the cylinders No. 1 to No. 4, in a cylinder block 11 are formed, provided. This piston 13 is over a connecting rod 14 effective with a crankshaft 15 connected. As a result, the up and down movement of the piston 13 over the connecting rod 14 in a rotational movement of the crankshaft 15 transformed. A combustion chamber 16 is from the piston 13 , the cylinder block 11 and the cylinder head 12 educated. Likewise is a spark plug 17 for a spark ignition in the combustion chamber 16 intended. The ignition timing of the spark plug 17 is from an electronic control device 5 controlled, which will be described later. 1 shows the cross-sectional structure of the first of four cylinders (ie, only the cylinder No. 1 of the four cylinders No. 1 to No. 4). The cross-sectional structure of the other cylinders No. 2 to No. 4 are each substantially the same as the cross-sectional structure of No. 1 cylinder.

Both an intake passage 21 that the suction pipe 2 with the combustion chamber 16 connects, as well as an exhaust passage 31 who has the exhaust pipe 3 with the combustion chamber 16 are in the cylinder head 12 educated. An intake valve 22 and an exhaust valve 32 are also in the cylinder head 12 intended. The intake valve 22 selectively enables or disrupts connection between the suction passage 21 and the combustion chamber 16 , and the exhaust valve 32 selectively enables or disrupts a connection between the exhaust passage 31 and the combustion chamber 16 , The intake valve 22 opens and closes as an intake crankshaft rotates, working with the crankshaft 15 is coupled, and the exhaust valve 32 opens and closes as an exhaust crankshaft rotates, which also interacts with the crankshaft 15 is coupled. Likewise, a fuel injection valve 18 , which supplies fuel via an injection during the intake stroke of the engine, in the intake passage 21 intended. The fuel injection timing and the fuel injection amount are determined by the electronic control device 5 controlled.

An intake pipe 23 for the introduction of sucked air into the combustion chamber 16 is with the intake passage 21 connected, and a throttle 24 for the adjustment of the introduced intake air amount is in the intake pipe 23 intended. The opening degree of the throttle valve 24 is controlled by an electric motor that controls the throttle 24 controls and that of the electronic control device 5 is controlled. Likewise, an intake tank 25 that of an enlarged section of the intake manifold 23 is formed, on the intake side downstream of the throttle 24 in the intake pipe 23 intended.

An exhaust pipe 33 for the discharge of exhaust gas in the combustion chamber 16 is formed, outward is with the exhaust passage 31 connected. Likewise, the internal combustion engine is also with a starter motor 4 provided, the crankshaft 15 for example, during engine startup using power supplied by the battery. The timing at which the starter motor 4 is operated by the electronic control unit 5 controlled.

Also, various sensors for detecting the operating state of the engine and the running state of the vehicle are provided both in the internal combustion engine and in the vehicle in which the internal combustion engine is installed. For example, such sensors provided in the internal combustion engine include a crank angle sensor 91 , the speed of the crankshaft 15 , that is, the engine speed NE detected to a throttle sensor 92 , which is the opening degree of the throttle 24 , that is, the throttle opening degree TA detected to an intake air amount sensor 93 , which is the intake air volume (ie the intake air amount) GA, which enters the combustion chamber 16 is detected, to an intake air temperature sensor 94 detecting the intake air temperature ThA and a coolant temperature sensor 95 that detects the temperature ThW of a coolant passing through a water jacket 19 that flows in the cylinder block 11 and in the cylinder head 12 is trained.

Some of the sensors and switches provided in the vehicle include an accelerator element sensor 96 that detects a depression amount of the accelerator pedal, ie, an accelerator operation amount ACCP, about a vehicle speed sensor 97 detecting a speed of the vehicle (ie, a vehicle speed) V, and an ignition switch 98 that detects whether an engine operation command is present from the driver. Detection signals from these various signals and switches are sent to the electronic control device 5 output.

The electronic control device performs various controls with respect to the internal combustion engine based on detection signals from the various sensors. More specifically, the electronic control device 5 a residual torque calculating section 51 , a cylinder state determining section 52 ; a fuel injection control section 53 and a throttle opening degree control section 54 on.

When an engine start command is issued by the driver during the period after interruption of fuel injection due to automatic stop control until the engine is stopped completely (ie, when a start command is issued), the residual torque calculating section calculates 51 the remaining torque TR of the engine due to the then current engine operating condition. In this case, the residual torque TR of the engine is the moment of inertia Ti determined according to the engine speed NE minus the working resistance, such as the compression resistance and the sliding resistance of the cylinder No. 1 to No. 4.

Also, the cylinder state determination section determines 52 from the calculated residual torque TR, whether of the four No. 1 to No. 4 cylinders, the first No. N cylinder to start the intake stroke after the start command is issued will be able to complete the compression stroke before the engine stops completely.

When the cylinder No. N, that of the cylinder state determination section 52 is detected, will be able to complete the compression stroke, the fuel injection control section begins 53 On the other hand, if the cylinder No. N will not be able to complete the compression stroke, the fuel injection control section will operate from the intake stroke of this No. N cylinder with the fuel injection into this No. N cylinder 53 the starter motor 4 and then starts the fuel injection.

After a command for automatically stopping the engine has been issued (ie, after an automatic stop command has been issued), the throttle opening degree control section increases 54 Also, the throttle opening degree TA becomes larger than the throttle opening degree before the automatic stop command is issued, that is, greater than a target idling throttle opening degree TAi.

2 to 4 are flowcharts representing special routines for automatically stopping and restarting the engine, which are provided by the electronic control device 5 be executed. These routines are repeated at predetermined time intervals by the electronic control device 5 executed.

As in 2 In this sequence of routines, in step S101, it is first determined whether an automatic stop command has been issued. Here, an automatic stop command is issued when it is determined that both the accelerator opening degree ACCP and the vehicle speed V are 0, that is, the vehicle is idling, and that no auxiliaries such as a compressor need to be driven. If it has been determined that an automatic stop has been issued (ie, YES in step S101), the process proceeds to step S102 where the fuel injection is interrupted. Then, in step S103, an opening degree TA1 which is the sum of the then actual throttle opening degree, ie, the target engine opening idling throttle opening TAi plus a predetermined opening degree ΔTA (> 0), is set as the target throttle opening degree TAt. After the target throttle opening degree Tat has been increased by the predetermined opening degree ΔTA due to the automatic stop command in step S103, the target throttle opening degree TAt is maintained at this increased opening degree TA1.

If on the other hand, no automatic stop command was issued (i.e., NO in step S101), this cycle of the routine ends. If on this Way the fuel injection is interrupted and the target throttle opening degree TAt is increased as a result of step S103, Then, in step S104, it is determined whether a command to start the Motors (i.e., a start command) is present. Here it is determined that there is a command to start the engine when the accelerator pedal is depressed from a dissolved state, d. H. when the accelerator opening degree ACCP has become larger. If no command to start of the motor (i.e., NO in step S104), this cycle ends the routine.

On the other hand, if a start command has been issued (ie, YES in step S104), the process proceeds to step S105, where it is determined whether the engine speed NE is greater than a predetermined value α (≈ 0), ie, whether the engine is still running ( that is, not yet completely stopped). If it is determined that the engine is no longer running (ie, NO in step S105), ie, if the engine has been completely stopped), the process then proceeds to step S106, where the target throttle opening degree TAt is on the opening degree TA2 during a normal start is set, the starter motor 4 is pressed and fuel is injected. As a result, the engine starts normally, and this cycle of the routine ends.

On the other hand, if the engine is still running (ie not completely stopped) (ie, YES in step S105), the process proceeds to step S107 which is in 3 is shown where the residual torque TR of the engine is calculated based on the engine operating condition upon issuance of the start command. The routine for calculating the remaining torque TR will be described later in detail with reference to FIG 4 described.

When the remaining torque TR of the engine is calculated in this manner, it is next determined in step S108, based on the remaining torque TR, whether the first cylinder N, which should start an intake stroke after the start command has been issued, is capable is going to complete the compression stroke. More specifically, it is determined whether the remaining torque TR is at least as large as a predetermined torque TRth (> 0). This predetermined torque TRth is a constant value that is set in advance. If be is true that the cylinder No. N will be able to complete the compression stroke (ie, YES in step S108), the process then proceeds to step S109, where the fuel injection from the intake stroke of the cylinder no. N, ie the intake stroke, which immediately precedes the compression stroke, is started.

On the other hand, if the cylinder No. N will not be able to complete the compression stroke (ie, NO in step S108), that is, the piston 13 of the cylinder No. N is unable to reach the TDC of the compression stroke, the process proceeds to step S106, where the target throttle opening degree TAt is reset to the normal start opening degree TA2 (<TA1), the starter motor 4 is pressed and fuel is injected before the engine stops completely. Then this cycle of the routine ends.

If the fuel injection according to the firing order starting from the intake stroke of the cylinder No. N, will then in step S110 determines if the engine is within a given time period Start of fuel injection during the intake stroke of the Cylinder No. N started working again with its own power has resumed (that is, resumed the self-sufficient operation). If it is determined that the engine is self-sufficient in the given period has resumed (i.e., YES in step S100), this ends Cycle of the routine.

On the other hand, if the engine has not resumed the self-sustaining operation in the predetermined period (ie, NO in step S110), the attempt to return the engine to the self-sustaining state using only the injected fuel is abandoned, and the process goes to step S106 Further, in which the target throttle opening degree TAt is set to the opening degree TA2 (<TA1) for a normal start, the starter motor 4 is pressed and fuel is injected before the engine stops completely. Then this cycle of the routine ends.

Now, the routine for calculating the remaining torque of the engine (ie, the remaining torque calculation routine in step S107) will be described with reference to FIG 4 described. As in 4 11, in step S171 of this routine, first, the fuel injection cutoff period Δt due to the automatic stop command until output of the start command and the throttle opening degree TA, the engine speed NE, the intake air temperature ThA, and the coolant temperature ThW are read out upon issuance of the start command. Then, in step S172, the residual torque TR is calculated from a calculation map showing the relationship between the residual torque TR and the parameters indicative of those engine operating conditions. Once the remaining torque TR has been calculated in this way, this cycle of the routine ends.

Now, the characteristics of the calculation map for calculating the residual torque TR of the engine with reference to 5 to 8th described. The remaining torque TR of the engine is the moment of inertia Ti determined according to the engine speed NE minus the working resistance such as the compression resistance Fc and the sliding resistance Fs of the cylinders Nos. 1 to Nos. 4. In this embodiment, the relationships between the moment of inertia Ti of the engine, the compression resistance force Fc and the sliding resistance force FS and the various Pa rametem (ie the period .DELTA.t after interruption of the fuel injection due to the automatic stop command to the output of the start command and the engine speed NE, the throttle opening degree TA, the intake air temperature ThA and the coolant temperature ThW at output of the start command) correlated therewith, is set up as follows. Likewise, the computational map, with careful consideration of the correlation of the in the 5 to 8th set up parameters.

5 FIG. 12 is a graph showing the relationship between the moment of inertia Ti, the time period after interruption of the fuel injection due to an automatic stop command and the issuance of a start command, and the throttle opening degree TA. As shown in the drawing, the moment of inertia Ti becomes smaller as the period Δt increases. When the period Δ is equal to, the larger the throttle opening degree TA becomes, the larger the inertia becomes.

6 FIG. 12 is a graph showing the relationship between the moment of inertia Ti, the period of time Δt after interruption of the fuel injection due to an automatic stop command and the issuance of a start command and the engine speed NE when the fuel injection stops. As shown in the drawing, the moment of inertia Ti is determined according to the engine speed NE, therefore, when the time period Δt is equal, the higher the engine speed NE at the time of interrupting the fuel injection, the greater the moment of inertia Ti.

7 FIG. 12 is a graph showing the relationship between the compression resistance force Fc, the throttle opening degree TA, and the intake air temperature ThA. As shown in the drawing, the larger the throttle opening degree TA becomes, the larger the intake air amount GA introduced into the cylinders No. 1 to No. 4 becomes, and as a result, the compression resistance force Fc also increases. Likewise, the compression resistance decreases Fc decreases as the intake air temperature ThA increases and the density of the air decreases. Thus, when the throttle opening degree TA is equal, the compression resistance force Fc decreases as the intake air temperature ThA increases.

8th FIG. 12 is a graph showing the relationship between the coolant temperature ThW and the sliding resistance force Fs. As in 8th As the coolant temperature ThW increases, the viscosity of the lubricating oil on the sliding portions of the engine decreases, thereby improving the lubricity and thus decreasing the sliding resistance force Fc.

Now, the throttle opening degree TA, the fuel injection state and the operating state of the starter motor become 4 and the like, when the in 2 to 4 illustrated routines, with reference to the timing in 9 described. In 9 The solid lines indicate cases in which the engine is able to resume the autonomous operating state only by using the energy obtained from the combustion of the injected fuel, because the remaining torque TR of the engine was high Start command has been issued. The alternate long and short dashed lines indicate changes in the throttle opening degree TA and the engine speed NE and the like when the engine is unable to resume autonomous operation only by using the energy obtained by the combustion of the injected fuel because the residual torque TR of the motor was small when the start command was issued.

As in 9 (a) is shown, if an automatic stop command is issued at time t1, the throttle opening degree TA immediately thereafter at time t2 is set to an opening degree TA1 which is larger than the opening degree TAi before issuance of the automatic stop command as shown in FIG 9 (b) shown. Likewise, at the same time the fuel injection is interrupted, as in 9 (c) shown. As a result, after time t2, the engine speed gradually decreases from the idling engine speed NEi with the passage of time. Then, when a start command is issued at time t3, as in FIG 9 (e) is shown, which then calculates current remaining torque TR of the engine, and it is determined whether the cylinder No. N, which should first start an intake stroke after the start command is issued, is capable of the compression stroke due to this remaining torque TR to complete.

As from the solid line in 9 (f) Here, when the residual torque TR2 is at least as large as a predetermined torque TRth, the fuel injection according to the firing order is started from the intake stroke of the No. N cylinder at time t6. In addition, at that time, as indicated by the solid line in 9 (g) shown, the starter motor 4 not activated. As from the solid line in 9 (d) shown, thus, after the time t7, the engine speed NE is increased and the engine resumes autonomous operation again.

Here, the relationship between the time t3 at which the start command is issued, the No. 2 cylinder into which fuel is first injected, and the time t5 at which the fuel injection starts, with reference to the timing chart of FIG 10 described. The times t3 and t5 in 10 correspond to the times t3 and t5 in 9 ,

When the start command is issued at time t3, the cylinder to be the first to start an intake stroke thereafter is the second cylinder # 2, as in FIG 10 shown. If this second No. 2 cylinder will be able to complete the compression stroke until the engine is completely stopped, from the time t5 corresponding to the injection period of this intake stroke with the injection of fuel into the No. 2 second cylinder began. That is, after that, fuel is injected into the cylinders No. 1 to No. 4 according to a firing sequence set in advance (ie, first cylinder No. 1 → third cylinder No. 3 → fourth cylinder No. 4 → second cylinder No. 2).

Now, if the remaining torque TR3 when outputting a start command is smaller than the predetermined torque TRth, as from the alternately long and short dashed line in 9 (f) 11, the throttle opening degree TA is set to an opening degree TA2 smaller than the current opening degree TA1 at time t4, as indicated by the alternate long and short dashed line in FIG 9 (b) shown, and the starter motor 4 begins to work at time t5 as indicated by the alternate long and short dashed line in 9 (d) shown. As a result, the engine speed NE increases after the time t5 as from the alternate long and short dashed line in FIG 9 (c) shown. Thereafter, at time t8, fuel injection also starts as indicated by the alternate long and short dashed line in FIG 9 (c) as a result, the engine speed NE continues to increase after time t9. This is the starter motor 4 stopped at time t10, as indicated by the alternate long and short dashed line in 9 (g) shown.

The above control apparatus for a multi-cylinder internal combustion engine according to this embodiment is capable of following to achieve the effects. (1) When a start command is issued in the period after interruption of the fuel injection due to an automatic stop command until the engine is stopped completely, the remaining torque calculating section calculates 51 the remaining torque TR of the engine due to the then current engine operating condition. When the cylinder state determination section 52 because of the remaining torque TR, it is determined that the first cylinder No. N to start the intake stroke after the start command has been issued will be able to complete this compression stroke before the engine stops completely, that is, the piston 13 If this No. N cylinder is able to travel the distance from the UT of the compression stroke to the TDC of the compression stroke before the engine stops completely, the fuel injection control section will start 53 then from the intake stroke with the injection of fuel into this cylinder. On the other hand, when the cylinder state determination section 52 Due to the residual torque TR, it is determined that the No. N cylinder will not be able to complete the compression stroke, the starter motor will become 4 pressed and fuel is injected. Thus, when a start command is issued, fuel is injected when the engine speed NE may be increased to a predetermined speed, so that the engine is able to self-sustain using only the energy obtained from the combustion of the injected fuel Resume operation. When the engine is unable to resume autonomous operation merely by using the energy obtained from the combustion of the injected fuel, fuel is injected while the engine speed NE is increased by using the starter motor 4 is increased. Therefore, the engine is able to resume self-sustaining operation while avoiding wasteful fuel injection.

(2) When the fuel injection is interrupted, the force acting on the crankshaft decreases 15 to turn, ie the remaining torque TR, over time. The longer the period Δt after interruption of the fuel injection to the issuance of a start command, the more the residual torque TR decreases, and as a result, it becomes more difficult to return the engine to the self-sustaining operating state.

In view of this, in the above embodiment, the smaller the torque ΔT after the fuel injection is cut off until the output of the start command, the smaller the value is calculated for the remaining torque TR. As a result, the remaining torque TR can be accurately calculated so that the cylinder state determining section 52 can determine the cylinder state exactly.

(3) The throttle opening degree control section 54 makes the throttle opening degree TA after the automatic stop command is issued to an opening degree TA1 which is larger than the throttle opening degree TAi before the automatic stop command is issued.

Consequently can the pumping loss of the engine compared to the state in which the throttle opening degree TA is at most so is great as the opening degree before issuing the Automatic stop command, be reduced, leaving the rest Torque TR can gradually decrease. Even if a start command is issued at a time that is relatively late Interruption of fuel injection comes, is thus the engine nevertheless able to resume self-sufficient operation. Since the Throttle opening degree TA is greater than before the automatic drop command is issued, you can also use a correspondingly larger intake air quantity GA ensured become. When fuel is injected to the engine in the self-sufficient As a result, the operating condition can be returned Engine power can be increased, so that the engine self-sufficient operation can resume quickly.

(4) The larger the intake air amount GA becomes that in the cylinder is inserted, the more the compression resistance decreases Fc generated when the intake air is compressed to, so that the remaining torque TR of the engine decreases. If against the throttle opening degree TA increases, the pumping loss decreases of the engine, so that the remaining torque TR of the engine increases. That is, the remaining torque TR of the engine changes according to the throttle opening degree TA, which determines the intake air amount GA.

in view of in the above exemplary embodiment, this becomes the remaining torque T calculated according to the throttle opening degree TA, so that the remaining torque TA of the engine can be calculated exactly can. (5) With increasing intake air temperature ThA, d. H. with decreasing Density of the sucked air, takes the compression resistance force Fc generated when the sucked air is compressed so that the remaining torque TR of the engine increases.

in view of this is in the above embodiment for the remaining torque TR is greater Value calculated the higher the intake air temperature becomes, so that the residual torque TR of the engine can be calculated exactly.

Now, a second embodiment in which the control device for a Mehrzylin the internal combustion engine of the invention is applied to a control device that automatically stops and restarts an internal combustion engine in a vehicle, with emphasis on the differences from the first embodiment described above with reference to 11 to 14 described.

11 FIG. 12 is a block diagram of the configuration of mainly a control device for an internal combustion engine according to this second embodiment. FIG. As in 11 shown, has an electronic control device 205 This embodiment has a structure similar to the structure of the control device of the first embodiment described above, which in 1 is basically similar, and has a residual torque calculating section 251 , a final compression stroke cylinder determination section 252 and a fuel injection control section 253 on.

When the fuel injection has been interrupted due to an automatic stop command, the remaining torque calculating section calculates 251 the remaining torque TR of the engine due to the then current engine operating condition. In the first embodiment, in this case, the remaining torque TR was calculated based on the operating state upon outputting the start command. However, in this second embodiment, the residual torque TR is calculated based on the engine operating condition at the time of interruption of the fuel injection.

Also, the final compression stroke cylinder determination section determines 252 because of the residual torque TR, whether the last cylinder No. N to start a compression stroke immediately before the engine stops completely will be able to complete the compression stroke. If this No. N cylinder will be able to complete the compression stroke, and a start command is issued in the period after the fuel injection stop until the engine stops completely before the intake stroke immediately preceding this compression stroke, the fuel injection begins. control section 253 with the fuel injection from the intake stroke of this No. N cylinder. On the other hand, when a start command is issued after the injection period corresponding to the compression stroke, the starter motor becomes 4 pressed and the fuel injection is started.

12 and 13 are flowcharts representing special control routines for automatically stopping and restarting the engine and those from the electronic control device 205 be executed. These routines are taken at predetermined intervals by the electronic control device 205 repeatedly performed.

As in 12 is shown in this series of routines in step 201 First determines whether an automatic stop command has been issued. If it has been determined that an automatic stop command has been issued (ie, YES in step S201), the process proceeds to step S202 where the fuel injection is interrupted. Then, in step S203, the remaining torque TR of the engine is calculated based on the engine operating condition at the time when the fuel injection was interrupted. The routine for calculating the remaining torque TR will be described later in detail with reference to FIG 13 described.

On the other hand, if no automatic stop command has been issued (ie, NO in step S201), this cycle of the routine ends. Once the remaining torque TR of the engine has been calculated in this manner, it is determined in step S204, based on the remaining torque TR, whether the last cylinder N, which should start a compression stroke, immediately before the engine stops completely, will be able to complete this compression stroke. In step S205, it is then determined whether a start command has been issued before this compression stroke. Since it is assumed that fuel is injected during the intake stroke, it is determined whether a start command has been issued before the intake stroke immediately preceding this compression stroke. If it is determined that a start command has been issued before the compression stroke (ie, YES in step S205), then the process goes to step 207 Further, where from the intake stroke, which immediately precedes the compression stroke of the cylinder no. N according to the firing order, is started with the fuel injection.

On the other hand, if no start command has been issued before the compression stroke (ie, NO in step S205), then it is determined in step S210 whether a start command has been issued after the compression stroke. If yes (ie, YES in step S210), it is determined that the fuel injection for the intake stroke immediately preceding this compression stroke will not be timely, so that the process proceeds to step S206 where the starter motor 4 is pressed and fuel is injected. If the determination in step S210 is NO, it means that no start command has been issued before or after the compression stroke, so that the process returns to the beginning, that is, this cycle ends the routine.

In this way, if the fuel injection in accordance with the firing order from the intake stroke of the No. N cylinder commences in step S207, it is then determined in step S208 whether the engine is in a predetermined period after the start of the engine Fuel injection during the intake stroke of the cylinder no. N has resumed the self-sufficient operation. If it is determined that the engine has resumed the self-sustaining operation in this predetermined period (ie, YES in step S208), this cycle of the routine ends.

On the other hand, if the engine has not resumed the autonomous operation in this predetermined period (ie, NO in step S208), the attempt to return the engine to the self-sustaining state using only the fuel injection is abandoned, and the process proceeds to step S206 where the starter motor 4 is pressed and fuel is injected before the engine is stopped completely. Then this cycle of the routine ends.

Now, a routine for calculating the remaining torque TR of the engine (ie, the remaining torque calculating routine in step S203) will be described with reference to FIG 13 described. As in 13 That is, in step S231 of this routine, the engine rotational speed NE, the throttle opening degree TA, the intake air temperature ThA, and the coolant temperature ThW at the time when the fuel injection has been interrupted due to the automatic stop command are read out. Then, in step S232, the residual torque TR is calculated from a calculation map showing the relationship between the residual torque TR and the parameters indicative of those engine operating conditions. Once the remaining torque TR has been calculated in this way, this cycle of the routine ends.

Now, the characteristics of the calculation map for calculating the residual torque TR of the engine with reference to 14 described. The relationships between the compression resistance force Fc and the sliding resistance force Fs which determine the residual torque TR of the engine and the throttle opening degree TA, the intake air temperature ThA and the coolant temperature ThW are substantially the same as the characteristics shown in FIG 7 and 8th Therefore, we will omit their description here.

14 FIG. 12 is a graph illustrating the relationship between the moment of inertia Ti and the engine speed at the time when the fuel injection is interrupted. As shown in the drawing, the higher the engine speed NE is when the fuel injection is stopped, the larger the value of the inertia torque Ti becomes.

The above-mentioned control apparatus for a multi-cylinder internal combustion engine according to this embodiment is capable of achieving the following effects. (1) When fuel injection is interrupted due to an automatic stop command, the remaining torque calculating section calculates 251 regardless of whether a start command is issued thereafter, the remaining torque TR of the engine due to the then current engine operating condition. Then, the final compression stroke cylinder determination section determines 252 whether the last cylinder No. N, which is to start a compression stroke, immediately before the engine stops completely, will be able to complete this compression stroke, ie whether the piston 13 This No. N cylinder will be able to travel the distance from UT of the compression stroke to the TDC of the compression stroke. If this cylinder No. N will be able to complete the compression stroke, then the fuel injection control section will start 253 with the fuel injection from the intake stroke, which immediately precedes this compression stroke of this No. N cylinder when a start command has been issued in a period from after the fuel injection was stopped until the engine is stopped completely before this compression stroke. On the other hand, when a start command is issued after the injection period corresponding to the compression stroke, the starter motor becomes 4 pressed and fuel is injected. Thus, when a start command has been issued, fuel is injected when the engine speed NE can be increased to the predetermined speed NEth, so that the engine is capable of using only the energy obtained by the combustion of the injected fuel to resume self-sufficient operation. However, if the engine is incapable of resuming autonomous operation using only the energy received from the combustion of the injected fuel, fuel is injected while the engine speed is reduced using the starter motor 4 is increased. Therefore, the engine can resume the autonomous operation, while uneconomical fuel injection can be suppressed.

Now, a third embodiment in which the control apparatus for a multi-cylinder internal combustion engine of the invention has been applied to a self-parking control apparatus for a vehicle-mounted internal combustion engine will be described in detail with reference to FIG 15 to 18 described.

15 FIG. 12 is a block diagram of the configuration of mainly a control device for an internal combustion engine according to this third embodiment. As in 15 shown, has an electronic control device 305 This embodiment has a structure similar to the structure of the control device of the first embodiment described above, which in 1 is shown, and the structure of the control device of the second embodiment described above, in 11 is basically similar, and has a residual torque calculating section 351 , a cylinder state determining section 352 and a fuel injection control section 353 on. The internal combustion engine of this embodiment is equipped with a fuel injection valve capable of injecting fuel directly into the cylinder during the compression stroke, and injects fuel directly from this fuel injection valve during the compression stroke.

When an actuation command is issued and the engine speed NE decreases to or below a predetermined speed NE lower than the idle speed NEi, the residual torque calculation section calculates 351 the remaining torque TR of the engine due to the then current engine operating condition.

Also, the cylinder state determination section determines 352 due to the remaining torque TR, whether the first cylinder N, which is to start the compression stroke after the engine speed NE has fallen to or below the predetermined rotational speed NEth, will be able to complete this compression stroke.

When this cylinder is able to complete the compression stroke, the fuel injection control section is also set 353 the fuel injection continues. However, if this cylinder is unable to complete the compression stroke, the fuel injection control section prevents 353 a fuel injection.

16 and 17 are flowcharts that represent special control routines for returning the engine to the self-sustaining operating state of the electronic control unit 305 be executed. These routines are executed in predetermined cycles during the period in which an actuation command is issued by the electronic control device 205 repeatedly performed. In this embodiment, the operation command is issued, for example, when the ignition switch 98 stands on one.

As in 16 is shown in step 301 First of this routine, regardless of whether an operation command is issued, it determines whether the engine speed NE has dropped to or below a predetermined speed NEth lower than the idle speed NEi, as in the case where the engine is due to a sudden engagement of the clutch dies. When it is determined that the engine speed NE has dropped to or below the predetermined speed NEth (ie, YES in step S301), then in step S302, the remaining torque TR due to the engine operating condition at that time, that is, the engine speed NE of the predetermined speed NEth became equal. The routine for calculating the remaining torque TR will be described later in detail with reference to FIG 17 described.

If whereas the engine speed NE is higher than the predetermined one Rotational speed NEth (i.e., NO in step S301), the cycle thereof ends Routine. If the residual torque TR of the engine in this way is then calculated in step S303 due to the remaining Torque determines whether the first cylinder, the compression stroke should start after the engine speed NE of the predetermined speed NEth has become equal, will be able to do this compression stroke to complete. If it is determined that the cylinder is capable will be to complete the compression stroke (i.e., YES in step S303), then in step S304, the fuel injection is continued.

On the other hand, if it is determined that the cylinder will not be able to complete the compression stroke (ie, NO in step S303), that is, if the piston 13 of the first cylinder to start the compression stroke will not be able to reach the TDC of the compression stroke, then in step S305 the fuel injection is inhibited and this cycle of the routine ends.

If the fuel injection according to step S304 is continued, it is then determined in step S306 whether the engine resumed self-sufficient operation in a given period of time. If it is determined that the engine in the given period has resumed the self-sufficient operation (i.e., YES in step S306), this cycle ends the routine.

If however, the engine in the given period of autonomous operation has not resumed (i.e., NO in step S306) then becomes trying to use the engine just by using the injected Returning fuel to the self-sufficient operating state abandoned, and the fuel injection becomes in step A305 prevents this cycle from ending the routine.

Now, a routine for calculating the remaining torque TR of the engine (ie, the remaining torque calculating routine in step S302) will be described with reference to FIG 17 described. As in 17 That is, in step S321 of this routine, first, after a predetermined time Δt1 has elapsed since the engine speed NE has become equal to the predetermined engine speed NEth, the engine speed NE1 and the coolant temperature ThW, the intake air temperature ThA, and the throttle opening are equalized degree TA at the time when the engine speed NE has become equal to the predetermined engine speed NEth. Since it is known that the predetermined period .DELTA.t1 between the time at which the engine speed NE of the predetermined speed NEth becomes equal, and the time at which the engine speed NE of the rotational speed NE1 becomes equal, passes, the rate of change of the engine speed NE (ie = (NEth - NE1) / Δt1). That is, when the engine speed NE1 is high after the lapse of the predetermined period Δt1, the engine speed NE gradually decreases. In contrast, when the engine speed NE1 is low, the engine speed NE rapidly decreases. The relationships between the sliding resistance force Fs and the compression resistance force Fc that determine the residual torque TR of the engine and the throttle opening degree TA, the intake air temperature ThA, and the coolant temperature ThW are substantially the same as those in FIG 7 and 8th shown characteristics, therefore, their description is omitted here. Next, in step S322, the residual torque TR is next calculated using a calculation map showing the relationship between the residual torque TR and various parameters indicative of these engine operating conditions. Once the remaining torque TR has been calculated in this way, this cycle of the routine ends.

Now, the fuel injection state in performing the in 16 and 17 illustrated routines with respect to the timing of 18 described. In 18 The solid lines indicate cases in which the engine is able to resume self-sufficient operation only by using the energy obtained by the combustion of the injected fuel, because the remaining torque TR of the engine was high Engine speed NE of the predetermined speed NEth was equal. The alternate long and short dashed lines indicate changes in the fuel injection state and the like when the engine is unable to resume self-sustaining operation only by using the energy obtained by the combustion of the injected fuel, because the engine residual torque TR of the engine was low when the engine speed NE became equal to the predetermined speed NEth.

As in 18 (a) is shown, regardless of whether there is an operation command, when the engine speed NE at time t1 to the idle speed NEi decreases and then decreases further and at time t2 the predetermined speed NEth equal, the remaining torque TR of the engine is calculated based on the then current engine operating condition , As from the solid line in 18 (c) is shown here, when the residual torque TR1 is at least as high as a predetermined torque TRth, fuel in the first cylinder no. N, which is to start a compression stroke after the engine speed NE has reached the predetermined speed NEth, injected, if this Cylinder No. N will be able to complete this compression stroke. That is, in this case, fuel is already injected, so that the fuel injection is continued. As a result, the engine speed increases after time t5, as from the solid line in 18 (b) shown.

On the other hand, when the remaining torque TR2 is smaller than the predetermined value TRth as shown by the alternate long and short dashed lines in FIG 18 (c) shown, the fuel injection is interrupted at time t3, as of the alternately long and short dashed lines in 18 (d) shown. As a result, the engine speed NE and the remaining torque TR continue to decrease after time t3 until the engine is completely stopped at time t4, as from the alternate long and short dashed lines in FIG 18 (b) and 18 (c) shown.

The above-described control apparatus for a multi-cylinder internal combustion engine according to this embodiment can achieve the following effects. (1) When an operation command is issued and the engine speed NE becomes equal to the predetermined speed NEth lower than the idling speed NEi, the remaining torque calculating section calculates 351 the remaining torque TR of the engine due to the then current engine operating condition. Then, the cylinder state determination section determines 352 because of the residual torque TR, whether the first cylinder to start the compression stroke after the engine speed becomes equal to the predetermined rotational speed NEth will be able to complete this compression stroke, ie, the piston 13 This cylinder will be able to cover the distance from the UT of the compression stroke to the OT of the compression stroke. If this cylinder at that time will be able to complete the compression stroke, the fuel injection control section will continue 353 the fuel injection continues. On the other hand, if the cylinder will not be able to complete the compression stroke, the fuel injection control section will prevent 353 the fuel injection. Thus, the fuel injection is continued when the engine speed NE can be increased to the predetermined speed, so that the engine is able to resume autonomous operation only by using the energy obtained by the combustion of the injected fuel. If the engine is unable, just by using the energy resulting from the combustion of the engine injected fuel is received to resume the self-sufficient operation, an uneconomical fuel injection is prevented. Therefore, the engine can resume the autonomous operation, while uneconomical fuel injection can be suppressed.

The Control device for a multi-cylinder internal combustion engine the invention is not limited to the structure described above, each of which will be described in the embodiments. On the contrary, modified examples, such as those described below, are in which the structure has been suitably modified in each case, also possible.

In In the following embodiments, the parameters are indicating the engine operating condition, including the engine speed NE, the throttle opening degree TA, the intake air temperature ThA and the coolant temperature ThW, but without this to be limited. For example, too other parameters such as the intake air amount GA and the intake air pressure PA and the like.

In the above embodiments, a starter motor 4 given as an example of a starter device. However, this type of starter is not on the starter motor 4 limited. For example, in a hybrid vehicle, a motor / generator that can serve as a generator may also be used.

in the The first embodiment described above was the Throttle opening degree TA immediately after the automatic stop command is issued made larger than before the issue of the automatic stop command. However, this type of throttle opening control does not have to necessarily immediately after issuing an automatic stop command be performed. For example, in a first modified example of the first embodiment the throttle opening degree TA from the time of issue an automatic stop command and until the time of issuing a Start command remain the same as before the output of the automatic stop command, and after the issuance of the start command, the throttle opening degree TA be made larger than before the output of the Automatic-stop command. In this case, the throttle opening degree remains TA from the time of issuing an automatic stop command until at the time of issuing a start command the same as before the output of the automatic stop command. If no start command is issued until the engine is completely stopped, therefore the remaining torque TR will drop quickly, making the engine fast can be stopped completely. If, on the other hand, a start command after that, the throttle opening degree TA becomes thereafter made larger than before the output of the automatic stop command. As a result, the pumping loss can be reduced. Furthermore can by increasing the intake air amount before starting the fuel injection the engine power after starting the fuel injection quickly be increased, making the engine self-sufficient operation quickly can resume.

In the first embodiment described above, the starter motor 4 and fuel is injected if it is determined that the first cylinder No. N to start the intake stroke after the start command has been issued will not be able to complete this compression stroke before the engine stops completely. However, in a second modified example of the first embodiment, a second fuel injection may be prevented. Also in this case, the engine is able to resume the self-sufficient operation, while an uneconomical fuel injection is avoided. Also in this case, a starter device, such as the starter motor 4 , and fuel may be injected after the engine has stopped, as in a typical prior art launch control.

In the first embodiment described above, the described internal combustion engine performs fuel injection during a suction stroke. However, with an internal combustion engine provided with a fuel injection valve capable of injecting fuel directly into the cylinder during the compression stroke, the same effects as those achieved with the first embodiment can be achieved by the control device is modified as follows. That is, in a third modified example of the first embodiment, instead of the cylinder state determining section 52 a compression stroke determining section that determines whether the first cylinder No. N to start the compression stroke after the start command has been issued, based on the remaining torque TR, will be able to complete this compression stroke. Instead of the fuel injection control section 53 Further, a fuel injection control section may be used which injects fuel from the compression stroke of this No. N cylinder if this No. N cylinder will be able to complete the compression stroke, and which operates the starter device and injects fuel if that cylinder No. N will not be able to complete the compression stroke.

In the above second embodiment, the starter motor 4 Pressed and fuel is injected when in the period after interruption the fuel supply until the engine is stopped completely, a start command after the compression stroke of the cylinder, which will be able to complete the compression stroke output. Alternatively, in a first modified example of the second embodiment, the fuel injection may be prevented. Also in this case, the engine is able to resume the self-sufficient operation, while an uneconomical fuel injection is avoided. Also in this case, after the engine is stopped, a starter device such as a starter motor may be used 4 , and fuel can be injected as in a typical prior art launch control.

In In the second embodiment, it is assumed that the Fuel is injected during the intake stroke, and in a cylinder that will be able to make a compression stroke to complete before the engine stops completely, if a start command before the intake stroke, this compression stroke immediately precedes, a fuel injection Begin from this intake stroke. In a modified example of the second embodiment, however, in a construction, which is believed to be fuel during the compression stroke is injected in a cylinder that is capable of one Completing the compression stroke before the engine completes stops the fuel injection from this compression stroke be started when a start command before this compression stroke was issued.

In the third embodiment described above, the fuel injection control section prevents 353 a fuel injection when the cylinder state determining section 352 has determined that the first cylinder N, which should start the intake stroke before the engine speed NE has become equal to the predetermined speed, will not be able to complete the compression stroke before the engine stops completely. In a modified example of the third embodiment, the fuel injection control section may 353 however, operate the starter and inject fuel instead of preventing fuel injection. In this case, the engine can be returned to the self-sufficient operating state without stopping the engine completely.

In the third embodiment described above, a control apparatus applied to an internal combustion engine equipped with a fuel injection valve capable of injecting fuel directly into a cylinder during a compression stroke has been described. However, when fuel is injected during the intake stroke using this fuel injection valve, the same effects as obtained in the third embodiment can be obtained by modifying the control device as follows. That is, instead of the cylinder state determination section 352 For example, a cylinder state determining section that determines whether the first cylinder No. N to start the intake stroke after the engine rotational speed NE becomes equal to the predetermined rotational speed NEth based on the remaining torque TR will be able to perform this compression stroke to complete before the engine stops completely. Instead of the fuel injection control section 353 For example, if it has been determined that the cylinder No. N will be able to complete the compression stroke, and the fuel injection is prohibited, if it has been determined that this cylinder No. 1 may be used, a fuel injection control section may be used which continues the fuel injection. N will not be able to complete the compression stroke. The same is true even if fuel is during the intake stroke of the fuel injector 18 is injected in the intake passage 21 is provided, as well as in the first and second embodiments.

SUMMARY CONTROL DEVICE FOR MORE CYLINDER COMBUSTION ENGINE

A control device for a multi-cylinder internal combustion engine automatically stops the engine by interrupting the fuel injection when an automatic stop command is issued. When a start command is issued during a period after interruption of the fuel injection due to the automatic stop command until the engine is stopped completely, the remaining torque of the engine is calculated based on the then current engine operating condition. The controller determines, based on the remaining torque (TR), whether the first cylinder (# N) to start an intake stroke after the start command has been issued will be able to complete a compression stroke before the engine stops completely. If the cylinder (# N) will be able to complete the compression stroke, the controller will start fuel injection from the intake stroke of this cylinder (# N). However, if the cylinder (# N) will not be able to complete the compression stroke, the controller will actuate a starter motor (FIG. 4 ) and injects fuel.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - JP 2004-232489 [0002]
• - JP 2004-232489 A [0002, 0002]

Claims (20)

A control apparatus for a multi-cylinder internal combustion engine that automatically stops the engine by interrupting the fuel injection when an automatic stop command is issued, characterized by comprising: a residual torque calculating section (12); 51 ) which, when a start command is issued in a period after the interruption of the fuel injection due to the automatic stop command until the engine is stopped completely, calculates the remaining torque (TR) of the engine based on a then current engine operating condition; a cylinder state determination section (FIG. 52 determining, based on the remaining torque (TR), whether the first cylinder to start a suction stroke after the start command has been issued will be able to complete a compression stroke before the engine stops completely; and a fuel injection control section (FIG. 53 ), which only starts the fuel injection from the intake stroke of this cylinder when it has been determined that the cylinder will be able to complete the compression stroke. Control device according to claim 1, characterized in that the fuel injection control section ( 53 ) a starter device ( 4 ) and injects fuel if it has been determined that the cylinder will not be able to complete the compression stroke. Control device according to Claim 2, characterized in that the fuel injection control section ( 53 ) prevents fuel injection when it has been determined that the cylinder will not be able to complete the compression stroke. A control apparatus for a multi-cylinder internal combustion engine provided with a fuel injection valve that injects fuel directly into a cylinder during a compression stroke, and automatically stops the engine by interrupting the fuel injection when an automatic stop command is issued, thereby characterized in that it comprises: a residual moment calculating section ( 51 ) which, when a start command has been issued in a period after the interruption of the fuel injection due to the automatic stop command until the engine is stopped completely, calculates the remaining torque (TR) of the engine based on a then current engine operating condition; a compression stroke cylinder determination section that determines, based on the remaining torque (TR), whether the first cylinder to start the compression stroke after the start command has been issued will be able to complete this compression stroke; and a fuel injection control section which starts the fuel injection from the compression stroke of this cylinder when that cylinder will be able to complete the compression stroke. Control device according to claim 4, characterized in that the fuel injection control section comprises a starter device ( 4 ) and inject fuel if that cylinder will not be able to complete the compression stroke. Control device according to Claim 4, characterized in that the fuel injection control section prevents fuel injection, if this cylinder will not be able to do the compression stroke to complete. Control device according to one of claims 1 to 6, characterized in that for the remaining torque (TR) a smaller value is calculated, the longer the period after the interruption of the fuel injection until to issue the start command. A control apparatus for a multi-cylinder internal combustion engine that automatically stops the engine by interrupting the fuel injection when an automatic stop command is issued, characterized by comprising: a residual torque calculating section (12); 251 ) which, when fuel injection has been interrupted due to an automatic stop command, calculates the remaining torque (TR) of the engine based on a then current engine operating condition; a cylinder state determination section (FIG. 252 ) determining, based on the remaining torque (TR), whether the last cylinder to start a compression stroke immediately before the engine stops completely will be able to complete this compression stroke; and a fuel injection control section (FIG. 253 ), which, if this cylinder will be able to complete the compression stroke, will initiate fuel injection with that cylinder if a start command has been issued prior to that compression stroke in a period after the fuel injection has been interrupted until the engine is stopped completely. Control device according to Claim 8, characterized in that the fuel injection control section ( 253 ) the starter device ( 4 ) and fuel is injected when the start command has been issued after an injection period corresponding to the compression stroke. Control device according to claim 8, characterized characterized in that the fuel injection control section (15) 253 ) prevents fuel injection when the start command has been issued after an injection period corresponding to this compression stroke. A control device according to any one of claims 1 to 10, characterized by further comprising: an opening degree control section (12) 54 ), which has an opening degree (TA) of a throttle valve ( 24 ), which is provided in the intake passage and adjusts the intake air amount, makes larger than the opening degree before the issuance of the automatic stop command after the issuance of an automatic stop command. A control device according to claim 11, characterized in that after the issuance of the automatic stop command until the output of the start command, the opening degree control section (Fig. 54 ) the degree of opening (TA) of the throttle valve ( 24 ) is the same as the opening degree before the automatic stop command is issued, and the opening degree control section (FIG. 54 ) after the start command has been issued, the degree of opening (TA) of the throttle valve ( 24 ) is greater than the opening degree before the automatic stop command is issued. A control apparatus for a multi-cylinder internal combustion engine that injects fuel during a suction stroke, characterized by comprising: a residual torque calculating portion (16); 351 ) which, when an engine speed (NE) falls to a predetermined speed (NEth) lower than an idling speed (NEi) and an operation command is issued, the remaining torque (TR) of the engine is calculated based on a then current engine operating condition; a cylinder state determining section that determines whether the first cylinder to start an intake stroke after the engine rotational speed (NE) has become equal to the predetermined rotational speed (NEth) based on the remaining torque (TR) will be able to perform this compression stroke to complete before the engine stops completely; and a fuel injection control section that continues the fuel injection if the cylinder state determining section has determined that the cylinder will be able to complete the compression stroke. Control device according to claim 13, characterized in that the fuel injection control section comprises a starter device ( 4 ) and injects fuel if it has been determined that the cylinder will not be able to complete the compression stroke. Control device according to Claim 13, characterized in that the fuel injection control section controls the fuel injection prevented, if it was determined that the cylinder is not in the Will be able to complete the compression stroke. A control apparatus for a multi-cylinder internal combustion engine provided with a fuel injection valve which injects fuel directly into a cylinder during a compression stroke, and injects fuel from the fuel injection valve during the compression stroke, characterized by comprising: a residual torque Calculation section ( 351 ) which, when an engine speed (NE) falls to a predetermined speed (NEth) lower than an idling speed (NEi) and an operation command is issued, the remaining torque (TR) of the engine is calculated based on a then current engine operating condition; a cylinder state determination section (FIG. 352 ) determining, based on the remaining torque (TR), whether the first cylinder to start the compression stroke after the engine speed (NE) has become equal to the predetermined speed (NEth) will be able to complete this compression stroke, before the engine stops completely; and a fuel injection control section (FIG. 353 ), which continues the fuel injection, if the cylinder state determining section has determined that the cylinder will be able to complete the compression stroke. Control device according to Claim 16, characterized in that the fuel injection control section ( 353 ) a starter device ( 4 ) and inject fuel if that cylinder will not be able to complete the compression stroke. Control device according to Claim 16, characterized in that the fuel injection control section ( 353 ) prevents fuel injection if that cylinder will not be able to complete the compression stroke. Control device according to one of claims 1 to 18, characterized in that the residual torque (TR) according to an opening degree (TA) of a throttle valve ( 24 ), which adjusts an intake air amount. Control device according to one of claims 1 to 19, characterized in that for the rest Torque (TR) a higher value is calculated, depending more the intake air temperature (ThA) increases.