JP3772947B2 - Starter for in-cylinder injection internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a starter used for an in-cylinder injection type internal combustion engine (hereinafter referred to as an engine) that directly injects fuel into a combustion chamber.
[0002]
[Related background]
In recent years, in-cylinder injection engines that inject fuel directly into a combustion chamber have been put into practical use in order to achieve emission reduction and fuel efficiency improvement. In this type of engine, fuel is injected in the intake stroke to form a uniform mixture in the combustion chamber, and fuel is injected in the compression stroke, so that the mixture near the stoichiometric air-fuel ratio is around the spark plug. And the stratified combustion that achieves a super lean overall air-fuel ratio can be switched. The operating region in which stratified combustion is possible is generally limited to low rotation and low load. For example, in the engine described in Japanese Patent Application Laid-Open No. 10-30468, stratified combustion is executed by compression stroke injection from the start.
[0003]
[Problems to be solved by the invention]
As described above, the engine described in the publication performs stratified combustion at start-up in order to obtain the advantages of stratified combustion and fuel efficiency from the start-up. Therefore, the control procedure at the time of starting is the same as that of a normal engine. First, cylinder discrimination is performed by starting cranking, and when any cylinder reaches the compression stroke after completion of the cylinder discrimination, a predetermined process is performed for the cylinder. Fuel injection is executed with the injection amount and the injection timing.
[0004]
In other words, the engine described in the publication does not consider any shortening of the required start time, and cannot satisfy this demand. The engine start delay becomes a problem even when applied to a normal vehicle. However, particularly in a hybrid vehicle and an idle stop vehicle that have been put into practical use in recent years, there is a problem that the advantages cannot be fully utilized due to the start delay. For example, in a hybrid vehicle that also uses a motor as a power source, the engine is started to ensure output when accelerating from a low load run by the motor. It will get worse. Further, in an idle stop vehicle that automatically stops the engine by waiting for a signal or the like, there is a problem that the engine start delay is directly connected to the start delay.
[0005]
An object of the present invention is to provide a starter for a direct injection internal combustion engine that can quickly complete the start.
[0006]
[Means for Solving the Problems]
  To achieve the above objective,Claim 1In the invention, the cylinder located in the compression stroke of the stopped internal combustion engine is specified by the compression stroke cylinder discrimination means, and when the internal combustion engine is started, fuel is injected by the start control means for the remaining compression stroke of the specified cylinder. It is something to be executed. Accordingly, when cranking is started for start-up, fuel injection is immediately performed on the cylinders positioned in the compression stroke at that time, so that the initial explosion is quickly performed by subsequent ignition.
  According to a second aspect of the present invention, in the first aspect, the combustion prediction means predicts whether or not combustion is possible when fuel is injected for the remaining compression stroke of the compression stroke cylinder, and when it is predicted that combustion is impossible In addition, the start control means stops the fuel injection to the compression stroke cylinder. Therefore, it is possible to prevent a situation in which the fuel injection to the compression stroke cylinder is executed and the start-up fails in spite of the incombustibility.
  According to a third aspect of the present invention, in the second aspect, the combustion prediction means predicts whether or not combustion is possible based on at least one of the temperature of the internal combustion engine and the piston position of the compression stroke cylinder. Therefore, for example, the higher the temperature of the internal combustion engine and the lower the piston position, the more reliable the ignition of the compression stroke cylinder will be. Therefore, whether or not combustion is possible can be reliably predicted based on these requirements.
  According to a fourth aspect of the present invention, in the first to third aspects, the start control means has a fuel injection amount for the compression stroke cylinder based on at least one of the temperature of the internal combustion engine, the piston position of the compression stroke cylinder, and the property of the fuel used. And the injection timing. Accordingly, the in-cylinder air amount of the compression stroke cylinder is different according to the temperature of the internal combustion engine and the piston position, and the ignition characteristics are different according to the fuel properties.Therefore, the temperature of these internal combustion engines, the piston position of the compression stroke cylinder, Based on at least one of the properties of the fuel used, the optimum fuel injection amount and injection timing for the compression stroke cylinder can be determined.
  According to a fifth aspect of the present invention, in the first to fourth aspects, when the start of the internal combustion engine is not completed by fuel injection to the compression stroke cylinder, the cylinder following the compression stroke cylinder is regarded as the compression stroke cylinder, and the compression stroke cylinder In contrast, the fuel injection amount and the injection timing are determined to execute the fuel injection. Therefore, since the succeeding cylinder stays in the intake system of the internal combustion engine and the heated air is sucked and a considerably high in-cylinder temperature is secured, fuel injection is performed on the succeeding cylinder and started. Can be completed.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is embodied in a starter for a direct injection type engine used in an idle stop vehicle will be described.
In the overall configuration diagram of FIG. 1, reference numeral 1 denotes an in-cylinder injection gasoline engine, which is configured as a four-cycle in-line four cylinder that explodes at equal intervals every 180 ° CA, and a spark plug 2 is attached to each cylinder. At the same time, a fuel injection valve 3 is attached so that fuel can be directly injected into the combustion chamber. The combustion chamber and intake system of the engine 1 are designed exclusively for in-cylinder injection. When fuel is injected in the compression stroke, the injected fuel is transferred by the reverse tumble flow generated in the intake air, and the ignition plug 2 Layered combustion is possible in which an air-fuel mixture in the vicinity of the stoichiometric air-fuel ratio is formed around the fuel and combustion is performed at an ultra-lean total air-fuel ratio.
[0008]
A manual transmission 4 is connected to the engine 1, and this transmission is connected to driving wheels of the vehicle via a differential gear (not shown). A clutch 5 is provided between the engine 1 and the transmission 4, and this clutch 5 controls power transmission from the engine 1 side to the transmission 4 side in accordance with a clutch operation by the driver. The engine 1 is provided with a constantly meshing starter 6, and the pinion gear 6 a of the starter 6 is always in mesh with the flywheel 1 a of the engine 1. The flywheel 1a is provided with a one-way clutch (not shown). The one-way clutch transmits the driving force of the starter 6 to the engine 1 side at the time of start-up, performs cranking, and idles after the start-up is completed. Thus, the starter 6 is prevented from being reversely driven.
[0009]
The motor 11 of the starter 6 is connected to the battery 13 via the normally open relay contact 12a, and the relay coil 12b corresponding to the relay contact 12a is connected to the battery 13 via the ST contact 14a of the ignition switch 14. . Therefore, when the ignition switch 14 is operated to the position of the ST contact 14a, the relay contact 12a is closed by the excitation of the relay coil 12b, the motor 11 is energized, and the engine 1 is cranked by the starter 6. The relay coil 12b of the starter 6 is connected to the battery 13 via the relay contact 15a of the starter control controller 15 and the ON contact 14b of the ignition switch 14, and the relay coil 15b corresponding to the relay contact 15a is a battery. 13 is connected. Therefore, even when the ignition switch 14 is at the position of the ON contact 14b, when the relay contact 15a is closed by excitation of the relay coil 15b, the motor 11 is energized and cranking is performed.
[0010]
In the vehicle compartment, an input / output device (not shown), a storage device (ROM, RAM, BURAM, etc.) used for storing control programs and control maps, a central processing unit (CPU), an ECU 21 (engine) provided with a timer counter, etc. Control unit) is installed. On the input side of the ECU 21, an engine temperature sensor 22 that detects the temperature T of the engine 1, a crank angle sensor 23 that outputs a crank angle signal as the crankshaft of the engine 1 rotates, and a TOP signal that accompanies the rotation of the camshaft. A cam angle sensor 24 that outputs a vehicle speed, a vehicle speed sensor 25 that detects a vehicle speed V, a clutch sensor 26 that detects an operation state of the clutch 5, an accelerator sensor 27 that detects an accelerator operation amount Acc, and a shift that detects a shift position of the transmission 4. The position sensor 28 and other various switches and sensors are connected.
[0011]
Further, the ignition plug 2 and the fuel injection valve 3 are connected to the output side of the ECU 21, and the relay coil 15 b of the starter control controller 15 is connected. The ECU 21 executes various controls for operating the engine 1 including fuel injection control and ignition timing control based on each detection information described above, and executes an automatic stop start process of the engine 1 when the vehicle is stopped such as waiting for a signal. . Further, when the engine is started, the ECU 21 executes a start-only control to start early.
[0012]
In the in-cylinder injection engine 1 configured as described above, in addition to the uniform combustion in which fuel is injected in a normal intake stroke to form a uniform mixture in the combustion chamber, the fuel is injected in the compression stroke to be super It enables stratified combustion with a lean overall air-fuel ratio. The stratified combustion is generally executed in an operating region of low rotation and low load. The ECU 21 calculates the target average effective pressure Pe (representing the engine load) obtained from the accelerator operation amount Acc detected by the accelerator sensor 27, and the crank angle sensor 23. The compression stroke injection is executed in a region where the engine rotational speed Ne obtained from the crank angle signal of the engine is relatively low, the emission reduction and the fuel consumption improvement are achieved, and the intake stroke injection is executed in a region beyond that, which is required. Ensure engine torque.
[0013]
Next, an outline of the automatic stop start process of the engine 1 unique to the idle stop vehicle will be described.
The ECU 21 automatically stops the engine 1 when a preset engine stop condition is satisfied when the traveling vehicle stops due to a signal or the like, and also automatically starts the engine 2 when a preset engine start condition is satisfied. Therefore, emission emissions and fuel consumption while the vehicle is stopped are prevented. The engine stop condition is that the vehicle speed V detected by the vehicle speed sensor 25 is zero, the depression operation of the clutch 5 is not detected by the clutch sensor 26 (clutch engagement state), and the shift position sensor 28 When the detected shift position is set to the N (neutral) position and these conditions are satisfied, the ECU 21 determines that the engine stop condition is satisfied and stops the fuel injection control and the ignition timing control. Then, the engine 1 is stopped.
[0014]
As engine starting conditions, it is set that the clutch sensor 26 detects that the clutch 5 is depressed (clutch disengaged state), and that the shift position detected by the shift position sensor 28 is the N position. When these conditions are satisfied, the ECU 21 determines that the engine start condition is satisfied, excites the relay coil 15b of the starter control controller 15, and restarts the injection control and the ignition timing control. Since the relay contact 15a is closed by the excitation of the relay coil 15b, the motor 11 of the starter 6 is energized, cranking is performed, and the engine 1 is started to be able to start.
[0015]
The engine start and stop by a normal driver is the same as that of a general vehicle. When the ignition switch 14 is operated to the position of the ST contact 14a, the motor 11 of the starter 6 is energized and cranking is performed. At the same time, the fuel injection control and ignition timing control are started by the ECU 21 to start the engine 1, and when the ignition switch 14 is returned from the ON contact 14 b to an OFF contact (not shown) or the like during the operation of the engine 1, The injection control and the ignition timing control are stopped and the engine 1 is stopped.
[0016]
Regardless of the above automatic and manual operations, the ECU 21 stops the fuel injection control and the ignition timing control according to the engine stop routine of FIG.
The ECU 21 executes an engine stop routine every 180 ° CA in synchronization with the rotation of the engine 1, and first determines in step S2 whether or not the engine is stopped. If the determination is NO (no), that is, if the engine stop condition is not satisfied and the ignition switch 14 is not turned OFF by the driver, the injection command flag Ff is set in step S4, and the stop counter C is determined in step S6. Is reset, the ignition command flag Fi is set in step S8, and the routine is terminated. Based on the set of the injection command flag Ff and the ignition command flag Fi, the ECU 21 performs the fuel injection control and the ignition timing control, so that the operation of the engine 1 is continued.
[0017]
If the determination in step S2 is YES (affirmative), that is, if the engine stop condition is satisfied or the ignition switch 14 is turned off by the driver, the injection command flag Ff is cleared in step S10. In step S12, the stop counter C is incremented. Next, in step S14, it is determined whether or not the stop counter C has reached 3. If NO, the process proceeds to step S8. If the determination in step S14 is YES, the process proceeds to step S16, the ignition command flag Fi is cleared, and the routine is terminated.
[0018]
Accordingly, the fuel injection control is stopped when the injection command flag Ff is cleared in step S12, and after the two strokes have elapsed in the operation cycle of the engine 1 and the stop counter C reaches 3, the ignition is performed in step S16. The command flag Fi is cleared and the ignition timing control is stopped. The fuel injected in the compression stroke is ignited within one stroke, and even the fuel injected in the earlier intake stroke is ignited within two strokes. Therefore, the fuel of the cylinder injected last is also sure. As a result, inconvenience due to the liquefied fuel remaining in the combustion chamber, for example, sparking of the spark plug 2 at restart, discharge of unburned gas, and the like are prevented.
[0019]
Next, the start control executed by the starter of the direct injection type engine 1 configured as described above will be described.
The ECU 21 starts the engine shown in FIGS. 3 and 4 when a start condition is satisfied during engine automatic stop such as waiting for a signal or when the ignition switch 14 is ST-operated by the driver and cranking is started. Run the routine. First, the ECU 21 reads, from the storage device, information on a cylinder (hereinafter referred to as a compression stroke cylinder) in the compression stroke of the engine 1 stopped in step S22 and information on the piston position P of the cylinder.
[0020]
These pieces of information are calculated based on the crank angle signal detected by the crank angle sensor 23 immediately before the engine is stopped and the TOP signal detected by the cam angle sensor 24, and of course during the automatic engine stop. That is, even when the ignition switch 14 is turned off, it is kept in the storage device. In this embodiment, the crank angle sensor 23, the cam angle sensor 24, and the ECU 21 for executing the processing of step S22 function as a compression stroke cylinder discrimination means.
[0021]
Here, in the four-cycle in-line four cylinders, one of the cylinders is always located in the compression stroke, and at this time, the compression stroke cylinder is always specified. Further, the crank angle when the engine is stopped is concentrated around BTDC 90 ° CA. This is because in the in-line four-cylinder engine of the present embodiment, any cylinder reaches the compression top dead center every 180 ° CA, so that even if it stops in the vicinity of the compression top dead center, it reverses in response to the compression reaction force. It is.
[0022]
Next, the ECU 21 reads the engine temperature T detected by the engine temperature sensor 22 in step S24, and reads the knock learning value Kk in step S26. The knock learning value Kk is a learning value for setting the basic ignition timing to an optimum value immediately before knocking. That is, as is well known, in the knock control, the ignition timing is feedback controlled immediately before knocking based on the knock retard amount set from the detection of the knock sensor, but the knock learning value Kk is appropriately set based on the knock retard amount used at this time. By learning and correcting the basic ignition timing in advance with the knock learning value Kk, the control delay due to feedback is eliminated. That is, the knock learning value Kk is a value corresponding to the occurrence of knocking of the engine 1, and if the same engine is used, the occurrence of knocking differs depending on the octane number (regular or high-octane) of the gasoline used. Therefore, the knock learning value Kk can be regarded as an index representing the octane number of the gasoline used.
[0023]
Next, the ECU 21 determines in step S28 whether or not the knock learning value Kk is greater than the preset map switching determination value K0. If YES, the ECU 21 regards the gasoline being used as high-octet, and in step S30, FIG. Select the high-octane map shown in. Further, when the determination in step S28 is NO, it is considered that the gasoline being used is regular, and the regular map shown in FIG. 6 is selected in step S32.
[0024]
  Further, according to the selected map, it is determined in step S34 whether or not the early start control can be executed.In the present embodiment, the ECU 21 when executing the process of step S34 functions as a combustion prediction unit.That is, as described below, the early start control is a process in which the initial explosion is immediately performed by injecting and igniting the fuel to the compression stroke cylinder. In order to realize this, the temperature for vaporizing the fuel is used. And the pressure for successful ignition, for example, when the in-cylinder temperature at the time of starting is low, or the piston position P can hardly be compressed near the top dead center and the temperature rise due to compression cannot be expected The first explosion cannot be obtained due to misfire.
[0025]
Therefore, in the maps of FIGS. 5 and 6, the ignition possible region is set based on the engine temperature T correlated with the in-cylinder temperature and the piston position P. As is clear from the figure, the higher the engine temperature T and the lower the piston position P, the higher the probability of entering the ignitable region and the more reliable the ignition. Further, as is well known, regular gasoline is more easily ignited than high-octane gasoline, so that the regular ignition map has a larger ignitable region.
[0026]
The determination of the early start control in the step S34 is made based on whether or not the ignition is possible from these maps. Here, when the engine 1 is automatically stopped by waiting for a signal or the like, the temperature of the engine itself has increased due to the operation immediately before, so that the in-cylinder temperature has sufficiently increased due to heat transfer from the cylinder wall surface. As described above, since the crank angle when the engine is stopped is positioned around BTDC 90 ° CA with a high probability, it is held at a low piston position P. Therefore, in most cases, the determination in step S34 is YES, assuming that the region falls within the ignitable region.
[0027]
When the determination in step S34 is NO, the start mode is set as normal start control in step S36, the fuel injection amount is determined based on the cooling water temperature or the like of the engine 1 in step S38, and similarly based on the cooling water temperature or the like in step S40. The injection timing is determined, the ignition timing is set in step S42, and the start control is executed in step S44 based on these pieces of information. At this time, cranking is started in the case of automatic start (not necessary because cranking has already been started in the case of start by the driver's ST operation), and the intake stroke is first reached after cranking. Fuel injection and ignition are performed on the cylinder.
[0028]
Next, in step S46, it is determined whether or not the engine speed Ne is equal to or higher than a preset complete explosion determination value N0. When the determination is NO, it is considered that the engine has not yet been started, and the process returns to step S34 to repeat the process. If this determination is YES, this routine is terminated. After that, the routine shifts to normal engine control and selects compression stroke injection or intake stroke injection based on the target average effective pressure Pe and the engine rotational speed Ne. For example, when the idle operation is continued, the compression stroke injection is performed. In the case of rapid acceleration, the intake stroke injection is set, and control is performed by determining the fuel injection amount, injection timing, and ignition timing according to each operation state.
[0029]
If the determination in step S34 is YES, the start mode is set as early start control in step S48, the fuel injection amount is determined in step S50, the injection timing is determined in step S52, and the ignition timing is determined in step S54. Based on these pieces of information, start control is executed for the compression stroke cylinder in step S44. The fuel injection amount, injection timing, and ignition timing at this time are different from those in the normal start control described above, and are determined as follows.
[0030]
Since the in-cylinder air amount of the compression stroke cylinder differs according to the piston position P and the in-cylinder temperature, the fuel injection amount is an optimum value from a map (not shown) set in advance according to the piston position P and the engine temperature T. Ask for. Similarly, the optimum value for the injection timing is determined according to the piston position P and the engine temperature T. These maps are set for high-octane and regular, and an application map is selected according to the determination result in step S28. Note that the fuel injection amount and the injection timing may be obtained from a common map without changing the map according to the octane number.
[0031]
Here, the relationship between the fuel injection amount and the injection timing can be expressed as shown in FIG. 7 for high-octane gasoline and as shown in FIG. 8 for regular gasoline, and the optimum value ( As described above, depending on the in-cylinder air amount, it can be seen that the injection timing is easier to ignite near the bottom dead center. On the other hand, since ignition is performed immediately after the start of cranking as described above, the ignition timing is set to an optimum value that can effectively convert the initial explosion into the rotation of the engine 1, unlike the normal start control.
[0032]
If the determination in step S46 is YES, this routine is terminated and the routine shifts to normal engine control. Further, when the determination in step S46 is NO and the start is not completed, the processes in step S34, step S48 to step S54, and step S44 are repeated, and the subsequent cylinders of the cylinders subjected to the initial explosion as described above are performed. The same control is executed. However, at this time, since cranking has already started and compression is performed from the bottom dead center, the piston position P is set as the bottom dead center. Further, since the air that stays in the intake system of the engine 1 and is heated is sucked into the succeeding cylinder, a considerably high in-cylinder temperature is secured as in the first compression stroke cylinder. Accordingly, with respect to this subsequent cylinder, the determination of YES is made in step S34 with a high probability, the early start control is executed, and the rotation of the engine 1 is increased by the combustion.
[0033]
Even if the start-up is not completed due to the combustion of the subsequent cylinder (NO in step S46), the intake air of several cylinders remains in the intake system of the engine 1, and therefore the subsequent cylinders Early start control is performed under a higher in-cylinder temperature, and in most cases, the start is completed within a few strokes. If the starting is not completed yet, the determination in step S34 is NO due to a decrease in the in-cylinder temperature, etc., so the routine is automatically switched to the normal starting control in step S36 and subsequent attempts. In this embodiment, the ECU 21 when executing the processes of steps S44 and S48 to S54 described above functions as a start control unit.
[0034]
Next, the execution status of the early start control detailed above will be described with reference to the time chart of FIG.
When cranking is started in a state where the compression stroke cylinder is positioned at a certain crank angle, fuel injection is performed immediately after that, and ignition is performed immediately after the compression top dead center is passed. When ignition is successful and the first explosion is performed, the engine rotation speed Ne increases as the in-cylinder pressure increases, and when the value reaches the complete explosion determination value N0, the determination of completion of start is made. In this case, the start can be completed in an extremely short time of approximately 65 ° CA after the cranking start and a required time of approximately 140 msec. Further, when the start is not completed due to the first explosion, a similar start process is executed for the subsequent cylinders. Even in this case, the start can be completed in a required time of about 2 or 3 times.
[0035]
As is clear from the above description, in the starting device for the engine 1 of the present embodiment, fuel injection and ignition are immediately performed on the compression stroke cylinder of the stopped engine, so that the initial explosion is quickly started. Can be made. That is, as in the prior art, cylinder determination is performed by starting cranking, and compared with a case where fuel injection and ignition are started when one of the cylinders reaches the intake stroke or compression stroke after completion of the cylinder determination, The time required for starting can be drastically reduced. Therefore, of course, in the case of starting by the driver's operation, even when the engine 1 stopped by waiting for a signal or the like is automatically started, the starting can be completed almost instantly and the vehicle can be started quickly, and as a result The commercial value of the stop vehicle can be improved.
[0036]
In addition, the map (Figs. 5 and 6) is selected according to the octane number of the gasoline used, and the ignitable region is determined and the fuel injection amount and the injection timing are determined according to the map, so the octane number of the gasoline used is assumed. As much as possible, the opportunity for early start control is increased as much as possible, and the initial explosion can be reliably obtained by optimizing the fuel injection amount and injection timing in early start control, and as a result, the advantages of early start control are maximized. Can be made.
[0037]
By the way, due to the stop characteristic of the engine 1 as described above, the piston position P of the compression stroke cylinder is held at a low position suitable for the execution of the early start control with a high probability. There is a case where it stops at an inappropriate piston position P near the top dead center. Therefore, a process of correcting the piston position P to a suitable position using the constant mesh starter 6 may be added. This correction process is performed in advance when the engine is stopped because it will lead to a delay in starting if it is performed after the start of cranking.
[0038]
For example, when the piston position P is too high when the engine 1 is stopped by the engine stop routine of FIG. 2, the crank angle is moved to the optimum piston position P by operating the starter 6. As the piston position P at this time, for example, the vicinity of the bottom dead center where complete explosion is possible even if the in-cylinder temperature is low is set. Since the drive direction of the starter 6 is limited to normal rotation, the engine 1 is moved in the normal rotation direction and the subsequent cylinder becomes the compression stroke cylinder. With the configuration described above, cranking can always be started from the optimum piston position P. Therefore, it is determined that the ignition is possible even at a lower in-cylinder temperature, and the opportunity for executing the early start processing is greatly increased. be able to.
[0039]
This is the end of the description of the embodiment. However, the embodiment of the present invention is not limited to this embodiment. For example, in the above embodiment, the starter of the in-cylinder injection type engine 1 used for the idle stop vehicle is embodied. It may be embodied as an engine starting device. Even in this case, the startability can be improved in a normal vehicle, and in addition to that, in the hybrid vehicle, the engine can be started quickly at the time of acceleration or the like, and good acceleration response can be realized.
[0040]
In the above embodiment, the in-cylinder in-cylinder gasoline engine 1 is embodied as an in-line four-cylinder engine. However, the cylinder arrangement is not limited to this, and if the number of cylinders is four or more, the engine is compressed when the engine is stopped. Since there is always a cylinder located in the stroke, the same effects as in the embodiment can be achieved if the early start control is executed for the cylinder. Note that, for example, in an engine in which two cylinders are located in the compression stroke when stopped, such as a V-type eight cylinder, early start control may be executed for a cylinder having a lower piston position P. In a three-cylinder engine or the like, there may be a stop state in which there is no cylinder located in the compression stroke. In this case, normal start control is executed, and early start control is performed only when the cylinder stops in the compression stroke. Or the piston position may be moved by the starter 6 as described above.
[0041]
Further, in the above embodiment, the early start control is executed after determining whether or not the ignition is possible based on the engine temperature T and the piston position P. However, this determination is not necessarily performed. On the other hand, the early start control is executed unconditionally, and when the start is not started, the control may be switched to the normal start control.
[0042]
【The invention's effect】
As described above, according to the starter of the direct injection internal combustion engine of the present invention, the fuel injection is immediately performed on the cylinder located in the compression stroke at the time when the cranking is started for the start. Therefore, the first explosion is performed by the subsequent ignition, and the start can be completed promptly.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram illustrating a starter for a direct injection type engine according to an embodiment.
FIG. 2 is a flowchart showing an engine stop routine executed by an ECU.
FIG. 3 is a flowchart showing an engine start routine executed by an ECU.
FIG. 4 is a flowchart showing an engine start routine executed by an ECU.
FIG. 5 is an explanatory diagram showing a high-octane map for determining an ignitable region.
FIG. 6 is an explanatory diagram showing a regular map for determining an ignitable region.
FIG. 7 is an explanatory diagram showing the influence of the injection amount and the injection timing on the ignition possible region at the time of high-octane.
FIG. 8 is an explanatory diagram showing the influence of the injection amount and the injection timing on the ignitable region at the regular time.
FIG. 9 is a time chart showing an execution state of early start control.
[Explanation of symbols]
1 engine (internal combustion engine)
21 ECU (starting control means, compression stroke cylinder discrimination means)
23 Crank angle sensor (compression stroke cylinder discrimination means)
24 cam angle sensor (compression cylinder discrimination means)

Claims (5)

Compression stroke cylinder discrimination means for identifying a cylinder located in the compression stroke of the internal combustion engine being stopped;
In-cylinder injection type internal combustion engine comprising: start control means for executing fuel injection for the remaining compression stroke of the cylinder specified by the compression stroke cylinder discrimination means when the internal combustion engine is started Starting device. Combustion predicting means for predicting whether or not combustion is possible when fuel is injected for the remaining compression stroke of the compression stroke cylinder, and when the combustion predicting means predicts that combustion is impossible, the start control means 2. The starter for a direct injection internal combustion engine according to claim 1, wherein the fuel injection to the compression stroke cylinder is stopped. 3. The direct injection internal combustion engine according to claim 2, wherein the combustion predicting means predicts whether combustion is possible based on at least one of a temperature of the internal combustion engine and a piston position of the compression stroke cylinder. Starting device. The start control means determines a fuel injection amount and an injection timing for the compression stroke cylinder based on at least one of the temperature of the internal combustion engine, the piston position of the compression stroke cylinder, and the property of the fuel used. A starter for a direct injection internal combustion engine according to any one of claims 1 to 3. When the start of the internal combustion engine is not completed due to fuel injection into the compression stroke cylinder, the cylinder following the compression stroke cylinder is regarded as a compression stroke cylinder, and the fuel injection amount and injection timing are set to the compression stroke cylinder. 5. The starter for a direct injection type internal combustion engine according to claim 1, wherein the fuel injection is performed after being determined.

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