JP2000240489A - Fuel injection control device for internal combustion engine and fuel injection control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection control device and a fuel injection control method to perform excellent starting of an internal combustion engine. SOLUTION: A discrimination period G to discriminate a cylinder is set in correspondence to a crank pulse generated occasioned by rotation of a crank shaft. Each time a cam shaft performs one full turn, first - third can pulses CP1-CP3 are generated. When the crank shaft is in the discrimination period G, a cylinder is discriminated based on whether or not the first can pulse CP1 is generated. Even when, in the starting of an internal combustion engine, it is before discrimination of a cylinder, simultaneous fuel injection is made on all cylinders #1-#4 at a detecting timing of a first cam pulse. Thereby, a time elapsing from cranking to first ignition is shortened and an internal combustion engine is caused to effect excellent starting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fuel injection control device and a fuel injection control method for a multi-cylinder internal combustion engine, and more particularly to a technique for satisfactorily starting an internal combustion engine.

[0002]

2. Description of the Related Art In a general multi-cylinder internal combustion engine, a piston reciprocally housed in each cylinder is connected to a crankshaft via a connecting rod. As the piston reciprocates, the crankshaft and the camshaft operatively connected to the crankshaft rotate. Accordingly, the determination of the stroke position of the piston in each cylinder, that is, the determination of the cylinder can be performed by detecting the rotational position (crank angle) of the crankshaft. Various controls including ignition timing control and fuel injection timing control in the internal combustion engine are executed based on detection of a crank angle (expressed in ° CA).

The ratio between the rotation angle of the crankshaft and the rotation angle of the camshaft is set to 2: 1.
During two revolutions of the crankshaft, each cylinder executes one engine cycle including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke. Therefore, the rotation position of the crankshaft is represented by a rotation angle corresponding to two rotations of the shaft as one cycle.

[0004] In order to detect the rotational position of the crankshaft, a device as shown in FIG. 17 has been conventionally known. As shown in FIGS. 17 (a) and 17 (b),
In this conventional device, a crankshaft 507 of an internal combustion engine is used.
And a cam angle sensor 502 provided on a camshaft 508 of the internal combustion engine.

As shown in FIG. 17A, a crank angle sensor 501 includes a crank rotor 503 that rotates integrally with a crankshaft 507,
Crank pulse generator 50 disposed opposite to the outer peripheral surface of the crankshaft 3
And 4. The crank rotor 503 has a plurality of protrusions 503a provided at every 10 ° CA on the outer peripheral surface thereof. Further, the crank rotor 503 has a 30 ° CA formed by lacking two protrusions on its outer peripheral surface.
It has toothless portions 503b at intervals. Crankshaft 50
7, the projection 503a on the crank rotor 503 with the rotation of
Each time passes through the position facing the crank pulse generator 504, the crank pulse generator 504 generates a crank pulse as shown in FIG. When the toothless portion 503b passes through a position facing the crank pulse generator 504, the interval between the crank pulses becomes 30 ° CA.

As shown in FIG. 17B, the cam angle sensor 502 includes a cam rotor 505 that rotates integrally with a cam shaft 508, and a cam pulse generator 506 that is disposed on the outer peripheral surface of the cam rotor 505. . The cam rotor 505 has one protrusion 505a on its outer peripheral surface. The camshaft 508 makes one rotation while the crankshaft 507 makes two rotations, and the protrusion 5 on the cam rotor 505
Each time 05a passes a position facing the cam pulse generator 506, the cam pulse generator 506 generates a cam pulse as shown in FIG.

As shown in FIG. 18, a predetermined period from the generation of a crank pulse having a 30 ° CA interval is set as a determination period G for performing cylinder determination. The cam pulse is generated in synchronization with one of two discrimination periods G appearing during two rotations of the crank rotor 503.
The timing chart of FIG. 18 illustrates an example of an in-line four-cylinder internal combustion engine including first to fourth cylinders # 1 to # 4. In FIG. 18, a hatched area mainly corresponding to the intake stroke of each of the cylinders # 1 to # 4 indicates an opening period of the intake valve.

In the conventional apparatus, the discrimination period G
The rotational position of the crankshaft 507 is specified, that is, the cylinder is determined based on whether or not a cam pulse is generated during the operation.
Specifically, for example, as shown in FIG. 18, when a cam pulse is generated during the discrimination period G, the cam pulse is generated at a timing after the crank pulse corresponding to the end time of the discrimination period G by a predetermined number of crank pulses. It is determined that one cylinder # 1 is at the top dead center in the compression stroke (abbreviated simply as TDC in the drawing). If no cam pulse is generated during the discrimination period G, the fourth cylinder # 4 is set to the compression top dead center at the generation timing of the crank pulse that is a predetermined number after the crank pulse corresponding to the end time of the discrimination period G. It is determined that it becomes.

Therefore, when the cranking is performed to start the internal combustion engine, if the cylinder discrimination is completed as described above, thereafter, the crank angle is sequentially obtained based on the crank pulse and the cam pulse. it can. Therefore, fuel injection and ignition for each cylinder are appropriately controlled in accordance with the crank angle, and it is possible to shift to normal operation of the internal combustion engine.

[0010]

However, in the above-described conventional apparatus, if the internal combustion engine stops immediately after the toothless portion 503b has passed the position facing the crank pulse generator 504, the next internal combustion engine is stopped. At the time of starting, unless the crankshaft 507 is rotated about one revolution by cranking, the detection of the missing tooth portion 503b and the setting of the discrimination period G associated therewith cannot be performed. That is, the cylinder discrimination cannot be performed until the crankshaft 507 is rotated substantially one revolution by cranking. Therefore, the internal combustion engine cannot be shifted from the cranking to the normal operation state in a short time, and the internal combustion engine cannot be started satisfactorily.

In particular, in a sequential injection type internal combustion engine, fuel is sequentially and independently injected into each cylinder. Therefore, unless the cylinder discrimination is completed, fuel cannot be injected into each cylinder at an appropriate timing. However, if the fuel injection is started after the cylinder discrimination is completed, more time is required until ignition is performed on the cylinder on which the fuel injection has been performed.

Therefore, for example, a technique of injecting fuel into all cylinders before the completion of the cylinder discrimination and starting fuel injection and ignition at a normal timing for each cylinder after the cylinder discrimination has been known. Have been. However, depending on the fuel injection timing, the fuel introduced into the cylinder may be discharged as unburned gas before the ignition based on the cylinder determination is started.

In the conventional apparatus shown in FIG. 17, for example, as shown in FIG.
At the detection timings t51 and t53 of 3b, it is conceivable to inject fuel to all the cylinders # 1 to # 4. For example, at timing t51, all cylinders # 1 to # 4
In the case where the fuel injection is performed for the cylinder t, the cylinder determination is performed in the subsequent determination period G, and then the timing t
At 52, the first ignition can be performed on the third cylinder # 3 which is the compression top dead center. Similarly, the timing t
When fuel injection is performed on all cylinders # 1 to # 4 in 53, after the cylinder determination is performed in the subsequent determination period G, the second cylinder that becomes the compression top dead center at timing t54 The first ignition can be performed for # 2.

With this configuration, the ignition can be started earlier than in the case where the fuel injection is started after the cylinder discrimination, so that the startability of the internal combustion engine is improved. Moreover, the missing tooth portion 5
Since the fuel injected at the detection timings t51 and t53 of 03b is used for combustion in all cylinders # 1 to # 4, there is no emission of unburned gas.

However, even in this case, if the internal combustion engine is stopped immediately after the toothless portion 503b has passed the position facing the crank pulse generator 504, the crankshaft 507 is required at the next start of the internal combustion engine. All cylinder injection based on the detection of the toothless portion 503b cannot be performed until the rotation of the cylinder is made approximately one rotation. Therefore, in such a case, the time from cranking to the first ignition cannot be sufficiently reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a fuel injection control device and a fuel injection control method capable of satisfactorily starting an internal combustion engine.

[0017]

In order to achieve the above object, the present invention provides a piston housed in a plurality of cylinders, a crankshaft that rotates with reciprocating motion of the piston, and a crankshaft that rotates twice. A camshaft that makes one rotation each time the engine rotates, and wherein the piston reciprocates twice so that each piston executes one engine cycle while the crankshaft makes two rotations. A crank angle sensor for generating a crank signal indicating the rotation angle of the crankshaft; setting means for setting a specific discrimination angle range with respect to the crankshaft based on the crank signal; A plurality of cam signals including a discriminating cam signal for cylinder discrimination and an auxiliary cam signal corresponding to the rotation angles of A cam angle sensor that generates a discriminating cam signal in synchronization with one of two discriminating angle ranges that appear during two revolutions of the crankshaft, and assists at a timing that is not synchronized with the discriminating angle range. A cam angle sensor for generating a cam signal, cylinder discriminating means for discriminating a cylinder based on whether or not a discriminating cam signal is generated when the crankshaft is within the discrimination angle range, and injecting fuel to each cylinder, respectively. A fuel injection means for performing a fuel injection to a specific cylinder based on a timing of generating a cam signal when starting the internal combustion engine.
A fuel injection control device for an internal combustion engine, comprising: a control unit that controls the fuel injection unit.

According to the above configuration, when cranking is performed to start the internal combustion engine, fuel is injected into a specific cylinder based on the timing of the generation of the cam signal. Therefore, when the cam signal is generated before the cylinder discrimination, the fuel injection can be performed on a specific cylinder before the cylinder discrimination. Therefore, if the setting of the discrimination angle range and the cylinder discrimination based on the setting of the discrimination angle range are completed after the generation of the cam signal, it is possible to start the ignition as short as possible after the cylinder discrimination. Therefore, the time from cranking to the first ignition can be shortened, and the internal combustion engine can be started well.

In one embodiment of the present invention, an intake valve is provided for each cylinder, and when the intake valve is opened, a mixture of injected fuel and air is introduced into the corresponding cylinder. . The cam angle sensor is configured to generate a cam signal at a timing excluding the latter half of the opening period of the intake valve corresponding to the specific cylinder.

When fuel is injected in the latter half of the opening period of the intake valve, the injected fuel is not sufficiently supplied into the cylinder. Therefore, even if ignition is performed, the air-fuel mixture in the cylinder does not burn and unburned gas And may be discharged from the cylinder.
However, in the present invention, since the timing of generating the cam signal is set to a timing excluding the latter half of the opening period of the intake valve, even if fuel injection is performed at the timing of generating the cam signal, unburned gas may be discharged. There is no.

The above-described cam angle sensor preferably includes a cam rotor that rotates integrally with the cam shaft, and a cam signal generator that is arranged to face the cam rotor. The cam rotor has a discrimination index and an auxiliary index for cylinder discrimination provided at predetermined intervals along the rotation direction of the rotor. The cam signal generator generates a discrimination cam signal and an auxiliary cam signal corresponding to the discrimination index and the auxiliary index when the cam rotor rotates.

As described above, it is only necessary to provide another auxiliary index on the cam rotor in addition to the index used for cylinder identification, so that the structure is simple. In a preferred embodiment of the present invention, the cam rotor has two auxiliary indicators. In this case, the cam signal generator generates two auxiliary cam signals corresponding to both auxiliary indices during one rotation of the cam rotor. One auxiliary cam signal is generated after the discrimination angle range accompanied by generation of the discrimination cam signal and before the next discrimination angle range appears. The other auxiliary cam signal is generated after the discrimination angle range without the generation of the discrimination cam signal passes and before the next discrimination angle range appears.

With this configuration, the chances of executing the fuel injection based on the generation of the cam signal before the cylinder discrimination are increased as compared with the case where there is only one auxiliary index, for example. Therefore, the time from cranking to the first ignition can be more reliably shortened.

Further, the crank signal may include information indicating that the crankshaft is at a specific rotation angle. In this case, the setting means recognizes, based on the crank signal, that the crankshaft is at a specific rotation angle, and sets an angle range from that time until the crankshaft rotates by a predetermined angle as the determination angle range.

In this manner, the discrimination angle range is set accurately and reliably based on the specific rotation angle of the crankshaft. Further, when starting the internal combustion engine, if the cylinder discriminating means confirms twice the generation of the cam signal before the discriminating angle range is set, the cylinder discriminating means determines whether or not the crankshaft is disposed at the specific rotation angle thereafter. Is used to determine the cylinder.

That is, between the time when the crankshaft makes one rotation from a specific rotation angle and the time when it reaches the next specific rotation angle, the discrimination cam signal and one auxiliary cam signal are generated, and the other auxiliary cam signal is generated. Two patterns appear: a case where only a signal is generated. On the other hand, when cranking is performed from a state where the crankshaft is slightly past a specific rotation angle, even if the crankshaft is actually in the discrimination angle range immediately after the cranking, it is determined that the crankshaft is in the discrimination angle range. Not set as In such a case, before the crankshaft is arranged at a specific rotation angle, two cam signals, that is, a discrimination cam signal and one auxiliary cam signal, may be generated. Therefore, in this case, the cylinder can be determined at a point in time when the crankshaft is arranged at a specific rotation angle without waiting for the setting of the determination angle range. This further shortens the time from cranking to the first ignition as compared with the case where cylinder determination is performed after waiting for the setting of the determination angle range, thereby enabling a better start of the internal combustion engine.

When the internal combustion engine is an in-line four-cylinder engine, the control means operates such that fuel is injected to all cylinders in synchronization with the first cam signal generation timing.
And controlling the fuel injection means.

In this way, it is possible to immediately ignite the cylinder which first becomes the compression top dead center after the cylinder discrimination, and it is possible to perform a better start. The present invention also provides a fuel injection control method for an internal combustion engine. This method includes a step of setting a specific determination angle range with respect to the crankshaft, and a determination cam signal for cylinder determination and a cylinder determination determination signal corresponding to a predetermined rotation angle of the camshaft each time the camshaft makes one rotation. Generating a plurality of cam signals including an auxiliary cam signal, wherein the determination cam signal is generated in synchronization with one of two determination angle ranges appearing during two rotations of the crankshaft; Generating an auxiliary cam signal at a timing not synchronized with the angle range, and determining a cylinder based on whether or not a determination cam signal has been generated when the crankshaft is in the determination angle range;
A step of injecting fuel into a specific cylinder based on a timing of generating a cam signal when starting the internal combustion engine.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment in which the present invention is embodied in an in-line four-cylinder four-cycle internal combustion engine will be described below with reference to FIGS.

As shown in FIG. 1, the cylinder block 11 of the internal combustion engine 10 has four cylinders 12. These cylinders 12 include first to fourth cylinders # 1 to # 4 arranged in order.
including. FIG. 1 shows only the first cylinder # 1. A piston 13 is accommodated in each cylinder 12 so as to be able to reciprocate. Each piston 13 is connected to a crankshaft 15 via a connecting rod 14. Piston 1
The reciprocating motion of No. 3 is converted into a rotary motion of the crankshaft 15 by the connecting rod 14. The rotational position of the crankshaft 15 is determined by the crank angle (° CA).
It is represented by The cylinder head 17 is the cylinder block 1
1 is fixed to the upper part. The piston 13 and the cylinder head 17 define a combustion chamber 18 in each cylinder 12.

The intake camshaft 20 and the exhaust camshaft 21 are rotatably supported by the cylinder head 17. The intake valve 23 and the exhaust valve 24 are reciprocally supported by the cylinder head 17 so as to correspond to the respective cylinders 12. Intake port 26 and exhaust port 2
7 are formed on the cylinder head 17 so as to correspond to the respective cylinders 12.

The camshafts 20 and 21 are drivingly connected to the crankshaft 15 by a timing belt 22. While the crankshaft 15 makes two rotations, both camshafts 20 and 21 make one rotation. Both camshafts 20,
21 rotates, the intake valve 23 and the exhaust valve 2
4 are driven by the corresponding camshafts 20 and 21, respectively. With the operation of these valves 23 and 24,
The intake port 26 and the exhaust port 27 are opened and closed at a predetermined timing.

Between the intake camshaft 20 and the timing belt 22, there is provided a variable valve timing mechanism (hereinafter referred to as VVT) for changing the opening / closing timing of the intake valve 23.
30) is provided. The VVT 30 operates to change the rotation phase of the intake camshaft 20 with respect to the crankshaft 15 to change the opening / closing timing of the intake valve 23. The VVT 30 is controlled by an electronic control unit (hereinafter abbreviated as ECU) 40 including a computer and the like, which will be described later.

An injector 53 constituted by an electromagnetic valve functions as a fuel injection means, and is provided in the intake port 26 so as to correspond to each cylinder 12. Each injector 5
3 injects fuel into the corresponding intake port 26. The fuel injection timing and injection amount are adjusted by controlling the opening timing and closing timing of the injector 53 by the ECU 40. In this embodiment, a sequential injection system in which fuel is sequentially injected into the four cylinders 12 is employed. Of course, other injection methods can be employed.

The ignition plugs 50 are mounted on the cylinder head 17 so as to correspond to the respective cylinders 12. Each ignition plug 50 is electrically connected to an ignition coil 51, respectively. The ignition plug 50 ignites a mixture of fuel and air supplied from the intake port 26 to the combustion chamber 18 based on the high voltage supplied from the ignition coil 51, and burns the mixture.
When the high voltage occurs in the ignition coil 51,
That is, the ignition timing of the ignition plug 50 is adjusted by controlling the igniter 52 by the ECU 40.

As shown in FIG.
During the two rotations, one engine cycle including the intake stroke, the compression stroke, the expansion stroke, and the exhaust stroke is executed in each of the cylinders # 1 to # 4. Therefore, the rotation position of the crankshaft 15 is represented by a rotation angle corresponding to two rotations of the shaft 15, that is, 0 ° CA to 720 ° CA as one cycle.

Further, in the internal combustion engine 10 of the present embodiment, as shown in FIG.
Every time it rotates, the piston 13 in the first cylinder # 1, the piston 13 in the third cylinder # 3, and the piston 1 in the fourth cylinder # 4
3. The pistons 13 in the second cylinder # 2 are sequentially arranged at the top dead center (abbreviated as TDC in the drawing) in the compression stroke. In other words, the piston 13 in each cylinder 12
Reciprocates in the order of the first cylinder # 1, the third cylinder # 3, the fourth cylinder # 4, and the second cylinder # 2 with a phase shift of 180 ° CA. Therefore, by determining the rotational position of the crankshaft 15 in the angle range of 0 ° CA to 720 ° CA, the stroke position of the piston 13 in each cylinder 12 can be determined, in other words, the cylinder can be determined.

In FIG. 5, a hatched area mainly corresponding to the intake stroke of each of the cylinders # 1 to # 4 indicates an opening period of the intake valve 23. The mixture of fuel and air injected into the intake port 26 is generated by opening the intake valve 23.
It is introduced into the corresponding cylinder 12. However, in the latter half of the opening period, more specifically, 120 ° C from the top dead center in the intake stroke
120 ° from top dead center in compression stroke from time after A
The period up to the time before CA is set as the injection prohibition period E. When fuel injection is performed during the injection prohibition period E,
The injected fuel may not be sufficiently supplied into the cylinder 12, and the air-fuel mixture may not burn in the cylinder 12 even if ignition is performed. In such a case, the air-fuel mixture in the cylinder 12 is discharged as unburned gas. Therefore, it is not preferable to perform the fuel injection during the injection prohibition period E.

As shown in FIG.
Is fixed to the crankshaft 15 so as to rotate integrally with the crankshaft 15. The crank pulse generator 55 is attached to the cylinder block 11 so as to face the outer peripheral surface of the crank rotor 54. The crank rotor 54 and the crank pulse generator 55 are provided with a crank angle sensor 56.
Is configured.

The crank angle sensor 56 will be described in detail with reference to FIG. On the outer peripheral surface of the crank rotor 54, a number of protrusions 54a are provided as indices. 34 projections 54a are provided on the outer peripheral surface of the crank rotor 54 at equal angular intervals (10 ° CA in the present embodiment). However, at only one location on the outer peripheral surface of the crank rotor 54, the interval between two adjacent projections 54a is 30 ° CA.
It has become. Therefore, the crank rotor 54 shown in FIG.
Has a shape obtained by removing two consecutive projections from a crank rotor having 36 projections at equal angular intervals. A portion corresponding to the portion from which these two protrusions have been deleted is defined as a specific portion on the crank rotor 54 by a toothless portion 54b.
That.

As the crank rotor 54 rotates, each projection 5
Each time 4a passes through a position facing the crank pulse generator 55, the crank pulse generator 55 generates one pulse signal (crank pulse). As the crank pulse generator 55, a semiconductor sensor, for example, a magnetic sensor such as a Hall element and a magnetoresistive element, and various optical sensors can be used. Further, an electromagnetic pickup coil can be used as the crank pulse generator 55. The crank rotor 54 is adapted so that a pulse can be induced in the applied crank pulse generator 55,
The material or shape is determined. Therefore, on the crank rotor 54, the applied crank pulse generator 5
Indices other than the protrusion 54a, for example, a concave portion or a hole may be provided according to the type of the five.

As shown in FIG. 1, the cam rotor 60 is rotated so as to rotate integrally with the intake camshaft 20.
Fixed to The cam pulse generator 61 includes the cam rotor 6
0 is attached to the cylinder head 17 so as to face the outer peripheral surface of the cylinder head 17. Cam rotor 60 and cam pulse generator 6
Reference numeral 1 denotes a cam angle sensor 62.

The above-described cam angle sensor 62 will be described in detail with reference to FIG. On the outer peripheral surface of the cam rotor 60, three projections 60a, 60b, 60c are provided.
Second protrusion 60b and third protrusion 60c as auxiliary indices
Are arranged at an angular interval of 180 ° from each other. First protrusion 60 as a discrimination index used for cylinder discrimination
a is 90 to the second protrusion 60b and the third protrusion 60c.
It is arranged with an angle interval of °. The first protrusions 60a to 1
There is no projection at a position 80 ° away.

As the cam rotor 60 rotates, each protrusion 60
The cam pulse generator 61 generates one pulse signal (cam pulse) every time a, 60b, and 60c pass the position facing the cam pulse generator 61. Cam pulse generator 6
As 1, similarly to the above-described crank pulse generator 55, for example, a semiconductor sensor such as a magnetic sensor or an optical sensor, or an electromagnetic pickup coil can be used. The material or shape of the cam rotor 60 is also determined so that a pulse can be induced in the cam pulse generator 61 to which the cam rotor 60 is applied. Therefore, an index other than the protrusions 60a to 60c, for example, a concave portion or a hole may be provided on the cam rotor 60 according to the type of the cam pulse generator 61 applied.

As shown in FIG. 4, the ECU 40 has a ROM 4 in which function data and various control programs are stored.
1. CPU 42 for executing arithmetic processing based on various programs stored in ROM 41, RAM 43 for temporarily storing the arithmetic results of CPU 42 and data input from the outside, and stored in RAM 43 when power supply to ECU 40 is stopped And a backup RAM 44 for storing the obtained data. These CPU 42, ROM 4
1, the RAM 43 and the backup RAM 44 are connected to each other via a bidirectional bus 45, and are also connected to an input circuit 46 and an output circuit 47. The crank pulse generator 55 and the cam pulse generator 61 are connected to the input circuit 46. The VVT 30, the igniter 52, and the injector 53 are connected to the output circuit 47.

When the crank rotor 54 rotates together with the crankshaft 15, the crank pulse generator 55 generates a train of crank pulses as shown in FIG.
Output to 40. As shown in FIG.
The crank pulse generator 55 generates one crank pulse every time the crankshaft 15 rotates by 10 ° CA corresponding to the arrangement of the protrusions 54a on the top 4. However, since the toothless portion 54b on the crank rotor 54 passes once through the crank pulse generator 55 during one rotation of the crank rotor 54, the interval between the crank pulses is 30 ° C.
A. Therefore, the ECU 40 determines the crank rotor 54 based on the input of the crank pulse at the 30 ° CA interval.
The passage of the upper toothless portion 54b can be detected. In other words, the ECU 40 recognizes that the crankshaft 15 is at the specific rotation angle based on the input of the crank pulse at the interval of 30 ° CA.

The period from the generation of the crank pulse having an interval of 30 ° CA to the rotation of the crankshaft 15 by a predetermined angle is a discrimination period G for discriminating the cylinder.
(Determination angle range). In this embodiment,
This discrimination period G is a period until the thirteenth crank pulse is generated from the first crank pulse at a 30 ° CA interval, that is, the crankshaft 15 rotates by 120 ° CA from the detection of the toothless portion 54b. The angle range is set to

On the other hand, when the cam rotor 60 rotates together with the intake camshaft 20, the cam pulse generator 61, as shown in FIG.
The first to third cam pulses CP1 to CP3 corresponding to 0a to 60c are generated and output to the ECU 40. As shown in the figure, the crank angle sensor 56 and the cam angle sensor 62 are configured such that the first cam pulse CP1 corresponding to the first protrusion 60a is generated during the above-described determination period G.

It should be noted that while the intake camshaft 20 makes one rotation, the crankshaft 15 makes two rotations, and the discrimination period G appears twice. The first cam pulse CP1 as the discriminating cam signal is generated in synchronization with one of two discriminating periods G appearing during one rotation of the intake camshaft 20. Based on whether or not the first cam pulse CP1 is generated during the determination period G, the cylinder position can be determined by specifying the rotational position during two rotations of the crankshaft 15.

In this embodiment, as shown in FIG. 5, when the first cam pulse CP1 is generated during the discrimination period G,
At the timing when the crank pulse corresponding to the end time of the determination period G is set to the first and the tenth crank pulse is generated therefrom, that is, after the crank shaft 15 rotates by 90 ° CA after the determination period G ends, The piston 13 of one cylinder # 1 is arranged at the top dead center in the compression stroke. On the other hand, if the first cam pulse CP1 does not occur during the discrimination period G, the fourth cylinder # is generated at the timing when the tenth crank pulse is generated from the first crank pulse corresponding to the end time of the discrimination period G. The fourth piston 13 is arranged at the top dead center in the compression stroke.

When the piston 13 of the first cylinder # 1 is located at the top dead center in the compression stroke, the crank counter value CCR used as a value indicating the crank angle is set to "0". The crank counter value CCR is incremented by “1” each time the crankshaft 15 rotates by 30 ° CA, and then returns to “0” again when it reaches “23”. Therefore, based on the crank counter value CCR, the rotational position of the crankshaft 15 during two rotations can be specified, and the stroke position of the piston 13 in each cylinder 12 can be determined, that is, the cylinder can be determined.

The second cam pulse CP2 corresponding to the second protrusion 60b is generated during a period from the end of the discrimination period G accompanied by the generation of the first cam pulse CP1 to the next detection of the missing tooth portion 54b. Specifically, the second cam pulse CP2 as the auxiliary cam signal is generated after the intake camshaft 20 rotates 90 ° (corresponding to 180 ° CA) after the first cam pulse CP1 is generated. The third cam pulse CP3 corresponding to the third protrusion 60c is the next toothless portion 54 after the determination period G without the generation of the first cam pulse CP1 ends.
It occurs during the period until b is detected. More specifically, the third cam pulse CP3 as the auxiliary cam signal is generated by the intake camshaft 20 after the second cam pulse CP2 is generated.
Occurs after rotating by 80 ° (corresponding to 360 ° CA).

Further, first to third cam pulses CP1 to CP
The generation timing of P3 is the same for all cylinders # 1 to # 4.
Of the injection prohibition period E described above. Therefore, it is possible to execute the fuel injection to all the cylinders # 1 to # 4 regardless of the generation timing of the first to third cam pulses CP1 to CP3.

The timing chart of FIG.
0 shows the state at the time of starting. When the internal combustion engine 10 is started, the intake camshaft 20 is located at the most retarded position with respect to the crankshaft 15. Therefore, if the rotation phase of the intake camshaft 20 changes to the advanced side after the internal combustion engine 10 shifts to the normal operation state, the timing of the generation of the cam pulses CP1 to CP3 and the opening period of the intake valve 23 are changed to the state shown in FIG. Move to the left. However, even if the intake camshaft 20 moves between the most retarded position and the most advanced position, the range of the discrimination period G is set so that the generation timing of the first cam pulse CP1 does not deviate from the discrimination period G. Is set.

Next, the fuel injection control at the time of starting the internal combustion engine 10 will be described with reference to the timing chart of FIG. 5 and the flowcharts of FIGS.
When cranking is performed to start the internal combustion engine 10, the ECU 40 first determines the crank counter value CCR, the discrimination period counter value CNE, and the cam pulse counter value EC.
G is set to "-1" which is an initial value. Thereafter, the ECU 40 repeatedly executes the routine shown in the flowcharts of FIGS. 6 to 8 until the internal combustion engine 10 shifts to the normal operation state.

As shown in FIG. 6, the ECU 40 first determines in step 101 whether or not the cylinder discrimination has not been completed. This determination is made based on whether or not the crank counter value CCR is smaller than "0", that is, whether or not the initial value is "-1". Crank counter value CC
If R is not “−1”, the ECU 40 determines that the cylinder determination has been completed, and shifts to the normal control of the internal combustion engine 10. On the other hand, if the crank counter value CCR is “−1”, the ECU 40 determines that the cylinder determination has not been completed, and proceeds to step 102.

In step 102, the ECU 40
It is determined whether a crank pulse has been input. If the crank pulse has been input, the ECU 40 proceeds to step 103, where the toothless portion 54 on the crank rotor 54
It is determined whether or not b has not been detected yet. This determination is made as to whether or not the discrimination period counter value CNE used to measure the discrimination period G is smaller than “0”, that is, the initial value “−”.
1 ".

The ECU 40 calculates the period determination counter value CNE.
Is "-1", the routine proceeds to step 104, where it is determined whether or not the missing tooth portion 54b is detected. Specifically, the ECU 40 determines that the input crank pulse is 1
If the interval is 0 ° CA, the process is temporarily terminated on the assumption that the missing tooth portion 54b has not been detected. On the other hand, the ECU 40 determines that the input crank pulse is 30 °
In the case of the CA interval, it is determined that the missing tooth portion 54b has been detected, and the process proceeds to step 105.

For example, as shown in FIG.
The crank pulse input at timings t1 and t5 is
It is determined that the interval is 30 ° CA. Needless to say, in order to make such a determination, the ECU 40 needs to perform 10 cycles before detecting the crank pulse at the timings t1 and t5.
It is necessary to detect at least one cycle of the crank pulse at the CA interval. Therefore, when starting the internal combustion engine 10,
When the first crank pulse is generated at the timings t1 and t5, it is not determined that the crank pulse at the timings t1 and t5 is at a 30 ° CA interval.

Returning to FIG. 6, in step 105, E
The CU 40 sets the discrimination period counter value CNE to the initial value “−”.
Set from “1” to “0”. This discrimination period counter value C
NE detects the missing tooth portion 54b, and sets the crankshaft 15
Is incremented by "1" every time the motor rotates by 10 DEG CA, that is, every time a crank pulse is generated.

In the following step 106, the ECU 40
Determines whether the cam pulse counter value ECG is “1”. The cam pulse counter value ECG is incremented by "1" each time a cam pulse is input to the ECU 40. Cam pulse counter value ECG is "1"
If, the ECU 40 proceeds to step 107, sets the crank counter value CCR to “5”, and then starts normal control of the internal combustion engine 10.

The fact that the cam pulse counter value ECG whose initial value is "-1" is "1" means that step 10
4, the cam pulse has already been input twice to the ECU 40 when the missing tooth portion 54b is detected. Referring to FIG. 5, the two cam pulses are first and second cam pulses CP1 and CP at timings t2 and t4.
2, and the detection timing of the missing tooth portion 54b in step 104 corresponds to t5. Therefore, if the cam pulse counter value ECG is “1” in step 106,
At the time of detection of the missing tooth portion 54b, the crank counter value CCR can be specified to be "5", indicating that the cylinder discrimination processing has been completed.

As described above, when the cam pulse is detected twice before the toothless portion 54b is detected when the internal combustion engine 10 is started, the toothless portion 54b is detected after the detection of the two cam pulses. When this is done, cylinder discrimination can be performed. As will be described later, when a cam pulse is detected before the missing tooth portion 54b is detected, when the first cam pulse is detected, fuel injection is performed on all four cylinders # 1 to # 4. Done.

On the other hand, if the cam pulse counter value ECG is not "1" in step 106, the ECU 40
Shifts to step 108, where the cam pulse counter value E
It is determined whether or not CG is “−1”. If the cam pulse counter value ECG is not "-1", that is, if it is "0", the ECU 40 proceeds to step 109, sets the cam pulse counter value ECG to the initial value "-1", and executes the processing. Is temporarily terminated. Cam pulse counter value EC
If G is “−1”, the ECU 40 proceeds to step 1
Then, the process proceeds to step 10, where fuel injection is performed for the second cylinder # 2 and the third cylinder # 3, and then the process is temporarily terminated.

The fact that the cam pulse counter value ECG is "-1" means that in step 104 the toothless portion 54
This means that the cam pulse has not been input to the ECU 40 at the time point when b is detected. Referring to FIG. 5, the detection timing of the missing tooth portion 54b is t1 or t5.
However, it is impossible to determine whether to set the crank counter value CCR to “17” or “5” when the cam pulse has not been input yet. However, since both of the timings t1 and t5 are outside the injection prohibition period E in the second cylinder # 2 and the third cylinder # 3, fuel injection into those cylinders # 2 and # 3 is possible. . Therefore, even before the crank counter value CCR is specified, that is, before the cylinder discrimination is completed, the toothless portion 5
At the time of detection of 4b, fuel injection is executed for specific cylinders # 2 and # 3.

When the internal combustion engine 10 shifts to the normal operation state after the cylinder discrimination, the fuel injection timing for each cylinder 12 is set, for example, immediately before the opening period of the intake valve 23. Accordingly, although the fuel injection to the second and third cylinders # 2 and # 3 at the detection timings t1 and t5 of the toothless portion 54b is different from the fuel injection timing in the normal operation state, the start of the internal combustion engine 10 is started. There is no hindrance.

The fact that the cam pulse counter value ECG is "0" means that the cam pulse is output to the ECU 4 at the time when the missing tooth portion 54b is detected in step 104.
That is, it is input once to 0. As described above, when this cam pulse is input, all the cylinders # 1 to # 4
, The fuel injection is not performed if a negative determination is made in step 108.

On the other hand, if the missing tooth portion 54b has already been detected in step 103, the ECU 40
The process moves to step 111 in FIG. In step 111, the ECU 40 increments the determination period counter value CNE by "1". In the following step 112, the ECU 40 determines that the discrimination period counter value CNE is "1".
It is determined whether or not "2" has been reached, and if "12" has not been reached, the process is temporarily terminated. Then, the ECU 40
When the discrimination period counter value CNE reaches “12”, 12
It is determined that the determination period G corresponding to the angular interval of 0 ° CA has ended, and the process proceeds to step 113.

In step 113, the ECU 40
It is determined whether or not the cam pulse counter value ECG is “0”. If the cam pulse counter value ECG is “0”, the ECU 40 determines that the first cam pulse CP1 has been input during the discrimination period G, and proceeds to step 114.
, The crank counter value CCR is set to “21”, and the control shifts to the normal control of the internal combustion engine 10. On the other hand, the cam pulse counter value ECG is not “0”, that is, “−
1 ”, the ECU 40 determines that the determination period G
Assuming that the first cam pulse CP1 has not been input during this period, the routine proceeds to step 115, where the crank counter value C
CR is set to “9”, and the process shifts to the normal control of the internal combustion engine 10.

As described above, the cylinder discrimination can be performed by specifying the crank counter value CCR based on whether or not the first cam pulse CP1 is input during the discrimination period G.
On the other hand, if the crank pulse is not input in step 102 of FIG. 6, the ECU 40 proceeds to step 116 of FIG. 8 to determine whether or not the cam pulse is input. If a cam pulse has not been input, the ECU 40 once terminates the process. If a cam pulse has been input, the ECU 40 proceeds to step 117.

In step 117, the ECU 40
It is determined whether the cam pulse counter value ECG is smaller than “0”, that is, whether it is “−1”. If the cam pulse counter value ECG is "-1", the ECU
The routine proceeds to step 118, where it is determined whether or not the missing tooth portion 54b has not been detected, that is, whether or not the discrimination period counter value CNE is smaller than “0”. If an affirmative determination is made here, the ECU 40 proceeds to step 119 and performs fuel injection on all cylinders # 1 to # 4. After that, in step 120, the ECU 40 increments the cam pulse counter value ECG by “1” and ends the process once. On the other hand, if a negative determination is made in step 117 or step 118, the ECU 40
Moves to step 120 without performing fuel injection.

As described above, when the first cam pulse is input before the detection of the missing tooth portion 54b, the fuel injection is performed on all the cylinders # 1 to # 4 even if the cylinder determination is not completed. Is performed. As described above, all of the generation timings of the first to third cam pulses CP1 to CP3 fall outside the injection inhibition period E in all the cylinders # 1 to # 4. Therefore, all the cylinders #
Fuel injection can be performed simultaneously on # 1 to # 4.

As in the case of fuel injection into the second and third cylinders # 2 and # 3 at the detection timing of the missing tooth portion 54b,
The fuel injection to all the cylinders # 1 to # 4 at the timing of the generation of the cam pulse is different from the timing of the fuel injection in the normal operation state of the internal combustion engine 10, but does not hinder the start of the internal combustion engine 10.

An example of the operation performed according to the flowcharts of FIGS. 6 to 8 will be described with reference to the timing chart of FIG. As shown in FIG. 5, when the internal combustion engine 10 is started, for example, if the first cam pulse is input at the timing t2 before the missing tooth portion 54b is detected, the process proceeds to step 119, so that all the cylinders # 1 to # 1 are started. Fuel injection is simultaneously performed on # 4. Then, at timing t4
When the next cam pulse is input at step 11
7, the fuel injection is not performed. Subsequently, when the missing tooth portion 54b is detected at the timing t5, an affirmative determination is made in Step 106, and thus Step 1
At 07, the crank counter value CCR is set to “5”,
The cylinder discrimination is completed. Accordingly, the control can thereafter be shifted to the normal control of the internal combustion engine 10, and the crank counter value CC
Fuel injection and ignition are performed for each cylinder 12 at the timing of the normal operation of the internal combustion engine 10 based on R and the like. That is, at timing t6 when the crank counter value CCR becomes "6", the first ignition is performed on the third cylinder # 3 at the compression top dead center, and thereafter, the fourth cylinder # 4 and the second cylinder # 4
.. Are ignited in the order of cylinder # 2, first cylinder # 1,. FIG. 5 shows a fuel injection mode and an ignition mode in the above operation example.

When the internal combustion engine 10 is started, for example, if the first cam pulse is input at timing t4 before the missing tooth portion 54b is detected, the process proceeds to step 119, so that all the cylinders # 1 to # 1 are started. 4 are simultaneously injected. Thereafter, at the timing t5, the missing tooth portion 54b
Is detected, a negative determination is made in both step 106 and step 108, and no fuel injection is performed. Since no cam pulse is input during the subsequent determination period G, when the determination period G ends at the timing t7,
If a negative determination is made in step 113, step 11
Move to 5. Therefore, at timing t7, the crank counter value CCR is set to “9”, and the cylinder discrimination is completed. Therefore, the control can thereafter be shifted to the normal control of the internal combustion engine 10, and the fuel injection and ignition are performed on each cylinder 12 at the timing of the normal operation of the internal combustion engine 10 based on the crank counter value CCR and the like. The timing t8 when the crank counter value CCR becomes "12"
, The first ignition is performed on the fourth cylinder # 4 at the compression top dead center.

Alternatively, when the internal combustion engine 10 is started,
For example, if the missing tooth portion 54b is detected at the timing t1 before the input of the cam pulse, a negative determination is made in step 106 and an affirmative determination is made in step 108, so that the process proceeds to step 110. Therefore, the missing tooth portion 54
b at the detection timing t1, the second and third cylinders #
Fuel injection is performed for # 2 and # 3. Since a cam pulse is input during the subsequent determination period, the timing t3
When the discrimination period G ends, the determination at step 113 is affirmative, and the routine goes to step 114. Therefore,
At timing t3, the crank counter value CCR is set to "21", and the cylinder determination is completed. for that reason,
Thereafter, the control can be shifted to the normal control of the internal combustion engine 10,
Based on the crank counter value CCR and the like, fuel injection and ignition are performed at the timing of normal operation of the internal combustion engine 10 for each cylinder 1.
2 is performed. Note that the crank counter value CCR
At timing t6 at which the third cylinder # 3 is at the compression top dead center, the first ignition is performed.

Note that, for the cylinder 12 in which fuel injection was performed at a timing different from that during normal operation before the cylinder discrimination,
After the end of the first ignition after the cylinder discrimination, the fuel injection at the timing of the normal operation is started. For the cylinder 12 for which fuel injection was not performed before the cylinder discrimination, the fuel injection at the timing of the normal operation is started immediately after the cylinder discrimination.

As described above, in this embodiment, in addition to the cam pulse generated in synchronization with the discrimination period G, the discrimination period G
A total of three protrusions 60a to 60c are provided on the cam rotor 60 so that another cam pulse is generated even before the next tooth missing portion 54b is detected. Moreover,
The positions of the projections 60a to 60c on the cam rotor 60 are set so that a cam pulse is generated at a timing at which fuel can be injected into all the cylinders # 1 to # 4.

Therefore, when a cam pulse is detected before the toothless portion 54b is detected when the internal combustion engine 10 is started, all cylinders # 1 to # 4 are simultaneously detected at the timing of detecting the cam pulse. Fuel injection can be performed. In other words, even before the cylinder discrimination, the fuel injection can be performed to all the cylinders # 1 to # 4 at the cam pulse detection timing. Therefore, after the detection of the cam pulse, the detection of the missing tooth portion 54b and the corresponding determination period G
Is completed, it is possible to immediately ignite the cylinder 12 which first becomes the compression top dead center after the cylinder discrimination. Therefore, the time from cranking to the first ignition can be shortened, and the internal combustion engine 10 can be started well.

Further, not only the cam pulse is generated in synchronization with one of the two discrimination periods G, but also from the discrimination period G accompanied by the generation of the cam pulse until the next missing tooth portion 54b is detected, and the cam pulse is generated. A cam pulse is generated in any period from the determination period G without occurrence of the period to the detection of the next missing tooth portion 54b. Therefore, for example, the cam rotor 60
Compared to the case where either the second or third protrusions 60b and 60c are not provided, the chances of executing the fuel injection based on the generation of the cam pulse before the cylinder discrimination are increased. Therefore,
In this embodiment in which the three protrusions 60a to 60c are provided on the cam rotor 60, the time from cranking to the first ignition can be more reliably shortened.

If two cam pulses are detected before the missing tooth portion 54b is detected, the subsequent missing tooth portion 5b is detected.
When 4b is detected, the cylinder discrimination can be immediately performed without waiting for the end of the discrimination period G. This further shortens the time from cranking to the first ignition as compared with the case where cylinder discrimination is performed after the end of the discrimination period G, and enables a more favorable start of the internal combustion engine 10.

Further, in order to obtain the above effects,
On the cam rotor 60, the first
Since it is only necessary to provide another two projections 60b and 60c in addition to the projection 60a, the structure is simple.

Further, when the internal combustion engine 10 is started,
When the missing tooth portion 54b is detected without input of the cam pulse, that is, when the crankshaft 15 is arranged at a specific rotation angle, fuel is injected into another specific cylinder # 2, # 3. . This allows a better start of the internal combustion engine 10.

(Second Embodiment) Next, a second embodiment of the present invention will be described focusing on differences from the first embodiment. In the first embodiment described above, when the toothless portion 54b is detected in a state where no cam pulse is input when the internal combustion engine 10 is started, the second and third cylinders # 2 and # 2 are detected when the toothless portion 54b is detected. , # 3. However, in the present embodiment, if the missing tooth portion 54b is detected in the absence of the input of the cam pulse, the second and third cylinders # 2, # 3 based on the result of the cylinder discrimination when the cylinder discrimination is completed. Is performed on one of the two.

In order to realize such processing, FIG.
In addition to omitting the processing of step 110 of the flowchart of FIG. 7, the processing of the flowchart of FIG. 9 may be performed instead of the flowchart of FIG. Note that, in FIG. 9, the same processes as those in FIG. 7 are denoted by the same step numbers, and description thereof is omitted.

As shown in FIG. 9, in step 114, the ECU 40 sets the crank counter value CCR to "21".
, And in step 121, all cylinders #
It is determined whether or not there has been simultaneous injection of fuel for 1 to # 4. If a positive determination is made here, the ECU 40
The control directly shifts to the normal control of the internal combustion engine 10. On the other hand, if a negative determination is made, the ECU 40 proceeds to step 122.
Then, the fuel injection is performed on the third cylinder # 3, and thereafter, the control shifts to the normal control of the internal combustion engine 10.

After setting the crank counter value CCR to "9" in step 115, the ECU 40 determines in step 123 whether or not fuel injection has been performed simultaneously on all of the cylinders # 1 to # 4. If an affirmative determination is made here, the ECU 40 shifts to the normal control of the internal combustion engine 10 as it is. On the other hand, if a negative determination is made, the ECU 40 proceeds to step 124 and executes the second
Fuel injection is performed on the cylinder # 2, and then the internal combustion engine 1
The control shifts to the normal control of 0.

The fuel injection to the third cylinder # 3 in step 122 is performed at the end timing t of the discrimination period G shown in FIG.
3, that is, at timing t3 when the crank counter value CCR is set to "21". This timing t3
Is different from the injection timing during the normal operation as the fuel injection timing for the third cylinder # 3, but is outside the injection prohibition period E. Step 1
The fuel injection to the second cylinder # 2 of 24 is performed at the end timing t7 of the determination period G shown in FIG. 5, that is, at the timing t7 when the crank counter value CCR is set to “9”. The timing t7 also differs from the injection timing during the normal operation as the fuel injection timing for the second cylinder # 2, but is outside the injection inhibition period E. Further, in Steps 121 and 123, the fact that there was no simultaneous injection of fuel to all the cylinders # 1 to # 4 means that no cam pulse was input before the detection of the missing tooth portion 54b.

As described above, when the missing tooth portion 54b is detected in the absence of the input of the cam pulse, when the cylinder discrimination is completed, the second and third cylinders # are determined based on the discrimination result.
Even if fuel injection is performed for one of # 2 and # 3,
The same effects as those of the first embodiment shown in FIGS. 6 to 8 can be obtained.

(Third Embodiment) Next, a third embodiment of the present invention will be described focusing on differences from the first embodiment. Although the internal combustion engine 10 shown in FIG. 1 includes the VVT 30, the VVT 30 is omitted in the present embodiment. VV
When T30 is omitted, the generation timing of the cam pulse does not change with respect to the crank pulse. for that reason,
For example, as shown in the timing chart of FIG. 10, the determination period G is set to an angle range of 60 ° CA that is narrower than the determination period G shown in FIG. In other words, the period from the first crank pulse having a 30 ° CA interval to the generation of the seventh crank pulse therefrom is set as the determination period G.

In the present embodiment, when the first cam pulse CP1 is generated during the discrimination period G, the first crank pulse corresponding to the end time of the discrimination period G is set to the first, and the fourth crank pulse is generated therefrom. At the right time,
In other words, the crankshaft 15
Is rotated by 30 ° CA, the piston 13 of the first cylinder # 1 is placed at the compression top dead center. Note that the first cylinder # 1
Counter value CCR when is at compression top dead center
Is "0" as in the case of FIG.

Further, in this embodiment, the cam rotor 60
The arrangement intervals of the upper protrusions 60a to 60c are slightly different from the embodiment shown in FIG. Specifically, the second protrusion 60b and the third protrusion 60b
The projections 60c are arranged at an angular interval of 180 ° from each other, but the first projection 60a is 7 ° away from the second projection 60b.
They are arranged at an angular interval of 5 ° and an angular interval of 105 ° with respect to the third protrusion 60c. Therefore, as shown in FIG. 10, the generation interval between the first cam pulse CP1 and the second cam pulse CP2 corresponds to 150 ° CA, and the second cam pulse CP2
The interval between the second and third cam pulses CP3 is 360 ° CA
And the third cam pulse CP3 and the first cam pulse CP
1 corresponds to 210 ° CA.

Also in this embodiment, when the internal combustion engine 10 is started, basically the same processing as in the first embodiment shown in FIGS. 6 to 8 is performed. However, as can be seen from FIG. 10, the generation timing of the crank pulse and the cam pulse with respect to the crank counter value CCR, the determination period G, and the like are different from those of the embodiment of FIG. 5, and the flowcharts of FIGS. Need to be changed.

Specifically, when the missing tooth portion 54b is detected after the two cam pulses are detected, that is, when the affirmative determination is made in step 106 of FIG. 6, the ECU 40 determines in step 107 that the crank counter value CCR Is set to “9” instead of “5”.

As can be seen from FIG.
Fuel injection to all cylinders # 1 to # 4 is possible at the detection timing of b. Therefore, when the missing tooth portion 54b is detected in a state where no cam pulse is input, that is, when the affirmative determination is made in step 108 of FIG.
In step 110, the second and third cylinders # 2, # 3
In addition, fuel is injected into all cylinders # 1 to # 4.

Further, since the discrimination period G corresponds to an angle range of 60 ° CA, in step 112 of FIG.
When the determination period counter value CNE reaches “6” instead of “12”, the CU 40 proceeds to step 113. If an affirmative determination is made in step 113, EC
U40 determines that the first cam pulse CP1 has been input during the discrimination period G, and proceeds to step 114 to set the crank counter value CCR to "23" instead of "21". On the other hand, if a negative determination is made in step 113, the ECU 40 determines that the first cam pulse CP
Assuming that 1 has not been input, the routine proceeds to step 115, where the crank counter value CCR is set to “11” instead of “9”.

Further, as can be seen from FIG. 10, it is not preferable to perform the fuel injection to the third cylinder # 3 at the generation timing of the first cam pulse CP1, since the injection end timing falls within the injection inhibition period E. Therefore, when a cam pulse is generated before the detection of the missing tooth portion 54b, that is, in step 119 of FIG.
The fuel is injected into the first and fourth cylinders # 1 and # 4 instead of the fourth cylinder.

As described above, in the present embodiment, when the internal combustion engine 10 is started, if a cam pulse is detected before the missing tooth portion 54b is detected, a specific cylinder, That is, fuel injection is performed on the first and fourth cylinders # 1 and # 4. In other words, even before the cylinder discrimination, the fuel injection is performed to the specific cylinder at the timing of detecting the cam pulse. Therefore,
As in the first embodiment, the time from cranking to the first ignition can be shortened, and the internal combustion engine 10 can be started well. Other functions and effects are the same as those of the first embodiment.

The first detection is performed at the cam pulse detection timing.
After the fuel injection is performed on the fourth and fourth cylinders # 1 and # 4, the fuel injection may be performed on the second and third cylinders # 2 and # 3 at the detection timing of the missing tooth portion 54b. good. That is, after step 107 and step 109 in FIG. 6, a process for executing fuel injection to the second and third cylinders # 2 and # 3 may be added. This way,
The internal combustion engine 10 can be started more favorably.

Although the above-described first to third embodiments have been applied to the in-line four-cylinder internal combustion engine 10, the present invention relates to the in-line four-cylinder engine.
The invention is applicable not only to the cylinder type but also to other types of internal combustion engines. Hereinafter, examples of application to various types of internal combustion engines will be sequentially described. In the following description,
Members equivalent to those of the first embodiment in FIGS. 1 to 8 are denoted by the same reference numerals.

(Fourth Embodiment) First, the fourth embodiment shown in FIG.
The embodiment is an example of application to an in-line six-cylinder internal combustion engine 10 with or without a VVT 30. As shown in FIG. 11, an in-line six-cylinder internal combustion engine 10
Has first to sixth cylinders # 1 to # 6 arranged in order. The piston 13 in each cylinder 12 includes a first cylinder # 1, a fifth cylinder # 5, a third cylinder # 3, a sixth cylinder # 6, and a second cylinder #
In the order of the second and fourth cylinders # 4, they are arranged at the compression top dead center with the phases shifted by 120 ° CA.

The discrimination period G is 1 as in the embodiment of FIG.
The angle range is set to 20 ° CA. After the crankshaft 15 rotates by 30 ° CA after the end of the determination period G accompanied by the generation of the first cam pulse CP1, the first
The piston 13 of the cylinder # 1 is located at the compression top dead center, and the crank counter value CCR becomes “0”. Further, the three protrusions 60a to 60c on the cam rotor 60 are
Are arranged at equal angular intervals.

In the present embodiment, when the internal combustion engine 10 is started, the fuel is injected into the second, fourth, and fifth cylinders # 2, # 4, and # 5 at the timing when the first missing tooth portion 54b is detected. Is performed. In addition, regardless of whether or not the missing tooth portion 54b has not been detected yet, at the first cam pulse detection timing,
Fuel injection is performed on the first and third cylinders # 1 and # 3. Then, at the timing after the crankshaft 15 has rotated 90 to 120 ° CA from the detection timing of the first cam pulse, fuel injection is performed on the sixth cylinder # 6. Of course, any of the above-described fuel injection timings fall outside the injection prohibition period E.

The flow of the processing at the time of starting the internal combustion engine 10 as described above is similar to the flow charts of FIGS. Therefore, the processing at the time of startup executed in the present embodiment will be described with reference to FIG. 11 and mainly on the differences from the flowcharts of FIGS. 6 to 8. The processing other than the processing of the steps described below is the same as that in FIGS.

When the first missing tooth portion 54b is detected after the two cam pulses are detected, that is, when the affirmative determination is made in step 106 of FIG. 6, the ECU 40 sets the crank counter value CCR to "5" in step 107. ”Instead of“ 7 ”. Further, this step 107
After the processing of, the ECU 40 sets the second, fourth, and fifth cylinders #
Fuel injection is performed for # 2, # 4, and # 5. Further, the processing of steps 108 and 110 is omitted, and if a negative determination is made in step 106, the process proceeds to step 109. After the processing of step 109, the ECU 40 determines the second, fourth, and fifth
Fuel injection is performed for cylinders # 2, # 4, and # 5.

At step 114 in FIG.
Sets the crank counter value CCR to “2” instead of “21”.
3 ". On the other hand, in step 115, the ECU 4
0 indicates that the crank counter value CCR is “1” instead of “9”.
1 ".

The processing in step 118 in FIG. 8 is omitted, and if an affirmative determination is made in step 117, that is, if the detected cam pulse is the first one, step 11 is continued.
Move to 9. In step 119, the ECU 40 performs the fuel injection on the first and third cylinders # 1 and # 3 instead of all the cylinders. Note that the ECU 40 determines in step 11
7, the crankshaft 15 is kept at 90 to 120 ° C. after the first cam pulse is detected.
After the A rotation, fuel injection is performed on the sixth cylinder # 6. The injection timing for the sixth cylinder # 6 can be easily determined by counting the number of crank pulses from the time when the first cam pulse is detected.

According to the above-described processing, as shown in FIG. 11, for example, when cranking is started at timing t11, the first and third cylinders # 1 and # 1, at timing t12 when the first cam pulse is detected. Fuel injection is performed for # 3. Then, from the detection timing t12 of the first cam pulse, the crankshaft 15 is set at 90 to 120 ° C.
At timing t13 after the A rotation, fuel injection is performed on the sixth cylinder # 6. At timing t14 when the second cam pulse is detected, no fuel injection is performed.

Thereafter, at timing t15 when the first missing tooth portion 54b is detected, the second, fourth and fifth cylinders # 2 and #
4 and # 5 are subjected to fuel injection. In addition, tooth missing part 5
Since two cam pulses have been detected before the detection of 4b, the crank counter value CCR is set to “7” at timing t15, and the cylinder determination is completed. Therefore, the first ignition can be performed on the third cylinder # 3 which becomes the compression top dead center at the timing t16 immediately after that, and thereafter, the sixth cylinder # 6, the second cylinder # 2, and the fourth cylinder # 4, ...
・ Ignition can be performed in this order. After that, fuel injection to the cylinder 12 where ignition has been performed is sequentially started at normal timing.

As described above, in the present embodiment, when the internal combustion engine 10 is started, if the first cam pulse is detected, regardless of whether or not the missing tooth portion 54b has been detected earlier, The fuel injection is performed to a specific cylinder, that is, the first and third cylinders # 1 and # 3 at the detection timing of the cam pulse. In other words, even before the cylinder discrimination, fuel injection is performed on a specific cylinder at the first cam pulse detection timing. Therefore, similarly to the first embodiment, the time from cranking to the first ignition can be shortened, and the internal combustion engine 10 can be started well. Other functions and effects are the same as those of the first embodiment.

At the first cam pulse detection timing, fuel is injected into the first, second and third cylinders # 1, # 2 and # 3, and at the first detection timing of the missing tooth portion 54b, Fuel injection may be performed on the fourth and fifth cylinders # 4 and # 5. Such control is performed by the internal combustion engine 10.
It is preferable to perform the detection when the cam pulse is detected earlier than the missing tooth portion 54b at the start of the operation. Even in this case, the same operation and effect as in the above case can be obtained.

(Fifth Embodiment) The fifth embodiment shown in FIGS. 12 and 13 is a modification of the fourth embodiment. In the present embodiment, a cam rotor 70 as shown in FIG. 12 is used. On the outer peripheral surface of the cam rotor 70, three convex portions 70a having an angle range of 60 ° are provided at equal angular intervals of 120 °. A concave portion 70b having an angle range of 60 ° is formed between two adjacent convex portions 70a.
The cam pulse generator 61 includes a convex portion 70a and a concave portion 7a.
A sensor capable of outputting a signal corresponding to 0b, for example, a semiconductor sensor such as a magnetic sensor or an optical sensor is used.

When the cam rotor 70 rotates, the cam pulse generator 61 generates a cam signal as shown in FIG. The level of the cam signal is switched between high and low in accordance with the projection 70a and the recess 70b. The timing when the cam signal rises from low level to high level
This is the same as the timing of generating the cam pulse in the embodiment of FIG. Cylinder discrimination can be performed based on whether the cam signal has risen during the discrimination period G.

The rise of the cam signal during the discrimination period G corresponds to the discrimination cam signal. The rise of the cam signal at a timing outside the determination period G corresponds to the auxiliary cam signal. Then, three steps 70c between the protrusion 70a and the recess 70b corresponding to the rise of the cam signal are 1
One discrimination index and two auxiliary indices. Further, in this embodiment, all the falling edges of the cam signal correspond to the auxiliary cam signal. Then, three steps 70 between the convex portion 70a and the concave portion 70b corresponding to the fall of the cam signal.
d corresponds to three auxiliary indices.

In the present embodiment, when the internal combustion engine 10 is started, fuel is injected into the second and fifth cylinders # 2 and # 5 at the timing when the first toothless portion 54b is detected. Further, regardless of whether or not the missing tooth portion 54b has not yet been detected, fuel injection is performed on the first and third cylinders # 1 and # 3 at the first rising timing of the cam signal. Furthermore, regardless of whether or not the missing tooth portion 54b has not been detected yet,
At the first falling timing of the cam signal, fuel injection is performed on the fourth and sixth cylinders # 4 and # 6. Of course, any of the above-described fuel injection timings fall outside the injection prohibition period E.

Although the above-described processing at the time of starting the internal combustion engine 10 is not particularly shown in the flowchart, an example of operation according to the processing will be described with reference to FIG. For example, when cranking is started at timing t21,
Timing t at which the first rise of the cam signal is detected
At 22, fuel is injected into the first and third cylinders # 1 and # 3. Next, fuel injection is performed on the fourth and sixth cylinders # 4 and # 6 at timing t23 when the first falling of the cam signal is detected. At the second rising timing t24 of the cam signal, no fuel injection is performed.

Thereafter, fuel is injected into the second and fifth cylinders # 2 and # 5 at the timing t25 when the first missing tooth portion 54b is detected. Further, since the rising of the cam signal is detected twice before the detection of the missing tooth portion 54b, the crank counter value CCR becomes "7" at the timing t25.
And the cylinder discrimination is completed. Accordingly, the first ignition can be performed on the third cylinder # 3, which becomes the compression top dead center at the timing t26 immediately after that, and thereafter, the sixth cylinder # 6, the second cylinder # 2, and the fourth cylinder # The ignition can be performed in the order of 4,. After that, fuel injection to the cylinder 12 where ignition has been performed is sequentially started at normal timing.

As described above, in the present embodiment, when the internal combustion engine 10 is started, when the first rising of the cam signal is detected, regardless of whether or not the missing tooth portion 54b has been detected before that time, Fuel injection is performed for a specific cylinder, that is, the first and third cylinders # 1 and # 3. Further, even when the first fall of the cam signal is detected, regardless of whether or not the missing tooth portion 54b has been detected before that, the specific cylinders, that is, the fourth and sixth cylinders # 4 and # 6 Is injected.

Therefore, even before the cylinder discrimination, fuel injection is performed to a specific cylinder at the rising timing and the falling timing of the cam signal. Therefore, similarly to the fourth embodiment, the time from cranking to the first ignition can be shortened, and the internal combustion engine 10 can be started well. Other functions and effects are the same as those of the fourth embodiment.

However, in the fourth embodiment shown in FIG. 11, the fuel injection timing for the sixth cylinder # 6 could not be synchronized with the cam pulse generation timing. On the other hand, in the present embodiment, by using the cam rotor 70 as shown in FIG. 12, it becomes possible to perform fuel injection to the sixth cylinder # 6 in synchronization with the falling timing of the cam signal. Therefore, as compared with the fourth embodiment, the fuel injection timing for the sixth cylinder # 6 can be set more reliably by the cam signal.

It is to be noted that the fuel injection may not be performed at the timing when the first missing tooth portion 54b is detected. Instead, fuel is injected into the first, second and third cylinders # 1, # 2, and # 3 at the first rising timing of the cam signal, and the fuel is injected at the first falling timing of the cam signal. Fuel is injected into the fourth, fifth and sixth cylinders # 4, # 5 and # 6. Such control is performed by the internal combustion engine 10.
It is preferable to perform the detection when the rising or falling of the cam signal is detected earlier than the missing tooth portion 54b at the time of starting. Even in this case, the same operation and effect as in the above case can be obtained.

Sixth Embodiment A sixth embodiment shown in FIG. 14 is an example of application to a V-type six-cylinder internal combustion engine 10 having a VVT 30. The V-type six-cylinder internal combustion engine 10 includes a left bank and a right bank. The left bank is the first
The right bank has fourth to sixth cylinders # 4 to # 6 arranged in order. As shown in FIG. 14, the piston 13 in each cylinder 12 has a first cylinder # 1,
The second cylinder # 2, the third cylinder # 3, the fourth cylinder # 4, the fifth cylinder # 5, and the sixth cylinder # 6 are arranged at the compression top dead center in a state where the phases are shifted by 120 ° CA in this order. You.

The intake camshaft 20 and the exhaust camshaft 21 are provided corresponding to both banks. Therefore, the VVT 30 and the cam angle sensor 62 are provided corresponding to the two intake camshafts 20, respectively. As the cam angle sensor 62, the same one as in the fourth embodiment in FIG. 11 is used. Note that a cam pulse generated by the cam angle sensor 62 provided in the left bank is defined as a left cam pulse, and a cam pulse generated by the cam angle sensor 62 provided in the right bank is defined as a right cam pulse. The left cam pulse and the right cam pulse are out of phase with each other by 360 ° CA.

The discrimination period G is set in an angle range of 120 ° CA. After the determination period G involving the generation of the left cam pulse (first cam pulse CP1) ends, the crankshaft 1
After 5 rotates by 30 ° CA, the piston 13 of the first cylinder # 1 is placed at the compression top dead center. At this time, the crank counter value CCR becomes “0”. Further, after the determination period G accompanied by the generation of the right cam pulse (first cam pulse CP1) ends, after the crankshaft 15 rotates by 30 ° CA, the piston 13 of the fourth cylinder # 4 is disposed at the compression top dead center. You. At this time, the crank counter value CCR becomes “12”.

In the present embodiment, when the internal combustion engine 10 is started, fuel is injected into the second and fifth cylinders # 2 and # 5 at the timing when the first toothless portion 54b is detected. Also, regardless of whether or not the missing tooth portion 54b has not been detected yet, fuel injection is performed on the first and third cylinders # 1 and # 3 at the first left cam pulse detection timing. Further, fuel injection is performed on the fourth and sixth cylinders # 4 and # 6 at the first detection timing of the right cam pulse regardless of whether the missing tooth portion 54b has not been detected.

The above-described processing at the time of starting the internal combustion engine 10 is not particularly shown in the flowchart, but an operation example according to the processing will be described with reference to FIG. For example, when cranking starts at timing t31,
Fuel injection is performed on the first and third cylinders # 1 and # 3 at timing t32 when the first left cam pulse is detected. Next, fuel injection is performed on the fourth and sixth cylinders # 4 and # 6 at timing t33 when the first right cam pulse is detected. Second detection timing t of left cam pulse
At 34, no fuel injection is performed.

Thereafter, at timing t35 when the first missing tooth portion 54b is detected, fuel injection is performed on the second and fifth cylinders # 2 and # 5. The cam pulse immediately before the detection timing t35 of the missing tooth portion 54b is a left cam pulse. In this case, the crank counter value CCR can be set to “7” at the timing t35. On the other hand, if the first missing tooth portion 54b is detected at timing t38 following the detection of the right cam pulse at timing t37 after cranking, the crank counter value CC is detected at timing t38.
R can be set to "19". That is, based on whether the cam pulse immediately before the toothless portion 54b is a left cam pulse or a right cam pulse, the cylinder determination can be completed at the detection timing of the toothless portion 54b without waiting for the end of the determination period G.

When the cylinder discrimination is completed at the timing t35, the first ignition can be performed on the third cylinder # 3 which becomes the compression top dead center at the timing t36 immediately thereafter, and thereafter, the fourth cylinder # 4, Fifth cylinder # 5, sixth cylinder #
The ignition can be performed in the order of 6,. Also,
Thereafter, fuel injection to the cylinder 12 where ignition has been performed is sequentially started at normal timing.

As described above, in the present embodiment, when the internal combustion engine 10 is started, when the first left cam pulse is detected, the specific cylinders, that is, the first and third cylinders # 1, # 1 are set.
3 is subjected to fuel injection. Furthermore, when the first right cam pulse is detected, a specific cylinder,
And fuel injection is performed on the sixth cylinders # 4 and # 6.
In other words, even before the cylinder discrimination, fuel injection is performed on a specific cylinder at the first detection timing of the left cam pulse and the right cam pulse. Therefore, similarly to the fifth embodiment, the time from cranking to the first ignition can be shortened, and the internal combustion engine 10 can be started well. Other functions and effects are the same as in the fifth embodiment.

It is to be noted that the fuel injection may not be performed at the detection timing of the first missing tooth portion 54b. Instead, at the first left cam pulse detection timing, the first,
Fuel is injected into the third and fifth cylinders # 1, # 3, and # 5, and the second, fourth, and sixth cylinders # 2, # 4, and # 6 are detected at the first right cam pulse detection timing. Then, fuel injection is performed. Such control is preferably performed when the left cam pulse or the right cam pulse is detected earlier than the toothless portion 54b when the internal combustion engine 10 is started. Even in this case, the same operation and effect as in the above case can be obtained.

(Seventh Embodiment) A seventh embodiment shown in FIGS. 15 and 16 is an example of application to a V-type eight-cylinder internal combustion engine 10 provided with a VVT 30. V-type 8-cylinder internal combustion engine 10
Has a left bank and a right bank. The left bank has first to fourth cylinders # 1 to # 4 arranged in order, and the right bank has fifth to eighth cylinders # 5 to # 8 arranged in order. FIG.
As shown in FIG. 6, the piston 13 in each cylinder 12 is
Cylinder # 1, eighth cylinder # 8, fourth cylinder # 4, third cylinder #
3, the sixth cylinder # 6, the fifth cylinder # 5, the seventh cylinder # 7, and the second cylinder # 2 are arranged at the compression top dead center with the phases shifted by 90 ° CA in this order.

The intake camshaft 20 and the exhaust camshaft 21 are provided corresponding to both banks. Therefore, the VVT 30 and the cam angle sensor 62 are provided corresponding to the two intake camshafts 20, respectively.

As shown in FIG. 15A, each cam angle sensor 62 has first to third projections 80a to 80a as auxiliary indices.
0c is provided. Second protrusion 80b
Are arranged at an angular interval of 90 ° with respect to the first protrusion 80a, and the third protrusion 80c is formed by the first protrusion 80a and the second protrusion 8.
0b is arranged at an angular interval of 135 °.

The cam pulse generator 61 is the same as that shown in FIG. 3, and generates a cam pulse as an auxiliary cam signal corresponding to each of the projections 80a to 80c. As shown in FIG. 16, a cam pulse generated by the cam angle sensor 62 provided in the left bank is defined as a left cam pulse, and a cam pulse generated by the cam angle sensor 62 provided in the right bank is defined as a right cam pulse. The left cam pulse and the right cam pulse are out of phase with each other by 360 ° CA. These left cam pulse and right cam pulse are generated at timings outside the discrimination period G set as an angular interval of 90 ° CA.

In this embodiment, as shown in FIG. 15B, another cam angle sensor 90 for generating a cylinder-determining cam pulse is provided on one of the two exhaust camshafts 21.
Is provided. The cam angle sensor 90 includes a cam rotor 91 fixed to the exhaust camshaft 21 and a cam rotor 9.
1 and a cam pulse generator 92 which is arranged on the outer peripheral surface of the cam pulse generator. On the outer peripheral surface of the cam rotor 91, one projection 91a is provided as a discrimination index. Cam pulse generator 9
Numeral 2 generates a discrimination cam pulse as a discrimination cam signal corresponding to the projection 91a. This discriminating cam pulse is generated in synchronization with one of the two discriminating periods G appearing during one rotation of the exhaust camshaft 21. Therefore, as in the first to sixth embodiments, the cylinder discrimination can be performed based on whether or not the discrimination cam pulse is generated during the discrimination period G.

After the discrimination period G involving the generation of the discrimination cam pulse is completed and the crankshaft 15 rotates by 30 ° CA, the piston 13 of the first cylinder # 1 is placed at the compression top dead center. At this time, the crank counter value CCR becomes “0”. Further, after the determination period G without generation of the determination cam pulse ends, the crankshaft 15
° CA, the piston 13 of the sixth cylinder # 6
Is located at the compression top dead center. At this time, the crank counter value CCR becomes “12”.

Since the exhaust camshaft 21 is not provided with a VVT, the phase of the discriminating cam pulse with respect to the crank pulse does not change. Further, this determination cam pulse is used only for cylinder determination, and fuel injection is not performed in synchronization with the generation timing.

In this embodiment, when the internal combustion engine 10 is started, the second, sixth, and eighth timings are detected at the first left cam pulse detection timing regardless of whether or not the missing tooth portion 54b has not yet been detected. Fuel injection is performed on cylinders # 2, # 6, and # 8. Further, regardless of whether or not the missing tooth portion 54b has not yet been detected, fuel injection is performed on the first, third, and fifth cylinders # 1, # 3, and # 5 at the first right cam pulse detection timing. Done. Further, when the first missing tooth portion 54b is detected before the detection of the left cam pulse and the right cam pulse,
And fuel injection is performed to the seventh cylinders # 4 and # 7.
However, when the missing tooth portion 54b is detected following detection of the left cam pulse, fuel injection is performed only to the fourth cylinder # 4, and when the missing tooth portion 54b is detected following detection of the right cam pulse. , And fuel injection is performed only on the seventh cylinder # 7.

Although the above-described processing at the time of starting the internal combustion engine 10 is not particularly shown in the flowchart, an operation example according to the processing will be described with reference to FIG. For example, when cranking is started at timing t41,
Fuel injection is performed on the first, third, and fifth cylinders # 1, # 3, and # 5 at timing t42 when the first right cam pulse is detected. Next, at timing t43 when the first left cam pulse is detected, the second, sixth, and eighth cylinders # 2, # 2
6, fuel injection is performed for # 8. At the second detection timing t44 of the right cam pulse, no fuel injection is performed.

Thereafter, at timing t45 when the first missing tooth portion 54b is detected following the second right cam pulse,
Fuel injection is performed only on the seventh cylinder # 7. That is, the cam pulse immediately before the detection timing t45 of the toothless portion 54b is a right cam pulse. In this case, the crank counter value CCR can be set to “8” at the timing t45. On the other hand, after cranking, at timing t47
If the first missing tooth portion 54b is detected at timing t48 following the detection of the left cam pulse at
At 48, the crank counter value CCR can be set to "20". That is, based on whether the cam pulse immediately before the toothless portion 54b is a left cam pulse or a right cam pulse, the cylinder determination can be completed at the detection timing of the toothless portion 54b without waiting for the end of the determination period G.

Although fuel can be injected into the fourth and seventh cylinders # 4 and # 7 at the detection timing of the toothless portion 54b,
If the cylinder discrimination is completed at that time, the fourth and seventh cylinders #
The fuel injection to one of # 4 and # 7 can be performed at normal timing after the cylinder discrimination. Therefore, when the first missing tooth portion 45b is detected following the detection of the cam pulse, fuel injection is performed only to one of the fourth and seventh cylinders # 4 and # 7.

When the cylinder discrimination is completed at the timing t45, the first ignition can be performed on the third cylinder # 3 which becomes the compression top dead center at the timing t46 immediately thereafter, and thereafter, the sixth cylinder # 6 , Fifth cylinder # 5, seventh cylinder #
The ignition can be performed in the order of 7,. Thereafter, fuel injection to the cylinder 12 where ignition has been performed is sequentially started at normal timing. Further, the fuel injection to the fourth cylinder # 4 is performed at the normal timing after the cylinder discrimination.

As described above, in the present embodiment, when the internal combustion engine 10 is started, when the first left cam pulse is detected, the specific cylinder, that is, the second, sixth, and eighth cylinders # 2, # 2 6 and # 8 are subjected to fuel injection. Further, when the first right cam pulse is detected, the specific cylinder, that is, the first, third, and fifth cylinders # 1, # 3, # 5
Is injected. In other words, even before the cylinder discrimination, fuel injection is performed on a specific cylinder at the first detection timing of the left cam pulse and the right cam pulse. Therefore, similarly to the above-described sixth embodiment, the time from cranking to the first ignition is shortened, and the internal combustion engine 10
Can be started well. Other functions and effects are the same as in the sixth embodiment.

Note that the embodiments of the present invention are not limited to the above embodiments, and the following modifications are possible. -The number of protrusions 54a on the crank rotor 54 and the arrangement intervals thereof may be appropriately changed. Further, the projections 54a may not be provided at equal angular intervals. That is, if the recognition of the crank angle and the recognition of the toothless portion 54b can be performed without any trouble based on a crank signal (crank pulse) corresponding to an index such as a protrusion provided on the crank rotor 54,
Any configuration may be employed as the crank angle sensor 56. -The range of the discrimination period G set based on the detection of the toothless portion 54b is not limited to the range set in each of the above embodiments. -The number of protrusions on the cam rotors 60, 80, 91 and their arrangement intervals may be changed as appropriate. Similarly, the number of the protrusions 70a on the cam rotor 70 and the arrangement intervals thereof may be appropriately changed. In other words, if fuel injection can be performed to a specific cylinder based on a cam signal (cam pulse) corresponding to an index such as a protrusion provided on the cam rotor, what kind of configuration is used as the cam angle sensor 62 May be employed. Further, the cam angle sensor 62 may be provided on the exhaust camshaft 21. The fuel injection mode for a specific cylinder based on the detection of the cam signal and the missing tooth portion 54b is not limited to the mode disclosed in each of the above embodiments, but can be changed as appropriate. The fuel injection start timing for a specific cylinder does not have to be completely synchronized with the generation timing of the cam signal (cam pulse), and may be slightly shifted from the generation timing of the cam signal, for example. The internal combustion engine applicable to the present invention is not limited to the type disclosed in each of the above embodiments. In any of the internal combustion engines, the VVT 30 may or may not be provided. Further, the VVT 30 may be provided on the exhaust camshaft 21 in addition to or instead of the intake camshaft 20. In this case, a cam angle sensor 62 is provided on the exhaust camshaft 21 as necessary.

The technical ideas that can be grasped from the above embodiments will be described below. The fuel injection control device for an internal combustion engine according to any one of claims 1 to 7, wherein the crank angle sensor is a crank rotor that rotates integrally with a crankshaft, and one of the crank rotors is arranged along the rotation direction of the rotor. A crank rotor having a plurality of indices provided at equal angular intervals except for parts,
And a crank signal generating means for generating the crank signal corresponding to each index on the rotor when the crank rotor rotates. In the fuel injection control device for an internal combustion engine according to claim 1, the control means controls the fuel injection means such that fuel is injected to a specific cylinder based on a timing at which a first cam signal is generated. It is characterized by the following. In the fuel injection control device for an internal combustion engine according to claim 1, the control means controls the fuel injection means so that fuel is injected to a specific cylinder in synchronization with a timing of generating a cam signal. It is characterized by the following. The fuel injection control device for an internal combustion engine according to claim 5, wherein the control means further comprises:
When the crankshaft is first placed at a certain rotational angle, fuel is injected into another specific cylinder,
The fuel injection means is controlled. In the fuel injection control method for an internal combustion engine according to claim 8 or 9, when an intake valve provided corresponding to each cylinder is opened, a mixture of the injected fuel and the air in the corresponding cylinder is opened. The cam signal is generated at a timing excluding a specific period during the opening period of the intake valve in order to reliably burn the injected fuel introduced into the cylinder by ignition. It is characterized by.

[0146]

As described in detail above, according to the present invention,
By injecting fuel into a specific cylinder based on the timing at which the cam signal is generated, the internal combustion engine can be started satisfactorily.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of a fuel injection control device for an internal combustion engine according to a first embodiment of the present invention.

FIG. 2 is a front view schematically showing a crank angle sensor.

FIG. 3 is a front view schematically showing a cam angle sensor.

FIG. 4 is a block diagram showing an electrical configuration of the fuel injection control device of FIG. 1;

FIG. 5 is a timing chart for explaining an operation at the time of starting the internal combustion engine.

FIG. 6 is a flowchart for explaining the operation at the time of starting the internal combustion engine.

FIG. 7 is a flowchart for explaining an operation when the internal combustion engine is started.

FIG. 8 is a flowchart for explaining the operation at the time of starting the internal combustion engine.

FIG. 9 is a flowchart for explaining an operation when the internal combustion engine is started in the second embodiment.

FIG. 10 is a timing chart for explaining an operation at the time of starting the internal combustion engine in the third embodiment.

FIG. 11 is a timing chart for explaining an operation when the internal combustion engine is started in the fourth embodiment.

FIG. 12 is a front view schematically showing a cam angle sensor according to a fifth embodiment.

FIG. 13 is a timing chart for explaining an operation at the time of starting the internal combustion engine in the fifth embodiment.

FIG. 14 is a timing chart for explaining an operation when the internal combustion engine is started in the sixth embodiment.

FIG. 15A is a front view schematically showing a cam angle sensor according to a seventh embodiment, and FIG. 15B is a front view schematically showing another cam angle sensor.

FIG. 16 is a timing chart for explaining an operation when the internal combustion engine is started in the seventh embodiment.

17A is a front view schematically showing a conventional crank angle sensor, and FIG. 17B is a front view schematically showing a conventional cam angle sensor.

FIG. 18 is a timing chart for explaining an operation at the time of starting an internal combustion engine in a conventional technique.

[Explanation of symbols]

10 internal combustion engine, 12 cylinder, 13 piston, 15
Crankshaft, 20: intake camshaft, 21: exhaust camshaft, 23: intake valve, 40: setting means,
ECU constituting cylinder discriminating means and control means, 53: injector as fuel injection means, 54: crank rotor, 54a: protrusion as index, 54b: missing tooth part, 55
... Crank pulse generator, 56 ... Crank angle sensor, 6
0: cam rotor, 60a: primary projection as a discrimination index,
Reference numeral 60b: a second protrusion as an auxiliary index; 60c, a third protrusion as an auxiliary index; 61, a cam pulse generator; 62, a cam angle sensor; 70, a cam rotor;
... Recess, 80 ... cam rotor, 80a-80c ... projection as auxiliary index, 90 ... cam angle sensor, 91 ... cam rotor, 91a ... projection as discrimination index, 92 ... cam pulse generator.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 45/00362 F02D 45 / 00362E

Claims (9)

[Claims] An apparatus includes a piston housed in each of a plurality of cylinders, a crankshaft that rotates with reciprocating motion of the piston, and a camshaft that rotates once every two rotations of the crankshaft. A crank angle sensor for generating a crank signal indicating a rotation angle of the crankshaft with rotation of the crankshaft in an internal combustion engine in which each piston reciprocates twice so as to execute one engine cycle during rotation; Setting means for setting a specific discrimination angle range with respect to the crankshaft based on the crank signal; discrimination cam for cylinder discrimination corresponding to a predetermined rotation angle of the camshaft each time the camshaft makes one rotation A cam angle sensor that generates a plurality of cam signals including a signal and an auxiliary cam signal, wherein the crankshaft is A cam angle sensor for generating a discriminating cam signal in synchronization with one of two discrimination angle ranges appearing during two rotations, and generating an auxiliary cam signal at a timing not synchronized with the discrimination angle range; Cylinder discriminating means for discriminating a cylinder based on whether or not a discriminating cam signal is generated when is within the discriminating angle range, fuel injection means for injecting fuel into each cylinder, respectively, starting of the internal combustion engine At this time, fuel is injected into a specific cylinder based on the timing of the generation of the cam signal,
A fuel injection control device for an internal combustion engine, comprising: a control means for controlling the fuel injection means. 2. An intake valve is provided for each cylinder, and when the intake valve is opened, a mixture of injected fuel and air is introduced into the corresponding cylinder. 2. The fuel injection control of an internal combustion engine according to claim 1, wherein the cam angle sensor is configured to generate a cam signal at a timing excluding a latter half of an opening period of an intake valve corresponding to the specific cylinder. 3. apparatus. 3. A cam rotor, wherein the cam angle sensor is a cam rotor that rotates integrally with a cam shaft, the cam rotor having a discriminating index for cylinder discrimination and an auxiliary index provided at predetermined intervals along a rotation direction of the rotor. And a cam signal generator that is arranged to face the cam rotor, and that generates the discriminating cam signal and the auxiliary cam signal in response to the discriminating index and the auxiliary index when the cam rotor rotates. The fuel injection control device for an internal combustion engine according to claim 1 or 2. 4. The cam rotor has two auxiliary indices, and the cam signal generator generates two auxiliary cam signals respectively corresponding to the two auxiliary indices during one rotation of the cam rotor. The cam signal is generated after the discrimination angle range accompanied by the generation of the discrimination cam signal and before the next discrimination angle range appears, and the other auxiliary cam signal is generated by the discrimination angle without the generation of the discrimination cam signal. 4. The fuel injection control device for an internal combustion engine according to claim 3, wherein the signal is generated after the range has passed and before the next determination angle range appears. 5. The crank signal includes information indicating that the crankshaft is at a specific rotation angle, and the setting unit recognizes that the crankshaft is at a specific rotation angle based on the crank signal, 5. The fuel injection control device for an internal combustion engine according to claim 4, wherein an angle range from when the crankshaft rotates by a predetermined angle is set as the determination angle range. 6. The cylinder discriminating means, when starting the internal combustion engine, if the generation of a cam signal is confirmed twice before the discrimination angle range is set, then the crankshaft is arranged at a specific rotation angle. The fuel injection control device for an internal combustion engine according to claim 5, wherein the cylinder is determined at the time when the determination is made. 7. The internal combustion engine is an in-line four-cylinder internal combustion engine, and the control means controls the fuel injection so that fuel is injected to all cylinders in synchronization with the first cam signal generation timing. The fuel injection control device for an internal combustion engine according to any one of claims 1 to 6, wherein the control unit controls the means. 8. A piston provided in each of a plurality of cylinders, a crankshaft that rotates with reciprocating motion of the piston, and a camshaft that makes one rotation every two rotations of the crankshaft, wherein the crankshaft has two rotations. Setting a specific discrimination angle range with respect to the crankshaft in an internal combustion engine in which each piston reciprocates twice so as to execute one engine cycle during rotation; Generating a plurality of cam signals including a discriminating cam signal for cylinder discrimination and an auxiliary cam signal in correspondence with a predetermined rotation angle of the camshaft, respectively. The discriminating cam signal is generated in synchronization with one of the discrimination angle ranges, and the auxiliary cam signal is Generating a cylinder signal based on whether or not a discrimination cam signal has been generated when the crankshaft is within the discrimination angle range. A step of injecting fuel into a cylinder. 9. The auxiliary cam signal is generated twice during one rotation of the camshaft, and one auxiliary cam signal is output after the discrimination angle range accompanying the generation of the discrimination cam signal has passed. The auxiliary cam signal is generated before the appearance, and the other auxiliary cam signal is generated after the discrimination angle range without the generation of the discrimination cam signal and before the next discrimination angle range appears. The fuel injection control method for an internal combustion engine according to claim 8, wherein