JPH11270387A - Starting control device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ignite an air-fuel mixture sufficiently atomizing an injection fuel at the time of starting without causing increase of the number of parts, to be consistent improvement in startability with reduction of costs. SOLUTION: This control device judges whether the number of injection is more than the specified number of injection N or not (step 204) by counting the number of fuel injection at the time of starting (steps 200-203). Hereby, the specified number of injection N is the number of injection required necessary for time required until an air-fuel mixture which fuel injected for the first time is atomized and easy to ignite is formed and is set in accordance with cooling water temperature, fuel pressure, etc. When the number of injection is less than the specified number of injection N, atomization of fuel is considered to be still insufficient, and only fuel injection is carried out at the initial stage of an air intake process by cutting ignition (steps 205, 207). Thereafter, at the point of time when the number of injection becomes more than the specified number of injection N, ignition is started while continuously carrying out fuel injection (steps 206, 207). Consequently, it is possible to ignite fuel injected within an ignition cutting period after sufficiently atomizing it and to improve startability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-cylinder injection type internal combustion engine for directly injecting fuel into a cylinder, and more particularly to a start control device for an internal combustion engine having an improved control system at the time of starting.

[0002]

2. Description of the Related Art In recent years, the demand for an in-cylinder injection engine having features of low fuel consumption, low exhaust emission, and high output has been rapidly increasing. In the in-cylinder injection engine, a fuel injection valve is arranged in each cylinder, fuel is directly injected from the fuel injection valve into a combustion chamber, and mixed with intake air introduced from an intake port to form an air-fuel mixture. The mixture is ignited by a spark plug and burned.

However, the direct injection engine has a shorter time from when fuel is injected until it reaches an ignition position than an intake pipe injection engine that injects fuel into an intake pipe. Atomization tends to be insufficient, and there is a disadvantage that startability is deteriorated. In addition, if ignition is performed in a state where fuel atomization is insufficient, it happens
The ignition may occur only a few times or may occur only in some cylinders.As a result, if the engine speed temporarily exceeds the start completion judgment speed, it is judged that the start is completed, and the fuel increase at the start The correction is canceled, and thereafter, a rich air-fuel ratio required for completing the start cannot be obtained, and the combustion state deteriorates.

[0004] As a countermeasure, a high-pressure pump injects fuel at a high pressure from a fuel injection valve to atomize the fuel to promote atomization, or to disperse the fuel in Japanese Patent No. 2605.
As shown in Japanese Patent Application Publication No. 070, a fuel injection valve is also attached to the intake pipe in addition to the fuel injection valve for in-cylinder injection. There are things that ensured the conversion.

[0005]

However, in the former case,
Many high-pressure pumps use the power of the engine as a drive source. However, at the time of starting, since a sufficient driving force cannot be obtained from the engine, it is necessary to provide a motor or the like to drive the high-pressure pump. In the latter case, it is necessary to provide a new fuel injection valve in the intake pipe in addition to the fuel injection valve for each cylinder.
In either case, there is a disadvantage that the number of parts increases and the cost increases.

[0006] The present invention has been made in view of such circumstances, and it is therefore an object of the present invention to ignite a sufficiently atomized air-fuel mixture at start-up without increasing the number of parts. It is an object of the present invention to provide a start control device for an internal combustion engine that can achieve both improved startability and reduced cost.

[0007]

To achieve the above object, according to the first aspect of the present invention, in a direct injection type internal combustion engine, a start control means cuts off ignition during an ignition cut period at an early stage of starting. Only the fuel injection is performed, and after the ignition cut period has elapsed, the ignition is started while the fuel injection is continuously performed. In this case, the fuel injected during the ignition cut period in the early stage of the engine remains in the cylinder without exhausting a certain percentage of the fuel even after the exhaust stroke. As a result, before the first ignition is started after the lapse of the ignition cut period, a sufficient time for atomizing the fuel injected at the beginning of the start can be sufficiently secured, and the fuel is sufficiently atomized before ignition. Thus, the air-fuel mixture can be reliably ignited and burned at the time of starting, and the startability can be improved. Moreover, unlike the conventional case, there is no need to add a motor for driving the high-pressure pump or a fuel injection valve for the intake pipe injection, which reduces the number of parts,
The requirement for cost reduction can be satisfied.

In this case, the fuel injection may be started at an early stage of the intake stroke within the ignition cut period at the initial stage of the start. As described above, if the fuel injection is started at the earliest time of the intake stroke, which is the normal setting range of the fuel injection timing, from the intake stroke to the early stage of the intake stroke, the time from the fuel injection to the ignition, and eventually, the injected fuel is atomized. You can extend the time.

According to a third aspect of the present invention, there is provided a system including at least one of a throttle control unit, a swirl control unit for controlling a swirl flow intensity in a cylinder, and an exhaust gas recirculation control unit (EGR). It is preferable to control the at least one means to a position where the exhaust gas flow rate decreases during the ignition cut period at the initial stage of starting. By doing so, the residual ratio of the fuel injected during the ignition cut period at the initial stage of the start can be increased, and the air-fuel mixture at the first ignition after the elapse of the ignition cut period can be made richer, Starting performance can be further improved, and unburned HC
Emissions can be reduced.

Further, in the system having the exhaust valve control means for controlling the opening time of the exhaust valve, the opening time of the exhaust valve can be shortened or minimized during the ignition cut period at the beginning of starting. 0 is also included). Also in this case, since the exhaust gas flow rate during the ignition cut period is reduced, the residual ratio of the fuel injected during the ignition cut period at the initial stage of the start can be increased, as in the above-described third embodiment.

By the way, the injected fuel becomes more difficult to atomize as the cooling water temperature is lower and the fuel pressure is lower. In consideration of this point, the ignition cut period at the initial stage of the start may be set based on at least one of the cooling water temperature and the fuel pressure. This makes it possible to optimize the length of the ignition cut period in response to the time required for atomizing the fuel depending on the coolant temperature and the fuel pressure.

Further, the ignition cut period at the beginning of the start may be determined by any of the number of injections, the elapsed time, and the number of cycles since the start of the start. In any case, the progress of the ignition cut period can be counted by the counter, and the processing is easy.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Embodiment (1)] An embodiment (1) of the present invention will be described below with reference to FIGS.
First, a schematic configuration of the entire engine control system will be described with reference to FIG. An air cleaner 13 is provided at the most upstream portion of an intake pipe 12 of a direct injection engine 11 which is a direct injection internal combustion engine, and a step motor 14 which is a throttle control means is provided downstream of the air cleaner 13. A throttle valve 15 whose opening is adjusted is provided. When the step motor 14 is driven based on an output signal from an engine electronic control circuit (hereinafter referred to as “ECU”) 16, the opening of the throttle valve 15 (throttle opening) is controlled, and the throttle opening is controlled. The amount of intake air to each cylinder is adjusted according to. Near the throttle valve 15, a throttle sensor 1 for detecting a throttle opening is provided.
7 are provided.

A surge tank 19 is provided downstream of the throttle valve 15, and an intake manifold 20 for introducing air into each cylinder of the engine 11 is connected to the surge tank 19. Intake manifold 20 for each cylinder
A first intake path 21 and a second intake path 22 are respectively formed in the inside of the first intake path 21 and the second intake path 22.
Are connected to two intake ports 23 formed in each cylinder of the engine 11, respectively. Each intake port 23 is provided with an intake valve 43 (see FIG. 2).

A swirl control valve 24 (swirl control means) is disposed in the second intake passage 22 of each cylinder. The swirl control valve 24 of each cylinder has a common shaft 2
5 is connected to the step motor 26. When the step motor 26 is driven based on an output signal from the ECU 16, the opening of the swirl control valve 24 is controlled, and the swirl flow intensity in each cylinder is adjusted according to the opening. A swirl control valve sensor 27 that detects the degree of opening of the swirl control valve 24 is attached to the step motor 26.

As shown in FIG. 2, a fuel injection valve 2 for directly injecting fuel into the cylinder is provided above each cylinder of the engine 11.
8 is attached, and the piston 4
The fuel is injected toward the concave portion 42a formed on the upper surface of the fuel cell 2. As shown in FIG. 1, fuel sent from a fuel tank (not shown) to a fuel delivery pipe 29 through a fuel pipe 45 is injected into a combustion chamber from a fuel injection valve 28 of each cylinder, and is introduced from an intake port 23. The air-fuel mixture is mixed with the intake air to be formed. Fuel delivery pipe 29
Is provided with a fuel pressure sensor 30 as fuel pressure detecting means for detecting a fuel pressure (fuel pressure) PR.

Further, an ignition plug 31 (see FIG. 2) is attached to the cylinder head of the engine 11 for each cylinder, and the mixture in the combustion chamber is ignited by the spark discharge of each ignition plug 31. The cylinder discrimination sensor 32 generates an output pulse when a specific cylinder (for example, the first cylinder) reaches the intake top dead center. The crank angle sensor 33 detects that the crankshaft of the engine 11 has a constant crank angle (for example, 3).
0 ° C. A) Generates an output pulse each time it rotates. By these output pulses, the crank angle and the engine speed NE are calculated.
Is detected, and cylinder determination is performed. Also, the engine 11
Is provided with a water temperature sensor 34 as cooling water temperature detecting means for detecting the cooling water temperature THW.

On the other hand, an exhaust valve 44 (see FIG. 2) is provided at each of the exhaust ports 35 of the engine 11, and the exhaust discharged from each of the exhaust ports 35 is exhausted by the exhaust manifold 3.
6 to one exhaust pipe 37. This exhaust pipe 3
An EGR pipe 38 for recirculating a part of exhaust gas to the intake system is connected between the fuel tank 7 and the surge tank 19, and an EGR valve 39 (exhaust gas recirculation control means) is provided in the EGR pipe 38. E based on an output signal from the ECU 16
The opening of the GR valve 39 is controlled, and EGR is performed according to the opening.
The amount (exhaust gas recirculation amount) is adjusted. The accelerator pedal 18 has an accelerator sensor 40 for detecting an accelerator opening.
Is provided.

The output signals of the various sensors described above are supplied to the ECU
16 is input. The ECU 16 is mainly composed of a microcomputer, and controls the aforementioned step motors 14, 26, E based on various sensor outputs in accordance with a control program stored in a built-in ROM (storage medium).
The operation of the GR valve 39, the fuel injection valve 28, and the spark plug 31 is controlled.

The ECU 16 calculates the fuel injection amount at startup by executing a startup fuel injection amount calculation routine shown in FIG. 3 when the engine 11 is started.
By executing the routines shown in (1), the ignition control is cut at the initial stage of the starting until the number of injections reaches a predetermined number, and only the fuel injection is executed, and after the ignition cut period has elapsed, the ignition control is started while continuing the fuel injection. Functions as a means.
Hereinafter, the processing content of each routine will be described.

The start-time fuel injection amount calculation routine shown in FIG. 3 is repeatedly executed at predetermined time intervals or at predetermined crank angle intervals after an ignition switch (not shown) is turned on.
When this routine is started, first, in step 100, the engine speed NE detected by the crank angle sensor 33 is compared with a start completion determination value to determine whether or not the start is before completion. At this time, the start completion determination value is switched before and after the completion of the start as shown in FIG. 4 in order to have hysteresis in the start completion determination.
It is determined that the start is not completed until E exceeds, for example, 400 rpm, and once it is determined that the start is completed, exceeding 400 rpm, it is determined that the start is completed until the engine speed NE decreases to, for example, less than 200 rpm.

If it is determined in step 100 that the start is completed, this routine is terminated and a post-start fuel injection amount calculation routine (not shown) is executed to calculate the fuel injection amount after the start is completed.

On the other hand, if it is determined in step 100 that the starting is not completed, the routine proceeds to step 101, where the cooling water temperature THW detected by the water temperature sensor 34 is read, and in the next step 102, the cooling water temperature THW is set as a parameter. A map of the starting basic fuel injection amount q1 is searched to find the starting basic fuel injection amount q1 according to the current cooling water temperature THW.
The map of the basic fuel injection amount at the time of starting is set in advance by experimental data and theoretical formulas, and is stored in the ROM of the ECU 16. The fuel injection amount of the fuel injection valve 28 is:
For example, in step 103, the correction amount q2 is calculated on the basis of the battery voltage, and the correction amount q2 is added to the starting basic fuel injection amount q1 in step 103, and the correction amount q2 is calculated in step 103. The total fuel injection amount q is calculated (q = q1 + q2), and this routine ends.

The start-time injection / ignition control routine shown in FIG. 5 is executed as follows every predetermined time or every predetermined crank angle after turning on an ignition switch (not shown). First, in step 200, step 10 in FIG.
As in the case of 0, it is determined whether or not the start is completed. If it is determined that the start is completed, the routine is terminated. If the start is not completed, the process proceeds to step 201, and after the cranking is started,
Whether fuel injection has been executed (injection execution flag XFIN
J = ON or not), and each time fuel injection is executed,
Proceeding to step 202, the number of injections counter for counting the number of injections from the start of cranking is incremented by one, and at the next step 203, the injection execution flag XFI
NJ is reset to “OFF” and the process proceeds to step 204. On the other hand, in step 201, XFINJ
When it is determined that = OFF, the process proceeds to step 204 without counting up the injection number counter.

In step 204, in order to determine whether or not the ignition cut period in the initial stage of the start has been exceeded, it is determined whether or not the count value of the injection number counter (the number of injections from the start of cranking) is equal to or greater than a predetermined number of injections N. judge. here,
The predetermined number of injections N is, for example, the number of injections required for elapse of a time required until the first injected fuel is atomized to form an air-fuel mixture which is easy to ignite, and the cooling shown in FIG. A map using the water temperature THW as a parameter is searched, and the number of injections N according to the cooling water temperature THW at the time of starting is set. In general, the lower the cooling water temperature THW, the longer the time required for atomizing the injected fuel. Therefore, the characteristics of the map of the predetermined number of injections N in FIG. 7 indicate that the lower the cooling water temperature THW, the greater the number of predetermined injections N. It is set to be. The map of the predetermined number of injections N is set in advance by experimental data or theoretical formula, and is stored in the ROM of the ECU 16. The predetermined number of injections N may be a fixed value set in advance.

If it is determined in step 204 that the number of injections from the start of cranking is less than the predetermined number of injections N,
Since fuel atomization still seems to be insufficient, step 20
Proceeding to 5, the ignition is cut, and the fuel injection amount and fuel injection timing are set. Here, the fuel injection amount is shown in FIG.
Is set to the starting total fuel injection amount q calculated in step 104, and the fuel injection timing is set so as to start fuel injection at the beginning of the intake stroke. Thereby, as shown in FIG. 2, the fuel injection is set to start at the timing when the piston 42 is located near the top dead center of the intake stroke.

Thereafter, the routine proceeds to step 205, where a fuel injection / ignition execution routine shown in FIG. Thus, during the ignition cut period at the beginning of the start, the ignition is cut and only the fuel injection is executed at the beginning of the intake stroke. In this way, the fuel injected during the ignition cut period is
Even after the exhaust stroke, a certain percentage of the fuel remains in the cylinder without being discharged, so that the fuel injected at the beginning of startup is atomized before the first ignition starts after the ignition cut period. You have enough time to do it.

Thereafter, when this routine is started, if it is determined in step 204 that the number of injections from the start of cranking is equal to or greater than the predetermined number of injections N, the routine proceeds to step 206, where the ignition cut is canceled (ignition cut). At the end of the period), the ignition timing is set, and the fuel injection amount and the fuel injection timing are set. Thereafter, the routine proceeds to step 207, where a fuel injection / ignition execution routine of FIG. 6 described later is executed. Thus, after the lapse of the ignition cut period at the initial stage of the start, the fuel is injected from the fuel injection valve 28 and the ignition by the ignition plug 31 is started under the injection / ignition conditions set in the above-mentioned step 206, and the air-fuel mixture is discharged. Ignite and burn.

In the fuel injection / ignition execution routine shown in FIG.
Then, it is determined whether or not the fuel injection timing set in step 205 or 206 has come. This determination is made based on the count value of the timer counter that starts the timing operation at the same time as the processing of step 205 or 206 described above. If it is determined in step 300 that it is the fuel injection timing, the routine proceeds to step 301, where the fuel injection is executed, and the injection execution flag XFINJ is set to "ON". Thereafter, in step 302, it is determined from the count value of the timer counter whether or not the ignition timing set in step 205 or 206 has been reached.
Go to 03 and execute ignition.

According to the above-described embodiment (1), during the period in which the number of fuel injections is less than the predetermined number of injections N (ignition cut period) at the initial stage of starting, the ignition of the ignition plug 31 is cut off and only the fuel injection is executed. Thus, a sufficient time for atomizing the fuel injected into the cylinder at the beginning of the start can be secured before the first ignition is started after the elapse of the ignition cut period. As a result, the fuel injected at the beginning of the start can be sufficiently atomized to form an air-fuel mixture suitable for ignition and then ignited, and the air-fuel mixture can be reliably ignited and burned at the start, Startability can be improved. Further, unlike the conventional case, there is no need to add a motor for driving a high-pressure pump (not shown) for increasing the fuel pressure or a fuel injection valve for the intake pipe injection, so that the number of parts is reduced, the size is reduced, and the cost is reduced. Requirements can be satisfied.

In the above embodiment (1), during the ignition cut period at the beginning of the start, the fuel injection is started in the early stage of the intake stroke, which is the earliest time within the range in which the fuel can be injected. , And furthermore, the time for atomizing the injected fuel can be secured longer, and the atomization of the fuel can be further ensured. However,
The fuel injection start timing during the ignition cut period is not limited to the early stage of the intake stroke, and may be after the middle stage of the intake stroke.

Further, in the above embodiment (1), the predetermined number of injections N for determining the ignition cut period is determined from a map using the coolant temperature THW as a parameter. As shown in FIG. 8, a map of the predetermined number of injections N using the fuel pressure PR as a parameter is created based on experimental data or a theoretical formula, and the predetermined number of injections N is determined from this map. You may do it. In this case, as the fuel pressure PR becomes lower, the time required for atomizing the injected fuel becomes longer. Therefore, the characteristic of the map of the predetermined number of injections N in FIG.
The predetermined number of injections N is set to increase as R decreases. The predetermined number of injections N is determined by the cooling water temperature THW.
It may be determined comprehensively from a two-dimensional map or the like in consideration of both the pressure and the fuel pressure PR.

[Embodiment (2)] Since the fuel injected during the ignition cut period enters the exhaust stroke without being ignited, if the discharge ratio of the air-fuel mixture discharged in the exhaust stroke increases, the ignition cut is stopped. The residual ratio of the fuel injected during the period is reduced.

Therefore, in the embodiment (2) of the present invention, by executing the start-time injection / ignition control routine shown in FIG. 9, the air system control valve (throttle valve 1) is controlled during the ignition cut period.
5. The swirl control valve 24 and the EGR valve 39) are controlled to a position where the exhaust gas flow rate decreases to increase the residual ratio of the fuel injected during the ignition cut period.

In the start-time injection / ignition control routine shown in FIG. 9, the difference from FIG. 5 of the first embodiment is that step 205a is between step 204 and step 205.
That is, the processing of step 206a is added between step 204 and step 206.

In this routine, at step 204,
If it is determined that the number of injections since the start of cranking is less than the predetermined number of injections N (within the ignition cut period), the routine proceeds to step 205a, where the throttle opening TA and the swirl control valve opening SCV are both set to the full open KTA and KSCV. Set and E
The GR valve opening EGR is set to the fully closed KEGR. Thus, when the throttle valve 15 is fully opened, the air-fuel mixture easily flows back to the intake system during the period when the intake valve 43 is open at the beginning of the exhaust stroke, and an effect of reducing the exhaust flow rate can be obtained. In addition, when the swirl control valve 27 is fully opened, the swirl flow in the cylinder is stopped, and the blowing of fuel to the exhaust port 35 due to the swirl flow is prevented. Further, when the EGR valve 41 is fully closed, the flow of the EGR gas is stopped, and an effect of reducing the exhaust gas flow rate can be obtained. During the ignition cut period, each air system control valve is held at a position where the exhaust flow rate decreases (step 205a), and the ignition is cut to execute only the fuel injection at the beginning of the intake stroke (step 205).

On the other hand, if it is determined in step 204 that the number of injections is equal to or greater than the predetermined number N of injections (the end of the ignition cut period), the routine proceeds to step 206a, where the throttle opening T
A, swirl control valve opening SCV and EGR valve opening EGR
Is set by a map or the like according to the cooling water temperature THW, the engine speed NE, etc., the control of the throttle valve 15, the swirl control valve 24 and the EGR valve 39 is returned to the normal control, the ignition cut is released, and the ignition timing is released. Then, the fuel injection amount and the fuel injection timing are set (step 206). The processing other than the above is the same as that of the embodiment (1).

In the embodiment (2) described above, the air system control valves (the throttle valve 15, the swirl control valve 24 and the EGR valve 39) are controlled to the position where the exhaust gas flow decreases during the ignition cut period. The residual ratio of the fuel injected during the ignition cut period can be increased, the air-fuel mixture at the first ignition after the ignition cut period has elapsed can be made richer, and the startability can be further improved. The discharge amount of unburned HC at the time of starting can be reduced.

In the embodiment (2), the throttle valve 15 and the swirl control valve 24 are fully opened and the EGR valve 39 is fully closed during the ignition cut period. However, the present invention is not limited to this. Instead, for example, the throttle valve 15 and the swirl control valve 24 are controlled to open, and the EGR valve 3
9 may be controlled in the closing direction, that is, the exhaust gas flow rate (air flow in the cylinder) may be controlled in a direction in which the exhaust gas flow rate is reduced. In addition, for the air-based control valve having little effect on the airflow in the cylinder, it is not always necessary to perform the above-described control during the ignition cut period, and to perform the same control as before in the ignition cut period. Is also good. Incidentally, among the throttle valve 15, the swirl control valve 24, and the EGR valve 39, the effect of increasing the fuel residual ratio by fully opening the swirl control valve 24 (stopping the swirl flow) is the largest.

[Embodiment (3)] Next, FIG. 10 and FIG.
Embodiment 1 (3) will be described with reference to FIG. In the embodiment (2), the residual ratio of the fuel injected during the ignition cut period is increased by controlling the air system control valve to a specific position during the ignition cut period. When the present invention is applied to a system equipped with an exhaust valve timing mechanism 45 (exhaust valve control means) for varying the opening / closing timing of the exhaust valve 44, the start-up injection / ignition control routine of FIG. Then, during the ignition cut period, the opening time of the exhaust valve 44 is set to a minimum,
The residual ratio of the injected fuel may be increased.

In the start-time injection / ignition control routine of FIG. 11, if it is determined in step 204 that the number of injections from the start of cranking is less than the predetermined number of injections N (within the ignition cut period), the routine proceeds to step 205b. Then, the valve opening time VVT of the exhaust valve 44 is set to the minimum value minVVT that can be adjusted by the exhaust valve timing mechanism 45, ignition is cut off, and only fuel injection is executed at the beginning of the intake stroke (step 2).
05). In addition, the minimum value minVV of the valve opening time of the exhaust valve 44
T may be 0 (that is, the exhaust valve 44 is fully closed even during the exhaust stroke).

On the other hand, if it is determined in step 204 that the number of injections is equal to or greater than the predetermined number of injections N (the end of the ignition cut period), the routine proceeds to step 206b, in which the valve opening time VVT of the exhaust valve 44 is set to the cooling water temperature THW, The ignition timing, the fuel injection amount, and the fuel injection timing are set in accordance with the engine speed NE and the like, the control of the opening and closing timing of the exhaust valve 44 is returned to the normal control, the ignition cut is released, and the ignition timing, the fuel injection amount, and the fuel injection timing are set (step 20).
6). The processing other than the above is the same as that of the embodiment (1).

In this way, during the ignition cut period,
Since the opening time of the exhaust valve 44 can be minimized, the exhaust flow rate during the ignition cut period can be reduced, and the residual ratio of the fuel injected during the ignition cut period can be increased.

In this embodiment (3), the valve opening time VVT of the exhaust valve 44 is minimized during the ignition cut period. However, the valve opening time VVT of the exhaust valve 44 is set shorter than at the time of normal startup. Even in this case, the effect of increasing the residual fuel ratio by decreasing the exhaust gas flow rate can be obtained.

Further, during the ignition cut period, the opening time of the exhaust valve 44 is minimized or shortened, and the air system control valve (at least one of the throttle valve 15, the swirl control valve 24 and the EGR valve 39) is used in the above embodiment. As in the case of (2), the exhaust gas flow rate (air flow in the cylinder) may be controlled to decrease.

In each of the above embodiments (1) to (3), the ignition cut period at the start of the start is determined by the number of fuel injections. For example, the elapsed time or the number of cycles from the start of the start is counted by a counter. Alternatively, it may be determined from the count value whether or not it is the ignition cut period.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an entire engine control system according to an embodiment (1) of the present invention.

FIG. 2 is a longitudinal sectional view showing a configuration of a main part of the engine.

FIG. 3 is a flowchart showing a flow of processing of a fuel injection amount calculation routine at the time of starting.

FIG. 4 is a diagram for explaining a criterion for determining completion of starting;

FIG. 5 is a flowchart showing the flow of processing of a startup injection / ignition control routine according to the embodiment (1).

FIG. 6 is a flowchart showing the flow of processing of a fuel injection / ignition execution routine;

FIG. 7 is a diagram showing a relationship between a cooling water temperature THW and a predetermined number of injections N.

FIG. 8 is a diagram showing a relationship between a fuel pressure PR and a predetermined number of injections N.

FIG. 9 shows a fuel injection at start-up in the embodiment (2) of the present invention.
Flow chart showing the flow of processing of the ignition control routine

FIG. 10 is a longitudinal sectional view showing a configuration of a main part of an engine according to an embodiment (3) of the present invention.

FIG. 11 is a flowchart showing a processing flow of a start-time injection / ignition control routine according to the embodiment (3).

[Explanation of symbols]

11. In-cylinder injection engine (in-cylinder injection internal combustion engine), 1
2 ... intake pipe, 14 ... step motor (throttle control means), 15 ... throttle valve, 16 ... ECU (start control means), 24 ... swirl control valve (swirl control means), 2
6 Step motor, 28 Fuel injection valve, 30 Fuel pressure sensor (fuel pressure detecting means), 31 Spark plug, 34 Water temperature sensor (cooling water temperature detecting means), 37 Exhaust pipe, 39 E
GR valve (exhaust gas recirculation control means), 40 ... EGR pipe, 43
... intake valve, 44 ... exhaust valve, 45 ... exhaust valve timing mechanism (exhaust valve control means).

Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI F02D 43/00 301 F02D 43/00 301U 301N 301K F02M 25/07 550 F02M 25/07 550H F02P 11/04 301 F02P 11/04 301A

Claims (6)

[Claims] 1. A cylinder injection type internal combustion engine in which fuel is directly injected into a cylinder from a fuel injection valve and an air-fuel mixture is ignited by an ignition plug.
Starting control means for cutting off the ignition of the spark plug and executing only fuel injection, and starting ignition while continuously performing fuel injection after the ignition cut period has elapsed. Control device. 2. The start control of an internal combustion engine according to claim 1, wherein the start control means controls an injection timing so that fuel injection is started at an early stage of an intake stroke during the ignition cut period. apparatus. 3. At least one of throttle control means for controlling the opening of the throttle valve, swirl control means for controlling the swirl flow intensity in the cylinder, and exhaust gas recirculation control means for controlling the amount of exhaust gas recirculated to the intake system. 3. The start control device for an internal combustion engine according to claim 1, further comprising a control unit, wherein the start control unit controls the at least one unit to a position where an exhaust gas flow rate decreases during the ignition cut period. 4. 4. An exhaust valve control means for controlling an opening time of an exhaust valve, wherein the start control means controls the exhaust valve control means to shorten or minimize the opening time of the exhaust valve during the ignition cut period. 4. The start control apparatus for an internal combustion engine according to claim 1, wherein the control is performed so as to perform the following operations. 5. The engine according to claim 1, further comprising at least one of a cooling water temperature detecting means for detecting a cooling water temperature of the internal combustion engine and a fuel pressure detecting means for detecting a pressure of fuel supplied to the fuel injection valve. The apparatus according to any one of claims 1 to 4, wherein an ignition cut period is set based on at least one of the cooling water temperature and the fuel pressure. 6. The method according to claim 1, wherein the start control unit determines the ignition cut period based on any of the number of injections, the elapsed time, and the number of cycles from the start of the start. Start control device for internal combustion engine.