JP3273651B2 - Ignition timing control device for peripheral ignition engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling the ignition timing of each ignition source in a peripheral ignition engine in which ignition sources are arranged at a plurality of positions including a peripheral portion in one cylinder. .

[0002]

2. Description of the Related Art Conventionally, an ignition source for an engine is generally provided at the center of each cylinder. In recent years, however, ignition sources have been arranged at a plurality of positions including a peripheral portion in one cylinder. Thereby, particularly, rapid combustion of unburned gas components is performed. For example, Japanese Unexamined Patent Publication No. Hei 4-183925 discloses that a plurality of ignition sources are arranged around the periphery of the combustion chamber such that the combustion flame growing from the ignition source first reaches the center of the combustion chamber after reaching the entire length in the cylinder circumferential direction. In the figure, a plurality of components are arranged at intervals in the direction.

[0003]

The distribution of the mixture in the cylinder is generally non-uniform, and the distribution varies depending on the fuel injection timing. For example, in order to quickly mix intake air and fuel, fuel is injected during an intake stroke in which an intake port is opened, and in other periods, that is, fuel is injected during an exhaust stroke in which the intake port is closed. Inevitably, the air-fuel mixture distribution in the cylinder is different.

[0004] Such uneven distribution of the air-fuel mixture depending on the fuel injection timing leads to uneven combustion speed in the cylinder. In this way, if the combustion speed differs depending on the location, even if ignition is performed simultaneously by each ignition source, the flame caused by the ignition in the region where the combustion speed is fast spreads faster than the flame caused by the ignition in the region where the combustion speed is slow. As a result, uniform combustion cannot be expected.

In view of such circumstances, the present invention takes into account the distribution of the air-fuel mixture in a cylinder which is affected by the fuel injection timing, and controls the ignition timing of a peripheral ignition engine capable of achieving uniform combustion in the cylinder. It is intended to provide a device.

[0006]

As a means for solving the above problems, the present invention relates to a fuel injection means for a peripheral ignition engine in which ignition sources are arranged at a plurality of positions including a peripheral portion in one cylinder. And ignition for setting the ignition timing of an ignition source provided at a point where the combustion speed is faster than another point in correspondence with the fuel injection timing by the fuel injection means to a timing later than the ignition timing of the other ignition source. There is provided timing setting means, and ignition control means for controlling the ignition operation of each ignition source based on the set ignition timing.

Further, according to the first aspect of the present invention, when the fuel injection timing is set during the intake stroke, in the region where the operation is performed at an air-fuel ratio equal to or higher than the stoichiometric air-fuel ratio, the intake air on the cylinder wall surface of each ignition source. The ignition timing setting means is configured to set an ignition timing of an ignition source provided at a position facing the port or a position closest to the port later than other ignition timings.

Further, according to the present invention, when the fuel injection timing is set during a period other than the intake stroke, the operation of the ignition sources in the region where the air-fuel ratio is higher than the stoichiometric air-fuel ratio is performed. The ignition timing setting means is configured to set the ignition timing of an ignition source provided at a position closest to the intake port later than other ignition timings.

The invention according to claim 3 further comprises a fuel injection control means for changing the fuel injection timing according to the operating conditions, and when the fuel injection timing is set during the intake stroke, the stoichiometric air-fuel ratio is set. In the region where the operation is performed at an air-fuel ratio equal to or higher than the fuel ratio, the ignition timing of the ignition source provided at the position facing or closest to the intake port on the cylinder wall surface of each ignition source is set later than the other ignition timings If the fuel injection timing is set during a period other than the intake stroke, the ignition provided at the position closest to the intake port among the ignition sources in the region where the operation is performed at an air-fuel ratio equal to or higher than the stoichiometric air-fuel ratio. The ignition timing setting means is configured to set the ignition timing of the source later than other ignition timings.

Further, there is provided temperature detecting means for detecting the operating temperature of the engine, and only when the temperature detected by the temperature detecting means is equal to or lower than a preset temperature, the ignition timing of some of the spark plugs is set to another value. The ignition timing setting means may be configured to set a timing later than the ignition timing of the ignition plug (claim 4), or fuel determination means for determining the type of fuel may be provided. The ignition timing setting means may be configured to set the ignition timing of some of the ignition plugs to a timing later than the ignition timing of the other ignition plugs only when it is determined that the gasoline is gasoline. A swirl generating means for generating a swirl in a preset operation region, and only when the swirl is generated by the swirl generating means, the operation is performed at an air-fuel ratio equal to or higher than the stoichiometric air-fuel ratio. The ignition timing setting means so that the ignition timing of the ignition source provided at the position facing the intake port on the cylinder wall surface of the ignition source or the position closest thereto is set later than the other ignition timings. By configuring (claim 6), more excellent effects as described later can be obtained.

[0011]

As described above, the air-fuel mixture distribution in the cylinder is affected by the fuel injection timing. However, according to the apparatus of the present invention, the combustion speed becomes higher than other parts in accordance with the fuel injection timing. Since the ignition timing of the ignition source provided at the location is set to be later than the ignition timing of the other ignition sources, the ignition is performed by each ignition source at the set ignition timing.
In other words, later than the ignition in the part where the combustion speed is slow,
By performing the ignition at the portion where the combustion speed is high, substantially uniform combustion is executed regardless of the uneven distribution of the air-fuel mixture in the cylinder.

More specifically, when the fuel injection timing is during the intake stroke, the injected fuel rides on the intake air and tends to adhere to the cylinder wall at a position facing the intake port. Will be higher. On the other hand, as shown in FIG. 6, in a region where the operation is performed at an air-fuel ratio equal to or higher than the stoichiometric air-fuel ratio (that is, under the condition that the excess air ratio λ is 1 or more), the higher the fuel concentration, the higher the combustion speed. Therefore,
As in the device according to claim 1, in the fuel injection timing and the operating region, the ignition timing of an ignition source provided at a position facing the intake port on the cylinder wall surface or at a position closest to the intake port is different from each other. By setting the ignition timing later than the ignition timing, the combustion is made uniform. Furthermore, in the apparatus according to claim 6, only when swirl is generated, the fuel is particularly likely to get into the airflow and easily adhere to the cylinder wall surface.
The ignition timing control as described above is performed.

On the other hand, when the fuel injection timing is during a period other than the intake stroke, the injected fuel adheres to the closed intake valve and drips from the intake port. The fuel concentration increases. Therefore, in this case, the ignition timing of the ignition source provided at the position closest to the intake port among the ignition sources in the region where the operation is performed with the air-fuel ratio equal to or higher than the air-fuel ratio is set to another value. By setting the timing later than the ignition timing, the combustion is made uniform.

Further, in the device according to the third aspect, the fuel injection timing is controlled in accordance with the operating conditions, and when the fuel injection timing is set during the intake stroke, As described above, in the region where the operation is performed at the air-fuel ratio equal to or higher than the stoichiometric air-fuel ratio, the ignition timing of the ignition source provided at the position facing the intake port on the cylinder wall surface or the position closest thereto is the other ignition source. If the fuel injection timing is set later than the timing and the fuel injection timing is set during a period other than the intake stroke, each of the fuel injection timings is set in a region where the operation is performed at an air-fuel ratio equal to or higher than the stoichiometric air-fuel ratio as in the device according to claim 2. The ignition timing of the ignition source provided closest to the intake port in the ignition source is set later than the other ignition timings. Therefore, the ignition timing of each ignition source is controlled so that the combustion is always uniformed regardless of the change in the fuel injection timing.

[0015] In the device according to the fourth aspect, only when the operating temperature of the engine is equal to or lower than the preset temperature, that is, when the vaporization / atomization is not easily promoted and the air-fuel mixture is likely to be unevenly distributed, Control of the ignition timing is performed.

Similarly, in the apparatus according to the fifth aspect, vaporization
The above-described ignition timing control is performed only when heavy gasoline, which is difficult to promote atomization, is used as fuel.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS.

The peripheral ignition engine shown in FIGS. 1 and 2 includes a cylinder block 10 in which a piston 1 is mounted.
2 is inserted, and a combustion chamber 14 is formed above the piston 12. A cylinder head 18 is mounted on the upper surface of the cylinder block 10.

A first intake port 21 and a second intake port 22 open obliquely on one side (left side in FIGS. 1 and 2) of the combustion chamber 14, and the other side (right side in FIG. 1). The first exhaust port 23 and the second exhaust port 24 are similarly opened. The first intake port 21 and the second intake port 22 are opened and closed by the operation of the first intake valve 25 and the second intake valve 26, respectively, and the first exhaust port 23 and the second exhaust port 24 are respectively connected to the first exhaust valve 27. And the second
It is opened and closed by the operation of the exhaust valve 28.

In this engine, four spark plugs 31 to 34 are provided at different positions for one cylinder. As shown in FIG. 2, each of the spark plugs 31 to 34
Are arranged at positions facing the combustion chamber 14 in the cylinder block 18. As shown in FIG. 1, the ignition plug 31 is located at the center of the combustion chamber 14, and the ignition plugs 32 to 34 are located
4 are arranged in the periphery. More specifically, the ignition plug 32 is disposed at a substantially intermediate position between the intake ports 21 and 22, and the ignition plugs 33 and 34 are respectively connected to the intake ports 2 and 22.
It is arranged at a position near the cylinder side wall facing the cylinders 5 and 26.

The first intake port 21 and the second intake port 22 are joined at the upstream side thereof.
A fuel injection valve (fuel injection means) 20 shown in FIG. 3 is provided. Further, the swirl control valve 40 is provided only in the second intake port 22 of the two intake ports 21 and 22, and the intake is performed only from the first intake port 21 with the swirl control valve 40 closed. The swirl is generated in the combustion chamber.

This engine has various detection means,
As shown in FIG. 3, fuel determination means 42, water temperature detector 44,
A load detector 46, an engine speed detector 48, and the like are provided, and these detection signals are input to the ECU 50. The ECU 50 includes a basic ignition timing setting unit 51, a fuel determination unit 57, a fuel type correction unit 52, a cold correction unit 53, an ignition control unit 54, a swirl control unit 55, and a fuel injection control unit 56 as shown in FIG. It has.

The fuel injection control means 56, based on the detection results of the engine speed detector 48 and the load detector 46, operates during the intake stroke in the low-speed low-load operation range during the intake stroke.
To operate the fuel injection to obtain a high air-fuel ratio, while operating the fuel injection valve 20 before entering the intake stroke in other operating regions, and lowering the air-fuel ratio in the low-speed low-load region. In addition, fuel injection is performed to obtain an air-fuel ratio higher than the stoichiometric air-fuel ratio.

The swirl control means 55 closes the swirl control valve 40 and generates swirl only when the fuel injection is performed during the intake stroke, that is, when the engine is operated at low load and low rotation. That is, the swirl control means 55 and the swirl control valve 4
0 constitutes a swirl generating means for generating a swirl according to the operating conditions.

The basic ignition timing setting means 51 is adapted to
Ignition timing IG for one spark plug 31-34
1, IG2, IG3, and IG4 are set, and these basic ignition timings IG1 to IG4 are all set at the same time.

In view of the fact that the use of heavy gasoline having low volatility tends to cause uneven rotation of the engine at low temperatures, the fuel determination means 57 monitors, for example, fluctuations in the number of rotations of the engine in an idle state. If this is equal to or greater than the set value, it is determined that the fuel is heavy gasoline, and the determination result is maintained until the next vehicle stop.

The fuel type correction means 52 includes a fuel determination means 5
If it is determined in step 7 that the fuel used is heavy gasoline,
That is, the fuel is not sufficiently vaporized and atomized, and the combustion chamber 14
The basic ignition timing is corrected (in this case, the ignition timing is delayed) only when the air-fuel mixture is likely to be unevenly distributed, and the primary corrected ignition timings IG1 ', IG2', IG3 ', IG
4 'is set. More specifically, when swirl is generated by the swirl generating means (ie, when fuel is injected in the intake stroke), the ignition timing of the ignition plug 33 closest to the cylinder side wall portion facing the intake port 21 is determined. Particularly, when the swirl is not generated by the swirl generating means (that is, when fuel is injected outside the intake stroke), the ignition timing of the ignition plug 31 closest to both intake ports 21 and 22 is particularly delayed. Have been.

The details will be described later.

The fuel type correction means 52 includes a water temperature detector 44
Is constant (in this embodiment, a constant value).
88 ° C.) or less, that is, only when the fuel is not well vaporized and atomized and the air-fuel mixture is apt to be unevenly distributed in the combustion chamber 14 during a cold period, the primary ignition timing is corrected (here, the primary ignition timing is corrected). Ignition timing IG1 ″, I after secondary correction
G2 ", IG3", and IG4 ". More specifically, when swirl is generated by the swirl generation means (ie, when fuel is injected during the intake stroke), the intake port 21 If the ignition timing of the ignition plug 33 closest to the opposing cylinder side wall is particularly delayed, and swirl is not generated by the swirl generating means (ie, when fuel is injected outside of the intake stroke), both intake ports 21 and 22 are used. The ignition timing of the ignition plug 31 closest to is particularly delayed, the details of which will be described later.

Therefore, the basic ignition timing setting means 51,
By the fuel type correction means 52 and the cold correction means 53,
The ignition timing setting means in the present invention is constituted. Then, based on each ignition timing set by the ignition timing setting means, the ignition control means 54 controls each of the ignition plugs 31 to 3.
4 is controlled.

Next, the control operation performed by the ECU 50 will be described.

The fuel injection control means 56 grasps the operating state of the engine based on the engine speed and the engine load, and performs fuel injection at a high air-fuel ratio during the intake stroke in the low-speed low-load region (lean combustion mode). In other regions, during the period other than the intake stroke, fuel injection is performed at an air-fuel ratio lower than the air-fuel ratio in the lean combustion mode and higher than the stoichiometric air-fuel ratio (normal combustion mode). The swirl control means 55 closes the swirl control valve 40 in the low-speed low-load region to generate a positive swirl (lean combustion mode), thereby promoting the mixing of fuel and air, and in other regions. Then, the swirl control valve 40 is opened to perform intake from both intake ports 21 and 22 (normal combustion mode).

On the other hand, an ignition timing setting means comprising a basic ignition timing setting means 51, a fuel type correction means 52, and a cold correction means 53 sets different ignition timings in the lean combustion mode and the normal combustion mode. The setting operation will be described with reference to the flowcharts of FIGS.

A) Lean combustion mode (FIG. 4) The fuel type correcting means 52 receives the result of the determination by the fuel determining means 57, and if it is determined that fuel other than heavy gasoline is used (step S4). (NO in S11), the primary corrected ignition timings IG1 ', IG2', IG3 ', IG4' for each of the ignition plugs 31 to 34 are set to timings equal to the basic ignition timing set by the basic ignition timing setting means. It is set (step S12). That is, the ignition timing is not corrected. On the other hand, if it is determined that fuel other than heavy gasoline is being used (YES in step S11), the first corrected ignition timings IG1 'and IG2' for each of the spark plugs 31 to 34 are set. , IG3 ',
IG4 'is calculated and set based on the following equation (step S13).

[0035]

IG1 '= IG1 + Al IG2' = IG2 + Bl IG3 '= IG3 + Cl IG4' = IG4 + Dl where Al, Bl, Cl and Dl are primary correction constants and C
l>Dl>Bl> Al ≧ 0.

Therefore, in this fuel type correction means 52,
Only when the fuel used is heavy gasoline, a correction for delaying the ignition timing of each of the ignition plugs 31 to 34 is performed. When this correction is performed, the correction is performed on the cylinder side wall in a region opposed to the intake port 21 for performing intake. Closest spark plug 33
Is corrected most late.

Next, the cold correction means 53 is connected to the water temperature detector 4.
It is determined whether or not the water temperature T detected in Step 4 is equal to or higher than 88 ° C. (Step S15). If the water temperature T is equal to or higher than 88 ° C. (YES in Step S15), each of the spark plugs 31 to 34 is determined. Ignition timing IG1 ″ after the second correction of
IG2 ", IG3", and IG4 "are set to timings equal to the primary corrected ignition timings IG1 ', IG2', IG3 ', and IG4', respectively (step S16), that is, the ignition timing is not corrected. On the other hand, the water temperature T is 88
If the temperature is lower than C (NO in step S15), the ignition timing I after the second correction for each of the spark plugs 31 to 34
G1 ", IG2", IG3 ", IG4" are calculated and set based on the following equations (step S17).

[0038]

IG1 ″ = IG1 ′ + E1 (88−T) IG2 ″ = IG2 ′ + F1 (88−T) IG3 ″ = IG3 ′ + G1 (88−T) IG4 ″ = IG4 ′ + H1 (88−T) El, Fl, Gl, and Hl are secondary correction constants.
It is set so that l>Hl>Fl> El ≧ 0.

Therefore, in the cold correcting means 53, the correction is performed only in the cold state, and when this correction is made, the ignition timing of each of the spark plugs 31 to 34 is set to the difference between 88 ° C. and the actual water temperature T. The ignition timing of the ignition plug 33 closest to the cylinder side wall in the region facing the intake port 21 for performing intake is delayed by the proportional amount, and the ignition timing is corrected to be the latest.

On the other hand, in an actual engine, since fuel is injected during the intake stroke, the fuel tends to get on the intake and adhere to the cylinder side wall portion facing the first intake port 21, and the air-fuel mixture is deposited in this portion. It tends to be unevenly distributed. Here, since the air-fuel ratio exceeds the stoichiometric air-fuel ratio, as shown in FIG. 6, the higher the fuel concentration is, the higher the combustion speed is. Therefore, the combustion speed near the cylinder side wall portion is lower than the combustion speed at other portions. Get higher. Therefore, by setting the ignition timing of the ignition plug 33 closest to the cylinder side wall portion to be the latest, the combustion chamber in the combustion chamber 14 is made uniform.

B) Normal combustion mode (FIG. 5) Similar to the above-described lean combustion mode, the fuel type correction means 52
Receives the determination result of the fuel determination means 57, and if it is determined that fuel other than heavy gasoline is used (NO in step S21), each of the spark plugs 31 to 34
Ignition timing IG1 ', IG2', I
G3 'and IG4' are set to timings equal to the basic ignition timing set by the basic ignition timing setting means, respectively (step S22). That is, the ignition timing is not corrected. On the other hand, when it is determined that fuel other than heavy gasoline is used (YES in step S21),
The first corrected ignition timing IG1 ', IG2', IG3 ', IG4' for each of the spark plugs 31 to 34 is calculated and set based on the following equation (step S23).

[0042]

IG1 '= IG1 + Ar IG2' = IG2 + Br IG3 '= IG3 + Cr IG4' = IG4 + Dr Note that Ar, Br, Cr, and Dr are first-order correction constants.
It is set so that ≦ Cr <Dr <Br <Ar.

Therefore, in this fuel type correction means 52,
Only when the fuel to be used is heavy gasoline, a correction for delaying the ignition timing of each of the spark plugs 31 to 34 is performed. When this correction is made, the two intake ports 21 for performing the intake are used.
The ignition timing of the ignition plug 31 closest to 22 is corrected most late.

Next, the cold correction means 53 is connected to the water temperature detector 4.
It is determined whether or not the water temperature T detected in Step 4 is equal to or higher than 88 ° C. (Step S25). If the water temperature T is equal to or higher than 88 ° C. (YES in Step S25), each of the spark plugs 31 to 34 is determined. Ignition timing IG1 ″ after the second correction of
IG2 ", IG3", and IG4 "are set to timings equal to the primary corrected ignition timings IG1 ', IG2', IG3 ', and IG4', respectively (step S26), that is, the ignition timing is not corrected. On the other hand, the water temperature T is 88
If it is lower than C (NO in step S25), the ignition timing I after the second correction for each of the spark plugs 31 to 34
G1 ", IG2", IG3 ", IG4" are calculated and set based on the following equations (step S27).

[0045]

IG1 ″ = IG1 ′ + Er (88−T) IG2 ″ = IG2 ′ + Fr (88−T) IG3 ″ = IG3 ′ + Gr (88−T) IG4 ″ = IG4 ′ + Hr (88−T) Er, Fr, Gr, Hr are secondary correction constants, and are 0
It is set so that .ltoreq.Gr <Hr <Fr <Er.

Therefore, in the cold correcting means 53, the correction is performed only in the cold state, and when this correction is performed, the ignition timing of each of the spark plugs 31 to 34 is set to the difference between 88 ° C. and the actual water temperature T. The ignition timing of the spark plug 31 closest to the intake ports 21 and 22 for performing intake is delayed by the proportional amount, and the ignition timing is corrected to be the latest.

On the other hand, in an actual engine, fuel is injected at times other than the intake stroke. Therefore, the fuel adheres to the intake valve in the closed state and drips after the valve is opened. The mixture is more likely to be unevenly distributed in the vicinity of 22. Also in this case, the air-fuel ratio exceeds the stoichiometric air-fuel ratio. Therefore, as in the above-described lean combustion mode, the combustion speed is higher at a portion where the fuel concentration is higher, and the combustion speed near the intake ports 21 and 22 is different at other portions. It becomes higher than the burning rate. Therefore, the spark plug 33 closest to both intake ports 21 and 22
The ignition timing of the combustion chamber 1
The uniformization of the combustion chamber in 4 is achieved.

As described above, in this device, the ignition timing of the spark plug closest to the point where the combustion speed increases in each mode is particularly delayed based on the fuel injection timing controlled by the fuel injection control means 56. Therefore, the combustion in the combustion chamber 14 can always be made uniform regardless of the fuel injection timing.

Further, in this embodiment, the ignition timing is delayed only when using heavy gasoline, which hardly promotes the vaporization and atomization of fuel, and during cold operation.
It is possible to perform the ignition timing control in accordance with the actual operation condition.

Note that the present invention is not limited to such an embodiment, and the following embodiments can be taken as examples.

(1) In the above embodiment, the operating region in which fuel is injected during the intake stroke matches the operating region in which swirl is generated. However, both regions do not necessarily match. good. Also in this case, if the ignition timing of the ignition plug 33 is delayed only when the swirl is generated, in which the fuel is particularly likely to enter the airflow, it is possible to perform control in accordance with the actual operation state. However, the swirl generating means is not necessarily required in the present invention.

(2) In the present invention, regardless of the specific number of ignition sources, for example, as shown in FIG.
The present invention can be applied to a case where 1, 35 and 36 are arranged. Also in this case, when the fuel is injected during the intake stroke, the ignition timing of the ignition plug 35 closest to the cylinder side wall portion facing the intake port 21 is particularly delayed, and the fuel is injected at times other than the intake stroke. In this case, the ignition timing of the ignition plug 31 closest to the intake ports 21 and 22 may be particularly delayed.

(3) In the above embodiment, fuel injection is performed at an air-fuel ratio equal to or higher than the stoichiometric air-fuel ratio in all operation regions. ) Is performed, the ignition timing in this region may be freely determined. For example, in such a rich operation region, as shown in FIG. 6, the combustion speed tends to decrease as the fuel concentration becomes higher. Therefore, the ignition timing of the ignition plug arranged in this rich portion is set to the ignition timing of another ignition plug. You may make it ahead of time.

(4) In the above embodiment, the ignition timing of the ignition plug 33 is delayed in the lean combustion mode, and the ignition timing of the ignition plug 31 is delayed in the normal combustion mode. However, in the present invention, only the lean combustion mode is used. Alternatively, the ignition timing of a predetermined ignition plug may be delayed only in the normal combustion mode.

[0055]

As described above, according to the present invention, depending on the fuel injection timing, the ignition timing of the ignition source provided at the point where the combustion speed becomes faster than other points is later than the ignition timing of the other ignition sources. Since the timing is set, there is an effect that the combustion can be made uniform only by controlling the ignition timing irrespective of the uneven mixture in the cylinder.

More specifically, in the device according to the first aspect,
In the region where fuel injection is performed during the intake stroke, and the operation is performed at an air-fuel ratio equal to or higher than the stoichiometric air-fuel ratio, where the air-fuel mixture is likely to be unevenly distributed, that is, the position of each ignition source facing the intake port on the cylinder wall surface or By setting the ignition timing of the ignition source provided closest to the ignition timing later than the other ignition timings, the combustion can be made uniform.
In particular, in the device according to claim 6, since the ignition timing is set only when swirl is generated when the fuel easily gets on the airflow and the fuel easily adheres to the cylinder wall surface,
It is possible to perform control in accordance with the actual operation state.

On the other hand, in the device according to the second aspect, when fuel injection is performed during a period other than the intake stroke, that is, the injected fuel adheres to the closed intake valve and drips from the intake port. When the fuel concentration in the vicinity of the intake port becomes high due to, for example, the ignition timing of the ignition source provided at the position closest to the intake port among the ignition sources in the region where the operation is performed at the air-fuel ratio equal to or higher than the air-fuel ratio, By setting the ignition timing later than other ignition timings, combustion can be made uniform.

Further, in the device according to the third aspect, when the fuel injection timing is controlled according to the operating conditions, the control according to the first and second aspects is selectively used according to the fuel injection timing. There is an effect that the combustion can always be made uniform regardless of the change in the fuel injection timing.

Further, in the apparatus according to the fourth and fifth aspects, when the operating temperature of the engine is equal to or lower than a preset temperature or when heavy gasoline is used, vaporization and atomization are hardly promoted and the mixing is difficult. Since the above-described setting of the ignition timing is performed only when the uneven distribution of the air is likely to occur, there is an effect that the ignition timing can be controlled more in accordance with the actual operating condition.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a main part of an engine according to an embodiment of the present invention.

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

FIG. 3 is a block diagram showing a functional configuration of an ECU provided in the engine.

FIG. 4 is a flowchart showing a control operation performed by the ECU in a lean combustion mode.

FIG. 5 is a flowchart showing a control operation performed by the ECU in a normal combustion mode.

FIG. 6 is a graph showing the relationship between excess air ratio λ and combustion speed.

FIG. 7 is a schematic plan view showing a modification of the arrangement position of the ignition plug.

[Explanation of symbols]

Reference Signs List 10 cylinder block 12 piston 14 combustion chamber 18 cylinder head 20 fuel injection valve (constituting fuel injection means) 21 first intake port 22 second intake port 31-36 spark plug 40 swirl control valve (constituting swirl generating means) 44 water temperature Detector (temperature detecting means) 50 ECU 51 Basic ignition timing setting means (ignition timing setting means) 52 Fuel type correction means (ignition timing setting means) 53 Cold correction means (ignition timing setting means) 54 Ignition control means 55 Swirl control Means (constitutes swirl generating means) 56 Fuel Injection Control Means (constitutes Fuel Injection Means)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F02P 5/15 F02P 15/08 301

Claims (6)

(57) [Claims] In a peripheral ignition engine in which an ignition source is arranged at a plurality of positions including a peripheral portion in one cylinder, a fuel injection means and a combustion speed corresponding to a fuel injection timing by the fuel injection means are different. Ignition timing setting means for setting the ignition timing of the ignition source provided at a location faster than the location of the ignition source to a timing later than the ignition timings of the other ignition sources, and setting each ignition source based on the set ignition timing. Ignition control means for controlling an ignition operation, wherein the fuel injection timing
When set to medium, operation with an air-fuel ratio higher than the stoichiometric air-fuel ratio
Of the ignition source on the cylinder wall
At or closest to the intake port
The ignition timing of the ignition source provided
The ignition timing setting means is configured to set the ignition timing later.
An ignition timing control device for a peripheral ignition engine. 2. A plurality of cylinders including a peripheral portion in one cylinder.
In a peripheral ignition engine where an ignition source is
Fuel injection means and fuel injection timing by the fuel injection means.
Correspondingly, where the burning speed is faster than other places
The ignition timing of the selected ignition source
Ignition timing setting means for setting a later time;
Controls the ignition operation of each ignition source based on the ignition timing
Ignition control means, and when the fuel injection timing is set during a period other than the intake stroke, in the region where the operation is performed at an air-fuel ratio equal to or higher than the stoichiometric air-fuel ratio, the ignition source closest to the intake port is included. An ignition timing control device for a peripheral ignition engine, wherein the ignition timing setting means is configured to set an ignition timing of an ignition source provided at a position later than other ignition timings. 3. A plurality of cylinders including a peripheral portion in one cylinder.
In a peripheral ignition engine where an ignition source is
Fuel injection means and fuel injection timing by the fuel injection means.
Correspondingly, where the burning speed is faster than other places
The ignition timing of the selected ignition source
Ignition timing setting means for setting a later time;
Controls the ignition operation of each ignition source based on the ignition timing
Ignition control means, and fuel injection control means for changing the fuel injection timing in accordance with the operating conditions, and when the fuel injection timing is set during the intake stroke, the air-fuel ratio is not less than the stoichiometric air-fuel ratio. In the region where the operation is performed, among the ignition sources, the ignition timing of the ignition source provided at the position facing the intake port on the cylinder wall surface or at the position closest thereto is set later than the other ignition timings, and the fuel injection timing is reduced. If the ignition timing is set during a period other than the intake stroke, the ignition timing of the ignition source provided at the position closest to the intake port among the ignition sources in the region where the operation is performed at an air-fuel ratio equal to or higher than the stoichiometric air-fuel ratio is set. An ignition timing control device for a peripheral ignition engine, wherein the ignition timing setting means is configured to set the ignition timing later than the ignition timing. 4. The ignition timing control device of the peripheral spark engine according to any one of claims 1 or 3, comprising a temperature detecting means for detecting the operating temperature of the engine, the temperature detected by the temperature detecting means in advance A peripheral ignition characterized in that the ignition timing setting means is configured to set the ignition timing of some ignition plugs later than the ignition timing of other ignition plugs only when the temperature is equal to or lower than a set temperature. Engine ignition timing control device. 5. The ignition timing control device of the peripheral spark engine according to any one of claims 1-4, comprising a fuel determination means determines the type of fuel, the fuel is a heavy gasoline The fuel determination means Only when it is determined that the ignition timing of some of the ignition plugs is set to a timing later than the ignition timing of the other ignition plugs, Ignition timing control device. 6. The ignition timing control device of the peripheral spark engine of claim 1 or 3, provided with a swirl generating means for generating a swirl in the preset operating region, only when the swirl generating by the swirl generating means, In the region where the operation is performed at an air-fuel ratio equal to or higher than the stoichiometric air-fuel ratio, the ignition timing of the ignition source provided at the position facing the intake port on the cylinder wall surface or at the position closest thereto in each of the ignition sources is set higher than other ignition timing An ignition timing control device for a peripheral ignition engine, wherein the ignition timing setting means is configured to set the ignition timing late.