JPH0771353A - Combustion controller of engine - Google Patents

Abstract

PURPOSE:To secure idle revolution and increase accelerating performance, by setting the idle position of a throttle valve to be in a half-open position and controlling the ignition timing in accordance with the rotary degree of a cam mechanism to open the throttle valve on the basis of the controlled value of the accelerator. CONSTITUTION:In an engine 1, an ignition plug 7 is arranged at the cylinder head 6 and a throttle valve 15 is arranged in an air suction path 10. In this case, a cam mechanism 22 is arranged at the side of the throttle valve 15 and connected with an accelerator lever 24. The idle position of the throttle valve 15 is set at the middle opening between the fully opened position and the completely closed position and the throttle valve 15 is opened from the idle position at the pick-up position where the control value of the accelerator gets to a specified one. On the other hand, the ignition timing or the ignition plug 7 is controlled by ECU(electronic control unit) 30 in accordance with the rotational degree of the cam mechanism 22 until the pick-up position of the cam mechanism 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an engine combustion control device capable of improving acceleration.

[0002]

2. Description of the Related Art For example, in an engine for an outboard motor, there is a demand to improve acceleration performance from a state where a throttle valve is in an idling position, that is, a trolling state. It is necessary to supply a large amount of air. However, even if the throttle valve is suddenly fully opened, the amount of intake air according to the throttle opening is not immediately introduced into the engine due to the inertial effect of air or the like. For this reason, conventionally, it was not easy to improve acceleration.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an engine combustion control device capable of improving acceleration performance.

[0004]

According to a first aspect of the present invention, there is provided a combustion control system for an engine, wherein an idle position of a throttle valve disposed in an intake passage is substantially an intermediate opening between a fully closed position and a fully open position. A cam mechanism that is set to a position and operates in accordance with the accelerator operation amount and starts opening the throttle valve from the idle position at the pickup position where the accelerator operation amount becomes a predetermined amount. It is characterized in that ignition timing control means for controlling the ignition timing corresponding to the amount of rotation of the cam mechanism is provided.

Here, setting the idle position to the above-mentioned substantially intermediate opening position means that the conventional idle position is set to a position inclined by several degrees from the fully closed position, whereas in the case of the present invention, It means that the throttle valve is set to a position inclined from the fully closed position by an angle larger than the above-mentioned several degrees, for example, ten degrees. In addition, by using a throttle valve having holes or grooves formed therein, the throttle valve may be set to the fully closed position and substantially corresponds to the above-mentioned approximately intermediate opening position of a throttle valve having no holes or grooves formed. It will be included in this substantially intermediate opening position.

In the engine combustion control device according to the second aspect of the present invention, the throttle valve disposed in the intake passage is set at an idle position at a substantially intermediate opening position between the fully closed position and the fully open position, and the accelerator is opened. A cam mechanism is provided which starts to open the throttle valve from the idle position at a pickup position at which the accelerator operation amount becomes a predetermined amount while operating according to the operation amount, and a fuel injection injector is provided to the pickup position of the cam mechanism. Is provided with a fuel injection amount control means for controlling the injector so that the fuel injection amount per unit time is reduced as the accelerator operation amount is smaller.

[0007]

According to the first aspect of the present invention, the idle position of the throttle valve is set to a substantially intermediate opening position between the fully closed position and the fully opened position. The flow is already secured during idle operation. Further, until the cam mechanism reaches the pickup position, the ignition timing control means controls the ignition timing in accordance with the operation amount of the cam mechanism. That is, for example, at the time of idling, the ignition timing is controlled to the retard side, whereby the combustion of the engine is suppressed despite the increase of the intake air flow rate and the flow velocity, and the increase of the engine speed can be suppressed. During acceleration, the ignition timing is controlled to the advance side according to the operation amount of the cam mechanism, while the flow of intake air required during acceleration is already secured, so combustion of the engine is promoted and the engine is shortened. It becomes possible to rotate at high speed in a time, and the acceleration performance can be improved.

According to the second aspect of the present invention, by the control of the fuel injection amount control means, the fuel injection amount per unit time by the injector decreases as the accelerator operation amount decreases to the pickup position of the cam mechanism. Therefore, at the time of idling, the combustion of the engine is suppressed by the reduction of the fuel injection amount, and the low speed rotation can be secured. In addition, the total fuel injection amount increases during acceleration, and on the other hand, the flow rate and the flow rate of intake air required for acceleration have already been secured by the throttle valve located at the approximately intermediate opening position, so combustion of the engine is accelerated and acceleration is accelerated. It is possible to improve the sex.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 4 are views for explaining a combustion control device for an outboard engine according to an embodiment of the present invention, and FIG. 1 is a schematic configuration of an outboard engine employing the combustion control device. FIG. 2, FIG. 2 is an enlarged partial view of FIG. 1, FIG. 3 is a control flowchart of the combustion control device, and FIG. 4 is a diagram showing correlations between accelerator operation amount and throttle valve opening, ignition timing, and fuel injection amount. Is. In FIG. 1, F indicates the bow side, R indicates the stern side, and the lower left portion of FIG. 1 shows an AA cross section of the upper left portion.

In these figures, reference numeral 1 is an outboard motor of a vertically mounted V-type 6-cylinder two-cycle engine, which has a piston 3 slidable in a cylinder bore formed to form a V bank of a cylinder block 2. The piston 3 is movably inserted and arranged, and the piston 3 is connected to the crankshaft 5 by a connecting rod 4. A cylinder head 6 is mounted on the mating surface of the cylinder block 2, and a spark plug 7 is inserted in a combustion recess formed in the cylinder head 6. A crank chamber 8 is provided on the side opposite to the head of the cylinder block 2. A pressure sensor 31 for measuring the in-cylinder pressure is attached to the cylinder head 6. Further, the crankshaft 5 is provided with a sensor 33 for detecting the crank angle (engine speed), and the crank chamber 8 is provided with a pressure sensor 34 for measuring the pressure in the crank chamber.

An intake passage 10 is connected to the crank chamber 8. A reed valve 11 for preventing backflow of intake air is arranged near the opening of the intake passage 10 on the crank chamber side. An injector 12 for injecting fuel into the intake passage is installed in the intake passage 10, and a high-pressure fuel supply device 13 is connected to the injector 12. A temperature sensor 32 for measuring the intake air temperature is provided at the crank chamber side opening of the intake passage 10. Further, in the exhaust passage 26 (FIG. 1), an O ₂ sensor 35 for detecting the O ₂ concentration in the exhaust gas,
A pressure sensor 36 for detecting back pressure is provided. Further, a temperature sensor 37 for detecting the engine temperature
Is provided.

Further, a throttle valve 15 is arranged in the intake passage 10, and an idle position of the throttle valve 15 is set at a position inclined by α degrees from the fully closed position as shown in FIG. . This angle α is larger than the usual setting angle of 2-3 °, and is preferably 15 °.
It is set in the vicinity of 20 to 20 degrees. Thus, by setting the idle position of the throttle valve 15 to a substantially intermediate opening position between the fully closed position and the fully open position, the flow of intake air having a flow rate and a flow velocity required for acceleration is already secured during idle operation. Will be there. Although not shown, a sensor for detecting the amount of rotation of the throttle valve, that is, the throttle angle is provided. The throttle valve 15
Is a pickup bar 1 extending in a direction substantially perpendicular to the valve surface.
6 is attached. A spherical contact portion 17 is provided at the tip of the pickup bar 16.

On the other hand, a cam mechanism 20 is provided on the side of the throttle valve 15. The cam mechanism 20 has a cam member 22, and one end of the cam member 22 is
A support shaft 21 rotatably supported is fixed. One end of an accelerator bar 24 is attached to the cam member 22 via a pin 23, and the other end of the accelerator bar 24 is connected to the accelerator. Further, when the accelerator pedal is not depressed, the cam member 22 is located at the idle position shown by the solid line, and a predetermined gap s is formed between the cam member 22 and the contact portion 17 at the tip of the pickup bar 16. . Further, the support shaft portion 21 is provided with a cam sensor (not shown) for detecting the rotation amount of the cam member 22. With this configuration, the cam member 22 rotates in conjunction with the accelerator operation and contacts the contact portion 17 at the pickup position (see the dashed line in FIG. 2) and the throttle bar 15 at the fully open position via the pickup bar 16. The fully open position (see the position indicated by the chain double-dashed line in the figure) can be set.

The engine 1 has an ECU 3 as a control unit.
It has 0. In the ECU 30, the engine ignition timing, the fuel injection amount according to the engine speed and the cam angle,
A map for selecting the injection timing is stored. As the map, an idle map when the cam member 22 is at the above-mentioned idle position, and when the cam member 22 is between the idle position and the pickup position are stored. There are three types of maps, i.e., an idle pickup map and a map for the pickup position after the cam member 22 passes the idle pickup position.

The ECU 30 includes a cylinder pressure detecting sensor 31, a throttle opening detecting sensor, a cam angle detecting sensor, an intake air temperature detecting sensor 32, and a crank angle detecting sensor 3.
3, a crank chamber pressure detection sensor 34, an O ₂ sensor 35,
Input signals of the back pressure detection sensor 36, the engine temperature detection sensor 37, the atmospheric pressure detection sensor, and the cooling water detection sensor are input. The output signal of the ECU 30 is input to each of the spark plug 7 and the injector 12.

Next, the control operation of the ECU 30 will be described with reference to the graph of FIG. 4 and the flowchart of FIG. When the program starts, first in step S1 of FIG. 3, the cam member 2 of the cam mechanism 20 is
It is determined whether 2 has moved from the idle position (solid line position in FIG. 2). If the cam member 22 has not moved from the idle position, the process proceeds to step S2. In step S2,
The ignition timing, the fuel injection amount, and the fuel injection timing are read from the idling map according to the engine speed detected by the sensor 33. Next, in step S3, the spark plug 7, the injector 12 and the like are drive-controlled based on the data read from the map, and two cylinders out of the six cylinders are deactivated and the four cylinder operation is performed (see FIG. 4). This stabilizes the low speed rotation.

In this case, as shown in FIG. 4, the smaller the accelerator operation amount, the more the ignition timing is controlled to the retard side, so the throttle valve 15 is set to the above-mentioned intermediate opening position and the intake flow rate is increased. In addition, it is possible to prevent the combustion of the engine from being suppressed and the engine speed from increasing even though the flow velocity is increased. Further, the fuel injection amount per one engine revolution at this time is larger than the fuel injection amount when the accelerator operation amount is large, but the fuel injection amount per unit time decreases due to the low engine revolution speed. As a result, combustion of the engine is further suppressed, and low speed rotation can be secured. After the processing in step S3, the program returns to step S1.

If it is determined in step S1 that the cam member 22 has moved from the idle position, the process proceeds to step S4. A step S4 decides whether or not the cam member 22 has reached the pickup position (the position indicated by the alternate long and short dash line in FIG. 2).
If it is determined that the pickup position has not been reached yet, the process proceeds to step S5. In step S5, the sensor 33
The ignition timing, the fuel injection amount, and the fuel injection timing are read from the idle pickup map in accordance with the engine speed detected in step S1 and the rotation amount (cam angle) of the cam member 22 detected by the cam sensor. Next, in step S6, the spark plug 7, the injector 12 and the like are drive-controlled based on the data read from the map, and 5 cylinders out of 6 cylinders are selected to perform 5-cylinder operation (see FIG. 4).

In this case, during acceleration, the ignition timing is controlled to advance as the accelerator operation amount, that is, the cam angle increases. On the other hand, since the throttle valve 15 is located at the substantially intermediate opening position, the flow rate of the intake air at the flow rate and the flow velocity required for acceleration has already been secured. It becomes possible to rotate at high speed, and the acceleration performance can be improved. Further, although the fuel injection amount per engine revolution is reduced, the fuel injection amount per unit time is increased due to the increase in engine revolution speed. As a result, combustion of the engine can be further promoted, and acceleration performance can be further improved. After the processing in step S6, the program returns to step S1.

If it is determined in step S4 that the cam member 22 has reached the pickup position, the process proceeds to step S7. In step S7, the ignition timing, the fuel injection amount, and the fuel injection timing are read from the pickup position and subsequent maps according to the engine speed and the cam angle. In this case, since the throttle valve 15 rotates in conjunction with the rotation of the cam member 22, the cam rotation amount after the pickup position becomes equal to the throttle valve opening. Next, in step S8, the spark plugs of all cylinders are sparked and set to 6
Cylinder operation is performed (see FIG. 4). After the processing in step S8, the program returns to step S1.

As described above, in this embodiment, since the idle position of the throttle valve 15 is set to a substantially intermediate opening position between the fully closed position and the fully open position, the intake air of a flow rate and a flow velocity required for acceleration is set. The flow is already secured during idle operation. Further, as described above, the cam member 2
The ECU 30 controls the ignition timing in accordance with the rotation amount of the cam member 22 until 2 reaches the pickup position. That is, for example, at the time of idling, the ignition timing is controlled to the retard side, whereby the combustion of the engine is suppressed despite the increase of the intake air flow rate and the flow velocity, and the increase of the engine speed can be suppressed. In addition, during acceleration, the ignition timing is controlled to the advance side according to the amount of rotation of the cam member 22, while the flow of intake air required during acceleration is already secured, so combustion of the engine is promoted and the engine is driven. It becomes possible to rotate at a high speed in a short time, and the acceleration performance can be improved.

Further, until the cam member 22 reaches the pickup position, the ECU 30 reduces the fuel injection amount per unit time by the injector 12 as the accelerator operation amount becomes smaller. Therefore, at the time of idling, the combustion of the engine is suppressed by the reduction of the fuel injection amount, and the low speed rotation can be secured. Further, the fuel injection amount per unit time increases at the time of acceleration, while the flow rate and the flow rate of intake air required at the time of acceleration are already secured by the throttle valve 15 located at the substantially intermediate opening position. Can be accelerated and the acceleration can be improved.

In the above embodiment, an example in which the ignition timing and the fuel injection amount are simultaneously controlled has been shown, but the present invention can be applied to the case where only one of them is controlled.

Further, by using a throttle valve 15 having a hole or groove formed therein, the throttle valve 15 may be fully closed and substantially correspond to the substantially intermediate opening position.

In the above embodiment, the case where the present invention is applied to the 2-cycle engine is shown, but the present invention can be applied to the 4-cycle engine as well. Further, when only the ignition timing is controlled, the present invention can be applied to an engine equipped with a carburetor.

[0026]

As described above, in the engine combustion control system according to the invention of claim 1, since the idle position of the throttle valve is set to the substantially intermediate opening position, the flow of intake air having a flow rate and a flow velocity required for acceleration is set. Can be secured during idle operation. Since the cam mechanism is provided, the ignition timing control means for controlling the ignition timing corresponding to the rotation amount of the cam mechanism up to the pickup position of the cam mechanism is provided.
Idle rotation can be secured, and the ignition timing can be controlled to the advance side in correspondence with the rotation amount of the cam mechanism during acceleration, which can promote combustion of the engine in combination with the flow of the intake air,
You can rotate the engine at high speed in a short time,
As a result, there is an effect that acceleration performance can be improved.

According to the engine combustion control device of the second aspect of the present invention, the fuel injection amount per unit time up to the pickup position of the cam mechanism is controlled by the fuel injection amount control means so that the accelerator operation amount is small. Since the idle rotation is secured, the fuel injection amount per unit time can be increased at the time of acceleration, while the throttle valve located at approximately the intermediate opening position allows the intake flow of the flow rate and flow velocity required at the time of acceleration. Since it has already been secured, there is an effect that combustion of the engine can be promoted and acceleration can be improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an outboard engine that employs a combustion control device according to an embodiment of the present invention.

FIG. 2 is an enlarged partial view of FIG.

FIG. 3 is a control flowchart of the combustion control device.

FIG. 4 is a diagram showing each correlation among an accelerator operation amount, a throttle valve opening degree, an ignition timing, and a fuel injection amount in the engine.

[Explanation of symbols]

1 engine 10 intake passage 15 throttle valve 20 cam mechanism 30 ECU (ignition timing control means, fuel injection amount control means)

Claims (2)

[Claims] 1. An idle position of a throttle valve disposed in an intake passage is set to a substantially intermediate opening position between a fully closed position and a fully open position, and the throttle valve operates in accordance with an accelerator operation amount and the accelerator operation is performed. Ignition timing control means for providing a cam mechanism for opening the throttle valve from the idle position at a pickup position where the amount is a predetermined amount, and controlling the ignition timing up to the pickup position of the cam mechanism in accordance with the rotation amount of the cam mechanism. A combustion control device for an engine, comprising: 2. An idle position of a throttle valve disposed in the intake passage is set to a substantially intermediate opening position between a fully closed position and a fully open position, and the throttle valve operates in accordance with an accelerator operation amount and the accelerator operation is performed. In the pickup position where the amount becomes a predetermined amount, a cam mechanism that starts opening the throttle valve from the idle position is provided, and a fuel injection injector is provided, and the fuel injection amount per unit time is increased to the pickup position as the accelerator operation amount is smaller. A combustion control device for an engine, comprising fuel injection amount control means for controlling the injector so as to reduce the amount.