JP3258147B2 - Engine combustion control device - Google Patents

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 for an improvement in acceleration from a state in which a throttle valve is in an idling position, that is, a trolling state. A large amount of air needs to be supplied. However, even if the throttle valve is suddenly fully opened, the amount of intake air corresponding to the throttle opening is not immediately introduced into the engine due to the inertia effect of air or the like. For this reason, conventionally, it has not been easy to improve the acceleration.

[0003] The present invention has been made in view of such circumstances, and has as its object 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 apparatus for an engine, wherein an idle position of a throttle valve disposed in an intake passage is set to a substantially intermediate opening between a fully closed position and a fully opened position. And a cam mechanism that starts to open the throttle valve from the idle position at a pickup position where the throttle valve is rotated in accordance with the accelerator operation amount and the accelerator operation amount becomes a predetermined amount, and the rotation amount of the cam mechanism is determined by the pickup amount. The ignition timing control means for advancing the ignition timing as the rotation amount of the cam mechanism increases until the cam position is reached, and the fuel injection injector is controlled so that the fuel injection amount per one revolution of the engine decreases. And a fuel injection amount control means.

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

[0006]

[0007]

According to the first aspect of the present invention, the idle position of the throttle valve is set at a substantially intermediate opening position between the fully closed position and the fully opened position. The flow is already secured during idle operation. Until the cam mechanism reaches the pickup position, the ignition timing control means advances the ignition timing as the rotation amount of the cam mechanism increases. That is, in other words, the ignition timing is controlled to the retard side during the idling operation, whereby the combustion of the engine is suppressed irrespective of the increase in the intake air flow rate and the flow velocity, and the increase in the engine speed can be suppressed. . In addition, during acceleration, the ignition timing is controlled to the advanced side in accordance with the amount of rotation of the cam mechanism.On the other hand, since the intake air flow required during acceleration is already secured, combustion of the engine is promoted and the engine is shortened. It is possible to rotate at a high speed within a time, thereby improving acceleration.

[0008] Further, under the control of the fuel injection amount control means,
Up to the pickup position of the cam mechanism, as the accelerator operation amount, that is, the rotation amount of the cam mechanism increases, the fuel injection amount per one revolution of the engine by the injector decreases. Therefore, the fuel injection amount per one revolution of the engine decreases as the ignition timing is advanced, and the combustion of the engine is suppressed, and a stable low-speed rotation state commensurate with the cam mechanism rotation amount can be secured. Also, during acceleration, the total amount of fuel injected per unit time increases.On the other hand, the intake valve flows at the required flow rate and flow velocity during acceleration are already secured by the throttle valve at the approximately middle opening position, so that engine combustion is reduced. Acceleration can be improved by being promoted.

[0009]

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

In these figures, reference numeral 1 denotes an outboard motor of a vertical V-type 6-cylinder two-stroke engine with a crankshaft, which slides a piston 3 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 a 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 into a combustion recess formed in the cylinder head 6. A crank chamber 8 is provided on the side of the cylinder block 2 opposite to the head. The cylinder head 6 is provided with a pressure sensor 31 for measuring the in-cylinder pressure. Further, the crankshaft 5 is provided with a sensor 33 for detecting a crank angle (engine speed), and the crank chamber 8 is provided with a pressure sensor 34 for measuring a 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 disposed near the opening of the intake passage 10 on the crank chamber side. The intake passage 10 is provided with an injector 12 for injecting fuel into the intake passage, 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 opening of the intake passage 10 on the crank chamber side. Further, an O ₂ sensor 35 for detecting the O ₂ concentration in the exhaust gas is provided in the exhaust passage 26 (FIG. 1).
A pressure sensor 36 for detecting the back pressure is provided. A temperature sensor 37 for detecting the engine temperature
Is provided.

A throttle valve 15 is provided in the intake passage 10. The 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 normal setting angle of 2-3 °, preferably 15 °.
It is set around {-20}. By setting the idle position of the throttle valve 15 to a substantially intermediate opening position between the fully closed position and the fully opened position in this manner, the flow of intake air having a flow rate and a flow velocity required during acceleration is already secured during idle operation. Will be. Although not shown, a sensor is provided for detecting the amount of rotation of the throttle valve, that is, the throttle angle. The throttle valve 15
Has 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 beside the throttle valve 15. The cam mechanism 20 has a cam member 22, and one end of the cam member 22 has
A pivot 21 that is 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. When the accelerator pedal is not depressed, the cam member 22 is located at the idle position indicated by the solid line,
A predetermined gap s is formed between the abutting portion 17 at the six tips. Further, the support shaft portion 21 is provided with a cam sensor (not shown) for detecting a rotation amount of the cam member 22. With this configuration, the cam member 22 rotates in conjunction with the operation of the accelerator, and the pick-up position (see the dashed line in FIG. 2) abuts on the abutting portion 17, and the throttle valve 15 is fully opened through the pick-up bar 16. (See the two-dot chain line position in the figure).

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

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

Next, the control operation by 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.
2 is moved from the idle position (the position indicated by the solid line 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 ignition plug 7, the injector 12, and the like are drive-controlled based on the data read from the map, and two of the six cylinders are stopped to perform the four-cylinder operation (see FIG. 4). This stabilizes the low-speed rotation.

In this case, as shown in FIG. 4, the smaller the accelerator operation amount is, the more the ignition timing is controlled to the retard side. Also, despite the fact that the flow velocity is increasing, it is possible to suppress the combustion of the engine and the increase in the engine speed. In this case, the fuel injection amount per one engine revolution is larger than the fuel injection amount when the accelerator operation amount is large, but the fuel injection amount per unit time is reduced due to the low engine speed. Thus, combustion of the engine is further suppressed, and low-speed rotation can be ensured. 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 (1) and the rotation amount (cam angle) of the cam member 22 detected by the cam sensor. Next, in step S6, the ignition plug 7, the injector 12 and the like are drive-controlled based on the data read from the map, and five cylinders are selected from the six cylinders to perform the five cylinder operation (see FIG. 4).

In this case, during acceleration, the ignition timing is controlled to be advanced as the accelerator operation amount, that is, the cam angle increases. On the other hand, since the throttle valve 15 is at the substantially intermediate opening position, the flow of the intake air having the flow rate and the flow velocity necessary for acceleration has already been secured, whereby the combustion of the engine is promoted and the engine is started in a short time. It is possible to rotate at high speed, and the acceleration can be improved. Further, although the fuel injection amount per one revolution of the engine is reduced, the fuel injection amount per unit time is increased by increasing the engine speed. Thereby, the combustion of the engine can be further promoted, and the acceleration 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 amount of cam rotation after the pickup position becomes equal to the throttle valve opening. Next, in step S8, spark plugs of all cylinders
The cylinder operation is performed (see FIG. 4). After the processing in step S8, the program returns to step S1.

As described above, in the present embodiment, the idle position of the throttle valve 15 is set at a substantially intermediate opening position between the fully closed position and the fully opened position. The flow is already secured during idle operation. Further, as described above, the cam member 2
Until 2 reaches the pickup position, the ECU 30 controls the ignition timing according to the amount of rotation of the cam member 22. 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 irrespective of the increase in the intake air flow rate and the flow velocity, and the increase in the engine speed can be suppressed. Also, during acceleration, the ignition timing is controlled to the advanced side in accordance with the amount of rotation of the cam member 22. On the other hand, the flow of intake air required during acceleration is already secured, so that combustion of the engine is promoted and the engine is started. High-speed rotation can be performed in a short time, and acceleration 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 is smaller. Therefore, during idling, combustion of the engine is suppressed by a decrease in the fuel injection amount, and low-speed rotation can be ensured. Also, during acceleration, the fuel injection amount per unit time increases. On the other hand, the throttle valve 15 at the substantially intermediate opening position has already secured the intake air flow at the flow rate and flow velocity required during acceleration, so that the engine combustion Is promoted, and the acceleration can be improved.

[0023]

Further, by using a throttle valve 15 having a hole, a groove or the like 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 a two-cycle engine is shown, but the present invention can be similarly applied to a four-cycle engine. Further, when only the ignition timing is controlled, the present invention can be applied to an engine provided with a carburetor.

[0026]

As described above, in the combustion control apparatus for an engine according to the first aspect of the present invention, the idle position of the throttle valve is set to a substantially intermediate opening position, so that the flow of intake air at the flow rate and flow velocity required during acceleration is obtained. During idle operation. In addition to the provision of the cam mechanism, the ignition timing control means for advancing the ignition timing with an increase in the amount of rotation of the cam mechanism up to the pickup position of the cam mechanism is provided. The ignition timing can be controlled to the advanced side in accordance with the amount of rotation of the mechanism, whereby the combustion of the engine can be promoted in conjunction with the flow of the intake air, and the engine can be rotated at a high speed in a short time. There is an effect that the property can be improved.

Further, by the control of the fuel injection amount control means,
Up to the pickup position of the cam mechanism, the fuel injection amount per revolution of the engine by the injector is reduced as the rotation amount of the cam mechanism increases, so idle rotation can be secured, and the fuel injection amount per unit time increases during acceleration. On the other hand, the intake valve having the flow rate and the flow velocity required for acceleration is already secured by the throttle valve at the substantially intermediate opening position, so that the combustion of the engine can be promoted and the acceleration performance can be improved. There is.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an outboard engine employing 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 a correlation among an accelerator operation amount, a throttle valve opening, an ignition timing, and a fuel injection amount in the engine.

[Explanation of symbols]

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

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-140436 (JP, A) JP-A-63-113134 (JP, A) JP-A-4-314688 (JP, A) JP-A 62-113 282148 (JP, A) Hira 1-74372 (JP, U) Hira 3-45431 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02P 5/02 F02D 41 / 10 F02D 9/02

Claims (1)

(57) [Claims] 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 opened position, and the throttle valve is rotated in accordance with an accelerator operation amount and the accelerator valve is rotated. operation amount provided a cam mechanism for the throttle valve starts to open from the idle position at the pickup position where the predetermined amount, with the amount of rotation of the cam mechanism until the amount of rotation of the cam mechanism reaches the pick-up position is increased
And ignition timing control means for advancing the ignition timing.
Inject fuel so that the amount of fuel injected per gin rotation decreases.
A combustion control device for an engine, comprising: a fuel injection amount control means for controlling an injection injector .