JPH1089098A - Operation controller for inner-cylinder injection type 2 cycle engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To retain an engine speed in a target idling rotational speed, by setting the opening of an exhaust control valve under an idling operation condition, smaller and larger than the opening of an accelerator reference exhaust control valve, respectively, when the engine speed is higher and lower than the target idling rotational. speed. SOLUTION: Detected signals showing an engine operating condition and so on, are inputted to an ECU 50 from various sensors. For example, an engine speed signal REV from an engine speed sensor 51, an accelerator opening signal ACC from an accelerator opening sensor 52, and so on, are inputted to the ECU 50. Then, the ECU 50 performs calculation on the basis of the detected signals inputted, showing the engine operating conditions, and outputs control signals to various kinds of actuators. Under an idling operating condition in which an accelerator opening is smaller than a predetermined idling opening, an exhaust control valve opening EXV is controlled smaller and larger than the opening of an accelerator reference exhaust control valve, respectively, when the engine speeded is higher and lower than a target idling rotational speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control system for a direct injection two-stroke engine designed to inject and supply fuel (gasoline) into a combustion chamber.

[0002]

2. Description of the Related Art Conventionally, fresh air is introduced into a crank chamber through an intake passage in which a throttle valve is disposed, and is primarily compressed, and the inside of a cylinder is scavenged by the primary compressed fresh air, while being disposed on a combustion chamber wall. Scavenging fuel (gasoline) from the fuel injector,
During the period from the exhaust stroke to the compression stroke, the fuel is injected during the compression stroke.
An in-cylinder injection two-cycle engine has been proposed in which burned gas is discharged from a combustion chamber to an exhaust passage prior to the next scavenging stroke.

In a two-stroke engine, particularly in a low-speed rotation and low-load operation range, the amount of fresh air itself for scavenging is small, and accordingly, the in-cylinder pressure decreases, and the burned gas in the exhaust passage becomes in the cylinder. There is a problem that irregular combustion is likely to occur due to reasons such as a backflow, a diffusion of injected fuel, a decrease in fuel concentration, and a low in-cylinder temperature, which makes flame propagation difficult.

Therefore, the present inventors have arranged an exhaust control valve for variably controlling the exhaust passage area in a direct injection type two-stroke engine. In the low speed rotation and low load operation range, the exhaust control valve is used. By reducing the pressure, the pressure at the start of compression and the temperature in the cylinder are kept high, and the generation of irregular combustion has been developed.

[0005]

In the idling operation, the engine is operated according to preset operating parameters such as a fuel injection amount, an injection timing, a throttle valve opening, and the like. In the operation according to the above-mentioned operation parameters, the target idling speed corresponding to the load may not be settled due to, for example, the atmospheric conditions, the engine temperature, and the combustion variation in each cycle.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and can maintain a target idling rotational speed corresponding to a load even if there are variations in each part, atmospheric conditions, engine temperatures and combustion variations in each cycle. It is an object of the present invention to provide an operation control device for a direct injection two-stroke engine.

[0007]

According to a first aspect of the present invention, there is provided an in-cylinder injection type two-cycle engine in which fuel is injected into a combustion chamber by a fuel injection valve, ignited by a spark plug, and burned. And an operation control device for controlling an engine operation parameter based on an accelerator opening, an operation state detection means for detecting an operation state of the engine, an exhaust control valve for variably controlling an exhaust passage area, and the exhaust control valve. In the normal operation state of the engine, the opening of the exhaust control valve is controlled to an accelerator reference exhaust control valve opening set based on the accelerator opening, and in the idling operation state, the opening of the exhaust control valve is set to the target idling rotation. Exhaust control valve opening degree control means which is smaller than the accelerator reference exhaust control valve opening degree when the number is higher than It is characterized in that.

According to a second aspect of the present invention, there is provided a fuel injection amount control means according to the first aspect, wherein the fuel injection amount is decreased when the engine speed is higher than the target idling speed and increased when the engine speed is lower than the target idling speed in the idling operation state. It is characterized by that.

[0009]

According to the first aspect of the present invention, in the idling operation state, the opening degree of the exhaust control valve is made smaller than the accelerator-based exhaust control valve opening degree when the engine speed is higher than the target idling speed. When the engine speed is low, the engine speed is increased, so that the engine speed can be maintained at the target idling speed.

That is, for example, when the engine speed is higher than the target idling speed, the opening of the exhaust control valve is narrower than the opening of the accelerator-based exhaust control valve, so that the flow resistance of the exhaust gas increases. Accompanying this, the intake air amount decreases, and as a result, the heat generation amount decreases, and the engine speed decreases. Conversely, when the engine speed is lower than the target idling speed, the exhaust control valve opening is opened more than the accelerator-based exhaust control valve opening, so that the exhaust gas flow path resistance decreases and the intake air As a result, the amount of heat generated increases and the engine speed increases. In this way, the engine speed is maintained at the target idling speed.

According to the second aspect of the invention, when the engine speed is higher than the target idling speed, the opening of the exhaust control valve is reduced and the fuel injection amount is reduced. Since the injection amount is increased, the fuel injection amount decreases and increases as the intake air amount decreases and increases, and the engine speed can be more quickly settled to the target idling speed.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIGS. 1 to 19 show the first and second embodiments.
FIGS. 1 and 2 are views for explaining an in-cylinder injection two-cycle gasoline engine according to an embodiment of the present invention. FIGS. 1 and 2 are a left side view and a cross-sectional plan view of an outboard motor employing the engine of the embodiment. 3 is a sectional rear view of the engine, FIG. 4 is a diagram showing an exhaust control valve, FIG. 5 is a block diagram of an operation control device,
6 to 8 are flowcharts for explaining the control operation, and FIGS. 9 to 19 are conceptual diagrams of control data.

In FIG. 1, reference numeral 1 denotes an outboard motor employing the engine according to the present embodiment, which pivots vertically around a support shaft 100 at a stern 2 a of a hull 2 via a swivel arm 9 and a clamp bracket 8. It is supported vertically, and is positioned vertically so that the crankshaft 20 is substantially vertical during traveling.

The outboard motor 1 has an upper case 5 connected to an upper portion of a lower case 4 in which a propelling propeller 3 is disposed.
An engine 6 is mounted on an upper part of the upper case 5 and has a schematic structure in which the periphery of the engine 6 is surrounded by a top cowl 7. The rotation of the engine 6 is controlled by an output shaft 6a connected to a crankshaft 20, a drive shaft 12 extending vertically, a bevel gear mechanism 10, and a propulsion shaft 11 extending horizontally.
Is transmitted to the propeller 3 via the.

The engine 6 is a water-cooled V-type 6-cylinder in-cylinder injection two-cycle engine.
And a cylinder body 23 in which six cylinders (cylinder bores) 21 are arranged so as to form a V bank, and a cylinder head 24 is mounted on the cylinder body 23. It has a schematic structure in which a piston 25 slidably inserted into each cylinder 21 is connected to the crankshaft 20 via a connecting rod 26.

An ignition plug 27 is screwed into the cylinder head 24. Electrodes of the ignition plug 27 face a combustion chamber surrounded by the cylinder head 24, the cylinder 21 of the cylinder body 23, and the piston 25. . The ignition plug 27 is driven by an ignition circuit 63 (see FIG. 5), and generates a spark in the combustion chamber at a predetermined timing.

The intake system of the engine 6 is configured as follows. Each opening 22b is formed in the crankcase 22 so as to communicate with each crank chamber 22a defined corresponding to each cylinder, and the intake passage 30 is connected to each opening 22b with a reed valve 32 interposed therebetween. A throttle body 3 having a throttle valve 31 built in upstream of the intake passage 30;
3 is connected. The throttle valve 31 is driven to open and close by a throttle actuator 61 (see FIG. 5).

Further, one opposed scavenging passage 35a and two main scavenging passages 35b and 35c are formed in the cylinder body 23 to communicate each crank chamber 22a and each cylinder 21, and scavenging ports of the scavenging passages 35a to 35c are formed. 35 to cylinder 21
Open inside.

A fuel injection valve 49 is mounted on the side wall of the cylinder body 23 for each cylinder 21. Although not shown, the fuel injection valve 49 is connected to a fuel supply rail provided with a pressure regulating valve having a return passage at the distal end, and high-pressure fuel is supplied to the fuel supply rail from a fuel pump. ing. When the injection nozzle is opened by moving the valve body of the fuel injection valve 49 by the built-in electromagnetic coil 62 (see FIG. 5), the high-pressure fuel is injected and supplied into the cylinder 21 during the period when the nozzle is open. .

The exhaust system of the engine 6 is configured as follows. An exhaust branch passage (independent passage) 42 communicating with an exhaust port 41 opened to each cylinder 21 is formed in the cylinder body 23, and each exhaust branch passage 42 is formed to extend in a vertical direction substantially parallel to the crankshaft 20. The exhaust gas is merged into the exhaust merging passages 40 of the respective banks, and the lower end exhaust ports 6 b of the respective exhaust merging passages 40 are opened on the lower surface of the cylinder body 23.

An exhaust guide 13 is connected to the lower surface of the cylinder body 23. The exhaust guide 13 has a pair of exhaust holes 1 communicating with the lower end exhaust ports 6b.
3a, 13a are formed, an exhaust pipe 14 communicating with the exhaust holes 13a and extending downward is connected, and a muffler 16 surrounding the exhaust pipe 14 and forming an exhaust expansion chamber is connected to the exhaust guide 13. The lower end of the muffler 16 is opened in the lower case 4.

An exhaust control valve 43 for variably controlling the cross-sectional area of the exhaust passage is provided in the exhaust guide 13, that is, in a portion downstream of a point where all the independent passages 42 of the respective banks merge. The exhaust control valve 43 is disposed in a valve hole 13b formed so as to be orthogonal to the axis of the exhaust pipe 14. As shown in FIG. 4, a part of a round bar made of stainless steel is cut out. The valve parts 43b, 43b formed by the above-mentioned construction and open and close the exhaust holes 13a are coaxial. A drive shaft 43a is integrally formed at one end of the valve portion 43b, and a support shaft 43c is integrally formed at the other end.

The exhaust control valve 43 is provided with
The valve portion 43b is pivoted between a fully open position where b is flush with the inner surface of the exhaust hole 13a and a fully closed position where the valve portion 43b stands in the exhaust hole 13a and narrows the exhaust hole 13a. .

A cooling jacket 13c is formed around the valve hole 13b of the exhaust guide 13, and the exhaust control valve 43 is cooled by the jacket 13c. An exhaust control valve 43 is rotatably supported at the opening of the valve hole 13b.
A lid member 45 for closing the opening of 3b is inserted.

The exhaust control valve 43 is opened and closed by a drive actuator 64 (see FIG. 5) via a pulley 46 fixed to a drive shaft 43a protruding outside the exhaust guide 13 and a drive cable (not shown).

The muffler 16 is provided with an exhaust pressure sensor 55 for detecting the pressure in the exhaust passage. The exhaust pressure sensor 55 is disposed so as to penetrate into the muffler 16 from outside the upper case 5.
The detection unit 5 is located near the downstream end opening of the exhaust pipe 14 in the muffler 16.

In FIG. 5, reference numeral 50 denotes an ECU for controlling the operation of the engine 6. The ECU 50 receives detection signals indicating the operating state of the engine from various sensors. For example, an engine speed signal REV from a speed sensor 51, an accelerator opening (for example, the amount of depression of an accelerator pedal) signal ACC from an accelerator opening sensor 52, an engine coolant temperature signal TW from a water temperature sensor 53, a crank angle sensor A crank angle (piston position) signal CA from an exhaust pressure sensor 55, an exhaust pipe pressure (back pressure) PE from the exhaust pressure sensor 55, a crank chamber pressure signal from a crank chamber pressure sensor 56, an atmospheric pressure signal from an atmospheric pressure sensor 57, An ambient temperature signal or the like from the ambient temperature sensor 58 is input.

The ECU 50 executes various types of control maps stored in the data storage device in accordance with preset programs based on the respective detection signals indicating the engine operating state input from the respective sensors. And outputs various control signals to various actuators. For example, a throttle valve opening signal TH to a throttle actuator 61 for opening and closing the throttle valve 31, a fuel injection period (amount) signal FD to an electromagnetic coil 62 for opening and closing the fuel injection valve 49, and a fuel injection start timing signal INJ. , An ignition signal IGN to an ignition circuit 63 that supplies a high-voltage current to the ignition plug 27, and an exhaust control valve opening signal EX to an actuator 64 that drives the exhaust control valve 43 to open and close.
V or the like is output.

The opening of the throttle valve 31 and the opening of the exhaust control valve 43 are determined by a throttle opening sensor (not shown).
The detected opening is detected by an exhaust control valve opening sensor, and the detected opening is fed back to the ECU 50.

Here, the various controls by the ECU 50 are basically performed in the following manner. First, as the control data is conceptually shown in FIG.
Based on V and accelerator opening ACC, throttle opening TH, ignition timing IGN, fuel injection timing INJ, injection amount F
D, values of control parameters such as the exhaust control valve opening EXV are set. Note that TH is determined by REV and ACC, and IGN, INJ, FD, and E are determined by TH and REV.
XV can also be determined, and this makes it easier to manage the engine load.

The throttle opening TH and the accelerator opening A
The CC is controlled according to the following relationship. Normally, the throttle opening TH and the accelerator opening ACC are set to have the same inclination. However, as shown in FIG. 17A, the inclination of the throttle valve opening TH is set to be larger than the accelerator opening ACC on the way. May be set as the acceleration, or the inclination and the idle opening may be changed depending on the engine speed as shown in FIG.

As for the ignition timing IGN, an ignition timing set at an engine operation point determined by the engine speed REV and the accelerator opening ACC is selected depending on which of output, fuel consumption, exhaust gas purification, and riding comfort is emphasized. Is done.

FIG. 1 shows the fuel injection start timing INJ.
As shown in FIG. 8, the angle is advanced as the engine speed is higher or the engine load is larger, and the fuel injection period FD is controlled to be longer as the accelerator opening ACC is larger and as the engine speed is higher.

As shown in FIG. 19, the exhaust control valve opening EXV is set smaller as the engine speed is lower and the load is lower. When the load is more than the medium load, it is fully opened regardless of the rotation speed.

Here, the ECU 50 has the following control functions unique to this embodiment. [Exhaust control valve opening control function] The accelerator opening is equal to or greater than a predetermined idling opening,
Normal (steady) when the rate of change of the accelerator opening is equal to or less than a predetermined value
In the operating state, the opening EXV of the exhaust control valve 43 is controlled to an accelerator / rotation speed reference exhaust control valve opening EXVo set based on one or both of the accelerator opening ACC and the engine speed REV. When the external load is large (for example, during uphill driving when the engine is used as power for the vehicle), there is an operation state in which the engine speed is small but the accelerator opening is larger than the predetermined idle opening. In this operation state, similar control is performed as part of the normal (steady) operation state.

In the start operation state or the warm-up operation state,
The exhaust control valve opening EXV is increased and controlled to be larger than the accelerator-based exhaust control valve opening EXVo. in this case,
The increment ΔEXV of the exhaust control valve opening EXV is controlled to be larger as the engine coolant temperature TW is lower (see FIG. 9A), and the exhaust control valve opening EXV at the time of warm-up operation is determined by the accelerator / rotation speed reference exhaust. Control is performed so as to have a magnitude between the control valve opening EXVo and the start-time exhaust control valve opening.

In the idling operation state where the accelerator opening is smaller than the predetermined idle opening, the exhaust control valve opening EXV is set to a value smaller than the accelerator reference exhaust control valve opening EXVo when the engine speed REV is higher than the target idling speed REVo. It is controlled to be small, and is controlled to be large when it is low. When the external load is small (for example, during downhill driving when the engine is used as power for the vehicle), there is an operating state in which the engine speed is large but the accelerator opening is smaller than the predetermined idle opening. In this operation state, the same control is performed as a part of the idling operation state.

In the transient operation state, the exhaust control valve opening E
XV is the accelerator / rotation speed reference exhaust control valve opening EXVo
Control to a larger opening. In the transient operation state (sudden acceleration state), the larger the one or both of the time increase rate dA / dt of the accelerator opening and the time increase rate dR / dt of the engine speed are, the larger the increase ΔEXV of the exhaust control valve opening is controlled. . In this case, the greater the opening of the exhaust control valve is, the greater the control is in the operating range where the Alcell opening and the engine speed are smaller (see FIGS. 13 and 14).

In a rapid deceleration state, the closing speed of the exhaust control valve is made slower as one or both of the accelerator opening and the time reduction rate of the engine speed are larger, so that the exhaust control valve opening EXV is set based on the accelerator / rotation speed. Exhaust control valve opening EX
Make it larger than Vo.

[Fuel Injection Amount Correction Function] In the start operation state or the warm-up operation state, the fuel injection amount F
D is increased from an accelerator reference injection amount FDo corresponding to the accelerator opening.

In the idling operation state, the fuel injection amount FD decreases when the engine speed REV is higher than the target idling speed OREV, and increases when the engine speed REV is lower.

[Throttle Valve Opening Correction Function] In the starting operation state or the warm-up operation state, the throttle valve opening TH is increased from the accelerator reference throttle valve opening THo corresponding to the accelerator opening ACC.

Next, various control operations by the ECU 50 will be described. [Starting mode control] In FIG. 6, when the control is started by turning on the main switch, the water temperature TW from the water temperature sensor 53 is read, and from the built-in map shown in FIG.
Initial values corresponding to the water temperature TW such as the ignition timing IGN, the fuel injection start timing INJ, the fuel injection amount FD, the exhaust control valve opening EXV, and the throttle valve opening TH are read, and the exhaust control valve opening EXV and the throttle valve opening are read. Each actuator operates so that the degree TH becomes the above initial value (steps S1 to S1).
4). As can be seen from FIG. 9, the ignition timing IGN among the above initial values is constant regardless of the water temperature.
For V, INJ, FD, and TH, a larger value and an advanced angle value are selected as the water temperature is lower.

When the ignition key is turned to the ON position of the starter motor, the starter motor starts operating, and the electromagnetic coil 62 for driving the fuel injection valve, the ignition circuit 63 for the ignition plug, the actuator 61 for the throttle valve,
The exhaust control valve actuator 64 operates with the initial value as a target (steps S5 to S7), and while the ignition key is held at the ON position of the starter motor and the cell switch is ON, the water temperature reading, ignition timing, Reading of fuel injection start timing... And setting operation are performed (steps S8, 9, 6, 7).

When the ignition key is returned in step S7 and the cell switch is turned off, the engine speed REV is read (step S10), and until the engine speed REV exceeds a preset start completion speed REVo. Detection of water temperature in start mode,
The reading of the ignition timing and the like and the operation of the actuator are repeated (steps S11 to S14, S10), and the start mode ends when the engine speed REV exceeds the start completion speed REVo.

[Idle Mode] In FIG. 7, when it is determined that the engine is in the idling operation range by an idle switch which is turned on / off based on the accelerator opening, the water temperature TW is read and a target corresponding to the water temperature TW is obtained from the map of FIG. The idling rotation speed OREV is read (steps S21 to S23). In this case, as shown in FIG. 10, when the engine temperature (water temperature) TW is in a predetermined low temperature range, the target idling rotational speed OREV is set higher as the water temperature is lower. As a result, when the engine temperature is low in the idle mode, the engine speed is raised more quickly by increasing the idling speed,
Engine rotation can be stabilized.

Subsequently, from the map shown in FIG. 11, the exhaust control valve opening EX corresponding to the target idling rotational speed OREV is determined.
V, the ignition timing IGN, the fuel injection start timing INJ, the fuel injection amount FD, and the target values of the throttle valve opening TH are read (step S24), and the actuator for the exhaust control valve is determined according to the target exhaust control valve opening EXV and the like. 64, ignition circuit 6
3. The fuel injection valve driving electromagnetic coil 62 and the throttle valve actuator 61 operate (step S25).

As can be seen from FIG. 11, the ignition timing IGN among the above control values is different from the target idling rotational speed OR.
EXV, IN is slightly retarded as EV increases
J, FD, and TH increase as the target idling speed increases.
That is, the lower the engine coolant temperature TW, the greater or the advance angle is set.

When the engine is in the idling state, the target idling rotational speed OREV corresponding to the water temperature TW is read again (steps S26 to S26).
8) The engine speed REV is read (step S).
29), the rotation speed REV and the target idling rotation speed OR
The difference ΔREV from the EV is obtained, and the exhaust control valve opening correction amount ΔEXV,
Throttle valve opening correction amount ΔTH, fuel injection amount correction amount ΔF
D and the like are obtained (steps S30 and S31), and the values corrected by the correction amounts are used as new control target values as the exhaust control valve opening EXV, the throttle opening TH, the fuel injection amount FD.
Are controlled (steps S32 and S33).

As shown in FIG. 12, the difference ΔREV between the engine speed REV and the target idling speed OREV is large on the negative side (right side in FIG. 12).
The larger the value is set to the positive side, the larger the value is set to the positive side (left side in the figure). That is, as the engine speed REV is lower than the target value OREV, the exhaust control valve opening and the throttle valve opening are corrected to the open side, so that the outflow resistance of the exhaust gas and the inflow resistance of the intake air decrease, and the fuel injection amount increases. And the engine speed increases toward the target value.

In step S26, when it is determined that the vehicle is out of the idling operation range due to the opening of the accelerator opening or the like, the engine speed REV, the accelerator opening AC
C, water temperature TW, etc. are read, and respective control target values such as the accelerator opening, the ignition timing according to the engine speed, the exhaust control valve opening, the fuel injection amount, etc. are read from the map for the normal operation state. Each of the actuators operates according to the value (steps S35 to S36).

[Sudden acceleration mode] If it is determined in step S21 or S26 that the vehicle is not in the idle state, the control in FIG. 8 is performed instead of steps S34 to S36 in FIG. 7, and operation control according to normal operation is performed. In addition, operation control according to the sudden acceleration operation is performed. That is, the engine speed REV and the accelerator opening ACC are read, and the ignition timing IGN, the exhaust control valve opening EXV, the fuel injection start timing INJ, the injection amount FD, and the throttle in accordance with the engine speed REV and the accelerator opening ACC. The opening degree TH and the like are read from the map for normal operation (steps S41 and S42), and the increasing speed dR / dt of the engine speed REV,
An increasing speed dA / dt of the accelerator opening ACC is obtained, and a comparison is made between the calculated values and the reference values X and Y of the increasing speed to determine whether the vehicle is in a normal operation state or a rapid acceleration operation state (step S).
43, 44).

If at least one of the two calculated values is smaller than the reference value, it is determined that the vehicle is in the normal operation state.
Each of the above-described actuators operates so that the ignition timing, the exhaust control valve opening, the fuel injection timing, the injection amount, and the throttle opening read in accordance with the throttle opening are obtained. In this step S47, the same operation as in step S37 shown in FIG. 7 is performed. From step S41 to step S44, and jump to step S47, the normal operation mode is set.

On the other hand, if the two calculated values are larger than the two reference values, it is determined that the vehicle is in a rapid acceleration operation state, and FIGS.
5 based on the map of FIG.
/ Dt, exhaust control valve opening correction amount ΔEXV, fuel injection amount correction amount ΔFD according to accelerator opening increase speed dA / dt,
A throttle opening correction amount ΔTH or the like is obtained, and a new control target value is obtained by adding the correction amount to the exhaust control valve opening or the like obtained in step S42. Operates (steps S45 to S47), and proceeds to step S21 in FIG. That is, in addition to steps S41 to S44 (also serving as the normal mode), steps S45 to S47 correspond to the rapid acceleration mode. When the ignition key is turned off, the start mode, the idle mode, the normal mode, and the rapid acceleration mode,
The engine stops immediately.

Here, the exhaust control valve opening correction amount ΔEXV
Is, as shown in FIG. 13, the accelerator opening increasing speed dA /
It increases quadratically as dt increases. More specifically, ΔEXV is sharply increased as the accelerator is rapidly accelerated (see the dashed line in the drawing) from a state where the accelerator opening ACC is small.

The exhaust control valve opening correction amount ΔEXV
Is the engine speed increase acceleration d as shown in FIG.
It increases as R / dt increases. More specifically,
ΔEXV is sharply increased as the engine speed REV increases rapidly (see the broken line in the drawing) from a low state.

As shown in FIG. 15, the fuel injection amount correction amount ΔFD and the throttle opening correction amount ΔTH are set to larger values as the exhaust control valve opening correction amount ΔEXV increases. As a result, the exhaust gas exhaust resistance decreases due to the increase in the exhaust control valve opening EXV, and the fresh air inflow resistance decreases due to the increase in the TH valve opening TH, so that the fuel injection amount FD increases. Immediately increases.

As described above, in this embodiment, the exhaust control valve 43 is disposed downstream of the junction of all the independent passages 42 in the merge passage 40, so that the exhaust gas from all the cylinders After passing through the exhaust passage 43, the exhaust passage resistance in all cylinders can be variably controlled by one exhaust control valve 43 in the above-mentioned start mode, idle mode, rapid acceleration mode, and rapid deceleration mode. The pressure at the start of compression and the temperature in the cylinder are kept high, irregular combustion can be suppressed, and combustion stability can be improved.

In the present embodiment, in the idling operation state, the exhaust control valve opening EXV is set to an accelerator reference exhaust set based on the accelerator opening when the engine speed REV is higher than the target idling speed OREV. Since the control valve opening degree is set smaller than the control valve opening degree and set larger when the control valve opening degree is lower, the engine speed can be maintained at the target idling speed.

That is, for example, when the engine speed REV is higher than the target idling speed OREV, the exhaust control valve opening EXV is made smaller than the accelerator-based exhaust control valve opening, and the flow resistance of the exhaust gas increases. As a result, the intake air amount is reduced, and the fuel injection amount FD is accordingly reduced, so that the heat generation amount is reduced and the engine speed is reduced. Conversely, when the engine speed REV is lower than the target idling speed OREV, the exhaust control valve opening EXV
Is opened more than the accelerator-based exhaust control valve opening, the flow resistance of the exhaust gas decreases, the intake amount increases, and the fuel injection amount FD increases accordingly, so that the heat generation amount increases And the engine speed increases. In this way, the engine speed is maintained at the target idling speed.

In the transient operation state, the exhaust control valve opening EX
V is controlled to an opening that is larger than the accelerator / rotation speed reference exhaust control valve opening set based on the accelerator opening and the engine speed. In the transient operation, higher acceleration performance can be obtained, or abnormal temperature rise and stall of the engine can be avoided.

That is, during rapid acceleration, the exhaust control valve 43 is opened more than the exhaust control valve opening for the same accelerator opening and engine speed during normal operation, so that the exhaust gas flow path resistance is reduced and the intake gas is sucked. The air volume increases,
The engine speed increases immediately and the acceleration performance improves.
Also, at the time of rapid deceleration, the exhaust control valve is opened more than the same accelerator opening during steady operation and the opening of the exhaust control valve with respect to the engine speed. Is avoided.

In this embodiment, the greater the accelerator opening ACC and the time increase rate dA / dt and dR / dt of the engine speed REV in the rapid acceleration state, the greater the increase ΔEXV of the exhaust control valve opening EXV. The accelerator opening ACC and the engine speed RE
Since the increase ΔEXV of the opening degree of the exhaust control valve is increased as V becomes smaller in the operating range, the rapid acceleration performance can be further improved.

Further, the time reduction rate dA / of the accelerator opening ACC and the engine speed REV in the rapid deceleration state.
Since the closing speed of the exhaust control valve decreases as dt and dR / dt increase, the opening of the exhaust control valve can be made larger than the accelerator / rotation speed-based exhaust control valve opening, and high-temperature exhaust gas can be discharged. The temperature rise or engine stall due to the hindrance can be avoided more reliably.

In the starting operation state and the warm-up operation state, the opening EXV of the exhaust control valve is set to be larger than the opening of the accelerator / rotation speed reference exhaust control valve based on the accelerator opening and the engine speed. Therefore, during low load operation in the normal operation state, the exhaust passage area is reduced by the exhaust control valve, so that the pressure at the start of compression and the in-cylinder temperature can be kept high to suppress the occurrence of irregular combustion, and the start operation state and the warm-up state can be suppressed. When the engine is in operation, the exhaust passage area is increased by the degree of opening of the exhaust control valve, the fresh air volume is increased, and the fuel injection amount is increased accordingly, so the engine speed increases rapidly. ,
The load on the starter motor and the battery can be reduced, or the warm-up time can be reduced.

Further, since the increment ΔEXV of the exhaust control valve opening in the above-mentioned start operation state and warm-up operation state is increased as the engine coolant temperature TW is lower, the engine speed can be quickly increased even when the engine temperature is low. Can reduce the warm-up time.

In the start operation state and the warm-up operation state, the throttle valve opening is set to be larger than the accelerator reference throttle valve opening corresponding to the accelerator opening. Therefore, the opening of the exhaust control valve and the throttle valve are increased. The increase in the opening cooperates with each other, the fresh air amount increases reliably, the engine speed during startup operation can be more reliably increased, and the warm-up time during warm-up operation can be further increased. Can be shortened reliably.

[Brief description of the drawings]

FIG. 1 is a left side view of an outboard motor including an in-cylinder injection two-cycle engine according to a first embodiment of the present invention.

FIG. 2 is a sectional plan view of the outboard motor according to the first embodiment.

FIG. 3 is a sectional rear view of the engine according to the first embodiment.

FIG. 4 is a view showing an exhaust control valve of the engine according to the first embodiment.

FIG. 5 is a block diagram of an operation control device for the engine according to the first embodiment.

FIG. 6 is a flowchart illustrating the operation of the engine according to the first embodiment.

FIG. 7 is a flowchart illustrating an operation of the engine according to the first embodiment.

FIG. 8 is a flowchart illustrating the operation of the engine of the first embodiment.

FIG. 9 is a map diagram conceptually showing control data of the engine of the first embodiment.

FIG. 10 is a map diagram conceptually showing control data of the engine of the first embodiment.

FIG. 11 is a map diagram conceptually showing control data of the engine of the first embodiment.

FIG. 12 is a map diagram conceptually showing control data of the engine of the first embodiment.

FIG. 13 is a map diagram conceptually showing control data of the engine of the first embodiment.

FIG. 14 is a map diagram conceptually showing control data of the engine of the first embodiment.

FIG. 15 is a map diagram conceptually showing control data of the engine of the first embodiment.

FIG. 16 is a map diagram conceptually showing control data of the engine of the first embodiment.

FIG. 17 is a map diagram conceptually showing control data of the engine of the first embodiment.

FIG. 18 is a map diagram conceptually showing control data of the engine of the first embodiment.

FIG. 19 is a map diagram conceptually showing control data of the engine of the first embodiment.

[Description of Signs] 6 In-cylinder injection two-cycle engine 21 Cylinder 27 Spark plug 41 Exhaust port 42 Independent passage 40 Merging passage 43 Exhaust control valve 49 Fuel injection valve 43, 70, 80 Exhaust control valve 71, 81 Valve plate 72, 82 Valve shaft 73 Connecting mechanism

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02D 43/00 301 F02D 43/00 301H 301Z

Claims (2)

[Claims] 1. An in-cylinder injection two-cycle engine in which fuel is injected into a combustion chamber by a fuel injection valve, ignited by a spark plug, and burned, the engine operation parameters are determined based on the engine speed and the accelerator opening. In an operation control device configured to control, an operation state detection means for detecting an operation state of an engine, an exhaust control valve for variably controlling an exhaust passage area, and an accelerator opening in a normal operation state of the engine. The control unit controls the accelerator-based exhaust control valve opening based on the opening, and in the idling operation state, sets the accelerator-based exhaust control valve open when the engine speed is higher than the target idling speed. An in-cylinder injection type two-cylinder system, comprising: Operation control device for a cruise engine. 2. The fuel injection amount control device according to claim 1, further comprising a fuel injection amount control means for decreasing the fuel injection amount when the engine speed is higher than the target idling speed and increasing the fuel injection amount when the engine speed is lower than the target idling speed in the idling operation state. Control device for in-cylinder injection two-cycle engine.