JP2893607B2 - Fuel injection control device for two-cycle engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection control device for a two-cycle engine that controls fuel injection timing and improves suction efficiency.

[Related Art] In recent years, in engine control, a technique of fuel injection control by a microcomputer has been generalized and widely adopted. In this technology, a microcomputer calculates a fuel injection amount based on engine operating state parameters detected by various sensors, and outputs a drive pulse width signal corresponding to the fuel injection amount to an injector at a predetermined timing to output fuel. Inject.

Such a fuel injection control technique is first established in a four-cycle engine, and also in a two-cycle engine, various attempts to control fuel injection by a microcomputer are being made.

A prior example relating to the fuel injection control of this two-cycle engine is disclosed in, for example, Japanese Patent Application Laid-Open No. 63-255543. In this prior example, a mainstream in which fresh air is introduced into a crank chamber via a reed valve is disclosed. Fuel injection valves (ink injectors) are arranged in the intake passage and a sub intake passage for introducing fresh air into the crank chamber via a piston valve, respectively.
The injection timing and injection amount of each fuel injection valve are controlled.

In many cases, the timing of the fuel injection in the fuel injection control of the engine is basically performed in synchronization with the rotation of the engine.
In supplying fuel necessary for combustion, in the case of port injection of a multi-cylinder engine, the following injection method is mainly employed.

Simultaneous injection of all cylinders Injects fuel simultaneously in all cylinders in synchronization with engine rotation. Since injection timing is simultaneous for all cylinders, cylinder discrimination is not required and the drive system for multiple injectors becomes one, and the system configuration On the other hand, the optimal injection timing cannot be obtained for each cylinder,
Output performance, transient air-fuel ratio characteristics, etc. are not necessarily good.

Group injection system This is a system in which fuel is injected for each group cylinder in synchronization with the engine rotation, and compensates for the disadvantage of the simultaneous injection of all cylinders.

Sequential injection system Injects fuel independently for each cylinder in synchronization with engine rotation. Fuel required for one combustion can be accurately injected to each cylinder at the optimum injection timing. For this reason, good output performance and good transient air-fuel ratio characteristics are obtained. Recently, many engines adopt this sequential injection system.

Therefore, when the sequential injection system is adopted and the fuel injection timing is set in accordance with the intake stroke in which the intake port is opened by the piston valve as in the above-described prior example, for example, in a six-cylinder engine, the injection to the # 1 cylinder is performed. The fuel injection timing of the piston valve side sub-intake passage is set to # 2
The injection starts slightly before the top dead center of the cylinder (60 ° before the top dead center of the # 1 cylinder), and ends at the top dead center of the # 1 cylinder.

[Problems to be Solved by the Invention] However, in a two-stroke engine, while the intake port is opened by the piston valve,
Since the timing at which the negative pressure in the crankcase reaches the maximum is delayed, when fuel is injected in accordance with the intake stroke when the intake port on the piston valve side is opened, there is a difference between the negative pressure in the crankcase and the fuel injection timing. As a result, all the injected fuel cannot be sucked into the crankcase, and there is a problem that the fuel is blown back and the output of the engine is reduced.

[Object of the Invention] The present invention has been made in view of the above circumstances, and aims to improve engine output performance by preventing fuel from being blown back during fuel injection and allowing fuel to be efficiently sucked into a crankcase. It is an object of the present invention to provide a fuel injection control device for a two-cycle engine that can be used.

[Means and Actions for Solving the Problems] To achieve the above object, a fuel injection control device for a two-stroke engine according to the present invention uses a piston valve M1 based on crank position information P1 as shown in FIG. Crank position determining means M4 for determining a period P2 during which the intake port M2 is closed for each cylinder M3, and an engine operating state parameter P3
And the fuel injection amount setting means M5 for setting the fuel injection amount P4 of the injector M6 provided in the intake port M2 for each cylinder M3 based on the above, and the intake port M2 determined by the crank position determining means M4 is closed. In period P2, the fuel injection amount setting means
An injection timing setting means M7 for setting a timing at which the injector M6 injects the fuel injection amount P4 set by M5 for each cylinder M3.

That is, the period P2 during which the intake port M2 is closed is determined for each cylinder M3 by the port timing of the piston valve M1, based on crank position information P1 such as a crank angle sensor and an ignition signal, for example, in the crank position determining means M4. Is done.

Then, the fuel injection amount P4 set by the fuel injection amount setting means M5 based on the engine operation state parameter P3 is injected from the injector M6 by the injection timing setting means M7 during the period P2 when the intake port M2 is closed. , Above cylinder
Fuel is injected into the intake port M2 for each M3.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

2 and subsequent figures show an embodiment of the present invention, FIG. 2 is a schematic diagram of an engine control system, FIG. 3 is a front view of a crank rotor, FIG. 4 is a front view of a flywheel, and FIG. 6 is a flowchart showing a procedure for determining a complete explosion, FIG. 7 is a flowchart showing a procedure for setting fuel injection timing, FIG. 8 is a timing chart of fuel injection, and FIG. 9 is a fuel injection timing chart. FIG. 4 is an explanatory diagram showing a correlation between a timing and an engine output.

(Configuration of Engine Control System) In FIG. 2, reference numeral 1 in the figure denotes an engine main body, for example, a three-cylinder two-cycle engine mounted on a snowmobile or the like. An intake port opened and closed by a piston 1a is provided in a cylinder block 2 of the engine body 1.
2a and an exhaust port 2b are formed, and so-called intake and exhaust by a piston valve is performed.

An ignition plug 4 whose tip is exposed to a combustion chamber is attached to each cylinder of the cylinder head 3 of the engine body 1, and a crankcase temperature sensor 6 faces a crankcase 5.

An intake manifold 9 is connected to each intake port 2a of the cylinder block 2, a throttle opening sensor 10 is connected to a throttle valve 9a provided in the intake manifold 9, and a throttle opening sensor 10 is connected to the intake manifold 9. An injector 11 is disposed immediately upstream of each intake port 2a of each cylinder.

An air box 12 containing an air cleaner (not shown) is communicated upstream of the intake manifold 9, and an air temperature sensor 13 faces the air box 12.

The injector 11 is supplied with fuel that is pressure-fed from a fuel tank 15 via a filter 16 by a fuel pump 17 and adjusted to a predetermined pressure by a pressure regulator 18.

(Circuit Configuration of Control Unit) On the other hand, reference numeral 20 denotes a control unit (ECU) composed of a microcomputer, and the CPU (Central Processing Unit) 21, ROM 22, RAM 23, backup RAM 24, and I / O of the ECU 20
Interfaces 25 are connected to each other via a bus line 26, and a predetermined stabilized voltage is supplied from a constant voltage circuit 27.

Based on the crank position information, the ECU 20 is provided at each intake port of each cylinder based on crank position information, based on crank position determination means for determining a period during which an intake port is closed by a piston valve for each cylinder. A fuel injection amount setting means for setting the fuel injection amount of the injector, and a fuel injection amount set by the fuel injection amount setting means for each cylinder during a period in which the intake port determined by the crank position determination means is closed. The functions of the injection timing setting means for setting the timing of injection from the injector are realized, and air-fuel ratio control, ignition timing control, and the like are performed.

The constant voltage circuit 27 is connected to a battery 30 via a relay contact of an ECU relay 28 to supply control power, and is also directly connected to the battery 30, and to the backup RAM 24 when the control power is OFF. Supply backup power to maintain data.

The ECU relay 28 has two sets of relay contacts, and its electromagnetic coil 28a is connected to the battery 30 via an ignition switch 31 and a kill switch 32. The ignition switch 31 and the kill switch 32 are
The ON terminals are connected in series, and the OFF terminals are connected in parallel.

When both the ignition switch 31 and the kill switch 32 are ON, the ECU relay 28 is turned ON, and a control power is supplied to the constant voltage circuit 27 via one of the relay contacts. At the OFF position, the ignition power supply line of the ignition device 33 is short-circuited, and the ignition is cut.

The kill switch 32 is an emergency stop switch provided on a grip of a snowmobile (not shown).

The input ports of the I / O interface 25 of the ECU 20 are connected to the sensors 6, 10, and 13, the atmospheric pressure sensor 36 built in the ECU 20, the crank angle sensor 46, and the like. A signal line from the ignition device 33 is connected, an ignition pulse is input, and the other relay contact of the ECU relay 28 is connected to monitor the voltage VB of the battery 30, while the I / O interface 25 The injector 11 and the like are connected to the output port via a drive circuit 40.

The crank angle sensor 46 is constituted by an electromagnetic pickup or the like, and is provided opposite to the outer periphery of a crank rotor 45 which is mounted on a crank shaft 1b of the engine body 1 as shown in FIG.

On the outer periphery of the crank rotor 45, for example, a projection 45a is formed at the position of the bottom dead center (BDC) of the # 3 cylinder.
45a is detected by the crank angle sensor 46, and #
The bottom dead center of the three cylinders is detected.

On the other hand, a magnet 41 is connected to the crankshaft 1b of the engine body 1, and a charging coil 41d of the magnet 41 is connected to the battery 30 via a rectifier 42 to charge the battery 30. . further,
The exciter coil 41a of the magneto 41 and the pulsar coil 41b opposed to the flywheel 41e are connected to the ignition device.
The ignition device 33 is connected to the primary side of the ignition coil 4a.

The ignition device 33 is, for example, an ignition device of a capacity discharge type or the like, and includes an ignition circuit, an engine stop circuit for short-circuiting an ignition power supply, a pulse circuit, and the like. In the ignition device 33, when ignition power is supplied from the exciter coil 41a and an ignition trigger signal is input to the ignition circuit from the pulsar coil 41b, the ignition coil
An ignition signal is output to 4a, and the ignition signal is shaped into a waveform by a pulse circuit to generate an ignition pulse, which is output to the ECU 20.

In addition, as shown in FIG.
Before the compression top dead center of each of the # 1, # 2, and # 3 cylinders (BTD
C) At the position of θ2 (for example, θ2 = 15 to 20 °), the protrusion 41f
(May be a slit) is θ1 (eg, θ1 = 120 °)
When the protrusion 41f passes through the pulsar coil 41b with the rotation of the flywheel 41e, the pulsar coil 41b transmits the ignition device 33
In this embodiment, an ignition trigger signal is output, and in this embodiment, ignition is performed simultaneously for all cylinders (three cylinders) three times per engine revolution.

The CPU 21 of the ECU 20 calculates the engine speed N from the input interval of the ignition pulse according to the control program stored in the ROM 22, and compares the engine speed N with the complete explosion speed NSET. And N <NS
At the time of ET, it is determined that the engine has started for the first time, and the ignition pulse is used as a trigger, and the fuel injection pulse width Ti at the time of starting all the cylinders at the same time is set to the injector of each cylinder once per engine revolution.
11 to inject fuel, and when the condition of N ≧ NSET continues for a predetermined time, it is determined that the engine has completely exploded, and based on the engine speed N and the throttle opening α from the throttle opening sensor 10, Thus, the basic fuel injection pulse width Tp is set.

Further, based on the various data stored in the RAM 23, various corrections are made to the basic fuel injection pulse width Tp and corrections are made based on the battery terminal voltage VB. The fuel injection pulse width Ti is calculated, and the fuel injection pulse width Ti is output to the injector 11 of the # 3 cylinder by the cylinder discrimination signal indicating the bottom dead center of the # 3 cylinder from the crank angle sensor 46 to output fuel. Then, fuel is injected at each bottom dead center in the order of # 1 cylinder and # 2 cylinder.

(Operation) Next, the operation of the embodiment having the above configuration will be described.

First, when the engine is cranked, ignition power is supplied from the exciter coil 41a of the magnet 41 to the ignition device 33, and an ignition trigger signal is output from the pulsar coil 41b at a predetermined crank position.

By this ignition trigger signal, an ignition signal by, for example, capacity discharge is output from the ignition device 33 to the primary side of the ignition coil 4a, and the ignition plug 4 connected to the secondary side is sparked. An ignition pulse is output to the ECU 20.

In the ECU 20, based on the ignition pulse, fuel injection for starting the engine is performed simultaneously for all cylinders, and when the engine has completely exploded, control is shifted to normal control, and based on the cylinder discrimination signal from the crank angle sensor 46 and the ignition pulse. Thus, the fuel injection timing is set to the bottom dead center of each cylinder, and fuel injection is performed for each cylinder.

(Fuel Injection Pulse Width Setting Procedure) Next, a fuel injection pulse width setting procedure for the injector 11 will be described with reference to the flowchart of FIG.

The flowchart shown in FIG. 5 is a program that is repeated at predetermined intervals in synchronization with engine rotation.
In step S101, the ignition pulse input interval time T1
20 and the crank angle θ1 (θ1 = 120 °; the angle between the protrusions 41f on the outer periphery of the flywheel 41e of the magneto 41) corresponding to the ignition pulse input interval time T120, the period f
(F = dT120 / dθ1), the engine speed N is calculated from this cycle f (N = 60 / (2πf)), and stored at a predetermined address in the RAM 23.

Next, in step S102, it is checked whether or not the start determination flag FLAG1 is set. FLAG1 = 1, that is,
When the engine is started for the first time, the process proceeds from step S102 to step S103, the crankcase temperature Tm C from the crankcase temperature sensor 6 is read, and the process proceeds to step S104.

In step S104, the basic pulse width at low rotation Ti LNTW is set using the crankcase temperature Tm C read in step S103 as a parameter, and the flow proceeds to step S105.

The low-revolution basic pulse width Ti LNTW is a basic fuel injection amount at low rotation before the complete combustion of the engine, and is, for example, ROM22.
Are set directly or by interpolation calculation by searching a map stored in a series of addresses.

In step S105, a rotation correction coefficient KLN is set using the engine speed N calculated in step S101 as a parameter.

The rotation correction coefficient KLN changes the correction amount in accordance with the engine speed N until the engine speed N reaches the complete explosion speed NSET. Is set to a larger value, and KLN is set to 0 at a predetermined rotational speed or more in order to shift to a normal fuel injection amount after the engine complete explosion. For example, a map stored in a series of addresses in the ROM 22 is used. Is set directly or by interpolation calculation.

Next, the process proceeds from step S105 to step S106, and the time correction coefficient KLT is set using the elapsed time T1 from when the first injection pulse was output as a parameter. The time correction coefficient KLT is such that when the engine is started, the time when the first injection pulse is output is set to KLT = 1, the value is reduced with time, and the time is corrected in the direction of decreasing the fuel injection amount. When the elapsed time T1 reaches the set time TKLY (for example, 180SEC), KLT = 0.

Note that the set time TKLY is set to be sufficiently long with respect to the time when the engine completely explodes, and to smoothly shift to a normal fuel injection amount after the engine is completely exploded.

Then, in step S107, the low-rotation basic pulse width Ti LNTW set in step S104 is changed to the value in step S10.
The rotation is corrected by the rotation correction coefficient KLN set in step 5 and the time is corrected by the time correction coefficient KLT set in step S106 to set the fuel injection pulse width Ti at start (Ti
← Ti LNTW × KLN × KLT), exit the routine.

On the other hand, in step S102, FLAG1 = 0, that is,
When the engine has completely exploded, the process proceeds from step S102 to step S108, and the throttle opening α from the throttle opening sensor 10 is read.

Next, in step S109, a basic fuel injection pulse width map MPα is searched using the engine speed N calculated in step S101 and the throttle opening α read in step S108 as parameters, and the basic fuel injection pulse width map MPα is directly or interpolated. After setting the fuel injection pulse width Tp, the process proceeds to step S110.

The basic fuel injection pulse width map MPα assigns the intake air amount to the throttle opening α and the engine speed N, and calculates the basic fuel injection pulse width Tp for this intake air amount.
This is stored as a three-dimensional table in a series of addresses of the ROM 22, and a fuel injection control with a good response can be achieved for the throttle valve 9a by a so-called throttle speed method.

In step S110, the crankcase temperature TmC from the crankcase temperature sensor 6, the intake temperature TmA from the intake temperature sensor 13, and the atmospheric pressure P0 from the atmospheric pressure sensor 36 are read, and the process proceeds to step S111.

In step S111, based on the crankcase temperature TmC, the intake air temperature TmA, and the atmospheric pressure P0 read in step S110, for example, each correction table stored in the ROM 22 is searched, interpolated, and the crankcase temperature correction is performed. , Intake air temperature correction,
Set the correction coefficient COEF for various increments related to altitude correction.

Then, the process proceeds to step S112, where the battery terminal voltage V
B, and in step S113, based on the battery terminal voltage VB read in step S112, the response delay time (pulse width) of the injector 11 that changes according to the battery terminal voltage VB is read by a table search or the like. An injector voltage correction pulse width TS for correcting the response delay time is set, and the process proceeds to step S114.

In step S114, the basic fuel injection pulse width Tp set in step S109 is corrected by the various increase correction coefficients COEF set in step S111, and the injector voltage correction pulse width TS set in step S113 is set.
And the normal fuel injection pulse width Ti after the complete combustion of the engine
Is set (Ti ← Tp × COEF + TS) to exit the routine.

(Completion Explosion Determination Procedure) The setting of the start determination flag FLAG1 is performed in accordance with the complete explosion determination procedure shown in the flowchart of FIG. 6. Next, the program will be described.

The program of the complete explosion determination procedure is a program that is started by interruption every predetermined time.
3, the engine speed N is read out, and then in step S20
In 2, the engine speed N is compared with the complete explosion speed NSET (for example, 700 rpm).

In step S202, when N <NSET, it is determined that the engine has not completely exploded, and the flow advances to step S208 to set the start determination flag FLAG1 (FLAG1 ← 1) and exit the routine. If NSET, the process proceeds from step S202 to step S203, where the start determination flag FLAG
It is determined whether 1 has been cleared.

In step S203, when FLAG1 = 0, the process jumps from step S203 to step S206.
When = 1, the process proceeds from step S203 to step S204 to start counting by the counter, and counts up the count value C1 (C1 ← C1 + 1).

Note that the count value C1 of the above counter is determined by the power supply of the ECU 20 being O.
Initialized and cleared when N is set (C
1 ← 0).

Next, proceeding from step S204 to step S205,
It is determined whether or not the count value C1 counted up in step S204 has reached the set value C1SET. If C1 <C1SET, the process proceeds from step S205 to step S208 to set the start determination flag FLAG1 ( FLAG1 ← 1) Exit the routine.

On the other hand, when C1 ≧ C1 SET in step S205, that is, when the state of N ≧ NSET continues for a predetermined time (for example, 2SEC), it is determined that the engine has completely exploded, and the process proceeds to step S206 to clear the start determination flag FLAG1. And step S207
Then, clear the count value C1 of the above counter (C1 ←
0), exit the routine.

(Fuel injection timing setting procedure) The fuel injection pulse width Ti at the start set in the above-described fuel injection pulse width setting procedure is output at the same time for all cylinders. The pulse width Ti is output at a timing for each cylinder.

Next, the fuel injection timing setting procedure will be described with reference to the flowchart of FIG.

The program shown in FIG. 7 (a) is an interrupt program by an ignition pulse, and the program shown in FIG. 7 (b) is an interrupt program by a cylinder discrimination pulse.

First, when an ignition pulse is input from the ignition device 33, an interrupt processing program shown in FIG. 7A is started, and in a step S301, it is determined whether or not the above-described start determination flag FLAG1 is set. , FLAG1 = 0, that is, if the engine has already exploded, step
Jump to S306 and select ignition pulse count value C2
Is cleared (C2 ← 0) and the routine exits, while FLAG1
= 1, that is, when the engine is started for the first time, step S3
Proceeding to 02, the ignition pulse count value C is counted up (C ← C + 1), and the process proceeds to step S303.

In step S303, it is determined whether or not the ignition pulse count value C2 counted up in step S302 has reached three pulses, that is, whether or not the crank angle has reached 360 ° after the fuel injection of the front cylinder has been performed. I do.

In step S303, when C> 3, that is, when the crank angle is less than 360 ° and the engine has not made one revolution since the last time fuel injection was performed by the injector 11, the program immediately exits the program and proceeds to the next ignition. Waiting for the input of a pulse, when C ≧ 3, that is, when the input of the current ignition pulse is a crank angle of 360 ° after the fuel injection of the front cylinder is performed, and when the engine gas makes one revolution, the above-described steps S303 Proceeding to step S304, the fuel injection pulse width Ti at the start set in the program of the above-described fuel injection pulse width setting procedure is read from the RAM 23, and the flow proceeds to step S305.

Then, in step S305, the starting fuel injection pulse width Ti read in step S304 is simultaneously output to the injectors 11 of the # 1, # 2, and # 3 cylinders. In step S306, the ignition pulse cant value C2 is cleared. (C2 ← 0) to exit the program and wait for the next ignition pulse input.

That is, when the engine is started, the rotation speed greatly fluctuates, and it is difficult to accurately set the injection timing for each cylinder. Therefore, as shown in FIG. 8, every three ignition pulses (360 ° crank angle) Fuel injection is performed simultaneously with the cylinder.

When a cylinder discrimination pulse indicating the bottom dead center of the # 3 cylinder is input from the crank angle sensor 46, an interrupt processing program shown in FIG. 7B is started, and in step S401, the start discrimination is similarly performed. It is determined whether or not the flag FLAG1 is set. When FLAG1 = 1, that is, when the engine is started for the first time, the routine exits. On the other hand, when FLAG1 = 0, that is, when the engine is completely exploded, the process proceeds to step S402 and subsequent steps. Then, fuel injection is performed for each cylinder.

That is, in step S402, the fuel injection pulse width Ti set in the program of the above-described fuel injection pulse width setting procedure is read from the RAM 23, and the process proceeds to step S403 to #
Output to the three-cylinder injector 11.

Next, the process proceeds to step S404, in which a counter is set to a count set value CT120 corresponding to the ignition pulse input interval time T120 for each crank angle of 120 ° (C3 ← CT120), and in step S405, the count value C3 of the counter is counted down. (C3 ← C3-1), and the process proceeds to step S406.

In step S406, it is determined whether or not the count value C3 counted down in step S405 becomes C3 ≦ 0, that is, the crank angle advances by 120 ° after the bottom dead center injection of the front cylinder,
It is determined whether the bottom dead center of the next cylinder has been reached.

In step S406, when C3> 0, it is determined that the fuel injection timing of the next cylinder has not been reached, and the process returns to step S405 to continue the countdown. When C3 ≦ 0, the process proceeds from step S406 to step S407. Go ahead, RAM2
Read the fuel injection pulse width Ti for the next cylinder from 3
Proceed to step S408.

In step S408, it is determined whether or not the cylinder determination flag FLAG2 is set.
If the cylinder is not yet injected into the next cylinder, FLAG2 = 0, so the process proceeds from step S408 to step S409, and the cylinder following the # 3 cylinder, ie, # 1
The fuel injection pulse width Ti read in step S407 is output to the injector 11 of the cylinder, the cylinder discrimination flag FLAG2 is set in step S410 (FLAG2 ← 1), and the process returns to step S404.

Then, after proceeding to step S408 via steps S404 to S407, since the cylinder discrimination flag FLAG2 has been set by fuel injection into the # 1 cylinder (FLAG2 = 1), the process proceeds from step S408 to step S411, The fuel injection pulse width Ti is output to the next cylinder of the # 1 cylinder, that is, the injector 11 of the # 2 cylinder, and the cylinder discrimination flag is set in step S412.
Clear FLAG2 (FLAG2 ← 0) and exit the routine.

As a result, fuel injection is performed during the period when the intake port 2a is closed by the piston valve, and fuel injection can be performed at an optimal timing with respect to the delay of the negative pressure in the crank chamber, thereby reducing the inertia effect of the piston valve. By making full use of the fuel, all the injected fuel can be sucked into the crankcase chamber.

The fuel injection during the period when the intake port 2a is closed is most effective at the injection timing at which the fuel injection is started at the bottom dead center of each cylinder, and compared with the conventional injection timing during the period when the intake port 2a is open. In comparison, as shown in FIG. 9, it has been confirmed by experiments that the engine output performance is improved over the entire range.

[Effects of the Invention] As described above, according to the present invention, based on crank position information, crank position determining means for determining a period during which an intake port is closed by a piston valve for each cylinder,
A fuel injection amount setting means for setting a fuel injection amount of an injector provided at an intake port of each cylinder based on an engine operation state parameter; and a period in which the intake port determined by the crank position determination means is closed. Injection timing setting means for setting the timing at which the fuel injection amount set by the fuel injection amount setting means is injected from the injector for each cylinder, so that the fuel injected by the delay of the negative pressure in the crankcase chamber due to the inertia effect of the piston valve. Is prevented, and fuel can be efficiently sucked into the crankcase chamber.

Therefore, excellent effects such as improvement in the output performance of the engine and improvement in the fuel consumption rate can be achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the basic configuration of the present invention, FIG. 2 and subsequent figures show an embodiment of the present invention, FIG. 2 is a schematic diagram of an engine control system, FIG. FIG. 4 is a front view of the flywheel, FIG. 5 is a flowchart showing a fuel injection pulse width setting procedure, FIG. 6 is a flowchart showing a complete explosion determination procedure, FIG. 7 is a flowchart showing a fuel injection timing setting procedure, and FIG. FIG. 9 is a timing chart of fuel injection, and FIG. 9 is an explanatory diagram showing a correlation between fuel injection timing and engine output. M1 ... Piston valve M2,2a ... Intake port M3 ... Cylinder M4 ... Crank position determining means M5 ... Fuel injection amount setting means M6,11 ... Injector M7 ... Injection timing setting means P1 ... Crank position information P2: Period during which the intake port is closed P3: Engine operating state parameter P4: Fuel injection amount

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Mitsuru Chonan 1-7-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Inside Fuji Heavy Industries Ltd. (56) References JP-A-63-25543 (JP, A) JP-A-2-298636 (JP, A) JP-A-3-175131 (JP, A) JP-A-2-271070 (JP, A) JP-A-1-301936 (JP, A) JP-A-3-222842 (JP) , A) (58) Field surveyed (Int. Cl. ⁶ , DB name) F02D 41/00-41/40

Claims (1)

(57) [Claims] Crank position determining means for determining, for each cylinder, a period during which an intake port is closed by a piston valve based on crank position information, and provided at an intake port for each cylinder based on engine operating state parameters. A fuel injection amount setting means for setting the fuel injection amount of the injector, and a fuel injection amount set by the fuel injection amount setting means for each cylinder during a period in which the intake port determined by the crank position determination means is closed. A fuel injection control device for a two-cycle engine, comprising: injection timing setting means for setting a timing at which the fuel is injected from the injector.