JPH0814264B2 - Fuel injection control device for two-cycle engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fuel injection control device for a two-cycle engine with improved startability.

[Problems to be Solved by Conventional Techniques and Inventions] In recent years, a technique for controlling fuel injection of an engine by a microcomputer has been established.
Already widely used in four-stroke engines.

Next, various proposals have been made to employ the above-described microcomputer fuel injection control technology also in a two-cycle engine. For example, Japanese Patent Application Laid-Open No. 63-255543 discloses a main intake passage for introducing fresh air into a crankcase. A fuel injection valve (injector) is disposed in each of a fuel injection valve and an auxiliary intake passage that directly introduces fresh air into the crank chamber, and a technique is provided in which control means for controlling the injection timing and injection amount of each fuel injection valve is provided. I have.

In this case, the fuel injection amount is, for example, JP-A-63-29039.
As disclosed in the publication, the fuel injection control device obtains the intake air amount Q by a map search or the like using the throttle opening α and the engine speed N as parameters, and based on this intake air amount Q, the basic fuel In many cases, the final fuel injection amount is calculated by calculating the injection amount Tp and adding various corrections based on the engine operating state to the basic fuel injection amount. Then, in general, various correction parameters based on the engine operating state for the basic fuel injection amount Tp, the cooling water temperature,
Intake air temperature, atmospheric pressure, etc. are used.

By the way, in the above-mentioned two-cycle engine, the air-fuel mixture is supplied to the combustion chamber via the crankcase, so the engine charging efficiency is affected by the temperature condition of the crankcase, and the charging efficiency decreases as the crankcase temperature increases. .

The temperature of the crankcase changes in a wide range of environmental conditions in snowmobiles, and for example, the temperature on the low temperature side is approximately −
While it decreases to 50 ° C, the high temperature side reaches about 100 ° C,
The temperature change range becomes so large that the crankcase temperature cannot be accurately detected only by the cooling water temperature, and it is difficult to obtain an appropriate air-fuel ratio.

Further, in general, the fuel injection control device is designed so that when an ignition switch or the like is turned off in order to stop the engine, the control power supply is cut off to stop the system, and the ignition switch is turned on to restart the engine. At the time of starting, power is supplied to the fuel injection control device again, and the system returns to the initial state and starts operating.

Therefore, when the engine is started, the fuel injection amount is uniquely determined and supplied to the engine regardless of the crankcase temperature, and when the engine is restarted after warming up, the fuel supply becomes excessive and the startability deteriorates. Not
Acceleration failure immediately after starting will be caused.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a fuel injection control device for a two-cycle engine that can obtain good starting performance over a wide range of temperature conditions at the time of starting the engine. Is intended.

[Means for Solving the Problems] To achieve the above object, the fuel injection control device for a two-cycle engine according to the present invention is based on the crankcase temperature when a control power source is turned on, as shown in FIG. A first injection fuel injection pulse width setting means for setting a first fuel injection pulse width during engine cranking, and a second injection based on a low revolution basic pulse width having a crankcase temperature as a parameter. Based on the first low rotation speed fuel injection pulse width setting means for setting a first low rotation speed fuel injection pulse width until the engine complete explosion, and based on the low rotation speed basic pulse width. Fuel for setting two fuel injection pulse widths, that is, a second low rotation speed fuel injection pulse width having a value smaller than the first low rotation speed fuel injection pulse width and a normal fuel injection pulse width for a normal operation state Injection pulse width setting means, and after the engine complete explosion, or when restarting with the engine stopped and the control power supply turned on,
Fuel injection pulse width comparison means for comparing the two fuel injection pulse widths set by the fuel injection pulse width setting means with each other and selectively outputting the one having the larger pulse width is provided.

In addition, as shown in FIG. 2, the fuel injection control device for a two-cycle engine according to the present invention starts timekeeping and keeps the control power supply in the ON state when ignition cut is made to stop the engine. It is provided with holding means and self-holding release means for shutting off the control power source when the time measured by the self-holding means reaches a predetermined set time.

[Operation] With the above configuration, first, when the control power is turned on and the system is started, the first-first-time fuel injection pulse width setting means sets the first-first-time fuel injection pulse width based on the crankcase temperature. The fuel injection pulse width signal is set and is output together with engine cranking.

Next, the first low speed fuel injection pulse width setting means sets the first low speed fuel injection pulse width based on the low speed basic pulse width using the crankcase temperature as a parameter. Is output from the second shot onwards until the engine is completely detonated.

Then, based on the two fuel injection pulse widths, that is, the low rotation speed basic pulse width, and a second low rotation speed fuel injection pulse width that is smaller than the first low rotation speed fuel injection pulse width, and the normal operation. The normal fuel injection pulse width with respect to the state is set by the fuel injection pulse width setting means, and when the engine is completely detonated or when the engine is stopped and the control power source is restarted, these fuel injection pulse widths are set. The fuel injection pulse width comparison means compares them with each other, and the one with a larger pulse width is selectively output.

Also, for example, turn off the ignition switch,
When the engine is stopped by cutting off the ignition, the self-holding means starts timekeeping, the control power supply is kept self-holding in the on state, and the system is restarted in the operating state.

Then, when the time measured by the self-holding means reaches a predetermined set time, the self-holding canceling means cuts off the control power source, cancels the self-holding, and stops the system.

Embodiments of the Invention Embodiments of the present invention will be described below with reference to the drawings.

3 and the following shows an embodiment of the present invention, FIG. 3 is a functional block diagram of a control device, FIG. 4 is a schematic diagram of an engine control system, FIG. 5 is a circuit diagram of a CDI unit, and FIG. A front view of the flywheel, FIG. 7 is an explanatory diagram of a first injection basic injection pulse width map, FIG. 8 is an explanatory diagram of an initial first injection injection altitude correction coefficient map, FIG. 9 is an explanatory diagram of an altitude correction coefficient map, First
FIG. 10 is an explanatory view of a basic pulse width map at low rotation speed, FIG. 11 is an explanatory view of a first rotation correction coefficient map, FIG. 12 is an explanatory view of a second rotation correction coefficient map, and FIG. 13 is an intake air temperature correction coefficient. Fig. 14 is an explanatory diagram of the map, Fig. 14 is an explanatory diagram of the time correction coefficient, Fig. 15 is an explanatory diagram of the crankcase temperature amount map, Fig. 16 is a flowchart showing the initial setting procedure, and Fig. 17 is engine stop / start / complete FIG. 18 is a flow chart showing the explosion determination procedure, FIG. 18 is a flow chart showing the timer control procedure for setting the time correction coefficient,
FIG. 19 is a flowchart showing the fuel injection control means, 20th
The figure is a flow chart showing the control procedure of the self-shut relay.

(Structure of Engine Control System) In FIG. 4, reference numeral 1 denotes an engine body, which is, for example, a three-cylinder two-cycle engine mounted on a snowmobile or the like. An intake port 2a and an exhaust port 2b are formed in a cylinder block 2 of the engine body 1,
Further, an ignition plug 4 whose tip is exposed to the combustion chamber is attached to each cylinder of the cylinder head 3.

A crankcase temperature sensor 6 faces the crankcase 5 of the engine body 1, and a water jacket 7 is provided on the crankcase 5, the cylinder block 2, and the cylinder head 3.

In addition, in each intake port 2a of the cylinder block 2,
An intake manifold 9 is communicated through an insulator 8, a throttle valve 9 a provided in the intake manifold 9 is provided with a throttle opening sensor 10. Immediately upstream, an injector 11 is provided.

An air box 12 storing an air cleaner (not shown) is connected to the upstream side of the intake manifold 9, and an intake air temperature sensor 13 is exposed to the air box 12.

The injector 11 is connected to a fuel tank 15 via a fuel supply path 14, and a fuel filter 16 and a fuel pump 17 are interposed in the fuel supply path 14 from the fuel tank 15 side.

Further, the injector 11 communicates with the pressure regulator 18, and the pressure regulator 18
As a result, the pressure difference between the internal pressure of the intake manifold 9 and the fuel pressure is kept constant, and the fuel injection amount from the injector 11 is controlled not to fluctuate due to the fluctuation of the internal pressure of the intake manifold 9.

(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, the ROM 22, the RAM 23, the backup RAM 24, and the I / O of the ECU 20
The interfaces 25 are connected to each other through a bus line 26, and a constant voltage circuit 27 supplies a predetermined stabilized voltage.

The constant voltage circuit 27 is connected to the battery 30 via two relay contacts connected in parallel with each other, a relay contact of the ECU relay 28 and a relay contact of the self-shut relay 29, and is supplied with control power. , Above battery 30
When the control power supply is turned off, backup power is supplied to the backup RAM 24 to retain 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, the OFF terminals are connected in parallel, and when the switches 31 and 32 are both ON, the ECU relay 28 is turned ON and the constant voltage circuit is connected through one of the relay contacts. Supply control power to 27.

On the other hand, when one of the ignition switch 31 and the kill switch 32 is in the OFF position, the line from the CDI unit 33, which is the ignition device, is short-circuited to perform ignition cut.

The kill switch 32 is a stop switch provided on a grip of a snowmobile (not shown) or the like, and the line from the CDI unit 33 is a line from an ignition power supply short circuit 33b to be described later.

Further, the battery 30 includes an electromagnetic coil 29a of the self-shut relay 29, the injector 11, and
One end of an electromagnetic coil 34a of the fuel pump relay 34 is connected, and the fuel pump 17 is connected via a relay contact of the fuel pump relay 34.

The self-shut relay 29 is used to supply power to the ECU 20 for a preset time (for example, 10 minutes) after one of the ignition switch 31 and the kill switch 32 is turned off and the engine is stopped. When restarting at a high temperature without cooling the engine,
This is to prevent the start-up fuel injection amount from the injector 11 from being increased and corrected so that the air-fuel ratio becomes overrich and the start becomes difficult.

Further, the input port of the I / O interface 25 of the ECU 20 is connected to the sensors 6, 10, 13 and the atmospheric pressure sensor 36 built in the ECU 20, and the CDI
CDI to be described later with the signal line from the unit 33 connected
A pulse is input, the other relay contact of the ECU relay 28 is connected, and the voltage VB of the battery 30 is monitored.

On the other hand, at the output port of the I / O interface 25, the injector 11, the electromagnetic coil 34a of the fuel pump relay 34, and the electromagnetic coil 29a of the self-shut relay 29 have a drive circuit 40 at the other end. Connected through.

In the above ECU20, when the power is turned on, the above CPU21
The control program stored in the ROM 22 is executed.
In this control program, first, for starting, the initial one-shot fuel injection pulse width TonOUT is set, and the drive pulse signal of the initial one-shot fuel injection pulse width TonOUT is output to the injector 11 together with the engine cranking. ,
The first fuel is injected.

Next, the first low rotation speed fuel injection pulse width TiNL1 is calculated, and a drive pulse signal of the first low rotation speed fuel injection pulse width TiNL1 is output to the injector 11 to perform fuel injection control for the initial start. Determines whether or not the explosion has been completed.

Then, when the engine is completely detonated, the second low speed fuel injection pulse width TiNL2 and the normal fuel injection pulse width Ti are calculated, and the fuel injection pulse width of the larger of these fuel injection pulse widths is calculated. To selectively output the drive pulse signal to the ink injector 11 to shift to normal fuel injection control.

Further, by the self-shut relay 29, either one of the ignition switch 31 or the kill switch 32 is turned off, even if the engine is stopped by ignition cut, the ECU 20 is not immediately turned off,
When the engine is restarted within a preset time (for example, 10 minutes), the first one-shot fuel injection pulse width To
nOUT and the first low-speed fuel injection pulse width TiNL1 are not output, normal fuel injection control is performed, and the second low-speed fuel injection pulse width TiNL2 and the normal fuel injection pulse width Ti are output. , Whichever is larger, the drive pulse signal having the larger fuel injection pulse width is output to the injector 11.

(Circuit Configuration of Ignition Device) The crank jet 1a of the engine body 1 is provided with a magneto 41 in series, and an exciter coil 41 of the magneto 41 is provided.
a, the pulsar coil 41b is connected to the CDI unit 33, and the primary side of the ignition coil 4a is connected to the CDI unit 33.

Further, the magneto 41 is provided with a lamp coil 41c and a charge coil 41d, and the lamp coil 41c is
Electric loads such as lamps and heaters via regulator 43
While being connected to 44 to supply power independently of the battery 30, the charge coil 41d is connected to the battery 30 via the rectifier 42 to charge the battery 30.

As shown in FIG. 5, the CDI unit 33 includes an ignition circuit 33a, an ignition power supply short circuit 33b, a pulse detection circuit 33c, a waveform shaping circuit 33d, a duty control circuit 33e, and a pulse generation circuit 33f. A primary side of each ignition coil 4a of each ignition plug 4 arranged in each cylinder is connected in parallel to the ignition circuit 33a, and the pulse detection circuit is also provided.
33c is connected, and the ignition power supply short circuit 33b is connected to the ignition circuit 33a and one end thereof is connected to the ground G.

The ignition circuit 33a and the ignition power supply short circuit 33b are connected to an ignition power supply VIG via the diode D1 from the exciter coil 41a of the magnet 41, and the ignition switch 31 and the kill switch 32 are connected to the cathode of the diode D1. Are connected in parallel and the resistor R
1. It is connected to the gate of the engine stopping thyristor SCR2 of the ignition power supply short circuit 33b via the diode D2.

The ignition circuit 33a is a well-known capacitive discharge ignition circuit including an ignition capacitor C1 and an ignition thyristor SCR1 connected to the ignition power supply VIG.
Pulsar coil 41b opposite to the flywheel 41e of 41
In addition, the gate of the ignition thyristor SCR1 is a diode D
3, connected via a resistor R2, and an ignition trigger signal is input from the pulser coil 41b at a predetermined timing.

As shown in FIG. 6, on the outer circumference of the flywheel 41e, before the compression top dead center (BTDC) θ2 of each of the # 1, # 2, and # 3 cylinders.
At positions (eg, θ2 = 15 to 20 °), protrusions 41f (slits may be formed) at intervals of θ1 (eg, θ1 = 120 °), and the protrusions 41f are rotated with the rotation of the flywheel 41e. When 41f passes through the pulsar coil 41b, an ignition trigger signal is output from the pulsar coil 41b by electromagnetic induction.

The ignition power supply short circuit 33b includes an anode of a first diode D4 and an anode of a second diode D5 connected to the ignition power supply VIG.
The cathodes of D4 and the second diode D5 are both connected to the anode of the engine stop thyristor SCR2 via a resistor R3 and a trigger capacitor C2, respectively, and the cathode of the engine stop thyristor SCR2 is connected to ground G. ing.

The cathode of the second diode D5 connected to the trigger capacitor C2 is connected to the emitter of the trigger transistor TR composed of a PNP type transistor, and the base of the trigger transistor TR is connected to the resistor R4.
Is connected to the anode of the thyristor SCR2 for stopping the engine.

Further, the collector of the trigger transistor TR is
It is connected to the gate of the engine stopping thyristor SCR2 via a resistor R5 and a diode D6, and noise or the influence of the critical off-voltage rise rate is applied between the gate of the engine stopping thyristor SCR2 and the ground G. A resistor R6 and a capacitor C3 are connected in parallel for preventing commutation due to.

The waveform shaping circuit 33d and the duty control circuit 33
The pulse generator circuit 33f is connected to the battery 30 via the ON terminals of the ignition switch 31 and the kill switch 32 connected in series, and the pulse generator circuit 33f connects the ignition power source VIG to the ignition power source VIG. The synchronized CDI pulse is output (see FIG. 5) and input to the I / O interface 25 of the ECU 20.

That is, in the present embodiment, the pulser coil described above is used.
An ignition trigger signal is output from the 41b at every crank angle of 120 °, ignition is performed simultaneously for all cylinders (three cylinders) three times per engine revolution, and a CDI pulse is generated from the pulse generation circuit 33f at every crank angle of 120 °. The fuel is injected from each injector 11 simultaneously from each injector 11 once per engine revolution, triggered by the output of the CDI pulse.

(Functional Configuration of Control Device) As shown in FIG. 3, the functions related to the fuel injection control of the ECU 20 are initial setting means 51, engine stop determination means 52, engine speed calculation means 53, start / complete explosion determination means 54. , RAM2
Storage means 55 consisting of 3, timer control means 56, timer means 5
7, engine stop identification means 58, first time identification means 59, first time 1
Ejection basic pulse width setting means 60, initial 1 injection basic pulse width map MPT0, initial 1 injection altitude correction coefficient setting means 6
1, first one-shot injection altitude correction coefficient map MPAT0, first one-shot fuel injection pulse width setting means 62, low rotation basic pulse width setting means 63, low rotation basic pulse width map MPN0, time correction coefficient setting means 64, altitude Correction coefficient setting means 65, altitude correction coefficient map MPAT, normal time / restart identification means 66, complete explosion identification means
67, first rotation correction coefficient setting means 68, first rotation correction coefficient map MPN1, first low speed fuel injection pulse width setting means 69,
Second rotation correction coefficient setting means 70, second rotation correction coefficient map
MPN2, basic fuel injection pulse width setting means 71, basic fuel injection pulse width map MPα, crankcase temperature increase correction coefficient setting means 72, crankcase temperature increase map MPTC, intake air temperature correction coefficient setting means 73, intake air temperature correction coefficient map MPAIR , Injector voltage correction pulse width setting means 74, fuel injection pulse width setting means 75, fuel injection pulse width comparison means 76, injector drive means 77, self-holding means 78, self-holding release means 7
9. Self-shut relay drive means 80.

In the initial setting means 51, immediately after the power supply of the ECU 20 is turned from OFF to ON, the initial determination flag FLAG1 of the storage means 55 (RAM23) is set.
Set (FLAG1 ← 1) and restart flag FLA
Clear G4 (FLAG4 ← 0).

The first-time discrimination flag FLAG1 indicates that the engine has been stopped for the first time from the state in which the ECU 20 is stopped by turning off the power, and FLAG1 = 1, while the restart flag FLAG4 indicates that the engine is Even if it is stopped, the state where the power supply of the above ECU20 is kept ON
This is indicated by G4 = 1.

In the engine stop determination means 52, the C from the CDI unit 33
The DI pulse input interval time T120 is measured, and this CDI pulse input interval time T120 and a predetermined set time TSET (for example, 1SE
C), and when T120> TSET, it is determined that the engine is stopped and the engine stop determination flag F of the storage means 55 (RAM23) is determined.
When LAG2 is set (FLAG2 ← 1) and T120 ≦ TSET, it is determined that the engine is operating and the engine stop determination flag FL is set.
Clear AG2 (FLAG2 ← 0).

In the engine speed calculating means 53, the CDI unit 33
From the CDI pulse input interval time T120 and the crank angle θ1 (θ1 = 120 °; the angle between the outer peripheral projections 41f of the flywheel 41e of the magneto 41) corresponding to this CDI pulse input interval. = DT120 / dθ1), this period f
The engine speed N is calculated from (N = 60 / 2πf).

In the start / complete explosion determination means 54, the engine speed N calculated by the engine speed calculation means 53 and the complete explosion speed NSET
(For example, 700 rpm), and when N <NSET, it is determined that the engine has started for the first time, and the start determination flag FLAG3 in the storage means 55 (RAM23) is set (FLAG3 ← 1).

On the other hand, when the engine speed N calculated by the engine speed calculation means 53 becomes N ≧ NSET, the start / complete explosion determination means 54 starts counting the counter, and the count value C1
Has reached a predetermined set value C1SET, that is, N ≧ NSET
When the above state continues for a predetermined time (for example, 2SEC), it is determined that the engine has completely exploded, and the start determination flag FLAG3 is cleared (FLAG3 ← 0).

The timer control means 56 determines the state of the engine stop determination flag FLAG2 of the storage means 55 (RAM23) for setting a time correction coefficient KLT described later, and resets the timer means 57 when FLAG2 = 1, that is, when the engine is stopped. While outputting the signal, the first pulse discrimination flag FLAG5 of the storage means 55 (RAM23) is set (FLAG5 ← 1).

And when FLAG2 = 0 and FLAG5 = 1,
That is, when the first injection pulse is output to start the engine, and the timer means 57 remains in the reset state, a trigger signal is output to the timer means 57 to instruct the start of timekeeping, and the initial pulse determination is performed. Flag FLAG5
Is cleared (FLAG5 ← 0).

The timer means 57 starts the time measurement by the timer TM by the trigger signal from the timer control means 56, and outputs the time measurement signal T1 to the time correction coefficient setting means 64.

In the engine stop identification means 58, the storage means 55 (RAM23)
Check the value of the engine stop determination flag FLAG2 of
When the engine is stopped, the injector drive means is identified.
When the operation of 77 is stopped, while FLAG2 = 0, it is identified that the engine is operating and the first identification means 59 is instructed to perform the first identification.

When the engine stop identifying means 58 identifies that the engine is running, the first identifying means 59 stores the memory 55 (RAM2
When the initial discrimination flag FLAG1 = 1 in 3), the power of the ECU 20 is turned off.
Since this is the first fuel injection pulse output after being turned ON from FF, the calculation instruction is output to the initial one-shot injection basic pulse width setting means 60 and the initial one-shot injection altitude correction coefficient setting means 61.

On the other hand, when FLAG1 = 0, the fuel injection pulse has already been output, so the low speed basic pulse width setting means
63, a time correction coefficient setting means 64, and an altitude correction coefficient setting means 65, and outputs a calculation instruction to the normal time / restart time discrimination means 66, and outputs a discrimination instruction of normal time fuel injection and restart fuel injection. To do.

The first-injection basic pulse width setting means 60 searches the first-injection basic pulse width map MPT0 using the crankcase temperature TmC from the crankcase temperature sensor 6 as a parameter, and directly or by interpolation calculation the first-injection basic pulse. Set the width TAONIJ.

As shown in FIG. 7, the above-mentioned first-injection basic pulse width map MPT0 is the basic pulse width for the first fuel injection from the injector 11 when the engine is started for the first time after the ECU 20 is powered on. TAONIJ is stored as a map at a series of addresses in the ROM 22 with the crankcase temperature TmC as a parameter. For example, for a cold start in which the crankcase temperature TmC is lower than 20 ° C, the fuel injection pulse width at the normal time is set. Is also set to a large value and the crankcase temperature TmC is set to be smaller than the fuel injection pulse width during normal operation when the crankcase temperature TmC is 20 ° C. or higher to improve startability.

First-injection altitude correction coefficient setting means 61 searches first-injection altitude correction coefficient map MPAT0 using atmospheric pressure ALT from atmospheric pressure sensor 36 as a parameter, and first-injection altitude correction coefficient TALOJ is calculated directly or by interpolation calculation. To set.

The first one-shot injection altitude correction coefficient map MPAT0 is
As shown in the figure, the altitude correction value for different intake density correction depending on the atmospheric pressure ALT is stored as a map in a series of addresses in the ROM 22 with the atmospheric pressure ALT as a parameter. A value larger than the altitude correction value is stored.

In the initial one-shot fuel injection pulse width setting means 62, the initial injection basic pulse width TAONIJ set by the above-mentioned initial one-shot injection basic pulse width setting means 60 is set by the above-mentioned initial one-shot injection altitude correction coefficient setting means 61. One-shot injection altitude correction coefficient TAL
The intake density is corrected by OJ, and the first first fuel injection pulse width
Set TonOUT (TonOUT ← TAONIJ × TALOJ), then E above
The first fuel injection pulse width signal is output to the injector 11 via the injector drive means 77 for the first time after the power of the CU 20 is turned on, and pre-injection is performed at the initial start.

The low revolution basic pulse width setting means 63 searches the low revolution basic pulse width map MPN0 using the crankcase temperature TmC from the crankcase temperature sensor 6 as a parameter,
Basic pulse width at low rotation TiLN directly or by interpolation calculation
Set TW.

The low-speed basic pulse width map MPN0 is, as shown in FIG. 10, the basic pulse width for fuel injection at low engine speed, R with the crankcase temperature TmC as a parameter.
It is stored as a map at a series of addresses in OM22.

The time correction coefficient setting means 64 reads the time T1 of the timer TM from the timer means 57, and sets the time correction coefficient KLT using this time T1 as a parameter.

As shown in FIG. 14, the time correction coefficient KLT is KLT when the first injection pulse is output at engine start.
= 1 is set, the value is decreased with the lapse of time, the fuel injection amount is decreased as the engine warms up, and the engine speed N is decreased to correct the time, and the time T1 of the timer TM is set. Time TKLY (eg 180SEC)
Is reached, KLT = 0, and thereafter, by the time correction coefficient KLT, the first low-speed fuel injection pulse width described later.
TiNL1 and the fuel injection pulse width TiNL2 at the time of the second low speed rotation become 0.

The altitude correction coefficient setting means 65 uses the atmospheric pressure ALT from the atmospheric pressure sensor 36 as a parameter for the altitude correction coefficient map MPAT.
For the altitude correction coefficient K
Set ALT.

As shown in FIG. 9, the altitude correction coefficient map MPAT stores the atmospheric pressure ALT as a map in a series of addresses in the ROM 22 as a parameter, and KALT under normal atmospheric pressure on flat ground (approximately 760 mmHg). = 1 and the value is reduced as the altitude rises, and the fuel injection amount is corrected so as to reduce the intake air density at high altitudes.

In the normal time / during start-up identification means 66, the first identification means
According to the identification instruction from 59, the restart flag FLAG4 of the storage means 55 (RAM23) is checked, and when FLAG4 = 0, the complete explosion identification means
When the complete explosion is instructed to 67, and when FLAG4 = 1, it is discriminated from the fuel injection at the time of normal or restart and the second rotation correction coefficient setting means 70, the basic fuel injection pulse width setting means 71, the crankcase temperature increase correction The calculation instruction is output to the coefficient setting means 72, the intake air temperature correction coefficient setting means 73, the injector voltage correction pulse width setting means 74, and the fuel injection pulse width setting means 75.

In the complete explosion identification means 67, the normal / restart identification means is used.
According to the complete explosion identification instruction from 66, the start determination flag FLAG3 of the storage means 55 (RAM23) is checked, and when FLAG3 = 1, it is identified as the first start before the engine complete explosion, and the first rotation correction coefficient setting means 68.
And a calculation instruction is output to the first low speed fuel injection pulse width setting means 69, and when FLAG3 = 0, it is discriminated as an engine complete explosion and the restart flag in the normal time / restart time discrimination means 66.
Similar to the FLAG4 identification result (FLAG4 = 1), second rotation correction coefficient setting means 70, basic fuel injection pulse width setting means 71, crankcase temperature increase correction coefficient setting means 72, intake air temperature correction coefficient setting means 73, injector voltage Correction pulse width setting means 7
4, and outputs a calculation instruction to the fuel injection pulse width setting means 75.

The first rotation correction coefficient setting means 68 searches the first rotation correction coefficient map MPN1 using the engine speed N calculated by the engine speed calculation means 53 as a parameter, and directly or by interpolation calculation the first rotation correction coefficient KLN1. To set.

As shown in FIG. 11, the first rotation correction coefficient map MPN1 has a series of ROM22 correction coefficient values corresponding to the cranking rotation speed with the engine rotation speed N as a parameter in order to improve startability at the initial start. The first rotation correction coefficient KLN1 is set to a larger value as the rotation speed is lower.

In the first low speed fuel injection pulse width setting means 69, the low speed basic pulse width TiLNTW set by the low speed basic pulse width setting means 63 is set by the time correction coefficient setting means 64 by the time correction coefficient setting means 64. And the altitude correction coefficient KAL set by the above-mentioned altitude correction coefficient setting means 65
The altitude correction is performed by T, and further the rotation is corrected by the first rotation correction coefficient KLN1 set by the first rotation correction coefficient setting means 68, and the first low rotation speed fuel injection pulse width at the initial start.
Set TiNL1 (TiNL1 ← TiLNTW × KLT × KALT × KLN
1), injector 11 via injector drive means 77
To fuel injection after the second injection at the initial start.

The second rotation correction coefficient setting means 70 searches the second rotation correction coefficient map MPN2 using the engine speed N calculated by the engine speed calculation means 53 as a parameter, and directly or by interpolation calculation the second rotation correction coefficient. Set KLN2.

As shown in FIG. 12, the second rotation correction coefficient map MPN2 has a correction coefficient value corresponding to the cranking rotation speed in order to prevent excessive concentration in consideration of the startability at the time of engine restart. N is stored as a parameter in a series of addresses in the ROM 22, and the second rotation correction coefficient KLN2
Is set to approximately 1/2 of the first rotation correction coefficient KLN1, and after the engine is restarted, a predetermined rotation speed is set in order to shift to the normal fuel injection pulse width set based on each engine operating state parameter. Above the number, KLN2 = 0 is set.

The basic fuel injection pulse width setting means 71 searches the basic fuel injection pulse width map MPα using the throttle opening α from the throttle opening sensor 10 and the engine speed N calculated by the engine speed calculating means 53 as parameters. , Basic fuel injection pulse width Tp is set.

In the basic fuel injection pulse width map MPα, the intake air amount is assigned to the throttle opening α and the engine speed N, and the basic fuel injection pulse width Tp for this intake air amount is calculated.
It is stored as a three-dimensional table in a series of addresses in the ROM 22, and a so-called throttle speed method can achieve fuel injection control with good response to opening and closing of the throttle valve 9a.

In the crankcase temperature increase correction coefficient setting means 72, the crankcase temperature TmC from the crankcase temperature sensor 6
Is read, the crankcase temperature increase map MPTC is searched using this crankcase temperature TmC as a parameter, and the crankcase temperature increase KTC is set directly or by interpolation calculation. From this crankcase temperature increase KTC, the crankcase temperature increase correction coefficient KTC1 ( = 1 + KTC) is set.

As shown in FIG. 15, the crankcase temperature increase map MPTC stores the increase correction amount related to the crankcase temperature TmC in a series of addresses in the ROM 22, for example, 2
It is a constant value in the crankcase temperature range of 0 ° C to 80 ° C, and the crankcase temperature increase KTC is taken into consideration in order to improve startability on the low temperature side and in consideration of intake efficiency on the high temperature side.
The value is increased to increase the correction amount.

The intake temperature correction coefficient setting means 73 reads the intake temperature AIR from the intake temperature sensor 13, searches the intake temperature correction coefficient map MPAIR with this intake temperature AIR as a parameter, and sets the intake temperature correction coefficient KAIR directly or by interpolation calculation. To do.

As shown in FIG. 13, the intake air temperature correction coefficient map MPAIR uses the intake air temperature AIR as a parameter to set the correction coefficient KAIR to RO.
It is stored in a series of addresses of M22 and corrects the intake density that varies depending on the temperature. For example, the intake air temperature AIR is based on the temperature range of 30 ° C to 110 ° C (KAIR = 1).
At temperatures lower than 30 ° C, the intake air temperature correction coefficient KAIR is made larger than 1 as the intake air density increases.

In the injector voltage correction pulse width setting means 74, the ECU
A voltage that reads the terminal voltage VB of the relay 28, that is, the battery voltage VB, reads the response delay time (pulse width) of the injector 11 that changes according to the battery voltage VB from a table not shown, and interpolates this response delay time. Set the correction pulse width TS.

The fuel injection pulse width setting means 75 includes a second low rotation speed fuel injection pulse width setting means 75a and a normal fuel injection pulse width setting means 75b. The second low speed fuel injection pulse width TiNL2 and the normal fuel injection pulse width are set. Two fuel injection pulse widths, which are the pulse width Ti, are set.

That is, the second low speed fuel injection pulse width setting means 75
In a, the low rotation basic pulse width TiLNTW set by the low rotation basic pulse width setting means 63 is time-corrected by the time correction coefficient KLT set by the time correction coefficient setting means 64, and the altitude correction coefficient setting means is set. The intake density is corrected by the altitude correction coefficient KALT set at 65, and further the rotation is corrected by the second rotation correction coefficient KLN2 set by the second rotation correction coefficient setting means 70, and the first low speed fuel injection pulse width TiNL1 is obtained. Set the second fuel injection pulse width TiNL2 at low speed, which is a smaller value (TiNL2 ← TiLNTW × KLT × KALT × KL
N2), and outputs to the fuel injection pulse width comparison means 76.

This second low rotation speed fuel injection pulse width TiNL2 is determined by the second rotation correction coefficient KLN2 and the time correction coefficient KLT when the engine is restarted or after the engine is completely detonated.
The fuel injection pulse width Ti is set to be larger than the normal fuel injection pulse width Ti in the low opening range of the throttle valve until the rotational speed is equal to or higher than a predetermined rotational speed or a predetermined time elapses.

In the normal fuel injection pulse width setting means 75b, the basic fuel injection pulse width Tp set by the basic fuel injection pulse width setting means 71 is added to the altitude correction coefficient KALT set by the altitude correction coefficient setting means 65 and the intake Temperature correction coefficient setting means 7
The intake air density correction coefficient KAIR set in 3 is added to the intake air density correction, and the crankcase temperature increase correction coefficient KTC set in the crankcase temperature increase correction coefficient setting means 72 is set.
The amount is increased by 1 (= 1 + KTC), and further the voltage is corrected by the voltage correction pulse width TS set by the injector voltage correction pulse width setting means 74 to set the normal fuel injection pulse width Ti for the normal operation state (Ti ← Tp × KALT × KA
IR × (1 + KTC) + TS), fuel injection pulse width comparison means 7
Output to 6.

In the fuel injection pulse width comparison means 76, the second low speed fuel injection pulse width setting means 75a sets the second low speed fuel injection pulse width TiNL2 and the normal fuel injection pulse width setting means 75b sets the same. While comparing with the fuel injection pulse width Ti at normal time, after the complete explosion of the engine or when the engine is restarted, whichever is larger is selectively output to the injector 11 via the injector drive means 77. , Restart flag F of storage means 55 (RAM23)
Set LAG4 (FLAG4 ← 1).

On the other hand, the self-holding means 78 is the ECU relay state determination means 78a.
The ECU relay state determination means 78a reads the ECU relay terminal voltage VB, and the ECU means
Whether the relay 28 is ON or OFF, the open / closed state is determined.

As a result of the determination, when the ECU relay 28 is ON, the self-shut relay 29 is turned ON via the self-shut relay drive means 80, and when the ECU relay 28 is turned OFF, the counter means 78b is instructed to start counting. To do.

In the counter means 78b, the ECU relay state determination means 78
The ECU relay 28 is turned on by the count start instruction from a.
The elapsed time after turning OFF from is counted by the self-shut control counter.

That is, even if the ignition switch 31 or the kill switch 32 is turned off and the ECU relay 28 is turned off, the ECU 20
The control power supply to is not cut off, but is self-held by the self-shut relay 29.

The self-shut control counter is, for example, an EC
It operates as a timer by counting the reference time clock obtained by dividing the system clock of U20.

The self-hold releasing means 79 determines whether or not the count value C2 of the self-shut control counter in the counter means 78b is equal to or greater than a set value C2SET (for example, a count value corresponding to 10 minutes), and when C2 <C2SET , Keep the self-shut relay 29 in the ON state, and when C2 ≧ C2SET, turn off the self-shut relay 29 via the self-shut relay drive means 80, cut off the power supply to the ECU 20, and release the self-holding. Stop the operation of the system.

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

First, the ignition switch 31 and the kill switch 32
When both are turned on and the power of the ECU 20 is turned on from the off state, the system is initialized and the initial setting program shown in FIG. 16 is executed.

This first-established program corresponds to the initial setting means 51, and in step S101, the initial determination flag FLAG
1 is set (FLAG1 ← 1), then the process proceeds to step S102, the restart flag FLAG4 is cleared (FLAG4 ← 0),
The program ends.

Then, when the engine cranks, the magneto 41
The intermittent voltage generated in the exciter coil 41a is half-wave rectified by the diode D1 and applied to the ignition circuit 33.
The ignition capacitor C1 of a is charged.

Then, a reference signal voltage is output from the pulsar coil 41b of the magneto 41 at a predetermined crank position, and this reference signal voltage is applied to the gate of the ignition thyristor SCR1 via the diode D3 and the resistor R2.

When the reference signal voltage reaches the trigger level of the ignition thyristor SCR1, the ignition thyristor SCR1 is turned on, the charge stored in the ignition capacitor C1 is the ignition capacitor C1 → ignition thyristor SCR1 →
Discharged instantaneously into the closed circuit consisting of the ignition coil 4a primary side → capacitor C1. As a result, a high voltage with a very large rise is generated on the secondary side of the ignition coil 4a, and the spark plug 4 is sparked.

At the same time, the ignition waveform of the primary side of the ignition coil 4a is detected by a pulse detection circuit 33c, is shaped by a waveform shaping circuit 33d, is set to a predetermined pulse width by a duty control circuit 33e, and is fired by a pulse generation circuit 33f. Power supply VIG
A CDI pulse synchronized with is output to the ECU 20.

On the other hand, in the ECU 20, when the program of the initial setting is completed, the program of the engine stop / start / complete explosion determination procedure shown in FIG. 17 and the program of the self-shut relay control procedure shown in FIG. 20 interrupt every predetermined time. Also, the program of the time correction coefficient setting timer control procedure shown in FIG. 18 and the program of the fuel injection control procedure shown in FIG. 19 are started, for example, at every predetermined cycle synchronized with the rotation of the engine. As a result, fuel is injected from the injector 11 and the engine starts.

(Engine Stop / Start / Complete Explosion Judgment Procedure) First, the interrupt routine for engine stop / start / complete explosion judgment will be described with reference to the flowchart shown in FIG.

In this routine, in step S201, the CDI unit 3
Input interval time T120 of CDI pulse from 3 is clocked, then
In step S202, the CDI pulse input interval time T120 measured in step S201 and a predetermined set time TSET (for example, 1
SEC).

In the above step S202, when T120> TSET, that is,
When the CDI pulse is not input from the CDI unit 33 even after the predetermined set time TSET has elapsed, the above step S20 is performed.
From step 2 to step S203, it is determined that the engine is stopped and the engine stop determination flag FLAG2 is set (FLAG2 ←
1) Exit the routine.

On the other hand, as described above, the engine is cranked and the CDI pulse of a predetermined cycle is sent from the CDI unit 33 to the EC
If it is input to U20 and T120 ≦ TSET in the above step S202,
From step S202 to step S204, the engine stop determination flag FLAG2 is cleared (FLAG2 ← 0), and the process proceeds to step S205.

In step S205, the CDI calculated in step S201 is calculated.
The cycle f is obtained from the pulse input interval time T120 and the crank angle θ1 corresponding to this CDI pulse input interval time T120 (f = dT120 / dθ), and the engine speed N is calculated from this cycle f.
Is calculated (N = 60 / 2πf) and stored in the RAM 23.

Next, in step S206, the engine speed N calculated in step S205 and the complete explosion speed NSET (for example, 700
rpm), and when N <NSET, it is determined that the engine has not completely exploded and the above steps S206 to S212.
Proceed to and set the start determination flag FLAG3 (FLAG3 ←
1) Exiting the program, and when N ≧ NSET, the process proceeds to step S207 to determine whether or not the start determination flag FLAG3 is set.

In step S207, if the start determination flag FLAG3 is cleared (FLAG3 = 0), jump to step S210, and if the start determination flag FLAG3 is set (FLAG3 = 1), start from step S207. Step S20
In step 8, the count value C1 of the counter is incremented (C1 ← C1 + 1) and the process proceeds to step S209.

In step S209, the count value obtained in step S208
Compare C1 with the preset value C1SET, and if C1 ≧ C1SET,
When it is determined that the engine has completely exploded, the process proceeds to step S210, the start determination flag FLAG3 is cleared (FLAG3 ← 0), the count value C1 is cleared (C1 ← 0) at step S211, and the program exits.

The count value C1 is initialized to C1 = 0 prior to the initial setting program described above.
The set value C1SET is a value set from the interrupt time period of this program, and is set to a value corresponding to 2SEC, for example.

That is, the engine speed N is N ≧ NSET (for example, 7
When the state of (00 rpm) continues for a predetermined time (for example, 2SEC) or more, it is determined that the engine has completely exploded, and the above step S209
When C1 <C1SET, the process proceeds from step S209 to step S212 to set the start determination flag FLAG3 (F
LAG3 ← 1) Exit the program.

In the interrupt routine of this engine stop / start / complete explosion determination, steps S201 to S204 are performed by the engine stop determination means 52,
Step S205 corresponds to the engine speed calculation means 53, and step S206 and subsequent steps are start / complete explosion determination means.
It corresponds to 54.

(Time Correction Coefficient Setting Timer Control Means) The flowchart showing the time correction coefficient setting timer control procedure in FIG. 18 corresponds to the timer control means 56, and in step S301, the state of the engine determination determination flag FLAG2 is determined. , FLAG2 = 1, that is, when the engine is stopped, the process proceeds to step S302 to reset the timer, and then in step S303, the first pulse determination flag FLAG5 is set to indicate that the fuel injection pulse to the injector 11 is not output. Set (FLAG5 ← 1) and exit the routine.

On the other hand, in step S301, FLAG2 = 0, that is,
When it is determined that the engine has started, the routine proceeds to step S304, where the state of the first pulse determination flag FLAG5 is determined, and FLAG5
= 1, that is, after the power of the ECU 20 is turned on, the first interrupt determines the first pulse determination flag FLAG5 to 1 (steps S301 to S303), and then the engine stop determination flag FLAG2 is cleared and the first injection is performed. When the pulse is output, or the engine is temporarily stopped due to an engine stall, etc., and immediately after that, the FLAG5 = 1 is set in steps S301 to S303 described above, and then the engine is started again, and the engine is stopped. Discrimination flag FL
When AG2 is cleared and the injection pulse is first output, the process proceeds from step S304 to step S305 to trigger the timer TM.

Then, the process proceeds from step S305 to step S306 to clear the first pulse discrimination flag FLAG5 (FLAG5 ←
0), exit the routine.

On the other hand, in step S304, FLAG5 = 0, that is,
If the timer TM was triggered in the previous routine and the clocking has already started, the process jumps from step S304 to step S306, and the initial pulse determination flag
Clear FLAG5 (FLAG5 ← 0) and exit the routine.

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

First, in step S401, the engine stop determination flag FLAG
It is determined whether or not 2 is set. When FLAG2 = 1, that is, when the engine is stopped, the routine exits as it is, and when FLAG2 = 0, that is, when the engine is started,
In step S402, it is determined whether or not the first-time determination flag FLAG1 is set. If FLAG1 = 1, that is, if the program is the first time, the process proceeds from step S402 to step S403 and FLAG1 = 0, that is, already. This fuel injection pulse width setting program is executed once
If the interrupt is more than one, the process proceeds from step S402 to step S410.

When the process proceeds from step S402 to step S403, in step S403, the atmospheric pressure ALT from the atmospheric pressure sensor 36 is read, and in step S404, the first one-injection altitude correction coefficient map MPAT0 is searched using the atmospheric pressure ALT as a parameter. ,
Set the first injection height correction coefficient TALOJ directly or by interpolation calculation.

Next, in step S405, the crankcase temperature TmC from the crankcase temperature sensor 6 is read, and in step S405
To 406, the first one-injection basic pulse width map MPT0 is searched using the crankcase temperature TmC as a parameter, and the first one-injection basic pulse width TAONI is directly or by interpolation calculation.
Set J and proceed to step S407.

In step S407, the initial single injection basic pulse width TAONIJ set in step S406 is corrected by the initial single injection altitude correction coefficient TALOJ set in step S404 to set the initial single fuel injection pulse width TonOUT ( TonOUT ←
TAONIJ × TALOJ), the process proceeds to step S408, this first one-shot fuel injection pulse width TonOUT is output, and the process proceeds to step S409 to clear the initial determination flag FLAG1 (FLAG1 ← 0).
Exit the routine.

Therefore, at the first start when the control power is turned on, the first one-shot fuel injection pulse width TonOUT based on the crankcase temperature
The pre-injection is carried out only once, and the engine is prepared for starting.

On the other hand, when the interrupt routine is the second time or later and the process proceeds from step S402 to step S410, the atmospheric pressure ALT from the atmospheric pressure sensor 36 is read in step S410, and the process proceeds to step S411 to set the altitude using the atmospheric pressure ALT as a parameter. The correction coefficient map MPAT is searched, the altitude correction coefficient KALT is set directly or by interpolation calculation, and the process proceeds to step S412.

In step S412, the crankcase temperature TmC from the crankcase temperature sensor 6 is read, and in step S413,
Using the crankcase temperature TmC as a parameter, the low revolution basic pulse width map MPN0 is searched, the low revolution basic pulse width TiLNTW is set directly or by interpolation calculation, and the process proceeds to step S414.

When the process proceeds to step S414, the time correction time T1 is read from the above-described time correction coefficient setting timer TM, the time correction coefficient KLT is set in step S415 using this time measurement time T1 as a parameter, and the restart flag FLAG4 is set in step S416. Determine whether it is set or not.

If FLAG4 = 1 in step S416, that is, if restarting, the process proceeds from step S416 to step S422.
If FLAG4 = 0, that is, if it is not a restart, the process proceeds from step S416 to step S417, and the start determination flag
FLAG3 is used to determine whether the engine has completely exploded.

Then, in step S417, FLAG3 = 0, that is,
When it is determined that the engine has completely exploded, the process similarly proceeds from step S417 to step S422, and in the case of FLAG3 = 1, that is, when the engine has not completely exploded and the engine is starting for the first time, the above step is performed.
From S417, proceed to step S418.

In step S418, the engine speed N is read from the RAM 23, the first speed correction coefficient map MPN1 is searched in step S419 using the engine speed N as a parameter, and the first speed correction coefficient KLN1 is set directly or by interpolation calculation. And advances to step S420.

In step S420, the basic pulse width TiLNTW during low rotation set in step S413 is altitude-corrected by the altitude correction coefficient KALT set in step S411, and
The time correction coefficient KLT set in step S415 is used for time correction, and the first rotation correction coefficient KLN1 set in step S419 is used for rotation correction to set the first low speed fuel injection pulse width TiNL1 (TiNL1 ← TiLNTW × KLN
1 x KLT x KALT).

Then, the process proceeds to step S421, where the first low speed fuel injection pulse width TiNL1 set in step S420 is used as the second or subsequent injection pulse following the first one fuel injection pulse width TonOUT output in the previous routine, and CDI Output to the injector 11 in synchronization with the pulse, and exit the routine.

Therefore, the initial one-shot fuel injection pulse width TonOUT at the initial start
The fuel injection pulse width TiNL1 at the time of the first low rotation in consideration of the crankcase temperature, the cranking speed, and the cranking time is output as the injection pulse after the second time based on The startability is improved by slightly increasing the injection amount.

On the other hand, if it is determined in step S416 that the engine is restarted (FLAG4 = 1) and the process proceeds from step S416 to step S422,
The engine speed N is read from RAM23, and step S423 is performed.
Then, the second rotation correction coefficient map MPN2 is searched using this engine speed N as a parameter, the second rotation correction coefficient KLN2 is set directly or by interpolation calculation, and the routine proceeds to step S424.

In step S424, the low-rotation basic pulse width TiLNTW set in step S413 is altitude-corrected by the altitude correction coefficient KALT set in step S411, and
The time correction coefficient KLT set in step S415 is used for time correction, and the second rotation correction coefficient KLN2 set in step S423 is used for rotation correction to set the second low speed fuel injection pulse width TiNL2 (TiNL2 ← TiLNTW × KLN2
X KLT x KALT).

Next, the process proceeds to step S425, the throttle opening α from the throttle opening sensor 10 is read, and step S426
Then, the basic fuel injection pulse width map MPα is searched with the engine speed N read in step S422 and the throttle opening α read in step S425 as parameters, and the basic fuel injection pulse width map MPα is searched for directly or by interpolation calculation. The ejection pulse width Tp is set and the process proceeds to step S427.

In step S427, the intake air temperature AIR from the intake air temperature sensor 13
Is read, the intake air temperature correction coefficient KAIR relating to the intake air temperature correction is set in step S428, the process proceeds to step S429, and the crankcase temperature increase map MPTC is searched using the crankcase temperature TmC read in step S412 as a parameter,
The crankcase increase correction coefficient KTC1 (= KTC) is set directly or by interpolation calculation.

Then, in step S430, the ECU relay terminal voltage VB is read, the process proceeds to step S431, the injector voltage correction pulse width TS is set based on the ECU relay terminal voltage VB read in step S430, and the process proceeds to step S432.

In step S432, the basic fuel pulse width Tp set in step S426 is corrected by the altitude correction coefficient KALT set in step S411 and the intake temperature correction coefficient KAIR set in step S428. The crankcase temperature increase correction coefficient KTC1 (= 1 + KTC) set in step S429 described above is used for increasing correction, and the injector voltage correction pulse width TS set in step S431 is added to calculate the normal fuel injection pulse width Ti.

Then, the process proceeds to step 433, the second low speed fuel injection pulse width TiNL2 calculated in step S424 is compared with the normal fuel injection pulse width Ti set in step S432, and if TiNL2> Ti, then Proceeding from step S433 to step S434, the fuel injection pulse width TiNL2 during the second low speed rotation
Is output, the restart flag FLAG4 is set in step S436 (FLAG4 ← 1), and the program exits.

On the other hand, in the above step S433, when TiNL2 ≦ Ti,
From step S433 to step S435, the normal fuel injection pulse width Ti is output, the restart flag FLAG4 is set (FLAG4 ← 1) in step S436, and the program exits.

That is, immediately after the engine complete explosion, the second low speed fuel injection pulse width TiNL2 is larger than the normal fuel injection pulse width Ti. Therefore, after the engine complete explosion, the fuel injection amount setting is the first low speed fuel injection pulse Ti. The fuel injection pulse width TiNL2, which is a value smaller than the width TiNL1, is shifted to the second fuel injection pulse width TiNL2, and the normal fuel injection pulse is set based on each engine operating state parameter with the increase in engine start time or engine speed. Since the width is changed to the width Ti, the fuel injection amount is optimally set according to the engine operating state.

Also, in a 2-cycle engine, after the engine has started and the complete explosion has occurred, the engine stalls for some reason,
When the engine is restarted, it may be difficult to restart the engine due to an excessive concentration of the required fuel injection amount due to a rise in the temperature of the cylinder or residual fuel in the crankcase. When the engine is stopped and the engine is restarted with the control power supply turned on (such as when the engine is restarted), the pre-injection with the first one-time fuel injection pulse width TonOUT is not performed, and the fuel is not supplied during the first low rotation speed. Injection pulse width Ti
Second low speed fuel injection pulse width TiNL2 smaller than NL1
Is used from the first time, excessive concentration at the time of restart is prevented, and restart is reliably performed. Then, as the time after the engine starts or the engine speed increases, the fuel injection pulse width Ti shifts to the normal time.

The program of this fuel injection control procedure is
S401 corresponds to the engine stop identification means 58, and step S402 corresponds to the first identification means 59, and it is determined whether the engine is stopped or not, and whether the ECU 20 is powered on for the first time or not.

Further, steps S403 and S404 are the first one shot injection altitude correction coefficient setting means 61, steps S405 and 406 are the first one shot injection basic pulse width setting means 60, and steps S407 to S409 are the first one shot.
Pre-injection at the time of initial start is performed corresponding to each of the emitted fuel injection pulse width setting means 62.

Further, steps S410 and S411 are the same as the altitude correction coefficient setting means 6
5, steps S412 and S413 are the low revolution basic pulse width setting means 63, and steps S414 and S415 are the time correction coefficient setting means 64.
In step S416, the normal / restart identification means 66, in step S417 the complete explosion identification means 67, in steps S418 and S419 the first rotation correction coefficient setting means 68, and in steps S420 and S421 the first low rotation. Corresponding to the hour fuel injection pulse width setting means 69, the fuel injection following the pre-injection is performed before the engine complete explosion.

Further, steps S422 and S423 are performed by the second rotation correction coefficient setting means 70, step S424 is performed by the second low speed fuel injection pulse width setting means 75a, steps S425 and S426 are performed by the basic fuel injection pulse width setting means 71, and steps are performed. S427 and S428 are the intake temperature correction coefficient setting means 73, step S429 is the crankcase temperature increase correction coefficient setting means 72, steps S430 and S431 are the injector voltage correction pulse width setting means 74, and step S432 is the normal fuel injection pulse. Step S433 to the width setting means 75b
The following correspond to the fuel injection pulse width comparison means 76, respectively, and the fuel injection at the normal time or the restart is performed.

(Engine prevention) On the other hand, when the engine is stopped, when the ignition switch 31 or the kill switch 32 is turned off, the ignition power supply VIG is connected to the gate of the engine stop thyristor SCR2 of the ignition power supply short circuit 33b through the resistor R1 and the diode D2. A current flows and the engine stop thyristor SCR2 turns on. Then, the ignition power source VIG is substantially short-circuited via the first diode D4 and the resistor R3, and the trigger capacitor C2 is charged via the second diode D5.

Since the ignition power source VIG is an intermittent voltage as shown in FIG. 5, the ignition power source VIG becomes the ground level until the engine is stopped, and the engine stopping thyristor SCR2 is turned off. In this case, a discharge current flows from the trigger capacitor C2, and a base current is supplied to the trigger transistor TR to turn on the trigger transistor TR.

Then, by the conduction of the trigger transistor TR,
With the generation of the next ignition power supply VIG, the second diode D5 →
A gate current is directly supplied to the engine stop thyristor SCR2 through the path of the trigger transistor TR → the resistor R5 → the diode D6, the engine stop thyristor SCR2 is turned off again, the ignition power supply VIG is short-circuited, and the trigger is generated. Charge capacitor C2.

This process is repeated, the ignition power supply VIG is short-circuited, and the ignition energy required for discharging the ignition plug 4 is not supplied to the primary side of the ignition coil 4a, and the ignition energy is below the ignition limit value, and the engine stops. .

At this time, for example, if the kill switch 32 is once turned off and the engine stopping thyristor SCR2 is turned on, even if the engine stopping thyristor SCR2 is turned off by the ignition power source VIG which is intermittently generated, the kill operation is performed. It is not necessary to keep the switch 32 in the OFF state, and the trigger capacitor C2 and the trigger transistor TR automatically turn the engine stop thyristor SCR2 on and off until the engine stops, and the engine stops reliably. To do.

(Self-shut relay control procedure) On the other hand, even after the engine is stopped, the ECU 20 is self-maintained by being supplied with power by the self-shut relay 29, and the above-described program is continuously executed. And
The self-shut relay 29 is turned off and the power of the ECU 20 is turned off to stop the operation only after a predetermined set time has elapsed.

Next, the control procedure for the self-shut relay 29
This will be described with reference to the flowchart in FIG.

First, in step S501, the ECU relay terminal voltage VB is read, then the process proceeds to step S502, and whether or not the ECU relay terminal voltage VB read in step S501 is 0, that is,
It is determined whether the ECU relay 28 is OFF.

In the above step S502, when VB = 0, that is, the ignition switch 31 or the kill switch 32 is turned off.
When the ECU relay 28 is turned off and the engine is stopped, the process proceeds from step S502 to step S503, and the self-shut control count value C2 is incremented (C2 ← C2
+1), in step S504, the self-shut control count value C2 is compared with a predetermined set value C2SET.

When C2 <C2SET in the above step S504, the routine proceeds from step S504 to step S507 to keep the self-shut relay 29 ON and the routine exits. When C2 ≧ C2SET, the routine proceeds from step S504 to step S505 to self-shut. Turn off relay 29. Thereby, the power supply to the ECU 20 is turned off and the operation is stopped.

On the other hand, in step S502, when VB ≠ 0, that is, when the ECU relay 28 is not turned off and the engine is operating, the process proceeds from step S502 to step S506 to clear the self-shut control count value C2. (C2 ←
0), in step S507, the self-shut relay 29 is kept ON and the routine is exited.

Therefore, even if the ignition switch 31 or the kill switch 32 is turned off and the ECU relay 28 is turned off, the control power is supplied to the ECU 20 by turning on the self-shut relay 29 within a predetermined time, and during this period, the system The data is retained and can be prepared for a restart.

In the program of the self-shut relay control procedure, steps S501 and S502 are executed by the ECU relay state determination means 78a of the self-holding means 78, and steps S503 and S506 are executed by the self-holding means 78.
The counter means 78b corresponds to step S504 to the self-hold release means 79, and steps S505 and S507 to the self-shut relay drive means 80.

[Effects of the Invention] As described above, according to the present invention, when the control power source is turned on, the cranking of the engine and the first fuel injection pulse width based on the first fuel injection pulse width based on the crankcase temperature are performed. The pulse is output, and then the fuel injection pulse for the second and subsequent fuel injection pulses is output with the first low revolution speed fuel injection pulse width based on the low revolution basic pulse width with the crankcase temperature as a parameter.

When the engine is completely detonated, a second low rotation speed fuel injection pulse width that is based on the low rotation speed basic pulse width and is smaller than the first low rotation speed fuel injection pulse width,
Two fuel injection pulse widths, the normal fuel injection pulse width for the normal operation state, are set and compared with each other, and the larger one of these pulse widths is selectively output.

Furthermore, when the engine is stopped and the engine is restarted with the control power supply turned on, two fuel injection pulse widths, that is, the second low speed fuel injection pulse width and the normal fuel injection pulse width are set. Are compared with each other, and the larger one of these pulse widths is selectively output.

Also, for example, turn off the ignition switch,
When the engine is stopped by cutting off the ignition, at this time, the clocking is started and the control power supply is kept in the ON state by itself, and the system remains in the operating state and waits for the engine restart.

Then, when the time count reaches a predetermined set time, the control power supply is cut off, the self-holding is released, and the system is stopped.

Therefore, an appropriate fuel injection amount can be set based on the crankcase temperature for a wide range of temperature conditions from low temperature start to high temperature restart, so the engine can be reliably shifted from initial explosion to complete explosion. It is possible to improve the sex.

Also, even if the ignition switch is turned off to cut off the ignition and the engine is stopped, the control power is not kept on and the system operation does not stop until the predetermined set time elapses. When the engine is restarted without the air-fuel ratio, the air-fuel ratio does not become excessively rich, the engine can be started easily, and the fuel consumption rate can be reduced.

[Brief description of drawings]

1 and 2 are diagrams corresponding to claims of the present invention, FIG. 3 and the following show an embodiment of the present invention, FIG. 3 is a functional block diagram of a control device, and FIG. 4 is a schematic diagram of an engine control system. , FIG. 5 is a circuit diagram of the CDI unit, FIG. 6 is a front view of the flywheel, FIG. 7 is an explanatory diagram of a first-injection basic pulse width map, and FIG. 8 is a first-injection altitude correction coefficient map. Explanatory drawing, FIG. 9 is an explanatory drawing of an altitude correction coefficient map, FIG. 10 is an explanatory drawing of a basic pulse width map at low rotation speed, FIG. 11 is an explanatory drawing of a first rotation correction coefficient map, and FIG. 12 is a second drawing. Explanatory drawing of rotation correction coefficient map, FIG. 13 is explanatory drawing of intake air temperature correction coefficient map, FIG. 14 is explanatory drawing of time correction coefficient, FIG. 15 is explanatory drawing of crankcase temperature increase map, and FIG. 16 is first time Fig. 17 is a flow chart showing the setting procedure, and Fig. 17 is a flow chart showing the engine stop / start / complete explosion determination procedure. FIG. 18 is a flowchart showing a timer control procedure for setting the time correction coefficient, FIG. 19 is a flowchart showing a combustion injection control procedure, and FIG. 20 is a flowchart showing a self-shut relay control procedure. 1 ... Engine body 62 ... First time fuel injection pulse width setting means 69 ... First low speed fuel injection pulse width setting means 75 ... Fuel injection pulse width setting means 76 ... Fuel injection pulse width comparison means 78 …… Self-holding means 79 …… Self-holding release means TmC …… Crankcase temperature TonOUT …… First time fuel injection pulse width TiLNTW …… Low speed basic pulse width TiNL1 …… First low speed fuel injection pulse width TiNL2 …… Second low speed fuel injection pulse width Tp …… Basic fuel injection pulse width Ti …… Normal fuel injection pulse width

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Fusao Tachibana 1-7-2 Nishishinjuku, Shinjuku-ku, Tokyo Fuji Heavy Industries Ltd. (72) Inventor Kazuo Suzuki 1-2-7 Nishishinjuku, Shinjuku-ku, Tokyo Within Fuji Heavy Industries Ltd. (72) Inventor Yoshiki Kuchi, 1671 Kasukawa-cho, Isesaki-shi, Gunma 1 Within NEC Electronics Co., Ltd.

Claims (2)

[Claims] 1. When the control power is turned on, the first first cranking of the engine is performed based on the crankcase temperature.
Based on the first one-time fuel injection pulse width setting means for setting the fuel injection pulse width of the first time and the basic pulse width at the time of low rotation with the crankcase temperature as a parameter, from the second time onward until the complete explosion of the engine. Between the first low rotation speed fuel injection pulse width setting means for setting the first low rotation speed fuel injection pulse width, and the first low rotation speed fuel injection pulse width based on the low rotation speed basic pulse width. Fuel injection pulse width setting means for setting two fuel injection pulse widths, that is, a second low rotation speed fuel injection pulse width having a smaller value and a normal fuel injection pulse width for a normal operation state, and after the complete explosion of the engine, or When the engine is stopped and restarted with the control power source turned on, the two fuel injection pulse widths set by the fuel injection pulse width setting means are compared with each other and the larger pulse width is selected. The fuel injection control device of a two-stroke engine, characterized in that a fuel injection pulse width comparing means for outputting to. 2. Self-holding means for starting timekeeping and holding the control power supply in an on state when ignition is cut to stop the engine, and the timekeeping by the self-holding means reaches a predetermined set time. A fuel injection control device for a two-cycle engine, comprising: a self-holding release means for shutting off the control power supply.