JPH04194343A - Staring control system of front engine front drive vehicle (ffv) engine and starting aiding device - Google Patents

Abstract

PURPOSE:To start a front engine frond drive vehicle (FFV) engine smoothly and quickly by controlling the extent of current-energization for a heating means by means of the compared result between engine temperature and startable judging temperature of warm-up completion temperature. CONSTITUTION:A startable judging temperature set up on the basis of fuel alcohol content out of an alcohol content sensor 19 is compared with an engine temperature at a controller 31. When an engine 1 is so judged that it is unstartable, a heater 13a for accelerating time and fuel carburetion preset befor fuel injection is energized with current. On the other hand, when so judged that it is startable, if the engine temperature is lower than a warm-up completion temperature, fuel is sprayed without energizing the heater 13a, but afterward this heater 13a is energized during a while till the engine temperature is reached to the specified value. In this connection, when the engine temperature is more than the warm-up completion temperature, the heater 13a is set down to a nonenergized state. With this constitution, the engine 1 is startable smoothly and quickly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a starting control method and a starting assist device for an FFV engine with improved startability.

[Conventional technology] In recent years, due to worsening fuel conditions and demands for exhaust purification,
Systems that can use alcohol as an alternative fuel in addition to conventional gasoline are being put into practical use, and vehicles such as cars equipped with this system (FFV
; FTexible Fuel Vehicle)
Now, it is possible to run on not only gasoline, but also a mixed fuel of alcohol and gasoline, or only alcohol.The alcohol concentration (content rate) of the fuel used in this FFV is determined by Depending on the user's circumstances, it varies from 0% (gasoline only) to 100% (alcohol only).

In general, compared to gasoline fuel, alcohol fuel
It has characteristics such as being difficult to vaporize at low temperatures, having a large latent heat of vaporization, and a high flash point, and when the alcohol concentration changes, the output characteristics will change significantly depending on the temperature conditions.
In particular, when the alcohol concentration is high, there arises a problem that low-temperature startability deteriorates.

To deal with this, a technique has been known that improves starting performance by promoting vaporization of fuel using a starter or heating element as a starting aid device. discloses a technique for controlling a heating device that heats the intake passage based on the output of an alcohol concentration sensor, and increasing the amount of heat generated by the heating device when the alcohol concentration is above a reference value. Showa 5
5-35179, both in the main and sub intake passages,
A technique has been disclosed in which a heating element is provided in the sub-intake passage to vaporize droplet fuel that collects in the sub-intake passage during a cold start.

[Problems to be Solved by the Invention] However, in order to smoothly transition the engine from startup to a normal state, it is necessary to promote vaporization of the fuel and increase the temperature of the combustion chamber of the engine using a heating means. For this reason, conventionally, it is necessary to correct the amount of fuel after starting, and increasing the amount of fuel after starting causes deterioration of exhaust emissions and deterioration of fuel efficiency.

Additionally, at low temperatures, alcohol and gasoline tend to separate in the fuel tank or piping, making the alcohol concentration distribution uneven and potentially making the startup control based on the output of the alcohol concentration sensor inaccurate. be.

Furthermore, when starting the engine, when promoting the vaporization of fuel using a heating means such as a heater, depending on the installation position of the heating means such as a heater, not all the fuel may be vaporized. Adhesion to the inner wall of the port,
Further, the evaporation of this adhering fuel may result in an inappropriate air-fuel ratio, leading to poor starting and poor fuel efficiency.

[Object of the Invention] The present invention has been made in view of the above circumstances, and it achieves precise control when starting an engine to maintain an appropriate air-fuel ratio, and effectively promotes vaporization of fuel at low temperatures. FF that can start the engine smoothly and quickly
The object of the present invention is to provide a starting control method and a starting assist device for a V engine.

[Means for Solving the Problems] In order to achieve the above object, a method for controlling the start of an FFV engine according to a first invention includes a procedure for setting a startability determination temperature based on the alcohol concentration of the fuel, and a step for setting a startability determination temperature based on the alcohol concentration of the fuel. A procedure for comparing the temperature with the engine temperature to determine whether or not the engine can be started; and a procedure for promoting vaporization of the fuel for a preset time before fuel injection when it is determined that the engine cannot be started in the above determination procedure. The procedure of energizing the heating means of When the temperature is lower than the completion temperature, fuel is injected without energizing the heating means in advance, and the heating means is energized until the engine temperature reaches a predetermined value, and the comparison result of the comparison procedure; The heating means is de-energized when the engine temperature is equal to or higher than the warm-up completion temperature.

Further, in the FFV engine starting control method according to the second invention, when starting the engine, driving of the starter motor is prohibited for a predetermined period of time, and the fuel pump is driven to forcefully feed the fuel in the fuel tank to the pressure regulator. Circulating fuel returned from the pressure regulator to the fuel tank equalizes the alcohol concentration distribution of the fuel.

Further, a method for controlling the start of an FFV engine according to a third invention includes a procedure for setting a startability determination temperature based on the alcohol concentration of the fuel, and comparing the startability determination temperature with the engine temperature, so that the engine can be started. When it is determined that it is impossible to start using the procedure for determining whether or not
The method includes a procedure for prohibiting fuel injection and cranking the engine for a predetermined period of time.

Further, a method for controlling the start of an FFV engine according to a fourth invention includes a procedure for setting a fixed ignition time according to the engine temperature, and a procedure for setting the ignition timing at a constant timing during the elapse of the fixed ignition time at the time of starting the engine. and fixing procedures.

Furthermore, in the FFV engine starting control method according to the fifth invention, when electricity is supplied to the heating means for promoting fuel vaporization at the time of starting the engine, the adhesion rate of the injected fuel to the inner wall surface of the intake port and the intake stroke in one cylinder are determined. and the fuel evaporation rate in the intake port during the next intake stroke are fixed at constant values.

Further, the starting assist device for an FFV engine according to a sixth aspect of the invention includes a heater that faces the injector disposed in each cylinder and receives and vaporizes the injected fuel from the injector, and this heater is integrally incorporated. For installation, a filter unit consisting of parts is mounted between the cylinder head and the intake manifold for each cylinder.

[Function] In the FFV engine starting control method according to the first invention, first, a startability determination temperature is set based on the alcohol concentration of the fuel, and this startability determination temperature is compared with the engine temperature to start the engine. It is determined whether or not it is possible to start.

If it is determined that starting is not possible, the heating means for promoting vaporization of the fuel is energized for a preset time before fuel injection, while if it is determined that starting is possible, the engine temperature and warm-up completion temperature are are compared.

As a result of this comparison, when the engine temperature is lower than the warm-up completion temperature, fuel is injected without energizing the heating means in advance, and thereafter, the heating means is energized until the engine temperature reaches a predetermined value. . Further, when the engine temperature is equal to or higher than the warm-up completion temperature, the heating means is de-energized.

In the FFV engine starting control method according to the second aspect of the invention, when starting the engine, driving of the starter motor is prohibited for a predetermined period of time, the fuel pump is driven, and the fuel in the fuel tank is pumped to the pressure regulator. Then, the pressure-fed fuel returns to the fuel tank via the pressure regulator, and the fuel is circulated and agitated.

As a result, the alcohol concentration distribution of the fuel is made uniform.

In the FFV engine starting control method according to the third invention, a startability determination temperature is set based on the alcohol concentration of the fuel, and the startability determination temperature is compared with the engine temperature to determine whether the engine can be started. It will be judged.

If it is determined that the engine cannot be started, the engine is cranked for a predetermined period of time while fuel injection is prohibited.

In the FFV engine starting control method according to the fourth aspect of the invention, the ignition timing is fixed at a constant timing when the engine is started, and is held while the fixed ignition time set according to the engine temperature elapses.

In the FFV engine start control method according to the fifth invention, when the heating means for promoting fuel vaporization is energized at the time of engine start, the adhesion rate of the injected fuel to the inner wall surface of the intake port and the intake stroke in one cylinder are determined. The fuel evaporation rate in the intake port during the next intake stroke is fixed at a constant value.

In the starting assist device for an FFV engine according to the sixth invention, a heater facing an injector disposed in each cylinder;
A heater unit including an integrally installed heater unit is installed between the cylinder head and the intake manifold for each cylinder, and the fuel injected from the injector is vaporized.

[Embodiments of the invention] Hereinafter, the present invention will be described in detail with reference to the drawings.

The drawings show an embodiment of the present invention, in which Fig. 1 is a flowchart showing the control procedure at startup, Fig. 2 is a schematic diagram of the engine control system, Fig. 3 (a> is a detailed view of the heater installation section, and Fig. Figure 3(b) is a sectional view taken along line A-A in Figure 3(a), Figure 4 is a front view of the crank rotor and crank angle sensor, Figure 5 is a front view of the cam rotor and cam angle sensor, and Figure 6 is a front view of the cam rotor and cam angle sensor. An explanatory diagram showing the startable region and the unstartable region, FIG. 7 is a conceptual diagram of the startable determination temperature, FIG. 8 is a characteristic diagram of the heater, and FIG. 9 is a conceptual diagram of the heater heating completion determination temperature. Fig. 10 is a conceptual diagram of the fixed ignition time map, Fig. 11 is a flowchart showing the starter motor control procedure, Fig. 12 is a cylinder discrimination,
Flowchart showing engine rotation speed calculation procedure, 13th
14 is a conceptual diagram of the wall surface adhesion rate map, FIG. 15 is a conceptual diagram of the fuel evaporation rate map, and FIG. 16 is a conceptual diagram of the basic ignition timing map. FIG. 17 is a conceptual diagram of the injection start crank angle map, FIG. 18 is a flow chart showing the ignition control procedure, FIG. 19 is a flow chart showing the fuel injection control procedure, and FIG. 20 is a time chart of fuel injection and ignition.

(Configuration of engine control system) In Fig. 2, reference numeral 1 indicates an FFV engine, and the figure shows a horizontally opposed four-cylinder (4-cycle) engine. Each intake port is formed in the cylinder head 2 of this engine 1. An intake manifold 3 is communicated with the intake manifold 2a, a throttle chamber is communicated with the intake manifold 3 via an air chamber 4, and an air cleaner 7 is attached to the upstream side of the throttle chamber 5 via an intake pipe 6.

Further, an air flow meter (a hot wire type air flow meter in the figure) 8 is interposed immediately downstream of the air cleaner 7 in the intake pipe 6, and a throttle valve 5a provided in the throttle champara is connected to adjust the throttle opening. A shifter 9a and an idle switch 9b for detecting fully closed throttle valve are connected.

Furthermore, an idle speed control valve (ISCV) 11 is interposed in a bypass passage 10 that communicates the upstream and downstream sides of the throttle valve 5a.

Further, an injector 12 is disposed immediately upstream of each intake port 2a of each cylinder of the intake manifold 3, and a heater unit 13 as a starting assist device is installed, and a heater unit 13 is installed for each cylinder of the cylinder head 2. , an ignition plug 14 is attached whose tip is exposed to the combustion chamber.

The recorder unit 13 is shown in FIGS. 3(a) and 3(a).
As shown in b), a heater 13a as a heating means consisting of a positive temperature coefficient thermistor (PTC thermistor) is integrated, and a bolt 13d is installed between the cylinder head 2 and the intake manifold 3.
The attachment section 13c is attached at the section 13c.

Further, the above-mentioned shutter 13a is formed, for example, in the shape of a disk,
Fins 13b are provided on the side facing the injector 12. The injector 13a is arranged at an angle that minimizes intake resistance, so that all the fuel injected from the injector 12 hits the fin 13b, and the fins 13b prevent the fuel from diffusing. There is.

Further, the injector 12 is communicated with a fuel tank 16 via a fuel supply path 15, and this fuel tank 16 includes:
Only alcohol, a mixed fuel of alcohol and gasoline having a predetermined alcohol concentration M, or only gasoline are stored, and when the alcohol concentration M is O, this mixed fuel is 100% gasoline and the alcohol concentration M is 1.
．． When it is 0, it is gasoline O% (alcohol 100%).

That is, the alcohol concentration M of the fuel changes between 0 and 1.0 depending on the circumstances when the user refuels.

Further, an in-tank type fuel pump 17 is provided in the fuel tank 16, and the fuel from the fuel pump 17 passes through a fuel filter 18 interposed in the fuel supply path 15 and an alcohol concentration sensor 19, and then flows to the injector. 12,
The fuel is fed under pressure to the pressure regulator 20, from which the fuel is returned to the fuel tank 16, and the fuel pressure is regulated to a predetermined pressure.

Further, the alcohol concentration sensor 19 includes, for example, a pair of electrodes provided in the fuel supply path 15, and detects a current change based on a change in electrical conductivity of the fuel, thereby determining the alcohol concentration M. Detected.

Note that the alcohol concentration sensor 19 is not limited to the type that detects changes in electrical conductivity as described above;
In addition, a resistance detection type, a capacitance type, and an optical type may be used.

In addition, a knock sensor 21 is attached to the cylinder block 1a of the engine 1, and a cooling water temperature sensor 22 is provided facing a cooling water passage (not shown) formed in the cylinder block 1a, and further, a cooling water temperature sensor 22 is provided to the cylinder block 1a. The 02 sensor 24 faces the gathering part of the exhaust manifold 23 that communicates with the exhaust port 2b of the 02 exhaust port 2b.

Note that the reference numeral 25 is a catalytic converter.

A crank rotor 26 is attached to the crankshaft 1b supported by the cylinder block 1a, and an electromagnetic pickup or the like is mounted on the outer periphery of the crank rotor 26 to detect a protrusion (or slit) corresponding to a predetermined crank angle. Further, a cam angle sensor 29 made of an electromagnetic pickup or the like is installed opposite to a cam rotor 28 connected to the camshaft 1c of the cylinder head 2.

As shown in FIG. 4, the crank rotor 26 has protrusions 26a, 26b, and 26c formed on its outer periphery, and each of these protrusions 26a, 26b, and 26c, for example,
#1. #2 and #3. #4) Before compression top dead center (BTDC)
θ1. θ2. The position of θ3 (for example, θ1=97°, θ2
-65°, 'θ3=10°).

That is, the protrusion 26a indicates the reference crank angle when setting the ignition timing and fuel injection timing, and the protrusions 26a, 26
The engine rotation period f is calculated from the transit time between b,
Further, the protrusion 26c serves as a reference crank angle indicating fixed ignition timing.

Further, on the outer periphery of the cam rotor 28, as shown in FIG. 5, there are protrusions 28a, 28b for cylinder discrimination.

28c is formed, and for example, the protrusion 28a is at #3° #4 compression top dead center (ATDC) θ4? If (for example θ4
The protrusion 28b is composed of three protrusions, and the first protrusion is formed at the ATDC θ5 position of the #1 cylinder (for example, θ5=5°). Furthermore, the protrusion 28
C is formed by two protrusions, and the first protrusion is A of #2 cylinder.
It is formed at the position of TDC θ6 (for example, θ6=20°).

Incidentally, the crank rotor 26 or the cam rotor 2
A slit may be provided in place of a protrusion on the outer periphery of the sensor 8. Further, the crank angle sensor 27 and the cam angle sensor 29 are not limited to magnetic sensors such as an electromagnetic pickup.
An optical sensor or the like may also be used.

(Circuit configuration of control device) On the other hand, reference numeral 31 is a control device (ECU) consisting of a microcomputer, etc., which includes a CPU 32, a ROM 33, an R
The AM 34 and the T10 interface 35 are connected to each other via a pass line 36, and a predetermined stabilized voltage is supplied from a constant voltage circuit 37.

The constant voltage circuit 37 is connected to a battery 39 via a relay contact of an ECU relay 38.
Eight relay coils are connected to the battery 39 via a key switch 40.

Further, a starter switch 41 is attached to the battery 39,
Relay contacts of heater relay 44 and fuel pump relay 4
The starter motor 43 is connected to the starter switch 41 via the relay contact of the starter motor relay 42, and the relay contact of the heater relay 44 is connected to each cylinder via the current sensor 45. The heater 13a is connected thereto, and the fuel pump 17 is further connected through the relay contact of the fuel pump relay 48.

In addition, the input ports of the T10 interface 35 are connected to the respective sensors 8.9a, 19, 21°, 22.24,
27.29, 45, the idle switch 9b, and the starter switch 41 are connected, and the battery 39 is connected to monitor the battery voltage.

Further, the igniter 30 of the spark plug 14 is connected to the output port of the T10 interface 35, and the ISC 11, the injector 12, the starter motor relay 42, and the heater relay 44 are connected to the output port of the T10 interface 35.
and each relay coil of the fuel pump relay 48, and the LE
ECS, which is composed of D, etc., and indicates the control state at the time of starting, which will be described later.
A lamp 47 is connected.

The ROM 33 stores a control program and fixed data such as various maps to be described later.
The RAM 34 stores data obtained by processing the output signals of the sensors and switches, and data processed by the CPU 32.

The CPU 32 executes startup control according to the control program stored in the ROM 33, and controls the ignition timing,
The fuel injection amount is set and a corresponding signal is output to the injector 12 and igniter 30.

(motion) Next, the operation of the embodiment with the above configuration will be explained.

(Starting control) The flowchart in FIG. 1 is a starting control program that starts when the ECU 31 is powered on. First, initialization is performed in step 5101, and each relay such as the starter motor relay 42 and heater relay 44 is activated. At the same time as turning it off, the timer is reset and each counter and each flag are cleared.

Next, in step 5102, the starter motor energization prohibition flag F[8G1 is set (FLAG1←1) to prohibit energization to the starter motor 43, and step 5103
Then, set the fuel pump energization permission flag FLAG2) L
(FLAG2←1), energization of the fuel pump 17 is permitted.

Next, in step 5104, the fuel injection prohibition flag F[^G
3 (FLAG3-1) to prohibit fuel injection, proceed to step 5105 and start counting the timer, then in step 5106 the ECS lamp 47 is lit,
In step 5107, the coolant temperature T- from the coolant temperature sensor 22 is read, and the coolant temperature T- as the engine temperature is read.
- is equal to or higher than the set water temperature RCHET-.

When T-≧RCHET- in step 5107, jump to step 3110, while TW < RCH
If ET-, proceed to step 3108 and set timer TI.
Step 81 until MER reaches the set time ■1
Repeat the loop of 08, and when TIMER≧■1, exit the loop and proceed to step 3109, where timer T
Clear lHER (TIMER←0) Step 51
Proceed to step 10.

That is, when the alcohol and gasoline in the fuel tank 16 or the fuel supply path 15 are separated at low temperatures, or when the alcohol concentration M in the fuel tank 16 is low (high), only alcohol (gasoline) is present. When the fuel is replenished, the alcohol concentration M of the fuel in the fuel supply #115 changes greatly, and the alcohol content becomes thicker or thinner over time.

Therefore, when the cooling water temperature T- is lower than the set water temperature RCHET%11, only the fuel pump 17 is driven before cranking the engine, the fuel is returned from the pressure regulator 20, and the fuel in the fuel tank 16 is circulated. I worship. By continuing this fuel circulation for a set time 1 determined by the fuel volume between the alcohol concentration sensor 19 and the injector 12 and the discharge capacity of the fuel pump 17, the alcohol concentration distribution of the fuel is made uniform. The installation of the injector 12 that actually supplies fuel to the engine depends on the position and alcohol concentration sensor 19.
The purpose of this installation is to improve controllability by eliminating temporal and spatial discrepancies in the alcohol concentration M between the positions.

Next, in step 5110, the startability determination water temperature map MPT@ is referred to with interpolation calculation using the alcohol concentration M as a parameter, and the startability determination water temperature TWH[T is set, and in step 5111, this startability determination water temperature TWH
Start determination is made by comparing ET and cooling water temperature T-.

That is, as shown in FIG. 6, a temperature condition range with an alcohol concentration M that allows starting without heating the fuel injected from the injector 12 by the heater 13a, and a temperature condition range where starting is not possible with this state are identified through experiments or the like. Then, from the startability determination water temperature map MPTW (see FIG. 7) consisting of a series of addresses in the ROM 33, the startability determination water temperature TWHET is set using the alcohol concentration M as a parameter. By comparing this startability determination water temperature T%4NET with the cooling water temperature T, it is possible to determine whether or not the engine can be started.

Note that, instead of the cooling water temperature 714 from the cooling water temperature sensor 22, fuel temperature or the like may be used as the engine temperature when determining whether the engine can be started.

As a result, in step 5111 above, T@≦TWM[
In the case of ■, it is determined that starting is not possible and the process proceeds to step 5112.
When TW > TWHET, it is determined that starting is possible and the process advances to step 5129.

Here, we will first explain the procedure when it is determined that the engine cannot be started.

If it is determined in step 5111 that starting is not possible and the process proceeds to step 5112, the fuel pump energization permission flag FLAG
2 is cleared (FLAG2-0) to stop driving the fuel pump 17, and in step 5113, the start-unable-time control determination flag FLAG4 is set (FLAG4←1), and the process proceeds to step 5114. F
8G4 is referred to in a starter motor control procedure to be described later, and start failure control is determined and the corresponding procedure is executed.

Next, in step 5114, the ECS lamp 47 is switched from lighting to blinking to indicate that the heater 13a is being warmed up, and in step 5115, the heater relay 44 is turned on to start energizing the heater 13a and warm up. Do the machine.

Next, in step 5116, the timer TIMER starts counting to measure the energization time of the counter 13a, and the process proceeds to step 5111, where the timer TIMER becomes equal to or longer than the set time TSET (for example, TSET=3 sec). Continue counting until.

Then, in step 5111 above, TIMER≧TSET
, proceed to step 8118 and set the timer TIM.
Clear ER Tl14ER←0), step 511
At step 9, the heater heating completion determination electric power MPH- is referred to with interpolation calculation using the cooling water temperature T- and alcohol concentration M as parameters, and the heater heating completion determination electric power w1 is set, and the process proceeds to step 5120.

In step 5120, the heater power consumption W detected by the current sensor 45 is calculated from the low current consumption I and the battery voltage VB (W4-IXVB), and step 512
Proceed to step 1 and calculate this heater power consumption W in step 51 above.
It is compared with the heater heating completion determination power W1 set in step 19.

That is, as shown in FIG. 8, when the temperature of the heater 13a made of a PTC thermistor rises after energization and reaches the Curie point, the resistance value rapidly increases and the current consumption I starts to decrease, so that the consumption decreases. Warm-up status cannot be determined based on electric power alone.

Therefore, by avoiding the initial stage of heater energization and determining the completion of heating of the heater 13a after the elapse of time TSET,
This prevents misjudgments.

This heating completion determination power W1 is the power consumption when the heater 13a is warmed up to a temperature sufficient to promote fuel vaporization when fuel injection is started, and as shown in FIG. Heater heating completion judgment electric kamatubu MP configured with cooling water temperature TW and alcohol concentration M as parameters
For each address of H-, a small The value recorder heating completion determination power W1 is stored.

Then, in step 5121, when W≧W1, the current consumption I of the heater 13a is read again from the current sensor 45, the heater power consumption W is calculated, and the loop is repeated to be compared with the heater heating completion determination power W1, W<Wl
When this happens, it is determined that heating is complete and the process proceeds to step 5122.

In step 5122, the starter motor energization prohibition flag FLAGI is cleared (FLAG1←0) to permit energization of the starter motor 43, and in step 5123, the fuel pump energization permission flag FLAG2 is set (FLAG1←0).
2-1) When the fuel pump 17 is driven again, step 5
At step 124, the ECS lamp 47 is switched from blinking to continuous lighting, and the process proceeds to step 5125.

In step 5125, the loop is repeated until the counter C0UNTST reaches the set value TC. This counter C0UNTST counts the closing during cranking in the starter motor control procedure described later, and the set value TC is, for example, , 2 to 3 Sec, and at this time, the fuel injection prohibition flag FLAG3 remains set, so that the starter motor 43 is driven without fuel being injected, resulting in so-called empty cranking.

That is, the temperature of the combustion chamber is raised by this dry cranking, and when the fuel mixture is supplied to the combustion chamber by execution of fuel injection, vaporization of the fuel is promoted and ignition is facilitated, thereby warming up the engine 1. This can save time.

After sono, the above Stellaf 5125 TeC0uNTS■≧Tc
When 5127, 5t28 exits the loop and proceeds to step 8126 onwards, 7S126.5127,5t28
Distortion, start failure control determination flag FLAG4, counter C0UNTST, fuel injection prohibition flag FLAG
Clear 3 FLAG4 ←01COUNTST ←
01FLAG3 ←O), the process when starting is not possible is completed and the process proceeds to step 5133.

On the other hand, if 1%1>Tl4NET in step 5111, steps 5111 to 5129
The process proceeds to the following steps and performs start-up possible processing, that is, in step 5129, the starter motor energization prohibition flag F[^
Clear G1 (FL^G1←0) Starter motor 4
At the same time, in step 5130, the fuel injection prohibition flag FLAG3 is cleared (FLAG3
←0) Fuel injection is permitted, and in step 5131 the cooling water temperature T- is set to the warm-up completion temperature TWLA4 (for example, 50 to 60 degrees Celsius).
) is reached.

When TW>TSILA4 in step 5131, the process jumps from step 5131 to step 5147, turns off the ECS lamp 47, and exits the program. On the other hand, when T-≦TWLA4, the process proceeds from step 5131 to step 5132, where the heater is turned off. relay 4
4 is turned on to start energizing the heater 13a, and the process proceeds to step 5133.

Next, when the process proceeds from step 8128 of the start-up impossible process or step 5132 of the start-up process to step 5133, the fixed ignition time map M P IGST is referred to with interpolation calculation using the cooling water temperature T- as a parameter, and the ignition timing is determined. A time fixed at a specific timing, that is, a fixed ignition time TADV is set.

As shown in FIG. 10, the fixed ignition time map M P
In each address of the IGST, a value determined in advance through experiments or the like is stored, and a fixed ignition time TADV having a larger value is stored as the cooling water temperature T- is lower. Then, until this fixed ignition time TADV elapses, a specific timing at which the ignition timing is retarded than usual, for example,
The ignition timing is fixed to the θ3 crank pulse input timing from the crank angle sensor 27.

As a result, the ignition timing is retarded than usual in accordance with the engine temperature, the combustion chamber temperature is increased, the air-fuel mixture can be reliably ignited, and the startability can be improved.

Furthermore, when the process proceeds from step 5133 to step 5134, the timer TIMER starts counting, and in step 5135, the engine speed Ne reaches the complete explosion speed NK^N.
If Ne<NWAH, that is, the engine has not completely exploded, step 513 is performed.
5 to step 5141 and counter C0UNT
Count up COUNT ← C0UNT +1
), and in step 5142 it is determined whether the set value COυNTSET has been exceeded.

In step 5142 above, C0UN T≦C0UNT
When SET, proceed to step 5143 and set timer TIM.
Clear the ER (TIMER-0), then return from step 5143 to step 5133, reset the fixed ignition time TADV, repeat the above procedure, and return to C0.
When IINT>C0INTSET, it is determined that the engine has stalled, and the process branches from step 5142 to step 5144, where the counter C0U14T is cleared and step 5145 Te9 is now TIME.
R Rough') 7 Shiku C0UNT ←0, TIHER←
0), in step 8146, it is determined whether the cooling water temperature TIII has reached the startability determination water temperature TWHET or not.

Then, in step 8146 above, Tit>TIIH
When ET, return to step 5133, and T-≦TWN.
In the case of ET, the process returns to step 5113 and subsequent steps of the start failure control.

On the other hand, when Ne≧N KAN in the above step 5135, that is, when the engine has completely exploded, the process proceeds from the above step 5135 to step 8136, and the cooling water temperature T-
It is determined again whether or not the temperature has reached the warm-up completion temperature T WLA4, and when TW≦T WLA4, step 51 is performed.
36 branches to step 5143 and sets the timer TIMER.
(TIMER←0) and returns to step 5133, and when TW>TWL^4, the above step 813
6, the process advances to step 5137.

In step 5137, it is determined whether or not the timer Tll4ER has reached the set time TL, that is, whether the engine rotational speed Ne is equal to or higher than the complete combustion rotational speed NKAM, and the cooling water temperature T- is equal to or higher than the warm-up completion temperature TWLA4. Continuing for the set time TE, determine whether or not the startup is completely completed, and set the TIMER
When <TL, the process returns to step 5135 to repeat the complete explosion determination, and when Tll4ER≧T[, it is determined that starting is complete and the process proceeds to step 5138.

Then, when the counter C0UNT is cleared in step 5138 (C0UNT←0>, the timer TIMER is cleared in step 5139 (TIMER←0), the heater relay 44 is turned off in step 3140, and the heater 13
The power supply to a is finished, and in step 5147, the ECS lamp 47 is turned off, and the program is finished.

By performing the precise startup control described above, it is possible to quickly raise the temperature of the engine's combustion chamber and significantly reduce the amount of fuel needed after startup, which shortens warm-up time and improves fuel efficiency. can be achieved.

(Starter Motor Control Procedure) On the other hand, the starter motor control procedure program shown in FIG. 11 is interrupted and executed at predetermined time intervals with respect to this initial control program.

In this time interrupt program, first, step 52
At 01, the value of the starter motor energization prohibition flag F[^G1 is checked to determine whether or not energization of the starter motor 43 is permitted.

When FLAGI = O in step 5201, that is, energization of the starter motor 43 is permitted, the process proceeds from step 5201 to step 5202, where it is determined whether or not the starter switch 41 is turned on. If it is determined to be ON, the process advances to step 8203, and the start failure control determination flag FLAG is set.
Check the value of 4.

When FLAG4 = O in step 5203 above, jump to step 3205 and set FLAG4 = 1
When , the cooling water temperature Tl1l is the starting possible determination water temperature T
Since it is less than WHET and is in the state of start failure control, the process proceeds from step 5203 to step 5204,
Count up the counter C0UNTST for measuring the idle cranking time explained in the startup control procedure above (COUNTsT - COuNTST +1).
.

The program then proceeds to step 5205, turns on the starter motor relay 42 to drive the starter motor 43, and exits the program. As a result, the engine 1 is cranked.

On the other hand, when FLAGl = 1 in the above step 5201 and energization to the starter motor 43 is prohibited, or when the starter switch 41 is OFF in the above step 5202, the process branches from each step to step 8206, and the starter motor 43 is turned off. Turn motor relay 42 to O
The starter motor 43 is set to a stopped state as FF, and the program exits.

(Cylinder discrimination and engine rotation speed calculation procedure) FIG.
7 and the output signal of the cam angle sensor 29, the ignition target cylinder of #l cylinder is determined, and in step 5302, #(
+2) Determine the target cylinder for fuel injection.

That is, as shown in the time chart of FIG. 20, for example, when a cam pulse of θ5 (projection 28b) is output from the cam angle sensor 29, the next compression top dead center is cylinder #3, and this #3 cylinder It can be determined that the cylinder becomes the ignition target cylinder and the #4 cylinder becomes the fuel injection target cylinder.

Furthermore, after the cam pulse of θ5, θ4 <protrusion 28
When the cam pulse a) is output, the next compression top dead center is the #2 cylinder, and this #2 cylinder becomes the cylinder to be ignited.
It can be determined that the #1 cylinder is the cylinder to which fuel is injected.

Similarly, the compression top dead center after the cam pulse of 06 (protrusion 28C) is output is the #4 cylinder, and the #4 cylinder becomes the ignition target cylinder, and the #3 cylinder becomes the fuel injection target cylinder.

Also, after the cam pulse of θ6, θ4 (protrusion 28a
) is output, it can be determined that the subsequent compression top dead center is the #1 cylinder, the #1 cylinder is the ignition target cylinder, and the #2 cylinder is the fuel injection target cylinder.

Further, after the cam pulse is output from the cam angle sensor 29, the crank pulse output from the crank angle sensor 27 indicates a reference crank angle (θ1) for setting the ignition timing and fuel injection start timing of the corresponding cylinder. It can be determined that it is a thing.

That is, the 4-stroke, 4-cylinder engine 1 of this embodiment
Then, the combustion stroke is the cylinder layer #1 → #3 → #2 → #4, and if the cylinder to be ignited in the #i cylinder is the #1 cylinder, the cylinder to be injected at this time is the #2 cylinder, Next #i(
+2) The target cylinder for fuel injection is cylinder #4. and,
Ignition is carried out in the cylinder layer #1 → #3 → #2 → #4, and fuel injection is performed at 720℃A (2 rotations of enshift) to the corresponding cylinder.
One sequential injection is performed every time.

Next, in 5303, the engine rotation speed Ne is calculated.

For example, BT output from the crank angle sensor 27
DCθ1. Calculate the period f by measuring the interval of pulses that detect θ2 (f=dt (θ1-θ2)/d (θ1-
θ2)), the engine rotation speed Ne is calculated from this period f (Ne-60/f), and is stored as rotation speed data at a predetermined address in the RAM 34, and the routine exits.

(Fuel injection amount and ignition timing setting procedure) On the other hand, the fuel injection amount and ignition timing are set by the interrupt routine at predetermined time intervals shown in FIG. When FLAG3 = 1, that is, fuel injection is prohibited during start-up control, step 540
Proceed to step 2 and set the fuel injection pulse width Ti to 0.
←0), the ignition system is cut in step 5403 and the routine exits.

On the other hand, when FLAG3 = O in step 5401, that is, fuel injection is permitted, the process proceeds from step 5401 to step 5404, where it is determined whether the engine speed Ne is "0", that is, whether the engine is in a stopped state. When Ne=O, step 5 described above is performed.
The routine exits through steps 402 and 5403, and when Ne≠0, the process advances from step 5404 to step 5405.

In step 5405, the engine rotation speed Ne stored in a predetermined address of the RAM 34 is read out, and the time t per 1/2 rotation of the engine is read out based on the engine rotation speed Ne.
i m e 1/2, t i m e 1/2 =
Calculated from 30/Ne - (1).

The above equation (1) calculates the time per stroke in a 4-cylinder engine, and in the case of an evenly spaced combustion engine with n cylinders, the above equation (1) calculates t i m e 1/n/
2 = (60/n/2) / Ne - (1)'
It can be calculated from

Thereafter, in step 8406, the weighting coefficient (
weighted average weight) TNnew, TNnew=timel/2 XC0F −
- (2) COF: Calculated from a fixed value.

And step 84G? Then, read the measured intake air flow velocity Q (g/sec) from the output of the air flow meter 8, and also set the weighting coefficient TNO set in the previous routine.
Id and corrected intake air flow rate QaO1d.

In addition, the first routine is TNO1d=O1Qaold=O
It is.

Thereafter, the process proceeds to step 5408, where the corrected intake air flow rate Qane'll that compensates for the -th delay is calculated from, and the process proceeds to step 3409, where the amount of air taken into one cylinder in the intake stroke Q+) is calculated from Qp= Qanewxtimel/2 -(4
). - By compensating for the next delay, it is possible to correct overshoot during transients.

The theoretical formula for the above-mentioned corrected intake air flow rate QaneW is detailed in Japanese Patent Application Laid-Open No. 2-5745, which was previously filed by the present applicant.

Next, the process proceeds to step 5410, where various increase correction coefficients CQEF are calculated based on the output values of the throttle opening sensor 9a, the idle switch 9b, and the cooling water temperature sensor 22, such as when starting, when the engine is cold, and when the throttle is fully open. Set. However, acceleration increase correction is not performed.

Thereafter, in step 5411, the air-fuel ratio feedback correction coefficient α is set based on the output signal of the O2 sensor 24, and in step 5412, the alcohol concentration correction coefficient is set based on the alcohol concentration M detected by the alcohol concentration sensor 19. Set by map search or calculation.

The above alcohol concentration correction coefficient KAL is based on the alcohol concentration M of the fuel when M=0 (100% gasoline) (KAL=1.0), and the higher the alcohol concentration M is, the larger the correction amount is. This is to correct the change in the stoichiometric air-fuel ratio due to M.

Next, when the process proceeds from step 5412 to step 5413, it is determined whether or not the heater is energized. If the heater is energized, the process proceeds to step 5414 and subsequent steps; when the heater is not energized, the process proceeds to step 5425 and subsequent steps.

First, to explain the procedure while the heater is energized, from step 5414 onwards, in step 5414, the rate at which the fuel adhering to the intake port 2a of the engine rotates twice (one cycle) evaporates, that is, the fuel evaporation rate β is determined. “1
Furthermore, in step 5415, the proportion of fuel that adheres to the wall surface of the intake bow 2a of the fuel injected from the injector 12, that is, the wall surface adhesion rate X is fixed to "0". Do (X←0).

That is, all the fuel injected from the injector 12 hits the heater 13a, and since the fins 13b prevent the fuel from spreading, the fuel is instantaneously vaporized while the heater is energized and does not adhere to the wall surface. There is no evaporation of fuel.

Therefore, the above fuel evaporation rate β is "1", and the wall surface adhesion rate X is "1".
By setting it to 0'', the air-fuel ratio can be made appropriate, preventing over-richness of the air-fuel ratio, and improving startability and fuel efficiency.

Then, when the process proceeds from step 5415 to step 5416, a complete explosion is determined by comparing the engine rotational speed Ne and the complete explosion rotational speed N KAM. When Ne<NKAN, in step 5411, the engine is started before a complete explosion. Set the engine start determination flag FLAG5, which indicates that the engine is in a state of
The fixed ignition timing (angle) is set to ADVC8 in synchronization with the crank pulse of BTDCθ3 (lO9CA) output from the CPU, and the process proceeds to step 343G.

On the other hand, when Ne≧N KAN in step 5416, the process proceeds from step 8416 to step 8418, checks the value of engine start determination flag FLAG5, and
[When AG5=1, the engine did not fully explode in the previous routine, and this time the engine completely exploded for the first time, so proceed to step 5419 and clear the timer TIER2 for measuring the elapsed time of fixed ignition.] T
IER2←0), in step 8420, this timer TI
Start counting ER2 and step 542
1, the engine start determination flag F[^G5 should be cleared (FLAG5←0), and the process proceeds to step 5424 described above.

Further, when FLAG5 = 0 in the above step 5418, the process branches from the above step 8418 to step 5422, and it is determined whether or not the timer TIMER2 has reached the fixed ignition time TADV. And TIHER2<T
For ADV throating, proceed from step 5422 to step 5424, and if ■IHER2≧TADv throating, X TERRA7' 5422 to step 542
Proceed to step 3 and clear timer TIHER2 7114
ER2←0), proceed to step 5427.

Next, a description will be given of the procedure when the heater is not energized, proceeding from step 5413 to step 5425 and subsequent steps.

After step 5425, in step 5425, the fuel evaporation rate map MPβ is referred to with interpolation calculation using the engine speed Ne, cooling water temperature Tw, and alcohol concentration M as parameters, and the fuel evaporation rate β is set for every two revolutions of the engine. .

The fuel evaporation rate β is controlled by the wall temperature, period, and alcohol concentration M. In other words, the higher the wall surface temperature, the larger the fuel evaporation rate β, and as the engine speed Ne increases, the cycle becomes shorter, so the fuel adhesion time until the next intake stroke is shorter, and the fuel evaporation rate β increases accordingly. The value becomes smaller.

Furthermore, the higher the alcohol concentration M is, the higher the latent heat of vaporization becomes, so as the fuel evaporates, the value of the fuel evaporation rate β becomes smaller.

Therefore, the fuel evaporation rate β can be captured as a function of the cooling water temperature Tw, the engine rotational speed Ne, and the alcohol concentration M. In this example, the engine rotational speed Ne and the cooling A fuel evaporation rate map MPβ is constructed using the water temperature TV and the alcohol concentration M as parameters, and the fuel evaporation rate β determined in advance through experiments or the like is stored in each region.

Next, in step 3426, the wall adhesion rate map MPX is referred to with interpolation calculation using the alcohol concentration M, the corrected intake air flow rate Qanew, and the fuel injection pulse width Ti set in the previous routine as parameters, and the wall adhesion rate X is calculated. Set. In addition, in the first routine, the fuel injection pulse width T
Since i is not set, set X=0.

The change in the wall surface adhesion rate X is controlled by the intake air flow rate Qanew, the fuel injection pulse width Ti (fuel injection amount), and the alcohol concentration M. That is, the intake air flow rate Q an
As ew becomes faster, the atomization time becomes shorter and the wall surface adhesion rate X becomes larger. Furthermore, when the intake air flow velocity Qanew is constant, the fluctuation range of the wall surface adhesion amount is minute with respect to the change in the fuel injection amount. Therefore, as the fuel injection pulse width Ti increases, the above wall surface adhesion rate X becomes relatively small. becomes a small value. Furthermore, as the alcohol concentration M of the fuel increases, the latent heat of vaporization increases, making it difficult for the fuel to evaporate.
is a relatively large value.

As shown in FIG. 14, the wall surface adhesion rate map MPX is composed of a map whose parameters are the alcohol concentration M, the corrected intake air flow velocity Qanew, and the fuel injection pulse width T1. The determined wall adhesion rate X is stored.

Then, step 8426, or step 5423 to step 54 of the process while the printer is energized, is performed.
Proceeding to step 27, the intake air weight Ga is calculated by converting the engine speed Ne and the amount of air taken into one cylinder during the intake stroke QD.
The basic ignition timing θBASE is set by referring to the basic ignition timing map MPθBASE with interpolation and calculation using the alcohol concentration M and the alcohol concentration M as parameters.

As shown in Fig. 16, each address of the basic ignition timing map MPθBASE has an optimum basic value determined in advance through experiments using engine speed Ne, intake air weight per stroke Ga, and alcohol concentration M as parameters. Ignition timing θBASE (crank angle based on θ1) is stored, and under the same Ga and N, the basic ignition timing (angle ) θBASE is stored.

Thereafter, the process proceeds to step 5428, where the knock control value (angle) θN is determined based on the signal from the knock sensor 21.
K is set, and then the process proceeds to step 5429, where this knock control value θ circle is added to the basic ignition timing θBASE set in step 5421 above to determine the ignition timing (
Calculate θIG (angle) θIG←θBASE+θNK)
, proceed to step 6430.

Then, when proceeding to step 843G from step 5429 in the process when the heater is not energized or step 5424 in the process when the heater is energized as described above, the intake port residual fuel amount set four strokes (one cycle) ago Mf4 is read, and in step 5431, the fuel injection amount Gf per injection is set from the following equation. Furthermore, until the fuel injection routine is executed four times from the first time, Mf4
=O.

G f = ((Q D/A/F)X C0EF-B
Mf4)/(1-X)...(5) As mentioned above, in the engine 1 of this embodiment, one fuel injection is performed to the corresponding cylinder every 720°C (two engine shift revolutions). When fuel is injected from the injector 12 of the corresponding cylinder to the intake port 2a of the corresponding cylinder, a portion of the fuel is not inhaled into the cylinder (combustion chamber) but adheres to the intake valve, intake port wall, etc. This adhering fuel evaporates appropriately while the engine rotates twice, and this evaporated fuel is taken into the cylinder together with the fuel injected in the next intake stroke.

Here, the amount of fuel actually supplied into the cylinder per injection Ge is the sum of the amount of fuel that does not adhere to the wall (1-X)Gf and the amount of evaporation Mf4・β, that is, Ge = (1- X)
Gf +Mf4・β ・(6) This (6
) to find the required fuel amount Gf per injection, Gf = (ce-Mf4・β) / (1-X)-
(7) becomes.

The actual amount of fuel supplied into the cylinder Ge is the target air-fuel ratio A/F
and air amount Ql), and the target air-fuel ratio after increasing the amount is (A/F)/C0EF, so G e = Q p -C0EF/ (A/F)
-(8), and by substituting equation (8) into equation (7), equation (5) is obtained.

The target air-fuel ratio A/F is generally a stoichiometric air-fuel ratio, but in a lean burn engine or the like, the target air-fuel ratio A/F is determined by a map or calculation based on the engine load and the like.

Next, in step 5432, the current intake port residual fuel amount Mf is set using the following equation.

Mf = (1 - β) XMf4 + β) It is the sum of xMf4 and the adhering portion X-Gf of the amount of fuel injected this time. Note that from the first time until the fourth injection is executed, Mf=X-Gf.

After that, in step 5433, a voltage correction pulse width TS for correcting the invalid time is set based on the batch voltage,
In step 5434, the fuel injection pulse width Ti that actually drives the injector 10 is set based on the following equation.

Ti=ni-ni^L-Gf -a+Ts...(1
G) K: Injector characteristic correction coefficient Since the above fuel injection amount Gf performs wall fuel adhesion prediction correction and evaporation correction for wall adhesion fuel, enrichment of the air-fuel ratio during transient times, especially at low rotation times, is prevented. This prevents sluggishness during transient periods and improves the responsiveness of the output.

Furthermore, acceleration increase correction becomes unnecessary, improving air-fuel ratio controllability and preventing wasteful consumption of fuel.

Then, in step 5435, the injection start crank angle θINJST is set based on the injection start crank angle map MPθINJST using the engine speed Ne and the fuel injection pulse width T1 as parameters.

As shown in FIG. 17, the injection start crank angle map MPθINJST is composed of a map using the engine speed Ne and the fuel injection pulse ILTi as parameters. A starting crank angle θINJsT is stored. This injection start crank angle θINJST is the engine speed N
e. The larger the fuel injection pulse width Ti is, the more the fuel injection pulse width Ti is set to the advance side.

Thereafter, the process proceeds to step 8436, and the process proceeds to step 840 described above.
The previous data TH with the weighting coefficient TNnew set in 6.
Update old (T No1d+T Nnew)
, Also, in step 5437, the previous data Qaold is updated by the corrected intake air flow rate qanew set in step 5408.
ew), exit the routine.

(Ignition and fuel injection control procedure) When the ignition timing θIG and fuel injection pulse width Ti are set according to the above procedure, an ignition signal and a fuel injection signal are output according to the flowcharts of FIGS. 18 and 19.

In the ignition control procedure shown in FIG. 18, an interrupt occurs when the current crank angle calculated based on the crank pulse input reaches the ignition timing (angle) θIG set in the above-mentioned routine (steps 5424 and 5429).
Executed for each CA.

That is, in step 5501, an ignition signal is output to the ignition target cylinder #i determined in the above-described cylinder determination and engine speed calculation procedure, and the routine exits.

In addition, in the fuel injection control procedure shown in FIG. 19, an interrupt occurs when the current crank angle calculated based on the crank pulse input reaches the injection start crank angle θINJST set in the aforementioned routine (step 5435). is executed every 180″CA.

First, in step 8601, the cylinder discrimination described above is performed.
A drive pulse signal with a fuel injection pulse width T1 is output to the injector 12 of the fuel injection target cylinder # i (+2) determined in the engine rotation speed calculation procedure.

Next, the process advances to step 5602, where the above-mentioned fuel injection amount,
The previous intake port residual fuel amount Mf1 is updated with the current intake port residual fuel amount Mf set in the ignition timing setting procedure (Mf1←Mf), and each data is similarly updated sequentially (M f2←Mf1. Mf3 ←Mf2. Mf
4←Mf3).

As a result, the intake port residual fuel amount Mf4 read in step 343G of the above-described fuel injection amount and ignition timing setting procedure is always one cycle earlier, that is, the residual fuel of the relevant cylinder.

In the case of an N-cylinder engine, the intake port residual fuel amount Mrn one cycle before is equal to the previous intake port residual fuel amount M
It will be updated with rn-t.

[Effects of the Invention] As explained above, according to the present invention, an appropriate air-fuel ratio can be obtained through precise startup control according to the engine temperature.
This makes it possible to significantly reduce the amount of fuel required after startup.

Furthermore, when starting the engine, it is possible to quickly raise the temperature of the combustion chamber and shorten the warm-up time.

Therefore, it is possible to smoothly and quickly shift the engine to the normal state after starting, and it is possible to simultaneously improve startability and fuel efficiency.

Furthermore, the heater that vaporizes the fuel can be effectively arranged, and the fuel injected from the injector can be vaporized before the start of the day to improve startability, and other excellent effects can be achieved.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a flowchart showing the control procedure at startup, Fig. 2 is a schematic diagram of the engine control system, Fig. 3(a) is a detailed view of the heater installation section, and Fig. 3(a) is a detailed view of the heater installation section. Figure 3(b) is a sectional view taken along line A-A in Figure 3(a), Figure 4 is a front view of the crank rotor and crank angle sensor, Figure 5 is a front view of the cam rotor and cam angle sensor, and Figure 6 is a front view of the cam rotor and cam angle sensor. An explanatory diagram showing a startable region and an unstartable region, FIG. 7 is a conceptual diagram of a water temperature map for determining whether a start is possible, FIG. 8 is a characteristic diagram of the heater, FIG. Fig. 10 is a conceptual diagram of the fixed ignition time map, Fig. 11 is a flowchart showing the starter motor control procedure, Fig. 12 is a flowchart showing the cylinder discrimination and engine rotation speed calculation procedure,
Figure 3 is a flowchart showing the procedure for setting the fuel injection quantity 1 ignition timing, Figure 14 is a conceptual diagram of a fuel deposition rate map, Figure 15 is a conceptual diagram of a fuel evaporation rate map, and Figure 16 is a conceptual diagram of a basic ignition timing map. Conceptual diagram, Fig. 17 is a conceptual diagram of the injection start crank angle map, Fig. 18 is a flowchart showing the ignition control procedure, Fig. 19 is a flowchart showing the fuel injection control procedure, and Fig. 20 is a time chart of fuel injection and ignition. It is. 1... Engine 2... Cylinder head 3... Intake manifold 12... Injector 13... Heater unit 13a... Heater (heating means) 13c... Mounting part 16... Fuel tank 17...Fuel pump 20...Pressure regulator 43...Starter motor M...Alcohol concentration T 5INET...Startability determination water temperature (startability determination temperature) T111...Cooling water temperature and engine temperature) T Praise L
A4...Warm-up completion temperature TADV...Fixed ignition timing θIG...Ignition timing - X...Intake port inner wall surface adhesion rate β...Fuel evaporation rate in intake port Figure 3 (0) Fig. 7 Fig. 8 Fig. 9 M-+ Fig. 10 rw--> Fig. 11 Fig. 12 Fig. 14 S υ1 amount Ga

Claims (6)

[Claims] (1) A procedure for setting the startability determination temperature based on the alcohol concentration of the fuel; A procedure for comparing the startability determination temperature with the engine temperature to determine whether the engine can be started; and a procedure for making the above determination. When it is determined that the engine cannot be started, the procedure is to energize the heating means to promote fuel vaporization for a preset time before fuel injection, and when it is determined that the engine can be started using the above determination procedure, the engine temperature and warm-up As a result of the comparison between the comparison procedure with the completion temperature and the comparison procedure described above, when the engine temperature is lower than the warm-up completion temperature, fuel is injected without energizing the heating means in advance, and the engine temperature reaches a predetermined value. The method includes a procedure for energizing the heating means until reaching the warm-up temperature, and a procedure for de-energizing the heating means when the comparison result in the comparison procedure indicates that the engine temperature is equal to or higher than the warm-up completion temperature. A method for controlling the starting of an FFV engine. (2) When starting the engine, driving of the starter motor is prohibited for a predetermined period of time, while the fuel pump is driven to pump the fuel in the fuel tank to the pressure regulator, and the circulating fuel is returned from the pressure regulator to the fuel tank. A method for controlling the start of an FFV engine, which is characterized by equalizing the alcohol concentration distribution of fuel. (3) A procedure for setting a startability determination temperature based on the alcohol concentration of the fuel; A procedure for comparing the startability determination temperature with the engine temperature to determine whether the engine can be started; and a procedure for making the above determination. 1. A method for controlling the start of an FFV engine, comprising the steps of: prohibiting fuel injection and cranking the engine for a predetermined period of time when it is determined that the engine cannot be started. (4) An FFV characterized by comprising a procedure for setting a fixed ignition time according to engine temperature, and a procedure for fixing the ignition timing at a constant timing while the fixed ignition time elapses when the engine is started. A method for controlling the start of an engine. (5) When electricity is applied to the heating means to promote fuel vaporization at the time of engine startup, the adhesion rate of injected fuel to the intake port inner wall surface and the fuel evaporation rate in the intake port between the intake stroke and the next intake stroke in one cylinder 1. A method for controlling the starting of an FFV engine, characterized in that: and is fixed at a constant value. (6) Install a heater unit for each cylinder, which consists of a heater that faces the injector installed in each cylinder and receives and vaporizes the injected fuel from the injector, and a mounting part that integrates this heater. FFV characterized by being installed between the cylinder head and intake manifold
Engine starting aid.