JPH03156139A - Auxiliary starting device of alcohol engine - Google Patents

Abstract

PURPOSE:To prevent a waste of energy without consuming electric power uselessly by providing a starting control means to control an electric power supply to a heating means so as to generate a required heating value calculated by a required heating value calculating means. CONSTITUTION:When a starter is driven to start an engine, a start possibility judging means 56 determines whether the engine is possible to be started ro not on the basis of alcohol concentration in the fuel and the engine temperature. In the case where the starting is determined impossible, a cranking revolution number calculating means 58 calculates the engine cranking revolution number based on a starter terminal electric voltage and a starter consuming electric current, and on the basis of the calculated cranking revolution number the fuel injection quantity per unit time is calculated by a fuel injection quantity per unit time calculating means 59. A required heating value calculating means 64 calculates the required heating value for a heating means on the basis of the alcohol concentration in the fuel, the engine temperature and the fuel injection quantity per unit time, and the electric power supply to a heating means 20 is controlled by a starting control means 65.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a starting assist device for an alcohol engine that facilitates starting by promoting vaporization of fuel supplied to the engine at the time of starting.

[Problems to be solved by conventional technology and inventions] In recent years, due to worsening fuel conditions and demands for exhaust purification, systems that can simultaneously use alcohol as an alternative fuel in addition to conventional gasoline have been put into practical use. Vehicles such as cars equipped with this system (Flexible F
The fuel vehicle (hereinafter referred to as rFFVJ) can run not only on gasoline, but also on a mixed fuel of alcohol and gasoline, or on alcohol alone, and the alcohol concentration ( The content rate varies between 0% (gasoline only) and 100% (alcohol only) depending on the user's circumstances when refueling.

In general, compared to gasoline fuel, alcohol fuel
It has characteristics such as being difficult to vaporize at low temperatures, has a large latent heat of vaporization, and has a high flash point.
The output characteristics change significantly due to the thirst condition f1,
In particular, when the alcohol or alcohol concentration is high, there arises a problem that low-temperature startability deteriorates.

To deal with this, a technique has been known that uses heating means such as a heater to promote vaporization of fuel and improve startability.
A technique has been disclosed in which a heating device that heats the intake passage is controlled by the output of the alcohol polisher, and the amount of heat generated by the above-mentioned heating ¥1ffl is increased when the alcohol concentration is higher than a set value.

However, the necessary calorific value of the heating device to start the engine must be determined by taking into account the engine temperature and the flow rate of fuel supplied to the engine per unit time. If the calorific value of the heating means is determined solely by the alcohol concentration, there is a risk that it will not be possible to cope with starting at low temperatures.

Furthermore, when starting an engine, the viscosity of the lubricating oil changes depending on the temperature, and the cranking rotation speed fluctuates greatly, so it is necessary to accurately grasp the cranking rotation speed and accurately calculate the fuel flow rate per unit time. There is. In other words, if this fuel dispatch per unit time is inaccurate,
The necessary amount of heat generated by the heating means cannot be set appropriately, and the amount of heat generated by the heating means may be insufficient to easily start the engine.

[Object of the Invention] The present invention has been made in view of the above circumstances, and it is an object of the present invention to accurately calculate the required heat generation period of the heating means for promoting the vaporization of fuel at the time of starting the engine, and It is an object of the present invention to provide a starting assist device for an alcohol engine that performs optimal control in consideration of power consumption and can reliably start the engine.

[Means and effects for solving the problem] In order to achieve the above object, the alcohol engine starting assist device according to the present invention determines whether or not the engine can be started based on the alcohol concentration of the fuel and the engine temperature. a cranking rotational speed calculation means for calculating the cranking rotational speed of the engine based on the starter terminal voltage and the starter current consumption when the startability determining means determines that the engine cannot be started; Calculate fuel injection m per unit time based on the cranking rotation speed calculated by the cranking rotation speed output means 16 Fuel injection per unit time t
JJffl calculation method and fuel alcohol? 11r! 1
Necessary heat generation resistance calculation means for calculating the required calorific value of the heating means for promoting vaporization of the fuel based on the engine temperature and the fuel injection amount per unit time calculated by the fuel injection amount per unit time calculation means; The apparatus further includes a start control means for controlling the energization of the heating means to generate the required heat generation amount calculated by the required heat generation resistance calculation means.

That is, when the starter is driven to start the engine, the startability determination means determines whether or not the engine can be started based on the alcohol concentration of the fuel and the engine temperature.

When it is determined that the engine cannot be started, the cranking rotation speed calculating means calculates the cranking rotation speed of the engine based on the starter terminal voltage and the starter current consumption, and the engine cranking rotation speed is calculated based on the cranking rotation speed. The fuel injection amount per unit time is calculated by the fuel injection amount calculation means.

Further, the required heat generation m calculation means calculates the required heat generation amount of the heating means based on the alcohol concentration of the fuel, the engine temperature, and the fuel injection amount per unit time, and the start control means energizes the heating means. is controlled to generate the necessary calorific value, promoting vaporization of the fuel and making it possible to start the engine.

[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 functional block diagram of a control device, Fig. 2 is a schematic diagram of an engine control system, and Fig. 3 is a schematic diagram of an engine control system.
Figure 4 is an explanatory diagram of the startability determination map, Figure 4 is an explanatory diagram of the fuel injection interval map at startup, Figure 5 is an explanatory diagram based on the characteristics of the starter motor, and Figure 6 is a flow chart showing the fuel injection control procedure. , FIG. 7 is a flowchart showing the control procedure at the time of starting.

(Configuration of Engine Control System) In FIG. 2, reference numeral 1 is an Alcor engine for FFV, and the figure shows a horizontal 3J li+] 4-cylinder engine. An intake manifold 3 is connected to an intake boat 2a formed in the cylinder head 2 of the engine 1, a throttle chamber 5 is connected to the intake manifold 3 via an air chamber 4, and an intake pipe 6 is connected to the upstream side of the throttle chamber 5. air cleaner 7
is installed.

Further, an intake air M sensor (a hot wire 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 chamber 5 is connected to a throttle valve 5a provided in the throttle chamber 5. The opening sensor 9a and the idle switch 9b that detects when the throttle valve is fully open are il! It is set up.

Further, an injector 10 is installed downstream of the thrower valve 5a of the intake manifold 3 collecting section, and a spark plug 11 whose tip is exposed to the combustion chamber is installed in each cylinder of the cylinder head 2. ing.

The injector 10 is communicated with a fuel tank 13 via a fuel supply path 12, and the fuel tank 13 is filled with only alcohol, a mixed fuel of alcohol and gasoline, or only gasoline when the user refuels. Due to these circumstances, fuels with different alcohol degrees A (%) are stored.

Further, a fuel pump 14 and an alcohol concentration regulator 15 are interposed in the fuel supply passage 12 from the fuel tank 13 side. It communicates with the combustion chamber 17a.

The pressure regulator 17 has a downstream side of the fuel chamber 17a communicating with the fuel tank 13, and a pressure regulating chamber 17b communicating with the intake manifold 3, as shown by the dot g1 line in the figure. The pressure regulator 17 maintains the differential pressure between the fuel pressure in the fuel v1 supply path 12 and the pressure in the intake manifold 3 constant, and controls the amount of fuel injected from the injector 10 so as not to fluctuate.

A crank rotor 18 is attached to the crankshaft 1b of the engine 1, and a crank angle sensor 19 is provided on the outer periphery of the crank rotor 18, such as an ff21M pickup, which detects a protrusion (or slit) corresponding to a predetermined crank angle. are set up opposite each other.

In addition, heating means such as the lower part M i, L of the air chamber 4 of the intake manifold 3 and the heater 20 are in question, and the cooling water passage (not shown) forming the riser formed in the intake manifold 3 is Cooling water temperature sensor 2
1 is coming.

Further, an 02 sensor 23 is provided on the exhaust pipe 22 communicating with the exhaust boat 2b of the cylinder head 2. In addition, the code|symbol 24 is a catalytic converter.

(Circuit configuration of control device) On the other hand, reference numeral 31 is a control device consisting of a microcomputer, etc., and a CPU (central processing unit) 32. ROM33. The RAM 34 and the I10 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 ignition relay 38 to supply power for control, and is directly connected to the battery 39.
When the ignition switch 40, which turns the ignition relay 38 on and off, is turned off, backup power is supplied.

Further, a starter switch 41 is connected to the battery 39, and a starter motor 43 is connected to the starter switch 41 via a relay contact of a starter motor relay 42. A current sensor 44 is interposed between them to detect the starter current consumption.

In addition, the input boat of the I10 interface 35 includes an intake air amount sensor 8, a throttle angle sensor 9a,
Idle switch 9b, crank angle hinge 19, cooling water temperature sensor 21, and 021! An engine operating condition parameter detecting means 45 consisting of an engine ( ) 23 is connected, an alcohol moisture sensor 15 and an i-flow sensor 44 are connected, and furthermore, a relay contact of an ignition relay 38 and a starter switch 41 are connected. ing.

Further, the output port of the I10 interface 35 is connected to a voltage adjustment circuit/I6 that adjusts the TX voltage to the heater 20, and also connects the injector 10, fuel pump 14, igniter 47, and heater heating display means. A certain LED 48 is connected via a drive circuit 49.

The ROM 33 contains a control program, a start possibility determination map MPST, which will be described later, and a starting fuel injection interval map MP
Fixed data such as the rST1 cranking rotational speed map MPV is stored, and the RAM 34 also includes:
The output Gi of each of the sensors and switches after data processing and the data processed by the CPU 32 are stored.

Further, in accordance with the control program stored in the ROM 33, when starting the engine, the starter switch 41 is turned on and a start determination is made in the CPU 32. If it is determined that starting is not possible, the CPU 32 controls the energization of the heater 20 and starts the injector. To promote vaporization of fuel injected from 10 and to enable easy starting.

After starting the engine, the control shifts to normal control, calculates the fuel injection amount, ignition timing, etc., and outputs a drive pulse width signal for the injector 10, an ignition signal for the spark plug 11, etc.

(Functional configuration of the illIII device) As shown in FIG. 1, the functions of the control device 31 related to control at the time of starting are an engine rotation speed output means 51, a complete explosion determination means 52, an alcohol concentration calculation means 53, and a function at the time of start. Fuel injection amount setting means 54, starting fuel injection amount map MPFST
, starter switch state determination means 55, startability determination means 56, startability determination map MPST, RAM 34
Storage means 57, cranking rotation speed calculation means 58, cranking rotation speed map MPV, fuel injection per unit time ffi calculation means 59, latent heat of vaporization calculation means 60
, fuel boiling point calculation means 61, temperature difference n calculation means 62, specific heat calculation means 63, required heat generation range calculation means 64, starting control means 6
5. Fuel boiling point calculating means 66, injector driving means 67
It consists of

Further, the start control means 65 includes a reference value comparison means 65a.
1 timer operation time setting means 65b, timer means 65c,
It is composed of heater voltage setting means 65d, heater energizing means 65e, and starter motor driving means 65f.

The engine rotation speed calculating means 51 measures the elapsed time t between crank pulses from the crank angle sensor 19 that detects the protrusion of the crank rotor 18, and calculates the elapsed time Δt and the angle difference Δθ between the protrusions of the crank rotor 18. The angular velocity ω is determined from ω=Δθ/Δt), and the engine rotation speed N is calculated based on this angular velocity ω (N=60ω/2π).

In the complete explosion determination means 52, the engine rotation speed calculation means 5
Engine speed N calculated in 1 and predetermined complete explosion speed NS
(for example, 5QQrpm), and when N≧NS, it is determined that the engine has completely exploded.

The alcohol concentration calculation means 53 reads the output signal of the alcohol m degree sensor 15 and calculates the alcohol degree S A of the fuel to be supplied to the injector 10.

In the starting fuel injection @ amount setting means 54, the cooling water temperature sensor 2
Cooling water Cut from 1 and the alcohol concentration calculation means 5
Using the alcohol concentration Δ calculated in step 3 as a parameter, search the starting fuel injection chamber map MP [3] and set the starting fuel injection amount Ti.

And this is the beginning! A fixed pulse width signal corresponding to the 71 o'clock fuel injection ff1Ti is output, and the injector driving means 67
The injector 10 is driven through.

The fuel injection resistance map M P FSr at startup is, as shown in Fig. 4, based on the fixed fuel injection l per injection α1 injected from the injector 10 at the time of startup, the cold fJI water thirst T- and the alcohol concentration A. The higher the alcohol concentration △, the lower the air-fuel ratio must be. Because GJ is low, a supplementary increase d- is required, so a large starting fuel injection titTi is stored.

The starter switch state determining means 55 determines whether the stator switch 41 is ON or OFF, and when the starter switch 41 is turned ON, a trigger signal 5) is output to the start possibility determining means 56. Also, Juki Starter Switch 41
is o t:r, the starter motor drive means 65f
Turn off the starter switch 42 via the

When the trigger signal is input from the starter switch state determining means 55, the start possibility determining means 56 determines the alcohol concentration A calculated by the alcohol concentration calculating means 53 and the cooling water temperature TW from the water temperature sensor 21. Using the engine temperature as a parameter, it is determined whether or not the engine can be started using the startability determination map MPST.

If it is determined that starting is possible, the starter motor drive means 65
The starter motor relay 42 is turned on via f, the starter motor 43 is turned on, and the fuel injection stop flag FLAG stored in the storage means 57 consisting of the RAM 34 is cleared (H^G←O). If it is determined that starting is not possible, the starting fuel injection enclosure leg means 5
4 and sets the fuel injection stop flag FLAG (FL^G←1) to stop fuel injection from the injector 10. Boiling point calculation means 61, temperature difference peak means 62, and specific heat calculation means 63
Outputs a calculation start signal to.

As shown in Fig. 3, the start possibility determination map MPST is based on the engine 4fff, which is represented by the cold water temperature TW, etc.
In contrast, the range of alcohol concentration A in which the fuel injected from the injector 10 can be started without being heated by the heater 20, and the range in which it is impossible to start the fuel as it is are identified in advance through experiments, and the series of R○M33 It is stored as a map at a predetermined address.

Note that instead of the cooling water humidity T- from the cooling water temperature sensor 21, oil temperature, fuel temperature, etc. may be used.

The cranking rotational speed calculating means 58 searches the cranking rotational speed map MPV using the terminal voltage E of the starter motor 43 and the starter current consumption I detected by the current sensor ++44 as parameters, and searches the cranking rotational speed map MPV for the cranking rotational speed V of the starter motor 43. (rps: number of revolutions per second) is calculated.

That is, since there are large rotational fluctuations during engine cranking, the angular velocity ω calculated by the crank pulse from the crank angle sensor 19 has extremely large fluctuations. Therefore, based on this angular velocity ω, the engine revolutions per second, i.e. , when the cranking rotational speed V is calculated, the error becomes extremely large.

As is well known, a series-wound DC motor is normally used as the starter motor 43, and its rotation speed Nm is N+g = KX (E-IXR)/φ: Constant R: Internal resistance of the motor φ: ! Shown as one bundle, starter terminal voltage E1 star, low current consumption 1
The relationship between one motor rotation speed N- is shown in FIG.

Therefore, using the starter terminal voltage E and the starter power consumption II as parameters, a map is stored in advance at a predetermined address in the ROM 33 in consideration of the motor rotation speed Nl determined from the characteristics of the starter motor 43 and the reduction ratio, etc. By searching for the cranking rotation speed V, the accurate cranking rotation speed V can be determined.

The medium time fuel injection fAfA output means 59 adds the cranking rotational speed ■ determined by the cranking rotational speed calculation means 58 to the starting fuel injection amount Ti set by the starting fuel injection amount setting means 54. Multiply to calculate fuel injection per hour ff1QF (Qr - VXTi)
.

In the latent heat of vaporization calculation means 60, the start possibility determination means 56
In response to the calculation start signal from the alcohol concentration calculating means 53, the latent heat of evaporation (heat of vaporization) J is calculated by 3A for the alcohol concentration Δ calculated by the alcohol concentration calculation means 53. This latent heat of vaporization J is determined by the alcohol concentration A, and is a function r of the alcohol concentration A.
1(A), LJ=rl(A) ).

In the fuel boiling point calculation means 61, the start possibility determination means 56
In response to the calculation start signal from , the boiling point TO of the fuel is calculated based on the alcohol mA output by the alcohol temperature output means 53. This fuel boiling point TO is determined by the alcohol concentration A, and is a function f2(A) of the alcohol concentration A.
(To −f2(A)).

In the temperature difference outlet means 62, since the coolant temperature TW from the coolant temperature sensor 21 can normally be equal to the fuel temperature T, the above-mentioned coolant temperature T- is determined by the calculation start signal from the start possibility determination means 56. As the fuel temperature TF, this fuel temperature TF is subtracted from the fuel boiling point TO determined by the fuel boiling point calculation means 61 to calculate the temperature difference Δ1 between the fuel boiling point To and the fuel temperature TF (ΔT=TO−TF>.

In the specific heat calculation means 63, in response to the calculation start signal from the start possibility determination means 56, the alcohol output means 5
Determine the specific heat R of the fuel based on the alcohol concentration A determined in step 3. It is determined by this specific heat 1 or the alcohol concentration Δ, and can be determined by the function f 3 (A) of the alcohol concentration Δ (R=f 3 (8)).

The necessary heat generation early output means 64 calculates the fuel injection amount per hour calculated by the fuel injection amount calculation means 59 in 1 above.
The amount of heat required to vaporize the fuel is determined by multiplying F by the latent heat of vaporization J calculated by the latent heat of vaporization calculating means 60, and
The above-mentioned temperature i difference calculation means 62 between the above-mentioned fuel injection amount per hour QF and the above-mentioned temperature i difference calculation means 62
The amount of heat required to heat the fuel to the boiling point To is determined by multiplying the temperature difference ΔT determined by the temperature difference ΔT and the specific heat R calculated by the specific heat calculation means 63. Then, by adding these heat♀, the necessary heat generation ff1W (unit: watt) of the heating means consisting of the heater 20 is determined (W=QF xJ+Qr
TXR).

In addition, in the starting control means 65, the reference value comparison means 65a compares the necessary heat generation amount W @ reference value WS determined by the above-mentioned required heat generation unit calculation means 64, and if WSWS is determined, the RAM 34
Clear the fuel injection stop flag FLAG (FLAG
←0) Fuel is injected from the injector 10 and output to the heater energizing means 65e to energize the heater 20, and the LED 48 is turned on to display the heater heating.

In the case of W>WS, the heater energizing means 65e1
．． : Output to energize the heater 20 and connect the starter motor relay 4 via the starter motor drive means 65.
2 to stop the starter motor 43, and instruct the timer operation time setting means 65b to set the timer.

In the timer operation time setting means 65b, the timer means 65C
A predetermined timer operation time (for example, 3 SEC) is set at , and a trigger signal is output to the timer means 65c according to an instruction from the reference value comparison means 65a.

In the timer means 65c, the timer operation time setting means 6
In response to the trigger signal from 5b, the heater 20 and the LED 48 are energized via the heater energizing means 65e, and time measurement is started. Then, after a predetermined period of time has passed, the heater 20 and the LED
48 is terminated, and the starter motor drive means 65f is turned off.
The starter motor 43 is actuated via the starter motor relay 42 ONL, and the fuel injection stop flag "L" is activated.
^ Clear G ([[8G4-0) Injector 10
Inject fuel from.

The heater voltage setting means 65d calculates the heater voltage EH to the heater 20 required to generate the necessary heat generation ff1W determined by the above-mentioned required heat generation period calculation means 64. If the resistance of the heater 20 is R11, this heater voltage EH can be outputted by EII=W/R11, and is outputted to the heater 20 by the above equation through the heater energizing means 65e. heater voltage F 1
Apply 1 and cover.

Specifically, when starting the engine, if the starter switch state determination stage 1 55 determines whether the starter switch/11 is ON, the start possibility determination means 56 determines whether or not the start is possible, and determines that the start is not possible. If it is determined, the cranking rotation speed V of the engine is extracted from the starter terminal voltage E and the starter consumption current I, and this cranking rotation speed V is determined.
Based on this, the fuel injection value QF per hour is determined, and the required heat generation ff1W of the heater 20 is determined to be 0.

In this case, when fuel is injected from the injector 10,
Heater 20 for promoting vaporization of fuel to enable starting
Since the required heat generation tlLw changes, the fuel injection should be stopped and the fuel injection should be injected per time 1) Jffi
Calculate QF, and calculate fuel injection per time ff1QF,
Latent heat of vaporization J, temperature difference Δ between fuel boiling point TO and fuel temperature TF
Calculate the required heat generation JAW from J and specific heat R.

Then, it is determined whether the power required to cover the required heat generation Ja W calculated by the necessary heat generation output means 64 is enough to simultaneously energize the heater 20 and drive the starter motor 43, and When the required calorific value W is less than the reference value WS, the heater 2
The starter motor 43 is driven to inject fuel from the injector 10 to start the engine.

On the other hand, when the required calorific value W is larger than the reference value WS, the power consumption is large, so the timer means 65
At c, the heater 20 is energized for a predetermined period of time, during which time the starter Tanabata 43 is stopped.

Further, in the fuel injection amount setting means 66, when the complete explosion determination means 52 determines that the engine has completely exploded, the fuel injection amount setting means 66 calculates the engine rotation speed N determined by the engine rotation speed outputting means 51 and the intake air amount sensor. A basic fuel injection ratio Tp is set from the intake air amount Q by calculation or map search, and this basic fuel injection R'ITp is provided with air-fuel ratio feedback based on the engine operating state parameters detected by the engine operating state parameter detection means 45. Based on the correction coefficient α, the various stone increase correction coefficients C0FF, and the alcohol concentration A calculated in the alcohol m degree calculation stage f 53), the fuel injection f
Set d l”i (Ti=TllXαXC0EF
XKA1. ).

Then, a pulse width signal corresponding to the fuel injection DJ N T i is outputted to the injector 10 via the injector driving means 67 to inject fuel.

(Operation) Next, the operation of the embodiment with the above configuration will be explained based on the flowcharts of FIGS. 6 and 7.

(Fuel injection control m> The program shown in the flowchart of FIG. 6 shows a fuel injection control procedure, and is an interrupt processing routine that is started at every predetermined period.

That is, first, in step 5101, it is determined whether or not the fuel injection stop flag FLAG is cleared, and when the fuel injection stop flag FLAG=1, that is, the fuel injection is currently in the stopped state, the routine is exited and no fuel injection is performed. .

On the other hand, when FLAG=O, the above step 510
1 to step 5102, the crank angle sensor 19
The engine speed N is calculated based on the signal from the engine, and in step 5103 it is determined whether the engine speed N determined in step 5102 has reached a predetermined complete explosion speed NS.

In step 5103, if N<NS, it is determined that the engine has not completely exploded, and the process proceeds from step 5103 to step 5104, where the coolant WT14 signal from the coolant temperature sensor 21 is read, and the alcohol concentration sensor 15 is read. The alcohol concentration A is calculated from the output signal, and the process proceeds to step 5105.

In step 3105, the starting fuel injection transmission map M P FST is searched using the cooling water WT- and alcohol Il [fA obtained in step 5104 as parameters, and the starting fuel injection amount Ti is set, and the process proceeds to step 5107. move on.

On the other hand, in the above step 5103, if N≧NS, it is determined that the engine has completely exploded, and the process proceeds from the above step 5103 to step 8106, where the engine rotation speed N and the intake air ω are determined.
The basic fuel injection amount Tp calculated from and set the fuel injection amount Ti (Ti =
Tl)Xαx C0EFx K^shi) Step 5107
Proceed to.

Then, in step 5107, the fuel injection ff1 set in step 5105 or step 8106 is determined.
．． A pulse width signal corresponding to T is output to the injector 10 to inject fuel, and the routine exits.

(Start Opening Control I) The program shown at 70-dissert in FIG. 7 shows the control procedure at the time of starting, and is an initial control program that starts when the starter switch 41 is turned on.

First, in step 5201, initialization is performed,
Initialize the counter and turn off the starter motor relay 42
At the same time, the heater voltage E11 of the heater 20 is initialized to O.

Next, in step 5202, the cold water temperature TlI4 signal from the cooling water temperature sensor 21 is read, and the alcohol concentration is calculated from the output signal of the alcohol concentration sensor 15.

Next, proceed to step 5203, and proceed to step 520 described above.
Using the cooling water UT- obtained in step 2 and the alcohol concentration as parameters, it is determined whether or not the engine can be started from the startability determination map MPST.

If it is determined in step 5203 that the engine can be started, the process proceeds to step 5204, where the fuel injection flag FLAG is cleared (FLAG←0) to permit fuel injection from the injector 10, and the process proceeds to step 5205.

In step 5205, the starter motor relay 42 is
The starter motor 43 is driven by NL, and step 3206
Then, it is determined whether the starter switch 41 is turned off.

If the starter switch 41 is not turned off, continue to turn on the starter motor relay 42 in step 8206, and if the starter switch 41 is turned off, proceed from step 8206 to step 5207 and turn off the starter motor relay 42. Then, the drive of the starter Tanabata 43 is stopped and the program is ended.

On the other hand, if it is determined in step 3203 that starting is not possible, the process proceeds from step 5203 to step 3208, where the fuel injection stop flag "LAG" is set (FLA
G←1) Stop fuel injection from the injector 10, and in step 5209, turn on the starter motor relay 42 to drive the starter motor 43.

Next, the process advances to step 5210 to read the starter terminal voltage E and starter current consumption I, and in step 5211,
Starter terminal voltage E read in step 5210 above
The cranking rotational speed map MPV is searched using the and starter current consumption I as parameters, the cranking rotational speed V is calculated, and the process proceeds to step 5212.

In step 5212, the starting fuel injection amount map M P FST is searched using the cooling water mTW and alcohol concentration obtained in step 5202 as parameters, and the fuel injection amount per injection at starting 1 is set. Step 52
Proceed to step 13, and set the cranking rotation speed ■ calculated in step 5211 above and 1 set in step 5212 above.
Fuel injection per injection ITi and fuel injection per unit time! ) Calculate IfflQF (QF - VXTI )
.

Next, in step 5214, the latent heat of vaporization J is calculated based on the alcohol concentration calculated in step 5202, and Ll = f1 (A)), step 5215
Calculate the boiling point TO of the fuel as TO=f2(A) ),
Proceeding to step 8216, the temperature difference ΔT between the boiling point TO calculated in step 5215 and the fuel temperature TF based on the cooling water temperature T- read in step 5202 is determined (ΔT=TO-TF), step 5217. in,
Calculate the specific heat R from the alcohol concentration (R= C
3(8)).

Next, the process proceeds to step 8218, and the step 521 described above is performed.
Tit mouth opened at 3, fuel injection between 'i' 2J1
From QF, the latent heat of vaporization J calculated in step 5214, the temperature difference Δd determined in step 3216, and the specific heat R determined in step 5217, calculate the required calorific value W of the heater 20 (W= QF xJ+Qr x
ΔTxR).

Then, in step 5219, the required heater heat generation 111W generated in step 5218 and the group Q'f++'t
It is determined whether it is possible to energize the heater 20 while the starter 43 is being driven by the starter.

If WS≧W, it is determined that the heater 20 can be energized while the power consumption is small and the starter motor 43 is being driven.
Proceed from step 5219 to step 5220 to clear the fuel injection stop flag FLAG (FL^G←0)
to permit fuel injection and proceed to step 5221.

In step 5221, the required heat generation 1i1W calculated in step 8218 and the resistance RH of the heater 20 are used to calculate the 1-e-1m pressure EH required for the heater 20 to generate the necessary heat generation ωW, and (Ell = W /RH),
Proceed to step 5222.

In step 5222, the heater 20 is
The heater voltage EH calculated in step 21 is applied to heat the fuel injected from the injector 10, and the LED
48 to indicate that the heater is energized.

Next, in step 5223, it is determined whether the starter switch 41 is turned off, and the starter switch 41 is set to 0.
FFL, if not, leave heater 20 and LED as is.
48 is turned ON, and if the starter switch 41 is turned OFF, the steps 5223 to 522 are performed.
Proceed to step 4.

In step 5224, the starter motor relay 42 is turned OFF to stop driving the starter motor 43, and the voltage EH applied to the heater 20 is set to O to stop energization, and the LED 48 is turned off to display the heating display. Stop and exit the program.

On the other hand, if WS < W in step 219, it is determined that the heater 20 cannot be energized while the starter motor 43 is being driven due to its large power consumption, and step 5
Proceeding from step 219 to step 5225, the starter motor relay 42 is turned off to stop driving the starter motor 43.
Proceed to step 8226 and calculate the heater voltage E11 in the same way as step 5221. Elf = W/R
I+), proceed to step 5227.

Proceeding to step 5227, the heater voltage Et+ calculated in step 5227 is applied to the heater 20, and the LED 48 is lit to indicate that the heater is energized.In step 8228, the count value C of the counter is
1 count is added (C4-C+1').

Then, in step 5229, the count value C of the counter
Determine whether the tfi setting value Cll1 has been reached, and
If the count is 11, the process returns to step 8228 to continue counting, and if C≧Cw+, that is, if a predetermined time (for example, 3 SEC) has elapsed, the process proceeds to step 5230.

In step 5230, the count value C is cleared (C10
) and then proceeds to step 5231 to set the heater voltage El+ to 0.
The power supply to the heater 20 is terminated, and the LED
48 is turned off to stop the heater heating display, and step 52
Clear the fuel injection stop flag FLAG at 32 (FL
AG←0) Allow fuel injection from the injector 10,
Proceed to step 5233.

In step 5233, the starter switch 41 is turned off.
The starter switch 41 is turned OFF.
If not, the starter motor relay 42 is turned ON in step 5234, and the starter motor 43 is driven until it is determined that the starter switch 41 is OFF in step 5233.

That is, when the starter switch 41 is turned OFF while the heater is energized,
In case of F, the starter motor 43
In order to prevent the starter switch 41 from being driven, the starter motor relay 42 is controlled by determining the state of the starter switch 41. If it is determined in step 5233 that the starter switch 41 is 0FFI, step 5235
The starter motor relay 42 is turned OFF to stop driving the starter motor 43, and the program ends.

Note that the present invention is not limited to the embodiments, and the present invention is not limited to the embodiments.
By providing a heater for each, it can be applied to an MP1 type engine, and furthermore, it can be applied to an electronically controlled 60 carburetor type engine.

[Effects of the Invention] As explained above, according to the present invention, when the engine starts
It is determined whether or not J is possible, and when it is determined that starting is not possible, the cranking rotational speed of the engine is calculated based on the starter voltage and starter consumption current.

And based on this cranking rotation speed! Since the required amount of heat generated by the heating means for promoting vaporization of the fuel is calculated by calculating the amount of fuel slanted injection per hour, it is possible to accurately calculate the required amount of heat generated to start the engine. Since the heating means is energized to generate the necessary amount of heat, the engine can be reliably started even in situations where the outside temperature is low and starting is conventionally difficult.

Further, since the required amount of heat generated by the heating means is accurately calculated, excellent effects such as no wasted power and energy waste can be achieved.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a vine diagram of the control device, FIG. 2 is a schematic diagram of the engine control system, and FIG. 3 is an explanatory diagram of a startability determination map. Figure 4 is an explanatory diagram of the 1-pan map (fuel injection at startup), Figure 5 is an explanatory diagram showing the characteristics of the starter motor, Figure 6 is a flowchart that does not show the fuel injection control procedure, and Figure 7 is the control procedure at startup. It is a flowchart which shows. 20...Heating means 56...Startability determining means 58...Cranking rotational speed calculating means 59...Fuel injection amount calculation means per unit time 64...Required calorific value calculating means 65...Starting Control means A...Alcohol concentration T...Cooling water temperature and engine temperature) E...Starter terminal voltage I...Starter consumption current■...Cranking rotation speed QF...Fuel injection per unit time岱W...Necessary heat generation period Fig. 4 Figure 3 Fig. 5 Sudar'y clearing with lightning 1 Fig. 6

Claims (1)

[Scope of Claims] Startability determination means for determining whether or not the engine can be started based on the alcohol concentration of the fuel and the engine temperature; and when the startability determination means determines that the engine cannot be started, the starter terminal voltage and a cranking rotation speed calculation means for calculating the cranking rotation speed of the engine based on the starter consumption current and the starter consumption current; and a cranking rotation speed calculation means for calculating the cranking rotation speed of the engine based on the cranking rotation speed calculation means; Promote vaporization of the fuel based on the fuel injection amount calculation means per unit time, the alcohol concentration of the fuel, the engine temperature, and the fuel injection amount per unit time calculated by the fuel injection amount calculation means. A necessary calorific value calculation means for calculating the necessary calorific value of the heating means, and a start control means for controlling energization to the heating means to generate the necessary calorific value calculated by the necessary calorific value calculating means. A unique starting aid for alcohol engines.