JPH05149169A - Starting control method for engine for ffv - Google Patents

Abstract

PURPOSE:To improve heat-exchange efficiency when fuel actually fed to an engine is heated and to save energy required for heating by controlling a fuel pump delivery amount in consideration of alcohol concentration of fuel and an engine temperature. CONSTITUTION:When, through comparison of a cooling water temperature TW with a startability deciding temperature TSET, it is decided to be impossible for an engine to start, a heater relay is turned ON to energize a PTC heater 34 and heating of fuel in a fuel passage 30 is started. When it is discriminated that heating is completed, the control duty ratio DUTY of a control signal is set based on alcohol concentration M and a cooling water temperature TW to drive a DC motor-driven fuel pump 31. The heat-exchange ratio of the PTC heater is improved and consumption power of a battery is reduced. Thereafter, when an engine completes explosion, execution of a control routine of a fuel pump during ordinary operation is permitted. Based on alcohol concentration, the control duty ratio DUTY is set and control of a fuel pump during ordinary operation is effected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a FFV engine start control method for heating a fuel supplied to the engine to improve startability.

[0002]

2. Description of the Related Art In recent years, due to deterioration of fuel conditions and demand for exhaust gas cleaning, a system that can simultaneously use alcohol as an alternative fuel in addition to conventional gasoline has been put into practical use. In such a vehicle (Flexible Fuel Vehicle, hereinafter referred to as “FFV”), it is possible to drive not only with gasoline but also with a mixed fuel of alcohol and gasoline, or only with alcohol. The alcohol concentration (content rate) of the fuel used varies from 0% (gasoline only) to 100% (alcohol only) depending on the user's circumstances when refueling.

In general, alcohol fuel is less likely to be vaporized at a low temperature and has a large latent heat of vaporization, as compared with gasoline fuel.
It has characteristics such as a high flash point, and when the alcohol concentration changes, the latent heat of vaporization, specific heat, startable temperature, stoichiometric air-fuel ratio, etc. will change and the starting conditions will change, especially at low temperatures. Therefore, there arises a problem that the startability is deteriorated.

In order to deal with this, a technique for heating fuel by heating means such as a heater to improve the starting property at low temperature has been conventionally known, for example, Japanese Patent Laid-Open No. 59-221.
Japanese Patent Laid-Open No. 451 and Japanese Patent Laid-Open No. 40774/1985 disclose a technique in which a heater is provided in a fuel passage from a fuel injection pump of a diesel engine, and the heater heats the fuel. Japanese Patent Laid-Open No. 2-75754 discloses a technique in which an annular glow plug is attached to the nozzle portion of a fuel injection valve and fuel heated by the glow plug is injected.

[0005]

However, in order to prevent vapor lock of the fuel due to heat in the engine room, the fuel supply system of the engine is generally different from the amount of fuel actually supplied to the combustion chamber of the engine. A large amount of fuel is pumped by a fuel pump, and excess fuel is returned to the fuel tank and circulated.

Particularly, in the FFV engine, the required fuel amount of the engine changes according to the alcohol concentration, and when the alcohol concentration is high, the required fuel amount of the engine increases due to the reduction of the stoichiometric air-fuel ratio. For example, in the case of 100% alcohol, the theoretical air-fuel ratio is approximately 1 as compared with the case of using only gasoline.
Since it becomes / 2, the required fuel amount of the engine is approximately doubled.

Therefore, the fuel pump used in the fuel supply system of the FFV engine inevitably has a large flow rate, and the fuel is heated by the heater provided in the fuel passage or the fuel injection valve (injector) at the time of cold start. At this time, if the fuel pump discharge amount is the same as in the normal state, not only the heat exchange efficiency of the heater deteriorates, but also the current consumption of the heater increases and the load of the battery increases.

The present invention has been made in view of the above circumstances, and the heat exchange efficiency when heating the fuel actually supplied to the engine by controlling the fuel pump discharge amount in consideration of the alcohol concentration of the fuel and the engine temperature. It is an object of the present invention to provide a starting control method for an FFV engine, which can improve the fuel efficiency, save the energy required for heating, and improve the startability.

[0009]

SUMMARY OF THE INVENTION A starting control method for an FFV engine according to the present invention comprises a procedure for determining whether or not the engine can be started without heating the fuel based on the alcohol concentration of the fuel and the engine temperature. When it is determined that the engine cannot be started in the procedure for determining whether the engine can be started, the fuel supplied to the injector is heated, and the fuel pump discharge amount is started based on the alcohol concentration of the fuel and the engine temperature. A procedure to control the required fuel supply amount,
After the engine is started, a procedure for controlling the discharge amount of the fuel pump to be the maximum required fuel supply amount based on the alcohol concentration of the fuel is provided.

[0010]

In the FFV engine start control method of the present invention, it is determined whether the engine can be started without heating the fuel based on the alcohol concentration of the fuel and the engine temperature. The fuel supplied to the injector is heated, and the discharge amount of the fuel pump is controlled based on the alcohol concentration of the fuel and the engine temperature so as to be the required fuel supply amount at the time of starting, so that the fuel supplied to the injector is efficiently heated. Then, after the engine is started, the discharge amount of the fuel pump is controlled to be the maximum required fuel supply amount based on the alcohol concentration of the fuel.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 11 relate to the first embodiment of the present invention, FIG. 1 is a flowchart showing an initial control procedure, FIG. 2 is a flowchart showing a normal fuel pump control procedure, and FIG. 3 is a flowchart showing a starter motor control procedure. FIG. 4 is a flowchart showing a fuel injection control procedure, FIG. 5 is a schematic diagram of an engine control system, FIG. 6 is a circuit configuration diagram of the engine control system,
7 is an explanatory view showing details of the heater portion, FIG. 8 is an explanatory view showing a startable region and a non-startable region, FIG. 9 is an explanatory diagram of a startable determination water temperature map, FIG. 10 is a characteristic diagram of the PTC heater,
FIG. 11 is an explanatory diagram of the starting fuel pump rotation speed map.

(Structure of engine control system) In FIG.
Reference numeral 1 is an FFV engine (a horizontally opposed four-cylinder engine in the figure), and a cylinder head 2 of the engine 1 has an intake port 2a and an exhaust port 2b. An intake manifold 3 is passed through the intake port 2a, and a throttle passage 5 is connected upstream of the intake manifold 3 through an air chamber 4. An air cleaner 7 is attached to the upstream side of the throttle passage 5 via an intake pipe 6, and the air cleaner 7 is in communication with an air intake chamber 8 which is an intake port for intake air.

On the other hand, an exhaust pipe 10 is communicated with the exhaust port 2b via an exhaust manifold 9, and a catalytic converter 11 is interposed with the exhaust pipe 10 and communicated with a muffler 12. A throttle valve 5a is provided in the throttle passage 5, and an intercooler 13 is provided in the intake pipe 6 immediately upstream of the throttle passage 5,
Further, a resonator chamber 14 is provided downstream of the air cleaner 7 in the intake pipe 6.

Further, an idle speed control valve (IS) is provided in a bypass passage 15 which connects the resonator chamber 14 and the intake manifold 3 and bypasses the upstream side and the downstream side of the throttle valve 5a.
CV) 16 is interposed. Furthermore, this ISCV1
A check valve 17 which is opened immediately downstream of the intake valve 6 when the intake pressure is negative is closed while the intake valve is supercharged by a turbocharger 18 to be described later and closed when the intake pressure becomes positive.

Reference numeral 18 is a turbocharger, and the turbine wheel 18 of the turbocharger 18 is shown.
a is a turbine housing 18 in which the exhaust pipe 10 is interposed.
A compressor housing 18e, which is housed in b, and has a compressor wheel 18d, which is connected to the turbine wheel 18a via a turbine shaft 18c, on the downstream side of the resonator chamber 14 of the intake pipe 6.
It is stored in.

A wastegate valve 19 is provided at the inlet of the turbine housing 18b, and a wastegate valve actuating actuator 20 is connected to the wastegate valve 19. This wastegate valve actuating actuator 20 is partitioned into two chambers by a diaphragm, one of which forms a pressure chamber communicating with the wastegate valve controlling duty solenoid valve 21, and the other of which forms the wastegate valve 19 in the closing direction. It forms a spring chamber that houses the spring that biases it.

The waste gate valve controlling duty solenoid valve 21 is provided in the resonator chamber 1
4 and the intake manifold 3 are provided in a passage communicating with each other, and the pressure on the side of the resonator chamber 14 and the intake manifold are determined according to the duty ratio of a control signal output from a control unit (ECU) 51 described later. The pressure on the side 3 is regulated and supplied to the pressure chamber of the waste gate valve actuating actuator 20, and the exhaust gas relief by the waste gate valve 19 is controlled to control the supercharging pressure by the turbocharger 18. Is becoming

Further, an absolute pressure sensor 22 is attached to the intake manifold 3, and an injector 23 as a fuel supply means faces the upstream side of each intake port 2a of each cylinder of the intake manifold 3. Further, an ignition plug 24 whose tip is exposed to the combustion chamber is attached to each cylinder of the cylinder head 2, and an igniter 25 is connected to the ignition plug 24.

On the other hand, fuel having a different alcohol concentration M (%) is stored in the fuel tank 26, only alcohol, a mixed fuel of alcohol and gasoline, or only gasoline, which has a different alcohol concentration M (%) depending on the circumstances of refueling by the user. The mixed fuel is pressure-fed from the fuel passage 30 to the injector 23 by the in-tank type DC motor driven fuel pump 31.

The fuel passage 30 is provided with a heater portion 34 for heating the fuel in the fuel passage.
Further, the fuel filter 36 and the alcohol concentration sensor 3
7, the injector 23, the pressure regulator 2
9 are inserted in order. A part of the fuel pressure-fed through the fuel passage 30 is injected from the injector 23 and supplied to the engine, and excess fuel is returned from the pressure regulator 29 to the fuel tank 26.

The heater section 34, as shown in FIG.
A PTC pill (Positive Temperature Coefficie) is formed on the outer peripheral surface of the fuel conduit 30a which forms a part of the fuel passage 30 and is made of a material having excellent thermal conductivity and conductivity.
PTC heater 34 as a heating element composed of
a is attached, and the outer peripheral surface of the PTC heater 34a is covered with a cover 34b made of a material having excellent electric insulation and heat insulating properties. Then, the PTC heater 34
The power supply terminal 34c is connected to a, and the fuel conduit 30a is grounded.
The TC heater 34a generates heat to heat the fuel in the fuel conduit 30a.

Further, the alcohol concentration sensor 37 is
For example, it is a sensor that is composed of a pair of electrodes provided in the fuel passage 30 and that detects the alcohol concentration by detecting a current change based on the electrical conductivity that changes depending on the alcohol concentration of the fuel. A detection type, capacitance type, optical type sensor or the like may be used.

The pressure regulator 29 is
For example, it is a diaphragm type regulator that controls the return amount of fuel such that the pressure of the intake manifold 3 is introduced and the differential pressure between the pressure of the intake manifold 3 and the fuel pressure becomes constant.

An intake air amount sensor (a hot wire type intake air amount sensor in the figure) 41 is provided immediately downstream of the air cleaner 7 of the intake pipe 6, and the throttle valve 5a is provided with a throttle opening degree. The sensor 42 is arranged in series. Further, a knock sensor 43 is attached to the cylinder block 1a of the engine 1, and a cooling water temperature sensor 45 is exposed to a cooling water passage 44 communicating between the left and right banks of the cylinder block 1a, so that the exhaust manifold of the exhaust pipe 10 is exposed. O2 in the 9 gathering section
The sensor 46 is exposed.

A crank rotor 47 is rotatably mounted on the crank shaft 1b supported by the cylinder block 1a, and a crank angle sensor 48 including an electromagnetic pickup is provided on the outer circumference of the crank rotor 47. Further, a cam rotor 49 connected to the camshaft 1c of the engine 1 is provided with a cam angle sensor 50 for discriminating a cylinder composed of an electromagnetic pickup or the like. still,
The crank angle sensor 48 and the cam angle sensor 50
Is not limited to a magnetic sensor such as an electromagnetic pickup, but may be an optical sensor.

(Circuit Configuration of Engine Control System) In FIG. 6, reference numeral 51 is a control unit (ECU) composed of a microcomputer and the like, and a CPU 52, a ROM 53, and an RA.
The M54 and the I / O interface 55 are connected to each other via a bus line 56, and a constant voltage circuit 57 supplies a predetermined stabilizing voltage to each unit.

The constant voltage circuit 57 includes an ECU relay 58.
The relay coil of the ECU relay 58 is connected to the battery 59 via an ignition switch 60.

A starter motor 63 is connected to the battery 59 via relay contacts of a starter switch 61 and a starter motor relay 62, and a PT via a relay contact of a heater relay 64 and a current sensor 65.
The C heater 34a is connected, and further, the DC motor drive fuel pump 31 is connected via a fuel pump control module (FPCM) 66 that drives the DC motor drive fuel pump 31.

The FPCM 66 drives the DC motor drive fuel pump 31 with a voltage corresponding to the control duty ratio of the input control signal, and varies the pump discharge amount according to the pump rotation speed according to the duty output.

The I / O interface 55 is also provided.
Of the absolute pressure sensor 22, alcohol concentration sensor 37, intake air amount sensor 41, throttle opening sensor 42, knock sensor 43, cooling water temperature sensor 45, O.
2 sensor 46, crank angle sensor 48, cam angle sensor 5
0, the current sensor 65, and the starter switch 61 are connected, and the battery 59 is connected to monitor the battery voltage.

On the other hand, the I / O interface 55
The igniter 25 is connected to the output port of the ISCV 16, the wastegate valve control duty solenoid valve 21, the injector 23, the FPCM 66, each relay (starter motor relay 62, heater relay 64) via the drive circuit 68. Coil and
ECS consisting of LEDs as heater heating display means
The lamp 69 is connected.

The ROM 53 stores a control program and fixed data such as various maps.
Further, the RAM 54 stores data after processing output signals of the sensors and switches and the CPU 52.
The data processed by the above is stored.

In the CPU 52, according to a control program stored in the ROM 53, when the ignition switch 60 is turned on at the time of engine start, a start determination is made, and the PTC heater 34a is energized / de-energized depending on the judgment result. Control the discharge amount of the DC motor drive fuel pump 31, and perform engine control such as air-fuel ratio control, ignition timing control, and boost pressure control.

(Initial Control Procedure) Next, initial control at the time of starting by the ECU 51 will be described. The flowchart of FIG. 1 is a program for initial control that starts when the power of the ECU 51 is turned on.

First, in step S101, initialization is performed to turn off each of the starter motor relay 62 and the heater relay 64, clear each flag and count value, and prohibit execution of a normal fuel pump control routine described later. ..

Next, in step S102, the starter motor energization prohibition flag FLAG1 is set (FLAG
1 ← 1) When energization to the starter motor 63 is prohibited, in step S103, the startable determination temperature map MPTW is referenced with the alcohol concentration M from the alcohol concentration sensor 37 as a parameter with interpolation calculation to determine the startable determination temperature TSE.
Set T.

Next, in step S104, the cooling water temperature sensor 4
From 5, read the cooling water temperature TW as the engine temperature,
The cooling water temperature TW is compared with the startable judgment temperature TSET set in step S103 to make a start judgment.

That is, as shown in FIG. 8, a temperature condition region of an alcohol concentration M that can be started without heating the fuel,
A temperature condition region in which the engine cannot be started as it is is specified by an experiment or the like, and the startable determination temperature TSET is set from the startable determination temperature map MPTW (see FIG. 9) consisting of a series of addresses in the ROM 53 with the alcohol concentration M as a parameter. .. Then, by comparing the startable determination temperature TSET with the cooling water temperature TW, it is determined whether or not the engine can be started.

As the engine temperature at the time of determining whether the engine can be started, a fuel temperature or the like may be adopted instead of the cooling water temperature TW from the cooling water temperature sensor 45.

As a result, in the step S104, TW> T
In the case of SET, it is determined that the engine can be started, the process proceeds to step S105, and if the execution of the normal fuel pump control routine described later is permitted, the starter motor energization prohibition flag FLAG1 is cleared (FLAG1 ← 0) in step S110. The power supply to 63 is permitted, and the program ends.

The starter motor energization prohibition flag F
LAG1 is referred to by a starter motor control procedure described later. When the starter motor 63 is driven and the engine is cranked, the fuel of the fuel injection amount Ti set in the fuel injection control procedure described later is injected from the injector 23. It

On the other hand, in step S104, TW≤TSET
When it is determined that the engine cannot be started, the process branches to step S107, the heater relay 64 is turned on to energize the PTC heater 34a, the heating of the fuel in the fuel passage 30 is started, and the ECS lamp 69 is turned on to energize the heater. To inform.

Next, in step S108, the current consumption I of the PTC heater 34a detected by the current sensor 65 is compared with the determination value ISET to determine the completion of heating, and I≤
When it is ISET, in step S108, a loop for reading the consumed current I from the current sensor 65 and comparing it with the determination value ISET is repeated.

As shown by the alternate long and short dash line in FIG. 10, the PTC heater 34a has a characteristic that when the temperature rises and reaches the Curie point after energization, the resistance value sharply rises and the current consumption I decreases. However, when the fuel is heated but not vaporized, as shown by the solid line in the figure, the consumed current I
Becomes saturated at a predetermined value and becomes constant.

Therefore, it is possible to judge the heating completion of the fuel by using the current value ISET before the consumed current I reaches the saturation as a judgment value, and in the step S108, when I> ISET, it is judged that the heating and heating is completed. It proceeds to step S109.

In step S109, the starting fuel pump rotation speed NPS is set based on the alcohol concentration M and the cooling water temperature TW by referring to the starting fuel pump rotation speed map MPNPS. In step S110, the starting fuel pump rotation speed NPS is set. Number N
The control duty ratio DUTY of the control signal to be output to the FPCM 66 based on PS, as described in the normal fuel pump control routine described later, is used for a map search using the fuel pump rotation speed NPS at start as a parameter, or the fuel pump at start It is set by calculation from the function of the rotation speed NPS.

The starting fuel pump rotation speed NPS is within a range in which the maximum required fuel supply amount at the time of starting can be ensured.
As shown in FIG. 1, the optimum values corresponding to the alcohol concentration M and the cooling water temperature TW are previously obtained by experiments and are stored in the starting fuel pump rotation speed map MPNPS.

That is, it is determined by the start determination that the engine cannot be started, the PTC heater 34a of the heater portion 34 causes the fuel passage 3
0 fuel is heated, and this heated fuel is injected into the injector 2
When injecting from 3, alcohol concentration M, cooling water temperature T
By setting the required fuel pump discharge amount corresponding to W, the heat exchange efficiency in the heater section 34 is improved to enable a quick start, and the improved heater efficiency saves battery power consumption.

The control duty ratio DUTY may be directly obtained based on the alcohol concentration M and the cooling water temperature TW without the steps S109 and S110.

Next, the steps S110 to S111
Then, the control duty ratio DUTY set in step S110 is set to the control signal output from the output port of the I / O interface 55 to the FPCM 66, and D
The C motor driving fuel pump 31 is driven, and step S112
Then, the starter motor energization prohibition flag FLAG1 is cleared (FLAG1 ← 0) to permit energization of the starter motor 63.

After that, the engine is cranked,
Fuel injection amount Ti set in the fuel injection control procedure described later
Fuel is injected from the injector 23, and the engine first explodes and rotates, at step S113, the engine speed N
It is determined whether or not E has reached the complete explosion rotation speed NESET (for example, 400 rpm). When NE ≤ NESET, the engine has not completed explosion, so the process returns to step S109, and NE
When> NESET, it is determined that the start is completed and the process proceeds to step S114.

In step S114, execution of the normal fuel pump control routine is permitted. In step S115, the heater relay 64 is turned off to complete the heating by the PTC heater 34a, the ECS lamp 69 is turned off, and the program ends. ..

In this embodiment, the injector 23 is
Either a side flow type injector that takes in a part of the fuel in the fuel passage 30 from a side portion and injects it, or a top flow type injector in which the fuel in the fuel passage 30 is supplied only to the injector nozzle from above. Although it is also possible to use, it is slightly disadvantageous when a top-flow type injector is used because it takes some time before the heated fuel is actually injected.

(Normal Fuel Pump Control Procedure) When execution of the normal fuel pump control routine is permitted in the above-mentioned initial control procedure, the normal fuel pump control routine shown in the flowchart of FIG. To be done.

In this normal fuel pump control routine,
In step S201, the fuel pump rotation speed NP corresponding to the maximum required fuel supply amount is set based on the alcohol concentration M. The fuel pump rotation speed NP is equal to the alcohol concentration M.
Since the higher the fuel consumption of the engine, the higher the required fuel amount of the engine becomes, as shown in step S201, the higher the alcohol concentration M becomes, the higher the rotation speed (fuel pump discharge amount) becomes. It can be obtained by searching the map.

Next, from step S201 to step S202
In step S201, the control duty ratio DUTY is set based on the fuel pump rotation speed NP set in step S201.
The control duty ratio DUTY has a value proportional to the increase of the fuel pump rotation speed NP, as shown in step S202, in accordance with the frequency conversion function of the FPCM 66, and is obtained by a map or the like.

The fuel pump rotation speed NP in step S201 is set by the function f (M) of the alcohol concentration M.
It may be set by calculation from (NP ← f (M)), and the control duty ratio DUT in step S202 is also set.
The Y may be set by calculation from the function f (NP) of the fuel pump rotation speed NP.

Further, the control duty ratio DUTY
May be directly calculated based on the alcohol concentration M without performing the steps S201 and S202.

After that, when the control duty ratio DUTY is set in step S202, the process proceeds to step S203, where I /
Output port of O interface 55 to FPCM 66
Set the control duty ratio DUTY to the control signal to be output to and output the output corresponding to the control duty ratio DUTY.
The C motor drive fuel pump 31 is driven, and the routine exits.

The control signal output of the control duty ratio DUTY set in step S203 is held until the next routine is executed.

(Starter motor control procedure and fuel injection control procedure) On the other hand, with respect to the above-mentioned initial control program,
Program of starter motor control procedure shown in FIG. 3, FIG.
The program of the fuel injection control procedure shown in is interrupted and executed at predetermined time intervals.

In the interrupt routine of the starter motor control procedure, first, in step S301, the starter switch 61 is turned off.
When it is determined that the starter switch 61 is ON, the process proceeds to step S302, the value of the starter motor energization prohibition flag FLAG1 is checked, and it is determined whether the energization of the starter motor 63 is permitted. ..

When FLAG1 = 0 in step S302, that is, when the energization of the starter motor 63 is permitted, the process proceeds from step S302 to step S303 to turn on the starter motor relay 62 to turn on the starter motor 63.
To drive the engine to crank the engine and exit the routine.

On the other hand, when the starter switch 61 is OFF in step S301, or when FLAG1 = 1 in step S302 and the energization of the starter motor 63 is prohibited, each step branches to step S304. And turn off the starter motor relay 62.
Then, the starter motor 63 is stopped and the routine is exited.

Further, in the interrupt routine of the fuel injection control procedure, in step S401, the engine speed NE is "
It is determined whether or not 0 ", that is, whether or not the engine is rotating. If NE ≠ 0, step S4
The routine proceeds from 01 to step S402 to call the fuel injection amount calculation routine, calculate the fuel injection amount Ti, set the fuel injection amount Ti in step S403, and exit the routine.
= 0 and the engine is stopped, step S401
To S404, the fuel injection amount Ti is set to "0" (Ti ← 0) and the routine is exited.

[Second Embodiment] FIGS. 12 and 13 relate to a second embodiment of the present invention. FIG. 12 is a schematic configuration diagram of an engine control system, and FIG. 13 is a cross-sectional view showing details around an injector.

In the second embodiment, as shown in FIG.
In contrast to the first embodiment described above, the heater portion 34 provided in the fuel passage 30 between the fuel tank 26 and the fuel filter 36 is eliminated, and a heater is provided in the fuel gallery of the side flow type injector 23.

That is, as shown in FIG. 13, in the injector 23 of this embodiment, the injector 23 is mounted on the injector mounting portion main body 32 provided in the fuel passage 30, and the fuel in the fuel passage 30 is fed from the side portion of the main body. It is designed to take in a part of the inside and inject it.

A heater portion 35 is provided in the fuel gallery 32a between the inner wall of the injector mounting portion main body 32 and the injector 23, and the heater portion 35 has an annular P shape.
The TC heater 35a is sandwiched between electrode members 35b and 35c made of a material having excellent thermal conductivity and conductivity.

Then, the injector mounting portion main body 32
The electrode member 35b on the inner wall side is connected to the ground, and the electrode member 35c on the inner periphery on the injector 23 side is connected to the heater relay 64 via the current sensor 65.

Other configurations are the same as those of the first embodiment described above, and the control procedure including the initial control procedure is also the same as that of the first embodiment. In the second embodiment, the PTC heater 35
Since the fuel heated by a can be immediately injected, a quicker start-up can be performed as compared with the first embodiment described above.

[0072]

As described above, according to the present invention, since the fuel pump discharge amount is controlled in consideration of the alcohol concentration of the fuel and the engine temperature, the fuel is efficiently heated and supplied to the engine at the time of starting. Besides, it is possible to save the energy required for heating, and it is possible to obtain an excellent effect such that the startability can be improved.

[Brief description of drawings]

FIG. 1 is a flowchart showing an initial control procedure according to a first embodiment of the present invention.

FIG. 2 is a flow chart showing a normal-time fuel pump control procedure according to the first embodiment of the present invention.

FIG. 3 is a flowchart showing a control procedure of the starter motor according to the first embodiment of the present invention.

FIG. 4 is a flowchart showing a fuel injection control procedure according to the first embodiment of the present invention.

FIG. 5 is a schematic diagram of an engine control system according to the first embodiment of the present invention.

FIG. 6 is a circuit configuration diagram of an engine control system according to the first embodiment of the present invention.

FIG. 7 is an explanatory view showing details of a heater unit according to the first embodiment of the present invention.

FIG. 8 is an explanatory view showing a startable region and a non-startable region according to the first embodiment of the present invention.

FIG. 9 is an explanatory diagram of a startable determination water temperature map according to the first embodiment of the present invention.

FIG. 10 is a characteristic diagram of a PTC heater according to the first embodiment of the present invention.

FIG. 11 is an explanatory diagram of a starting fuel pump rotation speed map according to the first embodiment of the present invention.

FIG. 12 is a schematic configuration diagram of an engine control system according to a second embodiment of the present invention.

FIG. 13 is a sectional view showing details of the vicinity of the injector according to the second embodiment of the present invention.

[Explanation of symbols]

 23 Injector 31 DC Motor Drive Fuel Pump 34a PTC Heater M Alcohol Concentration TW Cooling Water Temperature (Engine Temperature)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical display area F02D 45/00 364 K 8109-3G F02M 31/12 311 E 8923-3G 37/00 E 7049-3G 341 C 7049-3G 37/08 B 7049-3G F02N 11/08 G 9149-3G 17/04 D 9149-3G

Claims (1)

[Claims] 1. A non-startable procedure based on the alcohol concentration of the fuel and the engine temperature, a procedure for determining whether the engine can be started without heating the fuel, and a procedure for determining whether the engine can be started. When it is determined that the fuel to be supplied to the injector is heated, a procedure for controlling the discharge amount of the fuel pump based on the alcohol concentration of the fuel and the engine temperature to be the required fuel supply amount at startup, and after the engine is started, And a procedure for controlling the discharge amount of the fuel pump to be the maximum required fuel supply amount based on the alcohol concentration of the fuel.