JPH06101583A - Method for controlling heating of fuel ffv engine - Google Patents

Abstract

PURPOSE:To reduce battery consumption by properly setting a heat warm-up time and duration for a fuel heating means which helps evaporate fuel. CONSTITUTION:When a key is inserted into an ignition key cylinder, power is supplied to ECU, and when startup is recognized as being blocked from the concentration M of alcohol in fuel and from cooling water temperature Tw, a heater warm-up complete discriminating value (heat warm-up time)Cs is set (S212) based on the cooling water temperature Tw and the alcohol concentration M, and when the heater warm-up complete discriminating value (time)Cs is smaller (shorter) than a preset power supply starting time discriminating value CB, power supply to a PTC heater (fuel heating means) is started at the turning on of the ignition switch so as to start heater warm-up, while when the heater warm-up complete discriminating value (time) Cs is greater (longer) than the power supply starting time discriminating value CB, heater warm-up is immediately started. Since heater warm-up is controlled with time, controllability is good. Also, since the heater warm-up starting time is varied, a heater warm-up complete time is kept almost constant and operation feeling at startup is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel heating control method for an FFV engine capable of obtaining good starting performance while reducing the battery load.

[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. Vehicles such as automobiles (Flexible Fuel Vehicles, hereinafter,
In "FFV"), it is possible to run not only with gasoline but also with a mixed fuel of alcohol and gasoline, or only with alcohol, and the fuel alcohol concentration (content ratio) used in this FFV is , 0% (gasoline only) to 1 depending on the user situation when refueling
Varies between 00% (alcohol only).

In this type of FFV engine, due to the characteristics of the alcohol fuel as the alcohol concentration in the fuel increases, it is difficult to vaporize at low temperature, the latent heat of vaporization is large, the flash point is high, and so the low temperature startability is extremely high. There is a problem that gets worse.

In order to improve the low temperature startability of this FFV engine and to prevent exhaust gas, the applicant has arranged fuel heating means in the direction of fuel injection from the injector in the intake port, and at the time of starting. A technique for heating the injected fuel by the fuel heating means to promote vaporization has been proposed in, for example, Japanese Patent Laid-Open No. 3-253746.

In the above prior art, a heater is used as a fuel heating means, and it is judged whether the FFV engine can be started or not based on the cooling water temperature and the alcohol concentration in the fuel when the engine is started. The fuel vaporization is promoted to obtain good startability.

Further, in the fuel heating means such as the heater, it is necessary to warm up the surface of the fuel heating means to a temperature at which the fuel can be vaporized before starting the fuel injection.

An example of conventional fuel heating control will be described with reference to the time chart shown in FIG. When the ignition switch is turned on, the start determination is made based on the alcohol concentration in the fuel and the engine temperature, and when the start is impossible, that is, when the fuel needs to be heated by the fuel heating means, first, the fuel injection direction of the injector is installed oppositely. Energization of the fuel heating means is started, energization of the starter motor is prohibited, and heating and warming of the fuel heating means is started (elapsed time t0).

Therefore, even if the starter switch is turned on during this heating / warming period (elapsed time t1), the starter motor is not energized and the engine does not start.

Then, after the heating / warming period elapses for a predetermined period, energization to the starter motor is permitted, and at that time,
If the starter switch is ON, the starter motor is driven to start cranking (elapsed time t2).

After that, when the engine is started and the starter switch is turned off, the drive of the starter motor is also stopped (elapsed time t3).

On the other hand, when the engine temperature is relatively low, the fuel heating means continues to be energized even after the heating / warming period elapses until the engine temperature rises to the predetermined engine temperature, and the fuel heating means heats the fuel injected from the injector. To assist the vaporization of the fuel (elapsed time t2 to t4).

[0012]

As described above, in the conventional fuel heating control, the start of heating and warming for the fuel heating means is uniquely determined when the ignition switch is turned on, and therefore the heating and warming completion timing. (Cranking start time) is not constant and the starting operation feels bad.

When the heating / warming completion timing is determined by detecting the current consumption of the fuel heating means and comparing it with a reference value corresponding to the current consumption when the temperature rise reaches the saturation state, this reference value is used. Has a high alcohol concentration in the fuel, and is set as a unique value that allows sufficient heating and warming even at extremely low temperatures, so heating and warming tends to take longer as a whole. Therefore, the battery consumption increases and the battery exhaustion is caused.

If the fuel heating means is energized when the battery voltage is low, the starter drive voltage during cranking cannot be secured, and the engine cannot be started.

Further, in the case of judging the completion of heating / warming from the consumption current of the fuel heating means, a current sensor is additionally required, so that not only the number of parts increases but also the completion of heating / warming is indirectly measured. However, it is difficult to set the optimum heating / warming time.

Furthermore, when the fuel heating means is continuously energized to assist the vaporization of the fuel even after the completion of heating and warming up, the engine must be operated by cranking within a predetermined time after the completion of heating and warming up. However, the battery is not charged by the alternator or the like, and the battery is exhausted remarkably due to continuous energization of the fuel heating means, resulting in the battery going up.

The present invention has been made in view of the above circumstances, and a first object is not only to set an optimum heating / warming time for the fuel heating means, but also to eliminate the need for a current sensor. It is an object of the present invention to provide a fuel heating control method for an FFV engine, which reduces the fuel consumption.

A second object of the present invention is to provide, in addition to the above first object, a fuel heating control method for an FFV engine in which the operation feeling at the time of starting is improved.

A third object of the present invention is that, in addition to the first object, the heating / warming completion timing for the fuel heating means can be made substantially the same regardless of the engine temperature and the alcohol concentration in the fuel. SUMMARY OF THE INVENTION It is an object of the present invention to provide a fuel heating control method for an FFV engine, which can further improve the starting operation feeling.

A fourth object of the present invention is, in addition to the above-mentioned second or third object, for an FFV which can prevent the battery from rising due to heating and energizing the fuel heating means and prevent the engine from being disabled. An object is to provide a fuel heating control method for an engine. A fifth object of the present invention is to provide a fuel heating control method for an FFV engine, which is capable of effectively avoiding battery exhaustion with simple control.

[0021]

In order to achieve the above-mentioned first object, the first method for controlling fuel heating of an FFV engine according to the present invention is the alcohol concentration in the fuel and the engine temperature when the key switch is turned on. The procedure for deciding whether or not it is possible to start, and when it is decided that it is impossible to start, set the heating and warming time for the fuel heating means opposed to the fuel injection direction of the injector based on the alcohol concentration and the engine temperature. And a procedure.

In order to achieve the above second object, the second method for controlling fuel heating of an FFV engine according to the present invention can be started based on the alcohol concentration in the fuel when the key switch is turned on and the engine temperature. And the procedure for determining
If it is determined that the engine cannot be started, the procedure for setting the heating / warming time for the fuel heating means opposed to the fuel injection direction of the injector based on the alcohol concentration and the engine temperature, and the heating / warming time for the fuel heating means are set. And comparing the preset energization start timing determination value, if the heating and warming time is longer than the energization start timing determination value, start energizing the fuel heating means from the time when the key switch is turned on, Further, when the heating / warming time is shorter than the energization start timing determination value, a procedure for starting energization to the fuel heating means from when the ignition switch is turned on is provided.

In order to achieve the above-mentioned third object, a third method for controlling fuel heating of an FFV engine according to the present invention is a procedure for judging whether a door is opened, and if it is judged that a door is opened, the Of determining whether the engine can be started based on the alcohol concentration of the engine and the engine temperature, and when determining that the engine cannot be started, heating the fuel heating unit opposite to the fuel injection direction of the injector based on the alcohol concentration and the engine temperature. Procedure for setting warm-up time, heating / warming time for the fuel heating means, first preset energization start timing determination value, and second electrification start shorter than the first energization start timing determination value Compare with the time judgment value,
When the heating / warming time is longer than the first energization start timing determination value, energization to the fuel heating means is started from when the door is opened, and the heating / warming time is the first energization start. When it is shorter than the timing determination value and longer than the second power distribution start timing determination value, power supply to the fuel heating means is started from the time when the key switch is turned on, or the heating / warming time is the second power distribution. When the ignition timing is shorter than the start timing determination value, a procedure for starting energization of the fuel heating means from when the ignition switch is turned on is provided.

In order to achieve the fourth object, the fourth fuel heating control method for an FFV engine according to the present invention is any one of the first, second and third fuel heating control methods for an FFV engine. In the invention described above, a step of stopping the energization of the fuel heating means is added when the battery voltage is lower than the energizable voltage.

In order to achieve the fifth object, the fifth fuel heating control method for an FFV engine according to the present invention is the fuel heating control method for a second FFV engine according to the invention described in the fuel heating control method. After the completion of heating and warming up for, the addition of the procedure of determining whether the ignition switch is turned on and the step of stopping the continuous energization to the fuel heating means when the ignition switch is not turned on Is.

Similarly, in order to achieve the fifth object, the sixth fuel heating control method for an FFV engine according to the present invention is the same as the fuel heating control method for the third FFV engine described in the invention. After heating and warming up the heating means, determine whether the ignition switch or key switch is on, and if it is possible to start, after determining that the door has been opened and the ignition switch or key switch is turned on within the set time It is added that at least one of the procedure of determining whether the fuel cell is turned on and the procedure of stopping the power supply to the fuel heating means when it is determined that the ignition switch or the key switch is not on. It is a thing.

Similarly, in order to achieve the fifth object, the seventh aspect of the present invention is a fuel heating control method for an FFV engine, wherein the door is opened in the invention described in the third fuel heating control method for an FFV engine. After determining that the ignition switch or key switch has been turned on within the set time after determining that the ignition switch or key switch has been turned on, and if it is determined that the ignition switch or key switch has not been turned on, stop energizing the fuel heating means. And the addition of providing a procedure.

[0028]

[Operation] In the first fuel heating control method for the FFV engine, when the key switch is turned on, the start determination is made based on the alcohol concentration in the fuel and the engine temperature. The heating / warming time for the fuel heating means is set based on the engine temperature and the engine temperature.

In the second fuel heating control method for the FFV engine, the heating / warming time set based on the alcohol concentration in the fuel and the engine temperature is determined to be unstartable, and the preset energization start timing is determined. If it is longer than the value, energization to the fuel heating means is started from the time when the key switch is turned on.If it is shorter than the above energization start timing judgment value, the fuel heating means is turned on from when the ignition switch is turned on. Energization is started to.

In the third fuel heating control method for the FFV engine, the heating / warming time set based on the alcohol concentration in the fuel and the engine temperature is determined to be unstartable, and the preset first energization time is set. The start timing determination value and the second power distribution start timing determination value that is smaller than the first power distribution start timing determination value are compared. And the heating and warming time is
When it is longer than the first energization start timing determination value, energization to the fuel heating means is started from when the door is opened,
When the first energization start timing determination value is shorter than the second energization start timing determination value and longer than the second energization start timing determination value, energization to the fuel heating means is started when the key switch is turned on. When it is shorter than the energization start timing determination value of 2, energization is started to the fuel heating means from the time when the ignition switch is turned on.

In the fuel heating control method for the fourth FFV engine, in addition to the fuel heating control method for the first, second, or third FFV engine, when the battery voltage is lower than the energizable voltage, the fuel The power supply to the heating means is stopped.

In the fifth fuel heating control method for an FFV engine, in addition to the second fuel heating control method for an FFV engine, if the ignition switch is not turned on after the completion of heating and warming, the fuel heating means is used. Energization is stopped.

In the sixth fuel heating control method for an FFV engine, in addition to the third fuel heating control method for an FFV engine, the setting is made after heating and warming is completed and the engine can be started and the door is opened. If the ignition switch or the key switch is not turned on under at least one of the conditions for the time, the power supply to the fuel heating means is stopped.

In the fuel heating control method for the seventh FFV engine, in addition to the fuel heating control method for the third FFV engine, an ignition switch or a key switch is turned on within a set time after the door is opened. If not, the power supply to the fuel heating means is stopped.

[0035]

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

1 to 15 show a first embodiment of the present invention, FIGS. 1 and 2 are flowcharts showing a heater control routine, FIG. 3 is a flowchart showing an initialization routine, FIG. 4 is a flowchart showing a timer routine,
5 is a flow chart showing a starter motor control routine, FIG. 6 is a flow chart showing a starter switch ON → OFF interrupt routine, FIG. 7 is a flow chart showing a fuel injection control routine, FIG. 8 is an overall schematic diagram of an engine control system, and FIG. 10 is a circuit configuration diagram of the control device, FIG. 10 is a connection configuration table and a circuit diagram of the ignition key switch, FIG. 11 is a conceptual diagram of a heater warm-up completion determination value table, and FIG. 12 is a diagram showing alcohol concentration in fuel and heater warm-up time. FIG. 13 is a characteristic diagram showing the relationship for each cooling water temperature, FIG. 13 is a conceptual diagram showing a startable region and a non-startable region determined by the alcohol concentration and temperature conditions, and FIG. 14 is a conceptual diagram of a startable determination value table,
FIG. 15 is a time chart showing the heater control state in the startable region and the non-startable region.

In FIG. 8, reference numeral 1 is an FFV engine, which is a horizontally opposed engine in the figure. An intake port 2a and an exhaust port 2b are formed in the cylinder head 2 of the engine 1. An intake manifold 3 is connected to the intake port 2a, and a throttle passage 5 is connected to an upstream side of the intake manifold 3 via an air chamber 4. An air cleaner 7 is attached to the upstream side of the throttle passage 5 via an intake pipe 6,
The air cleaner 7 is communicated with an air intake chamber 8 which is an intake port for intake air.

An exhaust pipe 10 is connected to the exhaust port 2b via an exhaust manifold 9, and a catalytic converter 11 is inserted in the exhaust pipe 10 and connected to a muffler 12. On the other hand, 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 interposed 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.

Further, immediately downstream of this ISCV16,
A check valve 17 is provided which opens when the intake pressure is negative, and closes when the intake pressure becomes positive by supercharging by a turbocharger 18 described later.

Reference numeral 18 is a turbocharger, which connects an exhaust side turbine wheel 18a and an intake side compressor wheel 18b via a turbine shaft 18c. A wastegate valve actuating actuator 20 is connected to a wastegate valve 19 provided on the exhaust side of the turbocharger 18. This wastegate valve actuating actuator 20 is partitioned into two chambers by a diaphragm, one of which forms a pressure chamber that communicates with a wastegate valve control duty solenoid valve 21 which is an example of supercharging pressure control means, and the other of which forms the pressure chamber. A spring chamber is formed in which a spring for urging the waste gate valve 19 is closed.

The waste solenoid valve controlling duty solenoid valve 21 includes the compressor chamber 18 of the resonator chamber 14 and the turbocharger 18.
It is provided in a passage communicating with the downstream side of b, and the pressure on the resonator chamber 14 side and the compressor wheel 18b according to a duty ratio r of a control signal output from a control device (ECU) 50 described later. The pressure on the downstream side is regulated and supplied to the pressure chamber of the wastegate valve operating actuator 20, and the wastegate valve operating actuator 20 is operated to generate the wastegate valve 19
Is adjusted to control the supercharging pressure by the turbocharger 18.

An absolute pressure sensor 22 is connected to the intake manifold 3 via a passage 22a, and an intake pipe pressure / atmospheric pressure switching solenoid valve 22b is provided in the passage 22a. The intake pipe pressure / atmospheric pressure switching solenoid valve 22b selectively connects the absolute pressure sensor 22 to the intake manifold 3 side and the atmosphere side. The absolute pressure sensor 22 communicates with the intake manifold 3 to intake air. The pipe pressure (supercharging pressure when supercharging) can be detected.

Further, an injector 23 is provided immediately upstream of each intake port 2a of each cylinder of the intake manifold 3.
PT, which is an example of fuel heating means for assisting fuel vaporization in the fuel injection direction of the injector 23.
C (Positive Temperature Co
Efficient) The heater 3a is provided oppositely. Further, an ignition plug 24a whose tip is exposed to the combustion chamber is attached to each cylinder of the cylinder head 2, and an igniter 31 is connected to an ignition coil 24b which is connected to the ignition plug 24a.

A fuel tank 32 is attached to the injector 23.
Fuel is pressure-fed from an in-tank type fuel pump 33 provided inside through a fuel filter 34 a provided in a fuel passage 34, and the pressure is regulated by a pressure regulator 35. In addition, in the fuel tank 32, fuel containing only gasoline,
A fuel containing only alcohol or a mixed fuel of alcohol and gasoline, that is, a fuel in which the alcohol concentration M varies between 0% and 100% due to circumstances of refueling by the user is stored.

An alcohol concentration sensor 37 for detecting the alcohol concentration M in the fuel is attached to the fuel passage 34. As the alcohol concentration sensor 37, various types such as a capacitance type, a resistance detection type, and an optical type can be considered.

An intake air amount sensor (a thermal air flow meter in the figure) 41 is provided immediately downstream of the air cleaner 7 in the intake pipe 6, and a throttle opening sensor 42 is connected to the throttle valve 5a. It is set up.
Further, a knock sensor 43 is attached to the cylinder block 1a of the engine 1, and a water temperature sensor 45 is exposed to a cooling water passage 44 that communicates both the left and right banks of the cylinder block 1a, so that the exhaust manifold 9 of the exhaust pipe 10 is exposed. The O2 sensor 46 is exposed to the collecting portion of the.

A crank rotor 25 is attached to the crank shaft 1b of the engine 1, and a crank angle sensor 26 composed of an electromagnetic pickup or the like is provided on the outer periphery of the crank rotor 25. Further, a cam rotor 27 connected to the cam shaft 1c of the engine 1
Further, a cam angle sensor 28 for discriminating a cylinder, which is composed of an electromagnetic pickup or the like, is provided oppositely. The crank angle sensor 26 and the cam angle sensor 28 are not limited to magnetic sensors such as electromagnetic pickups, but may be optical sensors or the like.

Protrusions (or slits) are formed on the outer periphery of the crank rotor 25 at predetermined intervals corresponding to each cylinder. In the ECU 50 described later, the protrusions (or slits) detected by the crank angle sensor 26 are formed. The engine speed NE is calculated from the interval time, and the specific protrusion (or slit) serves as a reference crank angle when setting the ignition timing and the fuel injection start timing.

On the other hand, a protrusion (or slit) for cylinder discrimination is formed on the outer periphery of the cam rotor 27,
The ECU 50 determines the cylinder from the interruption of the pulse for detecting the protrusion (or slit) from the cam angle sensor 28.

Further, in FIG. 9, reference numeral 50 is a control unit (ECU) composed of a microcomputer, etc.
51, ROM 52, RAM 53, backup RAM 5
4, and the I / O interface 55 is a bus line 56.
Are connected to each other via.

The constant voltage circuit 5 is provided in the ECU 50.
9 is built in, and this constant voltage circuit 59 is connected to the battery 57 via the relay contact of the ECU relay 60,
The relay coil of the ECU relay 60 is connected to the battery 57 via the key switch 61.
When the key switch 61 is turned on, the ECU relay 6
The 0 contact turns on, the voltage of the battery 57 is supplied to the constant voltage circuit 59, and the stabilized voltage is supplied from this constant voltage circuit 59 to each part of the ECU 50. On the other hand, backup R
A backup voltage is constantly applied to the AM 54 from the constant voltage circuit 59. Further, the fuel pump 3 is connected to the battery 57 via a relay contact of the fuel pump relay 62.
3 is connected.

Further, the battery 57 is connected to relay contacts of a starter switch 63 and a heater relay 64. Further, a starter motor 66 is connected to the starter switch 63 via a relay contact of a starter motor relay 65.
On the other hand, the PTC heater 3a is connected to the relay contact of the heater relay 64.

On the other hand, the starter switch 6 is connected to the input port of the I / O interface 55 of the ECU 50.
3, alcohol concentration sensor 37, intake air amount sensor 4
1, crank angle sensor 26, cam angle sensor 28, throttle opening sensor 42, water temperature sensor 45, O2 sensor 4
6, the absolute pressure sensor 22, the knock sensor 43, the vehicle speed sensor 47, the ignition switch 49 are connected, and the battery 57 is further connected to monitor the battery voltage.

As shown in FIG. 10, the key switch 6 is used.
1 turns on when the key is inserted into the ignition key cylinder
In addition, the starter switch 63 is turned on when the key inserted in the ignition key cylinder is turned to the starter (ST) terminal position, and the ignition switch 49 is connected to the ignition key cylinder. IG) terminal ON terminal) or starter (ST) terminal position.

An igniter 31 is connected to the output port of the I / O interface 55, and further,
ISCV16, injector 2 via drive circuit 58
3, relay coil of fuel pump relay 62, relay coil of heater relay 64, relay coil of starter motor relay 65, waste gate valve control duty solenoid valve 21, intake pipe pressure / atmospheric pressure switching solenoid valve 22
b, and the instrument panel (not shown),
A heater check lamp 48a indicating a heater warm-up state and a battery check clamp 48b indicating a decrease in battery voltage are connected.

The ROM 52 stores fixed data such as control programs and various maps, and the RAM 53 and the backup RAM 54 output signals of the sensors and switches after data processing,
Also, data processed by the CPU 51 is stored.

When the key switch 61 is turned on, the CPU 51 makes a start judgment according to a control program stored in the ROM 52, and controls energization / de-energization of the PTC heater 3a according to the judgment result. At the same time, engine control such as air-fuel ratio control, ignition timing control and boost pressure control is performed.

Next, heater control by the ECU 50,
Starter motor control and fuel injection control etc.
~ It demonstrates according to the flowchart of FIG.

When a key is inserted into the ignition key cylinder, the key switch 61 is turned on and the ECU 50 is powered on. Then, first, the initialization routine of FIG. 3 is started only for the first time, and step (hereinafter abbreviated as “S”) 1
01, initialize the system (clear each flag,
Clear the count value, clear the output value of each I / O port to 0),
Exit the routine.

The flowcharts of FIGS. 1 and 2 are heater control routines that are repeated at predetermined time intervals after the initialization routine is completed. First, in step S201, refer to the start determination end flag F1, and if F1 = 0, the key is pressed. It is determined that the routine is the first routine after turning on the switch 61, and the process proceeds to S202 to perform the initial control. If F1 = 1, it is determined that the routine is the second or later routine, and the process proceeds to S203.

In the following, the first heater control routine will be described first, and then the second and subsequent heater control routines will be described.

In S201, it is determined that F1 = 0, and S1
In step 202, after setting the starter motor energization prohibition flag FST (FST ← 1, starter motor energization prohibited),
The process proceeds to S204, the I / O port output value G1 for the fuel pump relay 62 is set to 1, and the fuel pump relay 62 is turned on.
Then, the fuel pump 33 is driven, and the start discrimination end flag F1 is set (F1 ← 1) in S205, and then S2.
Proceed to 06.

When proceeding to S206, the alcohol concentration sensor 3
The startability determination value table TBTes is searched based on the alcohol concentration M in the fuel detected in step 7, and the startability determination value Tes is set directly or by interpolation calculation.

As shown in FIG. 13, this startability determination value table TBTes is defined by two regions specified by experiments or the like, that is, the fuel injected from the injector 23 is P
Areas that can be started without being heated by the TC heater 3a and areas that cannot be started as they are and indicate the boundary temperatures of these areas. As shown in FIG.
The alcohol concentration M is stored in advance as a parameter in the startability determination value table TBTes composed of a series of two addresses.

As a result, the cooling water temperature Tw representative of the engine temperature detected by the water temperature sensor 45 is set according to the alcohol concentration M at that time, and the startability judgment value Tes is set.
Whether or not the engine can be started can be determined by whether or not the following is true. In S207, the cooling water temperature Tw and the startable determination value Tes are compared to determine whether or not the engine can be started.

In S207, if Tw> Tes, it is determined that the PTC heater 3a can start the fuel without heating the fuel.
The routine proceeds to step 208, where the starter motor energization prohibition flag FST is cleared to permit energization of the starter motor relay 65, and then the routine is exited.

On the other hand, if Tw ≤ Tes in S207, it is determined that the engine cannot be started, and the process proceeds to S209, where the battery voltage E
Is compared with a preset heater energizable voltage Es, and E
If ≦ Es, the process proceeds to S210, the I / O port output value G5 for the battery check lamp 48b is set to 1, the battery check lamp 48b is turned on to notify the driver of the insufficient voltage, and then the process returns to S208.

If it is determined in S207 that the engine cannot be started, the PTC heater 3a is originally energized to warm up the heater to sufficiently raise the surface temperature of the PTC heater 3a, and then cranking is permitted to perform injection. Although it is necessary to promote the vaporization of the fuel, when the battery voltage E is low, not only can the PTC heater 3a not be sufficiently heated even if the PTC heater 3a is energized, but also if the heater is energized, the starter motor is started. The drive voltage of 66 cannot be secured, which hinders cranking. Therefore, when the battery voltage E is low, the PTC heater 3a is not energized, and the process returns to S208 to permit energization of the starter motor 66.

If E> Es in S209, S2
After setting the unstartable control flag F4 in 11 and proceeding to S212, the heater warm-up completion determination value table TB is set based on the cooling water temperature Tw and the alcohol concentration M in the fuel.
Set the heater warm-up completion determination value Cs from CS directly or by interpolation calculation.

As shown in FIG. 11, the heater warm-up completion determination value table TBCS has an appropriate heating / warming time (heater warm-up time) for the heater based on the alcohol concentration M in the fuel and the cooling water temperature Tw in advance through experiments or the like. Time), and the heater warm-up completion determination value Cs corresponding to this heating / warming time is set to R using the cooling water temperature Tw and the alcohol concentration M as parameters.
It is stored in a series of addresses of the OM 52. The heater warm-up completion determination value table TBCS stores a larger heater warm-up completion determination value Cs because it is necessary to lengthen the heater warm-up time for completing heater heating as the cooling water temperature Tw is lower. Further, the higher the alcohol concentration M in the fuel is, the larger the latent heat of vaporization is. Therefore, it is necessary to lengthen the heater warm-up time in order to raise the heater temperature when the heater heating is completed. Is stored.

The heater warm-up time differs depending on the heater capacity and engine type, but a concrete example of the heater warm-up time depending on the alcohol concentration M in the fuel is shown in FIG. 12A shows the case where the cooling water temperature Tw is -25 ° C., and FIG. 12B shows the case where the cooling water temperature Tw is 0 ° C.

When the process proceeds from S212 to S213, the heater warm-up completion determination value Cs is compared with a preset energization start timing determination value CB (e.g., 3 seconds), and Cs≤
In the case of CB, the process proceeds to S214, in which the ignition switch discrimination instruction flag F3 is set to start the energization of the PTC heater 3a from the time when the ignition switch 49 is turned on, and the routine exits. If Cs> CB, the process proceeds to S215 to immediately start the heater warm-up, the heater warm-up time count flag F2 is set, and the I / O port output value G2 for the heater check lamp 48a is set to 1 in S216 to check the heater. The lamp 48a is turned on to inform the driver that the heater is warming up.

Thereafter, in S217, the I / O port output value G3 for the relay coil of the heater relay 64 is set to 1, the heater relay 64 is turned on, the PTC heater 3a is energized to warm up the heater, and the routine exits.

Since the start determination end flag F1 is set in S205 of the first heater control routine, the process proceeds from S201 to S203 in the second and subsequent times, the start impossible control flag F4 is referred to, and if F4 = 1, the start is determined. If it is determined that it is impossible, the process proceeds to S218. If F4 = 0, it is determined that the heater warm-up is completed or the heater can be started, and the process proceeds to S219. S
In step 218, the ignition switch determination instruction flag F3 is referred to. If F3 = 0, it is determined that the heater is warming up, and the process proceeds to step S220. If F3 = 1, it is determined that the heater is warming up, and the process proceeds to step S221.

When the process proceeds to S220, the heater warm-up time count value C which is incremented by a timer routine described later.
1 is compared with the above heater warm-up completion determination value Cs, and C1 ≤
In the case of Cs, it is judged that the heater warm-up is continued and the routine is exited. When C1> Cs, it is judged that the heater warm-up is completed,
Heater warm-up time count flag F in S222 to S224
2. Clear the control flag F4 when unable to start, turn off the heater check lamp 48a with the I / O port output value G2 for the heater check lamp 48a set to 0, and then return to S208 to clear the starter motor energization prohibition flag FST. After permitting energization to the starter motor relay 65, the routine exits.

Further, when proceeding from S218 to S221, it is judged whether or not the ignition switch 49 is ON, and O
In the case of N, the ignition switch discrimination instruction flag F3 is cleared in S225 to start heater warm-up, and S
Return to 215. If it is OFF, the routine exits while waiting for the heater to warm up.

On the other hand, in S203, F4 = 0, that is, when it is determined that the heater warm-up is completed or start is possible and the process proceeds to S219, it is determined whether the ignition switch 49 is ON,
If OFF, jump to S228, heater relay 64
The I / O port output value G3 for the coil is set to 0, the heater relay 64 is turned off, the power supply to the PTC heater 3a is stopped, and the routine is exited.

In step S219, the ignition switch 4
When 9 is OFF, the driver can determine that he / she does not intend to start the engine in the routine after completion of warming up.
When it is determined in the start possibility determination (S207) of the first routine that the start is possible, the PTC heater 3a is forcibly de-energized at least until the ignition switch 49 is turned on. As described above, by deactivating the heater under a constant condition, it is possible to suppress battery consumption.

On the other hand, if it is determined in S219 that the ignition switch 49 is ON, the process proceeds to S226 in order to control the heater after the ignition switch is turned ON, and the cooling water temperature Tw and the fuel vaporizable temperature TLA4 (wall surface adhering fuel can be vaporized The temperature of the cooling water corresponding to the wall surface temperature is, for example, 25 ° C., where Tes <TLA4) is compared, and Tw> TLA
In the case of 4, even if the fuel adhering to the surface of the PTC heater 3a drops, it can be vaporized at the temperature of the intake port wall surface, and it is determined that heating by energizing the PTC heater 3a is unnecessary, and the process proceeds to S227 to determine whether the current operating state is idle. to decide. The idle determination condition is determined based on, for example, the throttle opening and the vehicle speed, and the throttle is fully closed and the vehicle speed sensor 47 detects the vehicle speed V = 0.
If it is detected, it is determined to be idle.

When it is judged in S227 that the heater is not idle, the routine proceeds to S228, where the I / O port output value G3 for the relay coil of the heater relay 64 is set to 0 as described above, and the heater is de-energized to exit the routine.

Further, when it is judged at S226 that Tw ≤TLA4 or at S227 that the current operating state is idle, the process proceeds from each step to S229.
Battery voltage E and preset heater energizable voltage ES
When E ≦ ES, it is determined that the battery voltage is insufficient, and the process proceeds to S230, the I / O port output value G5 for the battery check lamp 48b is set to 1, the battery check lamp 48b is turned on, and the driver is deficient in voltage. After informing, is returned to S228.

On the other hand, it is determined in S229 that E> ES, and S
When proceeding to 231, after setting the I / O port output value G5 to the battery check lamp 48b to 0, the process returns to S217 to energize the heater. For example, even if it is determined in S209 of the first routine that the voltage is insufficient and the I / O port output value G5 for the battery check lamp 48b is set to 1, when the battery voltage is restored by charging by the alternator after the engine is started, S2
By setting the I / O port output value G5 to 0 at 31, the battery check lamp 48b is turned off.

That is, even after the engine is started, T
When w ≤ TLA4, even if the fuel adhering to the surface of the PTC heater 3a drops on the inner wall of the intake port, etc., the wall temperature is low and it is difficult to vaporize, and the fuel injection amount during idle operation is small, and this fuel is When it collides with the PTC heater 3a, the surface temperature of the PTC heater 3a lowers due to latent heat of vaporization, and a relatively large amount of fuel drops into the amount of injected fuel, and the fuel supply to the combustion chamber becomes irregular, resulting in a combustion state. Will worsen and lead to idle instability. Therefore, in such a case, the PTC heater 3a is energized and heated to promote vaporization of the fuel.

As described above, according to this heater control routine, when the heater warm-up time set based on the coolant temperature Tw and the alcohol concentration M in the fuel is relatively long, the key is inserted into the ignition key cylinder. When (the key switch 61 is ON), the heater warm-up is started, and when the heater warm-up time is short, the ignition switch 49
Since the heater warm-up is started when is turned on, the starting operation feeling is good because the waiting time until the heater warm-up is completed at the start is almost constant.

Since the battery voltage E is constantly detected and the heater is energized only when the voltage value is equal to or higher than the predetermined voltage value, the surface temperature rise of the PTC heater 3a can be estimated only by measuring the heater energization time. Therefore, an appropriate heater warm-up time can be easily calculated, and when it is determined that the engine cannot be started, particularly when the alcohol concentration M in the fuel is low or when the engine temperature (cooling water temperature) is other than the extremely low temperature. The heater warm-up time can be set short to suppress battery consumption.

The flowchart shown in FIG. 4 is a timer routine for setting the heater warm-up time count value C1 read out in S220 of the heater control routine, which is repeated every set time after the initialization routine is completed.

First, in step S301, the value of the heater warm-up time count flag F2 set in the heater control routine is read. If F2 = 1 (count permitted), the process proceeds to step S302 to count up the heater warm-up time count value C1. (C1 ← C1 + 1), exit the routine. Also, F2 =
If 0, the process proceeds to S203 and the heater warm-up time count value C1
To clear the routine.

Further, the flow chart shown in FIG. 5 is a starter motor control routine, which is repeated every predetermined time only when the starter switch 63 is ON after the completion of the initialization routine.

First, in step S401, the value of the starter motor energization prohibition flag FST is read to determine whether energization of the starter motor 66 is permitted.

FST = 0, that is, the starter motor 66
If the power supply to the starter motor relay 65 is permitted, the process proceeds to S402, the output value G4 of the I / O port for the starter motor relay 65 is set to 1, the starter motor relay 65 is turned on, and the starter motor 66 is driven to crank the engine to execute the routine. Get out.

On the other hand, if FST = 1 in S401, that is, if energization to the starter motor 66 is prohibited, S4
03, I for the starter motor relay 65
The output value G4 of the / O port is set to 0, the starter motor relay 65 is turned off, the starter 66 cannot be driven, and the routine exits.

On the other hand, the flow chart shown in FIG. 6 is a starter switch ON → OFF interrupt routine which is activated when the starter switch 63 is turned ON → OFF.
When 01, the output value G4 of the I / O port for the starter motor relay 65 is set to 0, and the starter motor relay 65 is turned off.
F to exit the routine.

The flowchart shown in FIG. 7 is a fuel injection control routine, which is repeated at predetermined time intervals after the initialization routine is completed.

First, in step S601, it is determined whether the engine speed N is "0", that is, whether the engine is rotating. When N = 0 and the engine is stopped, the routine proceeds to S602, sets the fuel injection pulse width Ti to 0 (Ti ← 0), and exits the routine. If N ≠ 0, the routine proceeds from S601 to S603. A target air-fuel ratio set according to the intake air amount Q, the engine speed N, the alcohol concentration M, etc. is called by calling the injection pulse width calculation routine,
Then, the optimum fuel injection pulse width Ti is obtained from the air-fuel ratio feedback correction coefficient and the like, and in S604, the fuel injection pulse width Ti is set, and the routine exits. A drive pulse corresponding to the set fuel injection pulse width Ti is output to the injector 23 of the injection target cylinder at a predetermined timing to perform fuel injection.

Next, according to the time chart shown in FIG. 15, energization control for the PTC heater 3a, output control for the heater check lamp 48a, setting of the starter motor energization prohibition flag FST, and starter motor relay 65.
An example of ON / OFF control of will be described.

FIG. 9A shows that the cooling water temperature Tw when the key switch 61 is turned on is the startability determination value Tes and the set value TLA4 (fuel vaporization temperature) set based on the alcohol concentration M in the fuel. On the other hand, in the control example when TLA4 ≧ Tw> Tes, the figure (b) shows that Tw ≦ Tes and the heater warm-up completion determination value Cs is Cs> C with respect to the energization start timing determination value CB.
In the case of B, that is, when the alcohol concentration M in the fuel is high and the temperature is extremely low, the control example in FIG.
This is an example of control when Tes and Cs ≤ CB, that is, when the alcohol concentration M in the fuel is low even if the engine cannot be started, or when the engine temperature is other than the extremely low temperature.

First, the control operation of FIG. 9A will be described.

When the key is inserted into the ignition key cylinder and the key switch 61 is turned on and the ECU 50 is powered on, the cooling water temperature Tw is higher than the startable judgment value Tes, so the starter motor energization prohibition flag FST is cleared and the starter motor is turned off. Energization of the motor 66 is permitted, and the I / O port output value G for the heater check lamp 48a is
2 becomes 0 (light off). Further, since the starter switch 63 is still off, the I / O port output value G4 for the starter motor relay 65 remains 0, which is the initial value. On the other hand, the PTC heater 3a maintains the non-energized (OFF) state until the ignition switch 49 is turned on (elapsed time t0).

Then, the ignition switch 49 is turned on.
N (The key inserted in the ignition key cylinder is IG
Figure 1 shows the state of turning to the terminal position or ST terminal position.
Then, the PTC heater 3a is energized to assist the vaporization of the fuel (elapsed time t1).

Thereafter, when the starter switch 63 is turned on, the I / O port output value G4 for the starter motor relay 65 becomes 1 and the starter motor 66 is driven to start cranking (elapsed time t2).

When the starter switch 63 is turned off after the engine is started, the I / O port output value G4 for the starter motor relay 65 becomes 0 (elapsed time t3).

After that, when the cooling water temperature Tw reaches the fuel vaporizable temperature TLA4 and the non-idle state, the power supply to the PTC heater 3a is stopped (elapsed time t8).

Next, the control operation of FIG. 11B will be described.

When the key is inserted into the ignition key cylinder and the key switch 61 is turned on, the cooling water temperature Tw is lower than the startable judgment value Tes (unstartable), and the heater warm-up completion judgment corresponding to the heating and warming time is judged. Since the value Cs is larger than the energization start timing determination value CB, the PTC heater 3a is energized (ON) to immediately start the heater warm-up, and the I / O to the heater check lamp 48a is performed.
Heater check lamp 48 with port output value G2 set to 1
Notify the driver of heater warm-up by turning on a. Further, the starter motor energization prohibition flag FST is set to prohibit energization of the starter motor. When the energization of the starter motor is prohibited, the I / O port output value G4 for the starter motor relay 65 remains the initial value 0, and the engine does not start even if the starter switch 63 is turned on (elapsed time t0).

After that, when the heater warm-up time (the time corresponding to Cs) has elapsed since the key switch 61 was turned on, the I / O port output value G2 for the heater check lamp 48a is set to 0 and the heater check lamp 48a is turned off. The driver is notified of the completion of heater warm-up, and the starter motor energization prohibition flag FST is cleared to permit energization of the starter motor 66. If the starter switch 63 is turned on at this time, the I / O port output value G4 for the starter motor relay 65 is 1
Then, cranking is started (elapsed time t5).

When the starter switch 63 is turned off after the engine is started, the I / O port output value G
4 becomes 0 (elapsed time t7). Then, the cooling water temperature Tw
Has reached the fuel vaporizable temperature TLA4 and is in the non-idle state, the energization of the PTC heater 3a is stopped (elapsed time t8).

As described above, when the alcohol concentration M in the fuel is high and the engine is started at an extremely low temperature, the heater warm-up is started when the key switch 61 is turned on. Therefore, when the conventional ignition switch 49 is turned on. Since the heater warm-up can be completed earlier than in the case where the heater is warmed up, the starting operation feeling is good.

Next, the control operation of FIG. 11C will be described.

When the key is inserted into the ignition key cylinder and the key switch 61 is turned on, since Cs ≦ CB, the PTC heater 3a is maintained in a non-energized (OFF) state until the ignition switch 49 is turned on. Further, the starter motor energization prohibition flag FST is set to prohibit energization of the starter motor 66. Therefore, the output value G4 of the I / O port to the starter motor relay 65 remains the initial value 0, and the engine does not start even if the starter switch 63 is turned on (elapsed time t0).

Then, when the key inserted in the ignition key cylinder is turned to the IG terminal position, the ignition switch 49 is turned on to start energizing the PTC heater 3a and output the I / O port to the heater check lamp 48a. The value G2 is set to 1 and the heater check lamp 48a is turned on to inform the driver of the heater warm-up (elapsed time t1).

After that, when the heater warm-up time (time corresponding to Cs) elapses, the I / O port output value G2 for the heater check lamp 48a is set to 0, the heater check lamp 48a is turned off, and the heater warm-up is completed. The operator is notified, and the starter motor energization prohibition flag FST is cleared to permit energization of the starter motor 66. If the starter switch 63 is turned on at this time, the I / O port output value G4 for the starter motor relay 65 becomes 1 and cranking is started (elapsed time t4).

When the starter switch 63 is turned off after the engine is started, the I / O port output value G
4 becomes 0 (elapsed time t6). Then, the cooling water temperature Tw
Has reached the fuel vaporizable temperature TLA4 and is in the non-idle state, the energization of the PTC heater 3a is stopped (elapsed time t8).

As described above, when the alcohol concentration M in the fuel is low, the heater warm-up completion time is significantly shortened.
Even if the heater warm-up is started when the ignition switch 49 is turned on, the cranking start timing is substantially the same as that in the case of FIG. 7B, so that the operation feeling is good.

(Second Embodiment) FIGS. 16 to 22 show a second embodiment of the present invention, FIGS. 16 and 17 are flowcharts showing a heater control routine, and FIG. 18 is a flowchart showing a self-shut relay control routine. 19 is a flow chart showing a timer routine, FIG. 20 is a circuit configuration diagram of the control device, FIG. 21 is a time chart showing a heater control state in a non-startable region, and FIG. 22 is a time chart showing a control state of the self-shut relay. The same components as those in the first embodiment and the steps in the flowchart are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, as shown in FIG.
The relay coil of the CU relay 60 is connected to the battery 57 via the ignition switch 49, and
A key switch 61, which is turned on when the key is inserted into the ignition key cylinder, is connected to an input port of an I / O interface 55 provided in the ECU 50. Further, the door outer handle switch 67 and the relay contact of the self-power-holding self-shut relay 68 are connected in parallel to the relay contact of the ECU relay 60 arranged between the battery 57 and the constant voltage circuit 59 of the ECU 50. Then, the relay coil of the self-shut relay 68 is connected to the I / O described above.
It is connected to the output port of the interface 55 via a drive circuit 58. Further, the ignition switch 49 is connected to the input port of the I / O interface 55.

The door outer handle switch 67 is connected to the outer handle of the door on the driver's seat side and is turned on when the outer handle is pulled. When this door outer handle switch 67 is turned on, the self-shut relay 6
8 turns on.

Next, the control operation by the ECU 50 will be described.

First, when the door outer handle switch 67 is turned on or the self-shut relay 68 is turned off and then the ignition switch 49 is turned on, EC
The U50 is powered on, and the initialization routine shown in FIG. 3 of the first embodiment is executed only for the first time to initialize the system.

Then, after initialization, FIG. 16 and FIG.
The heater control routine shown in 7 is executed every predetermined time. Similar to the heater control routine shown in FIGS. 1 and 2 of the first embodiment, S201 to S207, S209, S2.
11, the process proceeds to S212, in which the heater warm-up completion determination value Cs is determined based on the cooling water temperature Tw and the alcohol concentration M in the fuel.
And the process proceeds to S701, the heater warm-up completion determination value Cs and the preset first energization start timing determination value CB1 are set.
(For example, corresponding to 10 seconds), and if Cs> CB1, the process proceeds to S215 to immediately start warming up the heater.

On the other hand, if it is judged at S701 that Cs ≤ CB1, the routine proceeds to S702, where the heater warm-up completion judgment value Cs.
And a preset second energization start timing determination value CB2 (however,
CB2 <CB1 and, for example, 3 seconds).

If Cs≤CB2, the routine proceeds to S214, sets the ignition switch determination instruction flag F3, and exits the routine. When the ignition switch discrimination instruction flag F3 is set, the energization of the PTC heater 3a is started when the ignition switch 49 is turned on.

When it is determined in step S702 that Cs> CB2 and the process proceeds to step S703, the key switch determination instruction flag F6 is set and the routine exits. When the key switch discrimination instruction flag F6 is set, energization of the PTC heater 3a is started when the key switch 61 is turned on.

On the other hand, if it is determined in S201 that the routine is the second and subsequent routines with F1 = 1, the process proceeds to S203 and S203.
If F3 = 0 at S218, the process proceeds to S704. S
At 704, the key switch discrimination instruction flag F6 is referred to,
If F6 = 1, proceed to S705 and turn on the key switch 61.
If it is OFF, the routine is exited. If it is ON, the routine proceeds to S706, where after the key switch discrimination instruction flag F6 is cleared, the routine returns to S215 to start the heater warm-up.

If F6 = 0 is determined in S704, the process proceeds to S220. If C1≤Cs, the routine is exited. If C1> Cs, S222 to S224 and then S7.
After the heater warm-up completion determination flag F7 is set, the flow returns to S208 to starter motor energization prohibition flag F.
After clearing ST and allowing the starter motor 66 to be energized, the routine is exited.

As described above, according to the heater control in the present embodiment, the energization start timing for the PTC heater 3a is determined according to the heater warm-up time by the door outer handle switch 6.
When 7 is turned on, when the key switch 61 is turned on,
Alternatively, since it is set to either one when the ignition switch 49 is turned on, the heater warm-up completion timing becomes substantially constant, and the operation feeling at the time of starting is further improved.

The flowchart shown in FIG. 18 is a self-shut relay control routine that is repeated at every set time after completion of the initialization routine. First, in S801, it is determined whether or not the ignition switch 49 is ON, and if it is OFF, the process proceeds to S802 and is turned ON. In the case of step S803.

In step S801, the ignition switch 4
When it is determined that 9 is OFF and the process proceeds to S802, the value of the ignition switch ON → OFF determination flag F5 is referred to, and F
If 5 = 0, the process proceeds to S804, and if F5 = 1, the process proceeds to S805.

The ignition switch is turned ON → OFF
The discrimination flag F5 is initialized (F5 ← 0) when the ECU 50 is powered on, and once the ignition switch 49 is turned on, the discrimination flag F5 is set in S803 described later. Therefore, F5 = 0 after the door outer handle switch 67 is turned on and the ECU 50 is powered on, and the ignition switch 49 is still on.
Further, F5 = 1 indicates that the ignition switch 49 is turned on and then turned off.

Then, when the operation proceeds from S802 to S804, the I for the relay coil of the self-shut relay 68 is set.
/ O port output value G6 is referred, and when G6 = 0, EC
Judging that this is the first routine after turning on the power to U50,
After proceeding to S806, the output value G6 of the I / O port is set to 1, the self-shut-down relay 68 is turned on to keep the power supply self, and then the routine exits. If G6 = 1, it is determined that the routine is the second or later routine, the process proceeds to S807, the heater warm-up completion determination flag F7 is referred to, the process proceeds to S808 if F7 = 0, and the process jumps to S811 if F7 = 1.

The heater warm-up completion determination flag F7 is cleared in the initializing routine for the first time, and is set in S707 of the heater control routine described above after the heater warm-up is completed. Therefore, in S807, F7 =
If it is determined to be 1, that is, if the ignition switch 49 is not turned on after the completion of heater warm-up, it is determined that the driver has no intention of driving the vehicle, and in S811, the I / O for the relay coil of the self-shut relay 68 is determined.
Set the O port output value G6 to 0 and set the self-shut relay 6
8 is turned off, the power supply to the ECU 50 is turned off, and the system is stopped to prevent unnecessary consumption of the battery.

On the other hand, if it is determined at S807 that F7 = 0 and the routine proceeds to S808, the elapsed time count flag F8 after the door outer handle switch is turned ON is set, and the routine proceeds to S809. When the heater warm-up completion determination flag F7 is F7 = 0, it means that the heater warm-up is not completed or the heater warm-up is not necessary. In step S809, after the door outer handle switch that is timed by a timer routine described later is turned on. Elapsed time count value C2 and preset elapsed time judgment value CS2
(For example, a value corresponding to 30 seconds) and C2> C
In the case of S2, the driver determines that he / she does not intend to drive the vehicle just by getting in the vehicle, jumps to S811, and cancels the self-power-holding of the ECU 50 by the self-shut relay 68,
Similar to the above, the system is turned off to prevent battery consumption.

If it is determined in step S809 that C2≤CS2, the routine is exited.

On the other hand, if it is determined in step S802 that F5 = 1, that is, if the ignition switch 49 has been switched from ON to OFF, the process proceeds to step S805. After the ignition switch is turned off, the elapsed time count flag F9 is set, and then the process proceeds to step S810. , The elapsed time count value C3 after the ignition switch is turned off and the preset elapsed time determination value CS3 (for example, 2
(Value corresponding to 0 sec), and if C3> CS3, S
811 and ECU5 by the self-shut relay 68
The self power supply hold of 0 is released and the system is turned off.
If C3 ≤ CS3, prepare for restart within a short time.
Leave the data used and leave the routine.

On the other hand, if it is determined in S801 that the ignition switch 49 is ON and the process proceeds to S803, the ignition switch ON → OFF determination flag F5 is set, and the door outer handle switch ON elapsed time count flag F8 and S812 and S813 are set. After clearing the elapsed time count flag F9 after the ignition switch is turned off, the process returns to S806.

As described above, in the self-shut relay control routine, after the outer handle is pulled to turn on the door outer handle switch 67 and the ECU 50 is powered on, the driver releases the outer handle to release the door outer handle. Even after the handlebar switch 67 is turned off, the power of the ECU 50 is self-held by the self-shut relay 68.

After the heater is warmed up, if the ignition switch 49 (or the key switch 61) is OFF, or the door outer handle switch 67 is ON.
After that, if the ignition switch 49 is off even after the lapse of the set time (CS2), it is presumed that there is no intention to drive the vehicle, and the self-shut relay 68 is turned off.
Turn off the CU power supply. As a result, the heater power source is also OF
It becomes F, and battery exhaustion is prevented.

It should be noted that the driver does not turn off the ignition switch 49 without getting off the vehicle and the self-shut relay 68 is turned off, and then the ignition switch 49 is turned on.
When the switch is turned on, the ECU relay 60 is turned on and the ECU
The power is turned on and therefore the self-shut relay 6
8 is also turned on.

By the way, the door outer handle switch 67 is uniquely turned ON without determining the completion of heater warm-up.
After that, the ignition switch 49
If is not turned on, the self-shut relay 68 is turned off.
The power may be turned off by F (G6 ← 0), and in that case, the step of S807 is unnecessary. Similarly, S707 in the heater control routine becomes unnecessary.

Further, in the flowchart shown in FIG. 19, the heater warm-up time count value C1 read in S220 of the heater control routine, and the door outer handle switch ON read in S809 of the self-shut relay control routine are turned on.
A timer routine for setting the elapsed time count value C2 and the elapsed time count value C3 after the ignition switch is OFF, which is read in S810, and is repeated at every set time after the initialization routine is completed.

First, as in the first embodiment, S301
After setting the heater warm-up time count value C1 in S302 or S303 according to the heater warm-up time count flag F2 value referred to in step S901, the process proceeds to step S901, and after the door outer handle switch set in the self-shut relay control routine is turned on. With reference to the value of the elapsed time count flag F8, if F8 = 1 (count enabled), the elapsed time count value C after the door outer handle switch is turned ON in S902
After counting up 2 (C2 ← C2 +1), S90
Go to 4. If F8 = 0, the process proceeds to S903 and the elapsed time count value C after the door outer handle switch is turned ON.
After clearing 2, proceed to S904.

Similarly, in S904, the value of the elapsed time count flag F9 after turning off the ignition switch, which is set in the self-shut relay control routine, is referred to,
When F9 = 1 (permission of counting), the routine proceeds to S905, and after counting the elapsed time count value C3 after the ignition switch is turned off (C3 ← C3 + 1), the routine is exited. When F9 = 0, the process proceeds to S906, and after clearing the elapsed time count value C3 after the ignition switch is turned off, the routine is exited.

Since the starter motor control routine and the fuel injection control routine in this embodiment are the same as those in the first embodiment, their explanations are omitted.

Next, an example of heater control will be described based on the time chart shown in FIG. In the figure, T
The case where w ≤ Tes (at the time of determination of start failure) is shown. Tw> Tes
In that case, the description is omitted because it is the same as in the first embodiment.

FIG. 14A shows the heater warm-up completion determination value Cs.
Shows a control example when Cs> CB1, that is, when the alcohol concentration M in the fuel is high, or when the engine temperature is extremely low, FIG. 7B shows the case where CB1 ≧ Cs> CB2, that is, in the fuel. Shows an example of control when the alcohol concentration M is not so high, and FIG. 7C shows the control when CB2 ≧ Cs, that is, when the alcohol concentration M in the fuel is low, or when the engine temperature is other than extremely low temperature. Here is an example:

First, the control operation (a) will be described.

When the door outer handle switch 67 is turned on by pulling the door outer handle, the ECU 50 is powered on and the self-shut relay 68 is turned on to turn on the ECU.
The power supply is self-maintained. At this time, since the cooling water temperature Tw is lower than the startable determination value Tes (unstartable) and the heater warm-up completion determination value Cs is larger than the first energization start timing determination CB1, it is necessary to immediately start the heater warm-up. The PTC heater 3a is energized (ON), the I / O port output value G2 for the heater check lamp 48a is set to 1, and the heater check lamp 48a is turned on to inform the driver of the heater warm-up. Further, the starter motor energization prohibition flag FST is set to prohibit energization of the starter motor 66. When the energization of the starter motor 66 is prohibited, the I / O port output value G4 for the starter motor relay 65 remains the initial value 0, and the engine does not start even if the starter switch 63 is turned on (elapsed time t0).

After that, when the heater warm-up time (the time corresponding to Cs) elapses, the I / O port output value G2 for the heater check lamp 48a is set to 0, the heater check lamp 48a is turned off, and the driver finishes the heater warm-up. Notify and starter motor energization prohibition flag FST
Is cleared to permit energization of the starter motor 66. If the starter switch 63 is turned on at this time, the output value G4 of the I / O port to the starter motor relay 65 becomes 1 and cranking is started (elapsed time t6).

When the starter switch 63 is turned off after the engine is started, the I / O port output value G
4 becomes 0 (elapsed time t9). Next, when the cooling water temperature Tw reaches the fuel vaporizable temperature TLA4 and the non-idle state, the power supply to the PTC heater 3a is stopped (elapsed time t10).

Next, the control operation (b) will be described.

When the door outer handle switch 67 is turned on and the ECU 50 is powered on, the self-shut relay 68 is turned on and the ECU power is self-maintained.

At this time, the cooling water temperature Tw is lower than the startable determination value Tes (starting impossible), and the heater warm-up completion determination value C
Since s is smaller than the first energization start timing determination value CB1 and greater than the second energization start timing determination value CB2, PTC
The heater 3a maintains a non-energized (OFF) state until the key switch 61 is turned on. Further, the starter motor energization prohibition flag FST is set to prohibit energization of the starter motor 66. Starter motor energization prohibition flag FST
Is set, the starter motor relay 65 I
The / O port output value G4 remains 0, which is the initial value, and the engine does not start even if the starter switch 63 is turned on after the key switch 61 is turned on (elapsed time t
0).

When the key switch 61 is turned on,
Energization of the PTC heater 3a is started, and at the same time, the I / O port output value G for the heater check lamp 48a
2 is set to 1 and the heater check lamp 48a is turned on to notify the driver of the heater warm-up (elapsed time t1).

After that, when the heater warm-up time (time corresponding to Cs) elapses, the I / O port output value G2 for the heater check lamp 48a is set to 0, the heater check lamp 48a is turned off, and the driver finishes the heater warm-up. Notify and starter motor energization prohibition flag FST
Is cleared to permit energization of the starter motor 66. At this time, if the starter switch 63 is turned on, the output value G4 of the I / O port for the starter motor relay 65 becomes 1 and cranking is started (elapsed time t5).

When the starter switch 63 is turned off after the engine is started, the I / O port output value G
4 becomes 0 (elapsed time t8). Next, when the cooling water temperature Tw reaches the fuel vaporizable temperature TLA4 and the non-idle state, the power supply to the PTC heater 3a is stopped (elapsed time t10).

Next, the control operation (c) will be described.

When the door outer handle switch 67 is turned on and the ECU 50 is powered on, the self-shut relay 68 is turned on and the ECU power supply is self-maintained, and the cooling water temperature Tw at this time is less than the startable determination value Tes. Is low (starting is impossible) and the heater warm-up completion determination value Cs is smaller than the second energization start timing determination value CB2, the PTC heater 3
“A” maintains a non-energized (OFF) state until the ignition switch 49 is turned on. Further, the starter motor energization prohibition flag FST is set to prohibit energization of the starter motor 66. Starter motor energization prohibition flag F
When ST is set, the output value G4 of the I / O port to the starter motor relay 65 remains the initial value 0, and the engine will not start even if the starter switch 63 is turned on after the ignition switch 49 is turned on (elapsed time). Time t0).

After that, the ignition switch 49 is turned on.
When N, energization to the PTC heater 3a is started,
At the same time, the I / O port output value G2 for the heater check lamp 48a is set to 1 and the heater check lamp 48a is turned on to notify the driver of heater warm-up (elapsed time t2).

After that, when the heater warm-up time (time corresponding to Cs) elapses, the I / O port output value G2 for the heater check lamp 48a is set to 0, the heater check lamp 48a is turned off, and the driver is notified of the completion of heater warm-up. Notify and starter motor energization prohibition flag FST
Is cleared to permit energization of the starter motor 66. At this time, if the starter switch 63 is turned on, the I / O port output value G4 for the starter motor relay 65 becomes 1 and cranking is started (elapsed time t4).

When the starter switch 63 is turned off after the engine is started, the I / O port output value G
4 becomes 0 (elapsed time t7). Next, when the cooling water temperature Tw reaches the fuel vaporizable temperature TLA4 and the non-idle state, the power supply to the PTC heater 3a is stopped (elapsed time t10).

As described above, when the heater warm-up time is relatively long, the PTC heater 3 is used from when the driver opens the door.
Since the energization of a is started, the heater warm-up can be completed relatively earlier than the conventional one in which the heater warm-up is started when the ignition switch 49 is turned on. Since the heater warm-up start timing is selected in accordance with the above, the heater warm-up completion timing becomes substantially constant regardless of the length of the heater warm-up time, and the starting operation feeling is improved.

A control example of the self-shut relay will be described with reference to the time chart shown in FIG.

FIG. 16A shows an example of control during normal use, that is, when the driver opens the door and gets into the vehicle, and then inserts the key into the ignition key cylinder and turns the cranking operation. (B) shows a control example in the case where the ignition switch 49 is not turned on even after a set time has elapsed after the door outer handle switch was turned on.

First, the control operation (a) will be described.

When the driver pulls the door outer handle, the door outer handle switch 67 is turned on, the ECU 50 is powered on, and the self-shut relay 68 is turned on (elapsed time t0).

Then, when the ignition switch 49 is turned on within the set time Cs2, the ECU relay 60 is turned on and the power supply to the ECU 50 is continued (elapsed time t1).

Then, turn the ignition switch 49 to O.
When FF, the ECU relay 60 is also turned off, but the self-shut relay 68 is turned on by the output from the ECU 50.
Therefore, the power supply to the ECU 50 is continued (elapsed time t4).

Also, turn the ignition switch 49 off.
If the engine is not restarted even after the set time Cs3 elapses after F, the self-shut relay 68 is turned off, and the ECU
The power supply to 50 is stopped (elapsed time t5).

Next, the control operation (b) will be described.

First, as in (a) above, the door outer handle switch 67 is turned on, the ECU 50 is powered on, and the self-shut relay 68 is turned on (elapsed time t0).

After that, if the ignition switch 49 is not turned on within the set time Cs2, the self-shut relay 68 is turned off and the power supply to the ECU 50 is stopped. Even if the ignition switch 49 is not turned on after the completion of heater warm-up from the state where it is determined that the engine cannot be started, the self-shut relay 6 is also similarly operated.
8 is turned off (elapsed time t2).

The self-shut relay 68 is OF
After F, when the ignition switch 49 is turned ON, E
The CU relay 60 is turned on, the ECU 50 is powered on, and as a result, the self-shut relay 68 is turned on again (elapsed time t3).

After that, the ignition switch 49 is turned on.
When FF, the ECU relay 60 is also turned off, but the self-shut relay 68 is turned on by the output from the ECU 50.
Therefore, the power supply to the ECU 50 is continued (elapsed time t4) and the ignition switch 49 is turned off.
If it is not restarted even after the set time Cs3 has passed, the self-shut relay 68 is turned off, and the ECU
The power supply to 50 is stopped (elapsed time t5).

[0174]

As described above, according to the present invention,
The effects listed below are achieved.

According to the first aspect of the invention, since the heating / warming time for the fuel heating means is set based on the alcohol concentration and the engine temperature, a current sensor or the like becomes unnecessary,
Not only can the number of parts be reduced by that amount, but the optimum heating / warming time can be set. Especially when the alcohol concentration is low or the engine temperature is not extremely low, the heating / warming According to the description of claim 2, the heating start time can be set according to the heating / warming time for the fuel heating means when the key switch is turned on or when the ignition switch is turned on. Since the selection is made, not only the heating / warming completion time can be relatively advanced, but also the heating / warming completion time is almost constant, so that the operation feeling at the time of starting is improved.

According to the third aspect of the present invention, the heating start time is set according to the heating / warming time for the fuel heating means when the door is opened, when the key switch is turned on, and when the ignition switch is turned on. Since it can be selected to either of the above, not only can the heating / warming completion timing be relatively advanced, but the heating / warming completion timing can be made substantially the same regardless of the alcohol concentration in the fuel and the engine temperature. The operation feeling at the time of starting is further improved.

According to the fourth aspect of the present invention, when the battery voltage is low, the energization of the fuel heating means is stopped, so the battery exhaustion due to heating and warming is prevented, and the engine start failure can be effectively avoided. it can.

According to the fifth aspect of the present invention, after the completion of heating and warming up the fuel heating means, the ignition switch is turned on.
If not, the energization of the fuel heating means is stopped, so that the battery exhaustion can be effectively avoided.

According to the sixth aspect of the present invention, the ignition switch or the key switch can be started after completion of heating and warming up the fuel heating means and at least one of the set time after opening the door and the set time. If is not turned on, the power supply to the fuel heating means is stopped,
The battery exhaustion can be effectively avoided.

According to the seventh aspect, after the door is once opened, the energization to the fuel heating means is stopped if the ignition switch or the key switch is not turned on even after the set time elapses. The battery exhaustion can be effectively avoided.

[Brief description of drawings]

1 to 15 show a first embodiment of the present invention, and FIGS. 1 and 2 are flowcharts showing a heater control routine.

[Fig. 2] Same as above

FIG. 3 is a flowchart showing an initialization routine.

FIG. 4 is a flowchart showing a timer routine.

FIG. 5 is a flowchart showing a starter motor control routine.

FIG. 6 is a flowchart showing a starter switch ON → OFF interrupt routine.

FIG. 7 is a flowchart showing a fuel injection control routine.

FIG. 8 is an overall schematic diagram of an engine control system.

FIG. 9 is a circuit configuration diagram of a control device.

FIG. 10 is a connection configuration table and circuit diagram of an ignition key switch.

FIG. 11 is a conceptual diagram of a heater warm-up completion determination value table.

FIG. 12 is a characteristic diagram showing the relationship between the alcohol concentration in the fuel and the heater warm-up time for each cooling water temperature.

FIG. 13 is a conceptual diagram showing a startable region and a non-startable region determined by alcohol concentration and temperature conditions.

FIG. 14 is a conceptual diagram of a startability determination value table.

FIG. 15 is a time chart showing a heater control state in a startable region and a non-startable region.

16 to 22 show a second embodiment of the present invention, and FIGS. 16 and 17 are flowcharts showing a heater control routine.

FIG. 17 Same as above

FIG. 18 is a flowchart showing a self-shut relay control routine.

FIG. 19 is a flowchart showing a timer routine.

FIG. 20 is a circuit configuration of a control device

FIG. 21 is a time chart showing a heater control state in the unstartable region.

FIG. 22 is a time chart showing the control state of the self-shut relay.

FIG. 23 is a time chart showing a conventional heater control state.

[Explanation of symbols]

 3a ... PTC heater (fuel heating means) 23 ... Injector 49 ... Ignition switch 61 ... Key switch CB, CB1, CB2 ... Energization start timing determination value Cs ... Heater warm-up completion determination value (heating / warming time) E ... Battery voltage M … Alcohol concentration Tw… Cooling water temperature (engine temperature)

Claims (7)

[Claims] 1. A procedure for determining whether or not the engine can be started based on the alcohol concentration in the fuel and the engine temperature when the key switch is turned on, and when it is determined that the engine cannot be started, based on the alcohol concentration and the engine temperature, And a procedure for setting a heating and warming-up time for a fuel heating means that is opposed to the fuel injection direction of the injector. 2. A procedure for determining whether the engine can be started based on the alcohol concentration in the fuel and the engine temperature when the key switch is turned on, and when it is determined that the engine cannot be started, based on the alcohol concentration and the engine temperature, The procedure for setting the heating / warming time for the fuel heating means, which is installed in the fuel injection direction of the injector, is compared with the heating / warming time for the fuel heating means and the preset energization start timing determination value, and the heating / warming time is compared. When the machine time is longer than the energization start timing determination value, the energization of the fuel heating means is started from when the key switch is turned on, and when the heating / warming time is shorter than the energization start timing determination value, An engine for FFV, comprising a procedure for starting heating energization to the fuel heating means when an ignition switch is turned on. Fuel heating control method. 3. A procedure for determining whether the door is opened, a procedure for determining whether the door can be opened based on the alcohol concentration in the fuel and the engine temperature, and a step for determining that the door cannot be opened. In this case, based on the alcohol concentration and the engine temperature, the procedure for setting the heating / warming time for the fuel heating means opposed to the fuel injection direction of the injector, and the heating / warming time for the fuel heating means are set in advance. The first energization start timing determination value is compared with a second energization start timing determination value that is shorter than the first energization initiation timing determination value, and the heating / warming time is the first energization start timing determination value. If it is longer, the energization of the fuel heating means is started from the time when the door is opened, and the heating / warming time is shorter than the first energization start timing determination value and the second energization start timing determination is performed. If it is longer than a fixed value, energization to the fuel heating means is started from the time when the key switch is turned on, or if the heating / warming time is shorter than the second energization start timing determination value, from when the ignition switch is turned on. And a procedure for starting energization of the fuel heating means. 4. The method according to claim 1, further comprising a step of stopping the energization of the fuel heating means when the battery voltage is lower than the energizable voltage. FFV engine fuel heating control method. 5. A procedure for determining whether or not an ignition switch is turned on after completion of heating and warming up for the fuel heating means, and a procedure for stopping energization of the fuel heating means when the ignition switch is not turned on. The fuel heating control method for an FFV engine according to claim 2, further comprising: 6. A procedure for determining whether or not an ignition switch or a key switch is turned on after completion of heating and warming up for the fuel heating means, and within a set time after determining that the door is opened when it is determined that start is possible. At least one of the procedures for determining whether the ignition switch or the key switch is turned on, and the procedure for stopping the power supply to the fuel heating means when it is determined that the ignition switch or the key switch is not turned on. 4. The method according to claim 3, further comprising:
A fuel heating control method for an FFV engine as described. 7. A procedure for determining whether an ignition switch or a key switch is turned on within a set time after it is determined that a door is opened, and the fuel heating when the ignition switch or the key switch is not turned on. 4. A procedure for stopping energization of the means.
A fuel heating control method for an FFV engine as described.