JPH10306740A - Control device for internal combustion engine with thermal type airflow meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for an internal combustion engine without the possibility of misjudgment and lowering of abnormality detecting capacity in abnormality detection in case of starting the engine after leaving an ignition(IG) ON without starting the engine in the internal combustion engine provided with a thermal type airflow meter integrated with an intake air temperature sensor. SOLUTION: A thermal type airflow meter 22 and an intake air temperature sensor 28 integrated with the airflow meter 22 are provided in an intake passage. When intake air temperature detected by the intake air temperature sensor 28 at the time of an ignition switch being turned on from an off state is made first intake air temperature, and intake air temperature detected by the intake air temperature sensor 28 at the starting time of an engine is made second intake air temperature, an ECU 30 compares the difference between the first intake air temperature and second intake air temperature with the specified judgment value, and uses the compared result as an execution condition at the time of performing control such as EGR valve flow lowering abnormality detection control of an engine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an internal combustion engine having a thermal air flow meter provided in an intake passage of an internal combustion engine mounted on a vehicle or the like.

[0002]

2. Description of the Related Art In recent years, thermal air flow meters such as a hot wire type have been adopted as air flow meters for automobiles due to their high detection performance. This thermal air flow meter is for detecting a flow rate of intake air passing through an intake passage. That is, the voltage value output from the thermal air flow meter fluctuates according to the intake air flow rate (for example, “0 V” to “5 V”), and the intake air amount is calculated based on the voltage value. The intake air amount thus calculated is employed as one of various engine control parameters. Also, in the intake passage,
In order to use the temperature of the intake air (intake temperature) as a parameter for engine control, an intake temperature sensor is provided in the intake passage. On the other hand, due to demands for cost reduction, many of the intake air temperature sensors are integrated with a thermal air flow meter.

Since the thermal type air flow meter has an electric heating element inside, if the engine is not started and the ignition (IG) is left on, the temperature of the air flow meter body itself becomes lower than the ambient temperature. Also rises.

[0004]

However, in the case of the above-mentioned integral type thermal air flow meter, the engine is not started as described above. Since the temperature is high, the phenomenon that the output value of the intake air temperature sensor becomes higher than the true intake air temperature continues for a while (for example, 7 to 8 minutes) even after the engine is started. for that reason,
The execution conditions for performing various control of the engine,
When used for various abnormality determination conditions, various control controls of the engine are performed based on the intake temperature that is not a true value even though the intake temperature is not actually high, or the abnormality detection or abnormality detection is performed. A problem occurs in which the performance is reduced.

The present invention has been made in view of the above circumstances, and has as its object to provide a thermal air flow meter with an integrated intake air temperature sensor, or an intake air temperature sensor that is not integrated. However, in an internal combustion engine arranged close to a thermal air flow meter, if the engine is started after leaving the ignition (IG) on without starting the engine, an erroneous determination or abnormal An object of the present invention is to provide a control device for an internal combustion engine having a thermal air flow meter capable of performing engine control under appropriate execution conditions without performing a variety of engine controls without the risk of lowering the detection capability.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, a first aspect of the present invention is to provide a detection signal provided in an intake passage of an internal combustion engine and corresponding to the amount of intake air passing through the intake passage. Along with outputting, when the ignition switch is turned on from off, a thermal air flow meter equipped with an electric heating element that starts generating heat, and integrated with the thermal air flow meter or in close proximity to the thermal air flow meter And a control unit for performing predetermined control of the internal combustion engine based on the intake air temperature detected by the intake air temperature sensor. The intake air temperature detected by the intake air temperature sensor when the ignition switch is turned on from off is set as the first intake air temperature, and the intake air temperature sensor detects the intake air temperature when the internal combustion engine is started. When the intake air temperature at this time is defined as a second intake air temperature, a first comparison means for comparing a difference between the first intake air temperature and the second intake air temperature with a predetermined first determination value is provided. The control means uses the comparison result of the first comparing means as an execution condition when performing predetermined control of the internal combustion engine. If the execution condition is satisfied, the control means performs the predetermined control. If not, the gist is a control device for an internal combustion engine having a thermal air flow meter that prohibits the predetermined control.

According to a second aspect of the present invention, a detection signal is provided in an intake passage of an internal combustion engine in accordance with an amount of intake air passing through the intake passage, and when an ignition switch is turned on from off, A thermal air flow meter having an electric heating element for starting heat generation, and an intake air temperature sensor provided integrally with or close to the thermal air flow meter, wherein the intake air temperature sensor is provided. A control device for performing predetermined control of the internal combustion engine based on the detected intake air temperature, the control device for the internal combustion engine having a thermal air flow meter, wherein an intake air temperature sensor is provided when the ignition switch is turned on from off. And a second comparing means for comparing the first intake air temperature with a predetermined second determination value when the detected intake air temperature is a first intake air temperature. The stage sets the comparison result of the second comparing means as an execution condition when performing predetermined control of the internal combustion engine. If the execution condition is satisfied, the stage performs the predetermined control, and the execution condition is satisfied. If not, the gist is a control device for an internal combustion engine having a thermal air flow meter that prohibits the predetermined control.

According to a third aspect of the present invention, a detection signal is provided in an intake passage of an internal combustion engine in accordance with an amount of intake air passing through the intake passage, and when an ignition switch is turned on from off, A thermal air flow meter having an electric heating element for starting heat generation, and an intake air temperature sensor provided integrally with or close to the thermal air flow meter, wherein the intake air temperature sensor is provided. A control device for performing a predetermined control of the internal combustion engine based on the detected intake air temperature, the control device for the internal combustion engine having a thermal air flow meter, wherein the internal combustion engine includes an intake air amount of the internal combustion engine and an engine temperature. Operating state detecting means for detecting the operating state of the engine, based on the amount of intake air detected by the operating state detecting means, the engine temperature, and the elapsed time from the start of the internal combustion engine. A correction coefficient calculating means for calculating a correction coefficient; a correction coefficient calculated by the correction coefficient calculating means; a first intake air temperature detected by an intake air temperature sensor when an ignition switch is turned on from off; Intake air temperature calculating means for calculating a true intake air temperature based on the second intake air temperature detected by the intake air temperature sensor at the time of starting; and the control means based on the true intake air temperature calculated by the intake air temperature calculating means The gist of the invention is a control device for an internal combustion engine having a thermal air flow meter for performing predetermined control.

According to a fourth aspect of the present invention, there is provided an electric motor which is provided in an intake passage of an internal combustion engine, outputs a detection signal in accordance with an amount of intake air passing through the intake passage, and generates heat by operating an ignition switch. A thermal air flow meter provided with a thermal heating element, and an intake air temperature sensor provided integrally with or adjacent to the thermal air flow meter. A control device for performing a predetermined control of the internal combustion engine based on the thermal air flow meter, wherein when the internal combustion engine is started by operating an ignition switch, A control device for an internal combustion engine having a thermal air flow meter, comprising an air flow meter control means for starting heat generation in the meter. Are you as its gist.

According to the first aspect of the present invention, the first comparing means sets the intake air temperature detected by the intake air temperature sensor when the ignition switch is turned on from off to the first intake air temperature, When the intake air temperature detected by the intake air temperature sensor when the internal combustion engine is started is defined as a second intake air temperature, a difference between the first intake air temperature and the second intake air temperature and a predetermined first determination value are determined. Compare. The control means uses the comparison result of the first comparing means as an execution condition when performing predetermined control of the internal combustion engine. If the execution condition is satisfied, the control means performs the predetermined control. If not, the predetermined control is prohibited.

According to the second aspect of the present invention, when the intake air temperature detected by the intake air temperature sensor when the ignition switch is turned on from the off state is set to the first intake air temperature, the second comparing means sets the first intake air temperature to the first intake air temperature. Is compared with a predetermined second determination value. The control means uses the comparison result of the second comparing means as an execution condition when performing predetermined control of the internal combustion engine. If the execution condition is satisfied, the control means performs the predetermined control. If not, the predetermined control is prohibited.

According to the third aspect of the present invention, the operating state detecting means detects the operating state of the internal combustion engine including the intake air amount and the engine temperature of the internal combustion engine. The correction coefficient calculating means calculates a correction coefficient based on the intake air amount detected by the operating state detecting means, the engine temperature, and the elapsed time from the start of the internal combustion engine. The intake temperature calculating means includes a correction coefficient calculated by the correction coefficient calculating means, a first intake temperature detected by the intake temperature sensor when the ignition switch is turned on from off, and an intake temperature sensor when the internal combustion engine is started. Calculates the true intake air temperature based on the detected second intake air temperature. The control means performs a predetermined control based on the true intake air temperature calculated by the intake air temperature calculating means.

According to the fourth aspect of the present invention, when the internal combustion engine is started by operating the ignition switch, the air flow meter control means causes the thermal air flow meter to generate heat.

For this reason, the control means controls the air flow meter based on the true intake air temperature which is not affected by the heat generated by the air flow meter, since the air flow meter does not generate heat even if the ignition switch is turned on and left. hand,
Perform predetermined control.

[0015]

Embodiment

(First Embodiment) A first embodiment in which the present invention is embodied in a control device for an internal combustion engine having a hot wire air flow meter as a thermal air flow meter will be described with reference to FIGS. This will be described in detail.

FIG. 1 is a schematic configuration diagram showing a gasoline engine system to which the control device according to this embodiment is applied. Engine 1 as an internal combustion engine mounted on a car
Has an intake passage 2 and an exhaust passage 3. An air cleaner 4 is provided at an inlet of the intake passage 2. Also,
A surge tank 5 is provided in the middle of the intake passage 2. An injector 6 for supplying fuel to each cylinder (four cylinders in this embodiment) of the engine 1 is supplied to an intake manifold 12 located downstream of the surge tank 5.
A, 6B, 6C, and 6D are provided, respectively. On the other hand, a catalytic converter 7 having a built-in three-way catalyst for purifying exhaust gas is provided on the outlet side of the exhaust passage 3.

The engine 1 takes in outside air from the air cleaner 4 through the intake passage 2. At the same time as the intake of the outside air, the engine 1 is connected to the injectors 6A to 6A.
The fuel injected and supplied from 6D is taken in. Further, the engine 1 explodes and burns the mixture of the taken fuel and the outside air in each combustion chamber to obtain a driving force, and then discharges the exhaust gas from the exhaust passage 3 to the outside via the catalytic converter 7. I do.

An upstream side of the surge tank 5 is provided with a throttle valve 8 which opens and closes in response to operation of an accelerator pedal (not shown). When the throttle valve 8 is opened and closed, the intake air amount Q in the intake passage 2 is adjusted. In the vicinity of the throttle valve 8,
A throttle opening sensor 21 for detecting the throttle opening TA is provided.

A hot wire type air flow meter (hereinafter, simply referred to as an air flow meter) 22 for measuring an intake air amount Q passing through the intake passage 2 is provided downstream of the air cleaner 4. The air flow meter 22 includes an electric heating element (hot wire). The hot wire is supplied with electric power from a battery (not shown) and starts to generate heat when an ignition switch 19 described later is operated from an off position to an on position. During traveling, the heated hot wire is cooled by the intake air passing through the intake passage 2, and this cooling changes the resistance value of the hot wire and changes the current. That is, the voltage value VA determined from the relationship between the air flow velocity and the amount of heat transferred by the hot wire is output from the air flow meter 22 as an electric signal.
In this embodiment, the relationship of the intake air amount Q to the voltage value VA output from the air flow meter 22 is obtained in advance through experiments or the like, and has a quadratic curve relationship. And in the electronic control unit 30 described later,
The intake air amount Q is calculated based on the voltage value VA output from the air flow meter 22.

In the middle of the exhaust passage 3, there is provided an oxygen sensor 23 for detecting the oxygen concentration in the exhaust gas, that is, for detecting the exhaust air-fuel ratio, in order to feedback-control the air-fuel ratio of the engine 1. Further, the engine 1 is provided with a water temperature sensor 24 for detecting a temperature (cooling water temperature) THW of the cooling water. In the present embodiment, the cooling water temperature corresponds to the engine temperature.

An ignition signal distributed by a distributor 10 is applied to ignition plugs 9A, 9B, 9C, 9D provided for each cylinder of the engine 1. The distributor 10 synchronizes the high voltage output from the igniter 11 with the crank angle of the engine 1 to each of the ignition plugs 9A to 9A.
It is for distribution to 9D. The ignition timing of each of the ignition plugs 9A to 9D is determined by the high voltage output timing from the igniter 11.

The distributor 10 has a built-in rotor (not shown) that rotates in conjunction with the rotation of the engine 1. The distributor 10 receives the rotation speed of the engine 1 (engine rotation speed) N from the rotation of the rotor.
A rotation speed sensor 25 for detecting E is provided. The rotation speed sensor 25 of the present embodiment has a crank angle (CA) of 3
A rotation pulse signal is output every 0 °.
Similarly, the distributor 10 is provided with a cylinder discrimination sensor 26 that detects a change in the crank angle of the engine 1 at a predetermined rate according to the rotation of the rotor. In this embodiment, the cylinder determination sensor 26 outputs the reference position signal GS at a rate of every 720 ° CA, assuming that the engine 1 makes two rotations per stroke. Also,
An automatic transmission (not shown) that is drivingly connected to the engine 1 is provided with a vehicle speed sensor 27 for detecting a vehicle speed SP.

Further, an intake air temperature sensor 28 for detecting an intake air temperature THA corresponding to the outside air temperature is provided in the intake passage 2 on the upstream side adjacent to the air flow meter 22. In this embodiment, the intake air temperature sensor 28
It is provided integrally with the air flow meter 22. At the same time, a control box (not shown) that stores an electronic control unit 30 described later for controlling the engine 1 and the like is provided with an atmospheric pressure sensor 29 for detecting the atmospheric pressure PA.

In this embodiment, the engine 1 is controlled by the aforementioned throttle opening sensor 21, air flow meter 22, water temperature sensor 24, cylinder discrimination sensor 26, vehicle speed sensor 27, intake air temperature sensor 28 and atmospheric pressure sensor 29.
Operating state detecting means for detecting the operating state of the vehicle.

Further, the engine 1 is provided with a starter 14 for applying a rotational force to the engine 1 by cranking at the time of starting. The starter 14 has a starter switch 20 for detecting its operation / non-operation.
Is provided. The starter switch 20 is turned on / off by operating the ignition switch 19 shown in FIG. As is well known, the ignition switch 19 is movable between an off position and an on position, and between the on position and a starter on position, and the ignition switch 19 is operated from the on position to the starter on position. During this time, since the starter 14 is operated, the starter switch 20 outputs a starter signal STA of “ON”.

In this embodiment, although not shown, a well-known exhaust gas circulation (EGR) device and a purge control device are provided. The former EGR device includes an EGR passage and an EGR valve provided in the middle of the EGR passage. The EGR passage is provided so as to communicate between the intake passage 2 downstream of the throttle valve 8 and the exhaust passage 3. The EGR valve has a built-in valve seat, valve body, and step motor. E
The opening degree of the GR valve fluctuates when the stepping motor intermittently displaces the valve body with respect to the valve seat. When the EGR valve opens, a part of the exhaust gas discharged to the exhaust passage 3 flows to the EGR passage. The exhaust gas flows to the intake passage 2 via the EGR valve.
That is, a part of the exhaust gas is recirculated into the intake air-fuel mixture by the EGR device. At this time, the recirculation amount of the exhaust gas is adjusted by adjusting the opening degree of the EGR valve.

The latter purge control device is
A purge passage and a canister are provided. That is,
A canister is connected to the upper part of the fuel tank via a purge passage, and the fuel vapor generated in the fuel tank is guided to the canister through a vapor passage. The canister is an evaporative fuel adsorption container containing activated carbon, and the evaporative fuel is once adsorbed to the activated carbon. The canister is further connected to a sensing port near the throttle valve 8 via a purge passage so that fuel vapor in the canister is sucked into the engine 1. A purge control valve constituted by a vacuum switching valve (VSV) is provided in the middle of the purge passage. The purge control valve is for adjusting the purge amount of the evaporated fuel guided from the canister to the intake passage 2 by opening and closing the purge passage. In the present embodiment, the purge control valve is opened and closed by duty control.

In this embodiment, the fuel supply device shown in FIG. 2 is provided. In this device, a pump 41 discharges fuel in a tank 42. The discharged fuel passes through a fuel pipe 43 and a filter 44 and is delivered to a delivery pipe 45.
At a predetermined pressure. This delivery pipe 45
Distributes the fuel to each of the injectors 6A to 6D. Each of the injectors 6A to 6D injects fuel to each cylinder of the internal combustion engine (engine) 27. An electronic control unit (hereinafter simply referred to as “ECU”) 30 controls each injector 6A based on the fuel injection amount calculated according to the operating state of the engine 1.
~ 6D. The pressure regulator 49 provided in the delivery pipe 45 adjusts the fuel pressure in the high pressure side fuel pipe 43 and the like including the delivery pipe 45 so as to be constant with respect to the pressure in the intake manifold 12, and returns the surplus fuel. Tank 4 through pipe 51
Return to 2. For this purpose, the sensing port 4 provided in the diaphragm chamber 49a of the pressure regulator 49
9b communicates with the intake manifold 12 through a pipe 52. Then, through the pipe 52, the intake negative pressure in the intake manifold 12 is applied to the diaphragm chamber 49a as a reference pressure for adjusting the fuel pressure to be constant.

In the middle of the pipe 52, a three-way solenoid valve 53 is provided. The solenoid valve constitutes a control valve. When the ECU 30 determines that the engine 1 is started at a high temperature, the solenoid valve 53 is switched to communicate the diaphragm chamber 49b with the atmosphere, and the fuel pressure adjusted by the pressure regulator 49 is increased at once, and the ECU 30 performs the unit time. The amount of fuel injected from each of the injectors 6A to 6D is increased at a stroke. this is,
In particular, at the time of high-temperature start, vapor is easily generated, and the fuel tends to be thinner by that amount. Therefore, at the time of high-temperature start, the fuel injection amount is increased. As a result, engine 1
Startability is improved. Note that except for the high temperature start, the ECU
Numeral 30 switches the electromagnetic valve 53 to apply an intake negative pressure to the diaphragm chamber 49a.

Next, the electrical configuration of the control device will be described with reference to FIG. As shown in FIG. 3, each of the injectors 6A to 6D and the igniter 11 includes first comparing means,
It is electrically connected to the ECU 30 that constitutes the second comparing means and the control means, and the drive timing of the ECU 30 is controlled by the operation of the ECU 30. The ECU 30 executes the well-known fuel injection control and the ignition timing control based on the operating state of the engine 1 as described above, as well as the EGR valve flow rate decrease abnormality detection control, the fuel pressure increase control, the fuel tank system opening detection control, And the processing of the intake air temperature determination control is executed. The EGR valve flow rate decrease abnormality detection control, the fuel pressure increase control, and the fuel tank system hole opening detection control correspond to the predetermined control of the present invention.

FIG. 3 is a block diagram illustrating the configuration of the ECU 30. The ECU 30 is a central processing unit (CPU) 3
1, a read-only memory (ROM) 32 in which a predetermined control program or the like is stored in advance, a random access memory (RAM) 33 for temporarily storing the calculation results of the CPU 31, etc., and a backup RAM 34 for storing data stored in advance
And the like, and a logical operation circuit in which these units and the external input circuit 35 and the external output circuit 36 are connected by a bus 37. The CPU 31 includes the air flow meter 22, the starter switch 20, and the sensors 21 and
The output signals from 3 to 29 are read as input values through the external input circuit 35. The CPU 31 also controls the injector 6 through the external output circuit 36 based on these input values.
A to 6D, the igniter 11, the solenoid valve 53 and the like are suitably controlled.

Next, the processing operation for the intake air temperature determination control in the control device in the gasoline engine system configured as described above will be described with reference to the flowchart of FIG.

FIG. 4 is a flowchart showing an "intake air temperature determination control routine" according to this embodiment, which is executed by a periodic interruption at predetermined time intervals with respect to the main routine.

When the process proceeds to this routine, it is first determined in step 10 whether or not the ignition switch has been operated. That is, it is determined whether or not the ignition switch 19 has been operated from the off position to the on position. When the ignition position is operated from the off position to the on position, the ECU 30 sets the IG flag XIG to "1" in another control routine.
Is set based on whether or not is set to “1”. If the IG flag XIG is set to "1", it is determined that the ignition switch 19 has just been turned from the off position to the on position, and the process proceeds to step 20. If the IG flag XIG has been reset to "0", the process jumps to step S30.

When the process proceeds to step 20, the same step 2
At 0, “-50 ° C.” is stored in a corresponding register as an intake air temperature at starter start (hereinafter, referred to as “start intake air temperature”) THast, and an ignition-on intake air temperature THAI (hereinafter, “IGO intake temperature”) is stored. ")
In the control cycle of this control routine, the intake air temperature TH which is the newest raw value detected by the intake air temperature sensor 28
A is stored in the corresponding register. Note that the starting intake air temperature THAst is set to “−50 ° C.” as an initial value because such a numerical value is actually selected as a small numerical value that is impossible at the time of starting. A small numerical value that cannot be realized in practice is not limited to a numerical value of “−50 ° C.”.

The IGO intake air temperature THAI corresponds to the first intake air temperature of the present invention, and the starting intake air temperature THast corresponds to the second intake air temperature. In step 20, I
The G flag XIG is reset to “0”. Accordingly, in the subsequent control cycle of the “intake air temperature determination control routine”, the process jumps from step 10 to step 30 until the IG flag XIG is set to “1” in another control routine.

In step 30, it is determined whether the ignition switch 19 has been operated from the ON position to the starter ON position and the starter 14 has been operated. That is, when the starter signal STA is input, the ECU 30 executes the start determination flag XST in another control routine.
A1 is set to "1". Therefore, in step 30, the start determination flag XSTA1 is set to "1".
Is determined based on whether or not is set. In addition,
The setting of the start determination flag XSTA1 is based on the rotation speed sensor 2
When the engine speed NE detected by the control unit 5 becomes equal to or more than a predetermined number of revolutions, for example, "450 rpm" or more, the start determination flag XSTA1 may be set to "1". Note that the start determination flag XSTA1 is a starter signal STA
Is reset to "0" when there is no input. In addition,
When the engine speed NE detected by the speed sensor 25 is equal to or higher than a predetermined speed, the start determination flag XSTA1 is set to “1”.
Is set to “0” when the engine speed NE detected by the speed sensor 25 has reached less than a predetermined speed.
Reset to.

In step 30, the start determination flag X
If STA1 is set to "1", it is determined that the starter 14 has been turned on, that is, immediately after the engine has started, and the process proceeds to step 40. When the start determination flag XSAT1 has been reset to "0",
Move to step 60.

In step 40, it is determined whether or not the initial value determination flag XSTA2 is set to "1". The initial value determination flag XSTA2 indicates the start-up intake air temperature T
This is a flag for determining whether or not the intake temperature THA, which is a raw value immediately after the engine is started, is already stored in the register corresponding to HAst. When the intake air temperature determination control routine is first performed, the intake air temperature THA at the time of starting is determined.
Since the intake air temperature THA, which is a raw value immediately after the engine is started, is not stored in the register for st, it is reset to “0”. Therefore, in step 40, “N
O ”is determined, and the routine goes to Step 50. If the initial value determination flag XSTA2 is set to "1", it is determined that the intake air temperature THA, which is a raw value immediately after the start of the engine, is already stored in the register for the intake air temperature THast at start. Jump to 60.

At step 50, the ECU 30
Stores the intake air temperature THA, which is a raw value immediately after the engine is started, in the register corresponding to the intake air temperature THast at start, and sets the initial value determination flag XSTA2 to “1”.

In this way, immediately after the starter 14 is turned on, steps 30 to 50 are processed only once. In the following step 60, the intake air temperature T at the time of starting is determined.
A difference ΔTHA between HAst and the IGO intake air temperature THAI is calculated, and it is determined whether or not the difference ΔTHA is equal to or greater than a determination value α.
The determination value α is detected by the intake air temperature sensor 28 due to the thermal influence of the hot wire of the air flow meter 22 when a long time elapses after the ignition switch 19 is turned on and the starter 14 is turned on. Intake air temperature T
This is to see the level of how high the HA has increased. If the difference ΔTHA is smaller than the determination value α, the starting intake air temperature THast is used as a precondition (execution condition) for executing another control routine, or the starting intake air temperature THast is used as a control parameter. When the temperature THAst is used for other control routines, the start-time intake air temperature THast is set to a reliable value so as not to adversely affect those control routines.
The determination value α is obtained in advance by an experiment or the like.
It is stored in the OM32. The determination value α corresponds to a predetermined first determination value of the present invention.

In step 60, if the difference ΔTHA is smaller than the determination value α, the start-time intake air temperature THast is determined to be a reliable value, and the routine proceeds to step 100, where the first intake air temperature THast is shifted to the first.
Is reset to “0”, and the routine goes to step 110. In step 60, the difference Δ
If THA is equal to or greater than the determination value α, the intake air temperature at startup THAs
Assuming that t is an unreliable value, the process proceeds to step 70 and sets the first true / false flag XTUSO to “1”;
Move to step 80.

In step 80, it is determined whether or not the difference ΔTHA is equal to or greater than a determination value β. The determination value β depends on the heat effect of the hot wire of the air flow meter 22 between the time the ignition switch 19 is turned on and the time the starter 14 is turned on, and determines the intake air temperature THA detected by the intake air temperature sensor 28. This is for checking the level of the increase to the extent, and is set to a value larger than the determination value α. If the difference ΔTHA is smaller than the determination value β, the process proceeds to step 110.

The determination value β is used as the IGO intake air temperature THAI in the “tank opening detection control routine” of FIG. This is for determining whether or not there is reliability. That is, when the difference ΔTHA is equal to or greater than the determination value β, the reliability of the IGO intake air temperature THAI as well as the start-time intake air temperature THast is lost. The determination value β is obtained in advance by an experiment or the like, and is stored in the ROM 32. And the determination value β
Corresponds to a predetermined first determination value of the present invention.

If the difference ΔTHA is larger than the judgment value β, the routine goes to step 90. In step 90, the second
Is set to "1", and this control routine is temporarily ended. When the process proceeds from step 80 or from step 100 to step 110, the second true / false flag XTOUSO is reset to "0", and this control routine is temporarily ended.

Steps 60 and 80 constitute first comparing means. Next, the EGR valve flow rate abnormality detection control in the control device of the gasoline engine system will be described with reference to the flowchart of FIG.

FIG. 5 is a flowchart showing the "EGR valve flow rate reduction abnormality detection control routine", which is executed by a periodic interruption at predetermined time intervals with respect to the main routine. In this routine, in step 200, it is determined whether or not the first true / false flag XTUSO has been reset to “0”. First true / false flag XTUS
If O is set to "1", it is determined that the intake air temperature THA currently detected by the intake air temperature sensor 28 is an unreliable value, and this control routine is temporarily terminated. Also, the first
If the true / false flag XTUSO is reset to "0", it is determined that the intake air temperature THA currently detected by the intake air temperature sensor 28 is a reliable value, and the routine proceeds to step 210, where the EGR valve flow rate abnormality detection is performed. The control is performed, and this control routine after the end of the control is temporarily ended.

The EGR valve flow rate reduction abnormality detection control in step 210 is a known control, and will not be described in detail. In this embodiment, the EGR gas temperature TH
G and (intake air temperature THA + 60 ° C.) are compared in magnitude,
If THG <THA + 60 ° C., the ECU 30
This is a control for determining that the flow rate of the R valve is decreasing and detecting an abnormality. Therefore, in step 200, the first
Is true, the intake air temperature TH
Since A has an unreliable value, this step 2
Thus, the EGR valve flow rate decrease abnormality detection control of No. 10 is prohibited. When the first true / false flag XTUSO is “0”, the intake air temperature THA has a reliable value.
The EGR valve flow rate abnormality detection control of step 210 is processed.

In this embodiment, although not shown, a temperature sensor for detecting the EGR gas temperature THG
In the R passage, downstream of the EGR valve (intake passage side)
, And is electrically connected to the ECU 30, and inputs a detection signal to the ECU 30.

Step 200 constitutes an execution condition judging means for judging whether or not the EGR valve flow rate reduction abnormality detection control should be performed. Whether or not the first true / false flag XTUSO is “0” corresponds to an execution condition when performing the GR valve flow rate reduction abnormality detection control.

Next, referring to the flowchart of FIG.
In the control device of the gasoline engine system,
The tank hole detection control will be described. FIG. 6 is a flowchart showing a "tank hole detection control routine", which is executed by a periodic interruption at predetermined time intervals with respect to the main routine.

Steps 300 to 320 of this routine are performed to determine whether or not the "tank hole detection control" of step 330 can be executed, that is, whether or not the precondition (execution condition) is satisfied. It is a step.

When the routine shifts to this routine, step 30
0, whether the IGO intake air temperature THAI is within a predetermined temperature range (in this embodiment, 10 ° C. ≦ THAI <35 ° C.)
Or not). Here, conventionally, at step 300, the detected intake air temperature THA
In st, it is determined whether or not the temperature is within the predetermined temperature range. In this embodiment, the IGO intake air temperature THAI is used because the reliability of the starting intake air temperature THast is not constant.

In step 300, the IGO intake air temperature T
If the HAI is within the predetermined temperature range, step 310
If the IGO intake air temperature THAI is outside the predetermined temperature range, the control routine is temporarily ended.

In step 310, it is determined whether or not the absolute value of the difference between the IGO intake air temperature THAI and the cooling water temperature THWst at the time of starting is not more than R ° C. Note that the cooling water temperature THWst at the time of starting is the cooling water temperature T
HW. And | THAI-THWst |
If <R ° C (R ° C is assumed to be 7 ° C in this embodiment) is not satisfied, the control routine is temporarily terminated, and if | THAI-THWst | <R ° C is satisfied, Move to step 320. Here, conventionally, in step 310, it is determined whether the absolute value of the difference between the detected intake air temperature THast at start and the coolant temperature THWst at start is 7 ° C. or less. In the embodiment, the IGO intake air temperature THAI is used because the reliability of the starting intake air temperature THAst is not constant.
In this step 310, “7 ° C.”
° C ”, but other temperatures may be used. In any case, the predetermined value R is obtained in advance by an experimental value or the like.

In step 320, it is determined whether or not the second true / false flag XTOUSO is "0". When the second true / false flag XTOUSO is “0”, the IGO adopted in the above steps 300 and 310 is used.
In step 33, it is determined that the intake air temperature THAI is reliable, that is, that the preconditions (execution conditions) in steps 300 and 310 are satisfied.
Move to 0. The second true / false flag XTOUSO is “1”
In the case of, the IGO intake air temperature THAI adopted in the above steps 300 and 310 is not reliable,
Assuming that the prerequisites (execution conditions) of steps 300 and 310 are not satisfied, that is, that the true intake air temperature THA at the time of starting cannot be detected, the tank system opening detection control is prohibited. This control routine is temporarily terminated.

In step 330, "tank hole detection control" is processed, and after this processing, the control routine is temporarily terminated. The tank system perforation detection control is for detecting whether or not perforations have occurred in the fuel tank, and is known as described in, for example, Japanese Patent Application Laid-Open No. 8-270480. Therefore, detailed description is omitted.

Steps 300, 310 and 320 constitute an execution condition judging means for judging whether or not the tank opening detection control should be performed. Also, the IGO intake air temperature THAI in step 300
Is within a predetermined temperature range, whether or not | THAI−THWst | <R ° C. in step 310 is satisfied, and whether the second true / false flag XTOU in step 320 is satisfied.
Whether or not SO is “0” corresponds to an execution condition when performing tank-system hole detection control.

Next, referring to the flowchart of FIG.
In the control device of the gasoline engine system,
The fuel pressure increase control will be described. FIG. 7 is a flowchart showing a "fuel pressure increase control routine", which is executed by a periodic interruption at predetermined time intervals with respect to the main routine.

When the routine shifts to this routine, step 40
At 0, it is determined whether or not the IGO intake air temperature THAI is equal to or higher than a predetermined temperature (in the present embodiment, the predetermined temperature is 70 ° C., and therefore, THAI ≦ 70 ° C.).
Step 400 is a process of determining whether or not a precondition (execution condition) for performing the fuel pressure increase process is satisfied. Here, conventionally, in step 400, it is determined whether or not the detected intake air temperature THast is equal to or higher than the predetermined temperature based on the detected intake air temperature THast. Since the reliability is not constant, the IGO intake air temperature T instead of the start-time intake air temperature THast
HAI is used.

In step 400, if the IGO intake air temperature THAI is equal to or higher than the predetermined temperature, it is determined that the fuel injection amount needs to be increased because the engine is being started at a high temperature.
In step 10, the "fuel pressure increase control" is performed, and if the IGO intake air temperature THAI is lower than the predetermined temperature, it is determined that it is not necessary and the control routine is ended once.

Step 400 constitutes a second comparing means, and the content of the comparison at step 400 as to whether or not the IGO intake air temperature THAI is equal to or higher than a predetermined temperature is used as the condition for executing the fuel pressure increase.

The control device for a gasoline engine system configured as described above has the following effects. (1) In the above embodiment, in the “EGR valve flow rate reduction abnormality detection control routine” of FIG.
Only when the first true / false flag XTUSO is "0" at 00, the EGR valve flow rate reduction abnormality detection control can be performed. As a result, the first true / false flag XTUSO becomes “1”.
In other words, when the intake air temperature THA is an unreliable value, the EGR valve flow rate reduction abnormality detection control is prohibited, so that erroneous detection due to the increased intake air temperature THA can be prevented. (2) In the above-described embodiment, in the “tank hole opening detection control routine” of FIG. 6, the processing of determining whether or not the preconditions (execution conditions) of steps 300 and 310 are satisfied. Differently, the intake air temperature at startup TH
The IGO intake air temperature THAI which is not affected by the heat of the hot wire of the air flow meter 22 was used in place of Ast. As a result, when the ignition key switch 19 is left in the ON position, the startup intake air temperature THast
By using, it is possible to prevent the precondition (execution condition) from being unsatisfied, thereby preventing the tank system hole detection control from being prohibited, and to secure the tank system hole detection opportunity.

In step 320, step 3
At 00 and step 310, the precondition is cleared, but the second true / false flag XTOUSO is set to "1".
In the case of, the tank hole detection control is prohibited.

This is because when the second true / false flag XTOUSO is “1”, the reliability of the IGO intake air temperature THAI itself is not reliable, and therefore the tank system hole due to the preconditions of steps 300 and 310 being satisfied. Erroneous detection of opening detection can be prevented. (3) In the “fuel pressure increase control routine” in FIG. 7, preconditions (execution conditions) for performing the fuel pressure increase process
In step 400, which is a process for judging whether or not the above condition is satisfied, since the reliability of the start-time intake air temperature THast is not constant, the IGO intake air temperature THAI is used instead of the start-time intake air temperature THast. As a result, when the ignition key switch 19 is left in the ON position, the use of the increased intake air temperature THast at the time of start can prevent unnecessary overriching due to execution of an increase in fuel pressure.
As a result, it is possible to prevent the startability of the ignition plugs 6A to 6D from being covered with fuel and the deterioration of exhaust gas. (Second Embodiment) Next, a second embodiment will be described with reference to FIGS.

In this embodiment, since the hardware configuration is the same as that of the first embodiment, the same components are denoted by the same reference numerals, and the description thereof will be omitted. explain.

The processing operation for the intake air temperature estimation control in the control device in the gasoline engine system according to this embodiment will be described with reference to the flowchart of FIG.

This embodiment is different from the first embodiment in that the starting intake air temperature is estimated. Therefore, in the first embodiment, the EGR valve flow rate abnormality detection control, the fuel pressure increase control, and the fuel tank system hole opening detection control corresponding to the predetermined control are based on the estimated intake air temperature at the start (hereinafter, referred to as “estimated Start-up intake air temperature) T
The difference is that HAR determines whether a precondition (execution condition) is satisfied or not, or is used as a control parameter. The details will be described below.

FIG. 8 is a flowchart showing an "intake air temperature estimation control routine" according to this embodiment, which is executed by a regular interruption to the main routine at predetermined time intervals.

When entering this routine, in step 500, a first correction value k1 is obtained by referring to the first map from the elapsed time t after the start. The first map includes a first correction value k1 and a post-start elapsed time t (FIG. 9).
(See (a)), which is obtained in advance through experiments or the like, and is stored in the ROM 32. Note that the elapsed time after starting t is the elapsed time since the starter 14 was turned on, that is, the elapsed time since the starter signal STA was input to the ECU 30, and based on an internal clock (not shown) provided in the CPU 31. The counted value corresponds to the elapsed time from the start of the internal combustion engine in the present invention.

In the next step 510, the second correction value k2 is calculated based on the intake air amount Q with reference to the second map.
Ask for. The second map is a map including the second correction value k2 and the intake air amount Q (see FIG. 9B).
It is obtained in advance through experiments and the like, and is stored in the ROM 32.

In the following step 520, a third correction value k3 is determined based on the cooling water temperature THW with reference to the third map. The third map has a third correction value k3,
FIG. 9 is a map (see FIG. 9C) composed of the cooling water temperature THW, which is obtained in advance by an experiment or the like, and is configured.
2 is stored.

In the next step 530, the correction coefficient K
Is calculated by the following equation. K = k1 × (k2 + k3) In the following step 540, an estimated starting intake air temperature THAR is calculated as a true intake air temperature by the following equation. THA R = THA− (THAst−THAI) × K where THA is the intake air temperature that is the current raw value. T
HAst and THAI are the same definitions as in the first embodiment.

After the processing of step 540 is completed, this routine is temporarily terminated. In this embodiment, the ECU
Reference numeral 30 denotes a correction coefficient calculation unit, an intake air temperature calculation unit, and a control unit. Steps 500 to 530 in FIG. 8 constitute a correction coefficient calculating unit. or,
Step 500 is a first correction coefficient calculating means relating to the elapsed time after starting, step 510 is a second correction coefficient calculating means relating to the intake air amount Q, and step 520 is a third correction coefficient relating to the cooling water temperature (engine temperature). Step 530 corresponds to a total correction coefficient calculating unit. Step 5
40 constitutes intake air temperature calculating means. The IGO intake temperature THAI constitutes a first intake temperature. Further, the air flow meter 22 and the water temperature sensor 24 constitute operating state detecting means for detecting an operating state.

Next, with reference to the flow chart of FIG. 10, the control for detecting the abnormality in the EGR valve flow rate decrease in the control device in the gasoline engine system will be described. FIG. 10 is a flowchart showing an “EGR valve flow rate reduction abnormality detection control routine”, which is executed by a periodic interruption at predetermined time intervals with respect to the main routine.

When the control routine is entered, step 21 is executed.
In step 1, the EGR valve flow rate reduction abnormality detection control is performed, and when this control ends, the routine is temporarily ended. The control in step 211 differs from the control in step 210 of the first embodiment in that the magnitude of the EGR gas temperature THG is compared with (estimated intake air temperature THAR + 60 ° C. at the time of starting), and THG <THAR + 60 ° C. , The ECU 30
Is a control for determining that the EGR valve flow rate is decreasing and detecting an abnormality.

Therefore, in this embodiment, erroneous detection due to the intake air temperature which is higher than the true value is prevented, and at the same time, EG
An opportunity for detecting an abnormality in the R valve flow rate decrease is secured. In this embodiment, the “EGR valve flow rate reduction abnormality detection control routine” corresponds to the predetermined control performed by the ECU 30.

Next, with reference to the flowchart of FIG. 11, the control for detecting the opening of the tank system in the control device in the gasoline engine system will be described. FIG.
Is a flowchart showing a "tank hole detection control routine", which is executed by a periodic interruption at predetermined time intervals with respect to the main routine.

Steps 301 and 311 of this routine are for determining whether or not the “tank hole detection control” of step 330 can be executed, that is, for determining whether or not the precondition (execution condition) is satisfied. It is a step.

When the routine shifts to this routine, step 30
1, whether the estimated intake air temperature THAR is within a predetermined temperature range (10 ° C. ≦ THAR ≦ 3 in this embodiment)
At 5 ° C). Conventionally, step 30
In step 1, it is determined whether or not the detected intake air temperature THast is within the predetermined temperature range.
In this embodiment, since the reliability of the start-time intake air temperature THast is not constant, the estimated start-time intake air temperature THAR is used.

In step 301, if the estimated starting intake air temperature THAR is within the aforementioned predetermined temperature range, step 3
Then, if the estimated starting intake air temperature THAR is out of the predetermined temperature range, the control routine is temporarily ended.

In step 311, it is determined whether or not the absolute value of the difference between the estimated starting intake air temperature THAR and the starting cooling water temperature THWst is 7 ° C. or less. Note that the cooling water temperature THWst at the time of starting is the cooling water temperature THW immediately after the engine is started. Conventionally, in step 311, it is determined whether the absolute value of the difference between the detected intake air temperature THast at start and the coolant temperature THWst at start is 7 ° C. or less. In this embodiment, Since the reliability of the starting intake air temperature THast is not constant, the estimated starting intake air temperature THAR is used.

Then, | THAR-THWst | <R ° C.
(In this embodiment, 7 ° C.), the control routine is temporarily terminated, and | THAR-THWst
If | <R ° C is satisfied, the process proceeds to step 330. Step 330 has been described in the first embodiment, and a description thereof will be omitted. When the process of step 330 ends, this routine is ended once.

As described above, in this embodiment, the prerequisites for “tank hole detection control” in step 330 are “10 ° C. ≦ THAR <35 ° C.” and “| THAR-THW”.
st | <7 ° C. ”.

Therefore, in this embodiment, by leaving the ignition switch 19 at the ON position, the prerequisite (execution condition) caused by the intake air temperature THA which is higher than the true value is prevented from being satisfied, and at the same time, the tank system hole detection is performed. Is detected.

In this embodiment, this “tank hole detection control routine” corresponds to the predetermined control performed by the ECU 30. Next, referring to the flowchart of FIG.
In the control device of the gasoline engine system,
The fuel pressure increase control will be described.

FIG. 12 is a flowchart showing the "fuel pressure increase control routine", which is executed by a periodic interruption at predetermined time intervals with respect to the main routine. This control routine is different from the first embodiment in that step 401 is performed instead of step 400.

That is, in step 401, it is determined whether or not the estimated starting intake air temperature THAR is equal to or higher than a predetermined temperature (in this embodiment, the predetermined temperature is 70 ° C., and therefore, THAR ≦ 70 ° C.). Is determined. This step 401 is a process for determining whether or not a precondition (execution condition) for performing the fuel pressure increasing process is satisfied. In addition,
Here, conventionally, in step 401, it is determined whether or not the detected intake air temperature THast is equal to or higher than the predetermined temperature based on the detected intake air temperature THast. In this embodiment, however, the reliability of the startup intake air temperature THast is determined. Is not constant, the estimated starting intake air temperature THAR is used instead of the starting intake air temperature THast.
You are using

Step 401 constitutes second comparing means. As described above, in this embodiment, the precondition of the “fuel pressure increase control” in step 401 is “THA
R ≧ 70 ° C. ”.

Therefore, in this embodiment, unnecessary control of the increase in fuel pressure is prevented by a precondition (execution condition) caused by the intake air temperature THA which is higher than the true value by leaving the ignition switch 19 at the ON position. In addition, overriching due to unnecessary fuel pressure increase execution is prevented, and deterioration of startability and exhaust gas deterioration due to fuel covering of the ignition plugs 6A to 6D are prevented.

In this embodiment, this "fuel pressure increase control routine" corresponds to the predetermined control performed by the ECU 30. The second embodiment has the following advantages. (1) In the above embodiment, in the "EGR valve flow rate abnormality detection control routine" in FIG. 10, in step 211, the magnitude of the EGR gas temperature THG is compared with the (estimated intake air temperature THAR at + 60 ° C.). And THG <TH
When AR + 60 ° C., the ECU 30 determines that the flow rate of the EGR valve has decreased, and detects an abnormality.
As a result, it is possible to prevent erroneous detection due to the intake air temperature rising above the true value, and at the same time, secure an opportunity to detect a decrease in the EGR valve flow rate abnormality. (2) In the above-described embodiment, in the “tank hole opening detection control routine” of FIG. 11, the processing of determining whether or not the prerequisites (execution conditions) of Step 301 and Step 311 are satisfied is the same as the conventional one. Differently, the intake air temperature T at the start
The estimated starting intake air temperature THAR was used instead of HAst. As a result, when the ignition key switch 19 is left in the ON position, the startup intake air temperature THast
By using, it is possible to prevent the precondition (execution condition) from being unsatisfied and to prevent the tank system hole detection control from being prohibited, and to secure a tank system hole detection opportunity. (3) In the “fuel pressure increase control routine” in FIG. 12, preconditions (execution conditions) for performing the fuel pressure increase process
Since the reliability of the intake air temperature THast at start is not constant in step 401, which is a process for determining whether or not the above-mentioned condition is satisfied, the estimated intake air temperature THAR at start is used instead of the intake air temperature THast at start. As a result, when the ignition key switch 19 is left at the ON position, the use of the increased intake air temperature THast at the time of start can prevent an over-rich due to unnecessary execution of a fuel pressure increase. It is possible to prevent the startability and the exhaust gas from deteriorating due to fuel coverage of ~ 6D. (Third Embodiment) Next, a third embodiment will be described with reference to FIG.
This will be described with reference to FIG.

In the first embodiment, when the ignition switch 19 is operated from the off position to the on position, the air flow meter 22 is supplied with power from a battery (not shown) and starts heating. In the embodiment, when the starter signal STA is input to the ECU 30,
The air flow meter 22 is connected to the ignition switch 19
Is operated from the off position to the on position, power is supplied from a battery (not shown). Less than,
This will be described in detail.

FIG. 13 shows a flow chart of the air flow meter control, which is executed by a periodic interruption after the ECU 30 is started. In this control routine, step 6
At 00, it is determined whether or not the start determination flag XSAT1 has been reset to “0”. If the start determination flag XSTA1 is set to "1", the flow shifts to step 630. If the start determination flag XSAT1 is "0", the process proceeds to step 610 to determine whether or not the starter signal STA has been input.
It is determined whether the A flag is set to “1”. The YSTA flag is for determining whether or not the starter signal STA has just been input to the ECU 30. If the YSTA flag is set to “1”, it is immediately after the starter signal STA is input, and
If it is reset to "0", it means that it is not immediately after the starter signal STA is input.

If it is determined in step 610 that the YSTA flag is "0", the flow proceeds to step 640, in which the energization of the air flow meter (indicated by "AFM" in the figure) 22 is not performed, and this control routine is executed. Is temporarily terminated.

If it is determined in step 610 that the YSTA flag is "1", the flow shifts to step 620 to set the start determination flag XSTA1 to "1", and shifts to step 630. Step 620 or step 600
From step to step 630, in step 630, the air flow meter 22 is energized, and the control routine is temporarily ended.

In this embodiment, the ECU 30 constitutes an air flow meter control means. In the flowchart, steps 600 to 640 correspond to an air flow meter control unit.

FIG. 14 is a time chart when the air flow meter 22 is controlled as described above.
Conventionally, when the ignition switch 19 is operated from the off position to the on position (t1), the air flow meter 2
2 is turned on and left as it is (leaving time)
At time t2, the intake air temperature THA detected by the intake air temperature sensor 28 deviates from the true intake air temperature at time t2.

On the other hand, in this embodiment, when the ignition switch 19 is operated from the ON position to the starter ON position (at time t2) as shown in FIG.
Is turned on, and the air flow meter 22 is turned on. As a result, since the hot wire generates heat from this point, the difference between the true intake air temperature caused by leaving the ignition key switch 19 at the ON position and the intake air temperature (THA in FIG. 14) detected by the intake air temperature sensor 28 is detected. Can be eliminated.

Therefore, in this embodiment, when the engine is started, the intake air temperature THA detected at the time t2 is
It is used as a control parameter or a precondition (execution condition) for various controls.

For example, in this embodiment, FIG.
In the "EGR valve flow rate abnormality detection control routine" of 0, during the processing in step 211, instead of the estimated startup intake air temperature THAR, the startup intake air temperature THA (t in FIG. 14) is used.
2 o'clock, hereinafter used interchangeably in this embodiment).

Therefore, in the "EGR valve flow rate abnormality detection control routine" in this embodiment, there is no erroneous detection due to the intake air temperature rising above the true value, and at the same time, an opportunity for EGR valve flow rate abnormality detection is secured. You.

In this embodiment, the “tank hole detection control routine” of FIG.
01 and step 311, the estimated intake air temperature T at the time of starting
Instead of HAR, the starting intake air temperature THA is used.

As a result, in this embodiment, the preconditions (execution conditions) caused by the intake air temperature THA higher than the true value are not satisfied due to the ignition switch 19 being left at the ON position, and at the same time, the tank system hole detection is performed. Is detected.

In this embodiment, in the "fuel pressure increase control routine" in FIG. 12, in step 401, the starting intake air temperature THA is used instead of the estimated starting intake air temperature THAR.

As a result, in the present embodiment, unnecessary control of fuel pressure increase is eliminated due to a precondition (execution condition) caused by the intake air temperature THA that has risen above the true value due to the ignition switch 19 being left at the ON position. In addition, overriching due to unnecessary fuel pressure increase execution is prevented, and deterioration of startability and exhaust gas deterioration due to fuel covering of the ignition plugs 6A to 6D are prevented.

The present invention is not limited to the above embodiments, but may be implemented as follows by appropriately changing a part of the configuration of the embodiments. (1) In the second embodiment, the estimated starting time THAR may be used for calculating the fuel injection amount. That is, the ECU
30 performs fuel injection amount calculation control for calculating the fuel injection amount based on various control parameters.

That is, the ECU 30 calculates the target fuel injection time TAU, which is the valve opening time of the injectors 6A to 6D, based on the following equation. TAU = K0 × (Q / NE) × (K1 + K2 +...) Here, K0 is a conversion coefficient of injection amount-injection time according to injector size, Q is intake air amount, NE is engine speed, and K0 · (Q / NE) is a basic injection time set to obtain a stoichiometric air-fuel ratio. That is, the injection time when the injector tip pressure-the pressure difference in the delivery pipe is constant. K1, K2, etc. are various correction coefficients corresponding to various control parameters, and include, for example, those relating to intake temperature, increase in warm-up, increase after start-up, feedback control of air-fuel ratio, and the like. The coefficient K1 relating to the intake air temperature is
This is for correcting a deviation due to the estimated intake air temperature THAR at the start, and is obtained based on the estimated intake air temperature THAR at the start with reference to a map shown in FIG. The coefficient K2 relating to the increase in the warm-up is for increasing the basic injection time for improving the operation control in the cold state, and is obtained based on the cooling water temperature THW. The coefficient related to the post-start increase is to stabilize the engine speed NE immediately after the engine is started, and is obtained based on the cooling water temperature THW.

By doing so, it is possible to prevent over-lean and deterioration of exhaust gas due to the intake air temperature THA which has risen from the true value beforehand. In this embodiment, the fuel injection amount calculation control corresponds to the predetermined control, and the ECU 30 that calculates the fuel injection amount constitutes a control unit.

(2) In the embodiment of (1),
It may be a combination of the third embodiment.
That is, in the above (1), the estimated intake air temperature TH at the time of starting is determined.
Instead of AR, the intake air temperature THA at t2 in FIG.
The same operation and effect as the above (1) can be obtained by using.

(3) Control of an internal combustion engine having an intake air temperature sensor which is provided separately from the air low meter 22 and the intake air temperature sensor 28 instead of being integrated, and which is arranged close to a range affected by the heat of the hot wire. It may be embodied for the device.

While the embodiments embodying the present invention have been described above, technical ideas other than those described in the claims that can be grasped from the above embodiments will be described below together with their effects.

(A) In claim 1, the predetermined control is:
A control device for an internal combustion engine having a thermal air flow meter which is an EGR valve flow rate reduction abnormality detection control for detecting whether or not the flow rate of EGR gas is reduced by an EGR valve. E
In the GR valve flow rate reduction abnormality detection control, the control is performed only when the execution condition is satisfied. If the intake air temperature at the time of starting the internal combustion engine is unreliable because the ignition key switch is left at the ON position, the EGR valve flow rate reduction Since the abnormality detection control is prohibited, erroneous detection due to the increased intake air temperature THA can be prevented.

(B) In claim 1, the predetermined control is:
A control device for an internal combustion engine having a thermal air flow meter which is a tank system hole detection control for detecting whether a hole is formed in a fuel tank. In the tank hole detection control,
Tank system perforation detection can be performed only when the execution condition is satisfied.If the intake air temperature at the time of starting the internal combustion engine is unreliable due to leaving the ignition key switch in the ON position, erroneous detection of tank system perforation detection will occur. Can be prevented.

(C) A control device for an internal combustion engine having a thermal air flow meter according to claim 2 or 3, wherein the predetermined control is a fuel pressure increase control for increasing a fuel injection amount at a start. In the fuel pressure increase control at the time of starting the internal combustion engine, the ignition key switch is left in the ON position, and by using the increased intake air temperature at the time of start, it is possible to prevent an over-rich due to unnecessary execution of the fuel pressure increase. As a result, it is possible to prevent the startability and the exhaust gas from being deteriorated due to the fuel plug fuel covering.

(D) The control device for an internal combustion engine according to claim 3, further comprising a thermal air flow meter for tank system perforation detection control for detecting whether or not a hole is formed in the fuel tank. In tank system hole detection control, erroneous detection of tank system hole detection using the true intake air temperature can be performed even when the intake air temperature at the start of the internal combustion engine is unreliable due to the ignition key switch being left in the ON position. Can be prevented.
In FIG. 8, the estimated intake air temperature THAR at the start corresponds to the true intake air temperature.

(E) In claim 3, the predetermined control is:
A control device for an internal combustion engine having a thermal air flow meter which is an EGR valve flow rate reduction abnormality detection control for detecting whether or not the flow rate of EGR gas is reduced by an EGR valve. E
In the GR valve flow rate reduction abnormality detection control, even if the intake air temperature at the time of starting the internal combustion engine is unreliable, the intake air temperature T increases even if the ignition key switch is left at the ON position.
Erroneous detection caused by HA can be prevented.

[0117]

As described in detail above, according to the first to fourth aspects of the present invention, the thermal air flow meter in which the intake air temperature sensor is integrated, or the air flow meter which is not integrated, In an internal combustion engine in which an air temperature sensor is disposed close to a thermal air flow meter, if the engine is started after the ignition (IG) is turned on without starting the engine, an erroneous determination in abnormality detection is performed. In addition, there is no possibility that the abnormality detection capability is reduced, and the engine can be controlled under appropriate execution conditions in performing various engine controls.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a control device of an engine system according to a first embodiment.

FIG. 2 is a schematic configuration diagram showing a fuel supply device.

FIG. 3 is a block diagram showing an electrical configuration of an ECU and the like.

FIG. 4 is a flowchart showing an “intake air temperature determination control routine”.

FIG. 5 is a flowchart showing an “EGR valve flow rate reduction abnormality detection control routine”.

FIG. 6 is a flowchart illustrating a “tank hole detection control routine”;

FIG. 7 is a flowchart showing a “fuel pressure increase control routine”.

FIG. 8 is a flowchart illustrating an “intake air temperature estimation control routine” according to the second embodiment;

FIGS. 9A, 9B, and 9C are explanatory diagrams of maps for calculating a correction coefficient, respectively.

FIG. 10 is a flowchart showing an “EGR valve flow rate decrease abnormality detection control routine”.

FIG. 11 is a flowchart showing a “tank hole detection control routine”.

FIG. 12 is a flowchart illustrating a “fuel pressure increase control routine”.

FIG. 13 is a flowchart illustrating an “air flow meter control routine” according to the third embodiment;

FIG. 14 is a time chart of THA, which is a detection value of an ignition switch, an air flow meter, a starter, and an intake air temperature sensor.

FIG. 15 is an explanatory diagram of a map including an estimated starting intake air temperature THAR and a correction coefficient K1.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine as an internal combustion engine, 2 ... Intake passage, 22 ...
Hot wire type air flow meter constituting operating state detecting means, 24 ... water temperature sensor constituting operating state detecting means, 28 ... intake air temperature sensor, 30 ... control means, first comparing means, second comparing means, correction coefficient EC constituting calculation means, intake air temperature calculation means, and air flow meter control means
U.

Claims (4)

[Claims] 1. An electric generator, which is provided in an intake passage of an internal combustion engine and outputs a detection signal in accordance with an amount of intake air passing through the intake passage, and generates heat when an ignition switch is turned on from off. A thermal air flow meter provided with a thermal heating element, and an intake air temperature sensor provided integrally with or adjacent to the thermal air flow meter. A control device for an internal combustion engine having a thermal air flow meter having a control means for performing predetermined control of the internal combustion engine based on the intake air temperature detected by an intake air temperature sensor when the ignition switch is turned on from off. Is the first intake air temperature, and the second intake air temperature is the intake air temperature detected by the intake air temperature sensor when the internal combustion engine is started.
A first comparison means for comparing a difference between the intake air temperature with a predetermined first determination value, and the control means performs predetermined control of the internal combustion engine based on a comparison result of the first comparison means. When the execution condition is satisfied, the predetermined control is performed. When the execution condition is not satisfied, the thermal air flow meter prohibits the predetermined control. A control device for an internal combustion engine, comprising: 2. An electric device which is provided in an intake passage of an internal combustion engine, outputs a detection signal according to an amount of intake air passing through the intake passage, and starts heat generation when an ignition switch is turned on from off. A thermal air flow meter provided with a thermal heating element, and an intake air temperature sensor provided integrally with or adjacent to the thermal air flow meter. A control device for an internal combustion engine having a thermal air flow meter having a control means for performing predetermined control of the internal combustion engine based on the intake air temperature detected by an intake air temperature sensor when the ignition switch is turned on from off. Is a first intake air temperature, a second comparison means for comparing the first intake air temperature with a predetermined second determination value, wherein the control means comprises: The comparison result of the comparison means is used as an execution condition when performing predetermined control of the internal combustion engine.If the execution condition is satisfied, the predetermined control is performed.If the execution condition is not satisfied, A control device for an internal combustion engine having a thermal air flow meter for inhibiting the predetermined control. 3. An electric device which is provided in an intake passage of an internal combustion engine, outputs a detection signal corresponding to an amount of intake air passing through the intake passage, and starts heat generation when an ignition switch is turned on from off. A thermal air flow meter provided with a thermal heating element, and an intake air temperature sensor provided integrally with or adjacent to the thermal air flow meter. A control device for performing predetermined control of the internal combustion engine, the control device for the internal combustion engine having a thermal air flow meter, wherein an operation state of the internal combustion engine including an intake air amount of the internal combustion engine and an engine temperature is detected. Operating state detecting means, and a correction coefficient is calculated based on the amount of intake air detected by the operating state detecting means, the engine temperature, and the elapsed time from the start of the internal combustion engine. Correction coefficient calculation means, a correction coefficient calculated by the correction coefficient calculation means, a first intake air temperature detected by an intake air temperature sensor when an ignition switch is turned on from off, and an intake air temperature when the internal combustion engine is started. An intake air temperature calculating unit that calculates a true intake air temperature based on the second intake air temperature detected by the sensor, and the control unit, based on the true intake air temperature calculated by the intake air temperature calculating unit, A control device for an internal combustion engine having a thermal air flow meter for performing control. 4. An electric heating element which is provided in an intake passage of the internal combustion engine, outputs a detection signal according to an amount of intake air passing through the intake passage, and starts heat generation by operating an ignition switch. An internal combustion engine based on the intake air temperature detected by the intake air temperature sensor, the intake air temperature sensor being provided integrally with or close to the thermal air flow meter. A control device for an internal combustion engine having a thermal air flow meter provided with control means for performing a predetermined control of the thermal air flow meter, wherein the ignition type switch operates to start heat generation in the thermal air flow meter when the internal combustion engine is started. A control device for an internal combustion engine having a thermal air flow meter, characterized by comprising an air flow meter control means for causing the air flow meter to operate.