JPH10131799A - Engine control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure travel performance safely and sufficiently even in the case where an abnormal condition is generated on control of an electric control throttle valve by failure of an acceleration opening sensor by setting a fuel injection rate and an ignition timing on the basis of the operating condition of an acceleration and a vehicle speed. SOLUTION: When an abnormal condition is generated on control of an electric control throttle valve 3, control of the throttle valve 3 which is electrically controlled by driving a motor 6 is stopped. The operating condition of an acceleration is detected by an output of an idling switch 7, fuel injection control and ignition control are carried out when the operation rate of the acceleration is 0. When the operation rate is not 0, vehicle speed is read from an output of the vehicle speed sensor 15, and the prescribed ignition timing and a fuel injection rate is set on the basis of the vehicle speed so as to obtain a target accelerating rate on a flatland. It is thus possible to safely carry out travel in which a driver's will is reflected, and prevent rapid acceleration so as to carry out proper evacuated travel while ensuring safety.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle engine control device, and more particularly to a vehicle engine control device provided with an electronically controlled throttle valve.

[0002]

2. Description of the Related Art In recent years, computerization of an engine control device of a vehicle has been advanced, and based on an output signal of an accelerator opening sensor for detecting an operation amount of an accelerator pedal, further taking into account an engine speed, a negative pressure of an intake manifold, and the like. An electronically controlled throttle valve that is controlled by a throttle valve actuator (motor) so as to have a calculated throttle valve opening has been put to practical use.

Conventionally, this electronically controlled throttle valve has been provided with a preliminary opening / closing mechanism capable of mechanically controlling the throttle opening during the failure since the opening / closing control of the throttle valve by the actuator becomes impossible at the time of failure. However, this preliminary opening / closing mechanism may be difficult to attach to the engine because of its size and layout problems, and is disadvantageous in terms of cost.

On the other hand, when such a preliminary opening / closing mechanism is not provided, when the electronically controlled throttle valve fails, the throttle opening is set so as to be fixed to the degree of safety in consideration of safety. However, in such a state where the throttle opening is fixed, the torque generated by the engine cannot be adjusted, and there is a disadvantage that a sufficient speed cannot be obtained when the vehicle travels in a limp mode.

In order to solve these problems, an engine control device for a vehicle equipped with an electronically controlled throttle valve has
When an abnormality occurs in the control of the electronically controlled throttle valve, the engine is generated by fixing the throttle opening to a predetermined value and adjusting the fuel injection amount and ignition timing according to the operation amount of the accelerator pedal detected by the accelerator opening sensor. A device that controls the torque to ensure traveling performance has been proposed (Japanese Patent Laid-Open No.
-280656).

[0006]

However, in such a conventional engine control device for a vehicle, when the accelerator opening sensor for detecting the driver's intention regarding acceleration / deceleration and the degree thereof is broken, the accelerator opening sensor is used. Only by turning on and off an idle switch provided in a separate system, the driver's intention can be grasped in a binary manner. Therefore, in the case of evacuation running in which an abnormality occurs in the control of the electronically controlled throttle valve due to a malfunction of the accelerator opening sensor, in order to prevent sudden acceleration etc. and to run safely, fuel injection with reduced engine generated torque is performed. The amount and ignition timing had to be set.

[0007] As described above, in the conventional vehicle engine control device, when the accelerator opening sensor fails, precise control of the engine-generated torque reflecting the driver's intention cannot be performed. There was a problem that it was done. The present invention has been made in view of the above-described conventional problems, and has been made in consideration of the above-described problems. Therefore, even in a case where an abnormality occurs in control of an electronically controlled throttle valve due to a failure of an accelerator opening sensor, a vehicle engine control device capable of ensuring safe and sufficient traveling performance. The purpose is to provide.

[0008]

Therefore, in the invention according to claim 1, as shown in FIG. 1, an accelerator opening detecting means A for detecting the depression amount of an accelerator pedal as an accelerator opening, Valve control means B for controlling the opening of an electronically controlled throttle valve based on the accelerator opening
Abnormality detecting means C for detecting the presence or absence of an abnormality between the accelerator opening detecting means and the throttle valve controlling means; and holding the electronically controlled throttle valve at a predetermined throttle opening when the abnormality is detected. Throttle opening holding means D
An accelerator operation detecting means E for detecting an operation state of the accelerator pedal, a vehicle speed detecting means F for detecting a vehicle speed, and detecting the accelerator operation when the abnormality is detected. When the accelerator operation state detected by the means is in a predetermined state, output control means G for controlling at least one of the fuel injection amount and the ignition timing based on the vehicle speed detected by the vehicle speed detection means and controlling the output of the engine. Are provided.

As a result, even when an abnormality occurs in the control of the electronically controlled throttle valve, and particularly when the accelerator opening cannot be accurately detected, the fuel injection amount and the ignition timing are set according to the vehicle speed. Ensuring proper driving performance. The output control means may set the fuel injection amount to be richer and the ignition timing to be advanced as the vehicle speed detected by the vehicle speed detection means increases, as in the invention according to claim 2. .

Further, in the invention according to claim 3, the vehicle speed change amount calculating means for calculating the change amount of the vehicle speed during a predetermined period, and the fuel injection amount and the ignition timing set by the output control means are used for changing the vehicle speed. Output control correcting means for correcting based on the amount is provided to cope with a change in running conditions such as uphill. Specifically, the output control correction means includes a target acceleration amount calculated based on a fuel injection amount and an ignition timing set by the output control means, as in the invention according to claim 4. The set fuel injection amount and ignition timing may be corrected in accordance with the magnitude of the change in vehicle speed.

The accelerator operation detecting means detects an operation state of the accelerator pedal based on an output of an idle switch for detecting a state in which the operation amount of the accelerator pedal is substantially zero. This is convenient.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a system configuration diagram showing an example of the vehicle engine control device of the present invention. An electronically controlled throttle valve 3 for controlling an intake air amount Qa is provided in an intake passage 2 of the engine 1. The electronically-controlled throttle valve 3 is not mechanically connected to the accelerator pedal 4 and outputs an output signal from a potentiometer-type accelerator opening sensor 5 for detecting an operation amount Ac of the accelerator pedal 4 (hereinafter referred to as an accelerator opening) Ac. Is controlled by the motor 6 as an actuator. Then, when the control by the motor 6 is stopped, the valve body is fixed to a predetermined position (slightly open side from the fully closed position) by a spring to maintain a predetermined throttle opening. Further, the accelerator pedal 4 is provided with an idle switch 7 which is turned on when the accelerator opening Ac is substantially fully closed, which is separate from the accelerator opening sensor 5.

A fuel injection valve 8 is provided on the downstream side of the electronically controlled throttle valve 3 in the intake passage 2 so that the injection hole faces the inside of the intake passage 2, and the injected fuel passes through the electronically controlled throttle valve 3. An air-fuel mixture is formed with the air. Then, the air-fuel mixture introduced into the combustion chamber 9 is ignited and burned by the ignition plug 10 and discharged to the exhaust passage 11 side. Also, the intake air amount Qa
Air flow meter 1 that outputs a signal proportional to
2. A water temperature sensor 13 that outputs a signal proportional to the cooling water temperature Tw of the engine 1, a crank angle sensor 14 that outputs a signal in synchronization with the rotation of the crankshaft, and detects a vehicle speed Vsp from a rotation speed on the output side of the transmission. Vehicle speed sensor 15,
Various sensors such as a throttle opening sensor 16 for detecting the actual opening of the electronically controlled throttle valve 3 are provided for detecting the operating state of the engine 1.

The outputs of the various sensors and switches are all processed by the control unit 17 to control the motor 6 for driving the electronically controlled throttle valve 3, the fuel injection valve 8, the spark plug 10 and the like. . FIG. 3 is a flowchart illustrating control by the device of the present invention,
It is executed every predetermined time.

First, in step 1 (referred to as S1 in the figure, the same applies hereinafter), it is determined whether there is an abnormality in the control of the electronically controlled throttle valve 3, that is, the accelerator opening sensor 5 as accelerator opening detecting means. It is determined whether or not there is an abnormality in the motor 6 as a throttle valve control means. Specifically, the output of the accelerator opening sensor 5 and the output of the throttle opening sensor 16 are compared, and if a difference equal to or more than a predetermined value has occurred, it is determined that an abnormality has occurred. This step 1 corresponds to the abnormality detecting means.

If there is no abnormality in the control of the electronically controlled throttle valve 3, the routine proceeds to step 11 as usual, and is calculated from the intake air amount Qa detected by the air flow meter 12 and the output of the crank angle sensor 14. The basic fuel injection amount Tp is calculated based on the engine speed Ne. Then, in the next step 12, the fuel injection amount Ti is calculated based on the basic fuel injection amount Tp, and the ignition timing Adv is calculated based on the basic fuel injection amount Tp and the engine speed Ne. After that, the routine proceeds to step 31, where fuel injection control and ignition control are performed based on the values calculated in the preceding stage.

On the other hand, when it is determined that the control of the electronically controlled throttle valve 3 is abnormal, the routine proceeds to step 2, where the motor 6
The control of the electronically controlled throttle valve 3 by the drive of is stopped. As a result, the valve body of the electronically controlled throttle valve 3 is fixed at a predetermined position by a spring, and maintains a predetermined throttle opening. Step 2 corresponds to the throttle opening holding means.

In the following step 3, the accelerator operation state is detected from the output of the idle switch 7 as accelerator operation detecting means. That is, the operation amount of the accelerator is 0
(Fully closed), and if it is 0, the routine proceeds to step 21, where the ignition timing Adv and the fuel injection amount Ti
The fuel injection control and the ignition control are performed in step 31 in accordance with the set values. By such control, even if the accelerator opening sensor 5 is abnormal, the driver can quickly decelerate according to the driver's intention.

On the other hand, when the operation amount of the accelerator is not 0, the vehicle speed Vsp is read from the output of the vehicle speed sensor 15 as the vehicle speed detecting means in step 4. Then, in the next step 5, based on the vehicle speed Vsp from a table as shown in FIG. 4, the predetermined ignition timing Adv ₀ and the fuel injection amount Ti ₀ (the higher the vehicle speed Vsp, The timing Adv ₀ is on the advance side, and the fuel injection amount Ti ₀ is on the rich side). Steps 4 and 5 correspond to output control means.

By doing so, it is possible to perform a proper evacuation traveling while preventing sudden acceleration and ensuring safety. Further, in order to enable the vehicle to climb up and down, in the next step 6, the difference ΔVsp between the vehicle speed Vsp and the previous vehicle speed Vsp-old is used.
Is calculated. Step 6 corresponds to the vehicle speed change amount calculating means.

In step 7, the ignition timing Adv ₀ and the fuel injection amount Ti ₀ are corrected based on the comparison between ΔVsp and the target acceleration amount α, and the final ignition timing Adv and the fuel injection amount Ti are set. Step 7 corresponds to output control correction means. Specifically, using a table as shown in FIG. 5, when ΔVsp falls below the target acceleration amount α, it is determined that the acceleration is insufficient, and the ignition timing Adv is advanced to the advance side.
The correction coefficient Hos is set so that the fuel injection amount Ti is on the rich side. Conversely, when ΔVsp exceeds the target acceleration amount α, it is determined that the acceleration is excessive, and the ignition timing Adv is set on the retard side. In addition, the correction coefficient H is set so that the fuel injection amount Ti becomes lean.
Set os. Then, using the correction coefficient Hos, the ignition timing Adv ₀ and the fuel injection amount Ti ₀ are corrected by the following equation.

[0022] In _{Adv = Adv 0 × (1 +} Hos) Ti = Ti 0 × (1 + Hos) Finally step 31, and ends the fuel injection control and the ignition control and the done processing based on the value after the correction. In this way, even when the acceleration amount is excessive or insufficient on a slope or the like, the ignition timing Adv and the fuel injection amount Ti can be corrected in accordance with this, and the engine generated torque can be adjusted.

In the vehicle engine control device having the above-described configuration, even if an abnormality occurs in the control of the electronically controlled throttle valve 3, the vehicle can perform the limp-home running reflecting the driver's intention. In addition, even if the accelerator opening sensor 5 fails, control based on the traveling speed is possible, so that sufficient evacuation traveling can be performed while securing sufficient traveling performance.

[0024]

As described above, according to the first aspect of the present invention, even if an abnormality occurs in the control of the electronically controlled throttle valve due to the failure of the accelerator opening sensor, the operation state of the accelerator and the vehicle speed are not affected. By setting the fuel injection amount and the ignition timing on the basis of this, there is an effect that the vehicle can safely travel while reflecting the driver's intention.

Further, by eliminating a preliminary control mechanism for the limp-home running, there is also an effect that the manufacturing cost of the actuator can be reduced. According to the second aspect of the invention, there is an effect that control according to the vehicle speed can be easily realized. Further, according to the third aspect of the invention, even when the acceleration amount is excessive or insufficient on a slope or the like, there is an effect that it is possible to correct this and obtain safe and sufficient traveling performance.

Further, according to the invention of claim 4, there is an effect that it is possible to accurately grasp the excess or deficiency of the acceleration amount and to appropriately correct the fuel injection amount and the ignition timing. Also,
According to the invention of claim 5, there is an effect that the intention of the driver can be detected easily and accurately.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating functions of a vehicle engine control device according to the present invention.

FIG. 2 is a system configuration diagram showing an example of a vehicle engine control device of the present invention.

FIG. 3 is a flowchart illustrating control by the apparatus of the present invention.

FIG. 4 is a diagram showing a table for setting an ignition timing and a fuel injection amount;

FIG. 5 is a diagram showing a table for setting a correction coefficient.

[Explanation of symbols]

 Reference Signs List 1 engine 2 intake passage 3 electronically controlled throttle valve 4 accelerator pedal 5 accelerator opening sensor 6 motor 7 idle switch 8 fuel injection valve 9 combustion chamber 10 spark plug 11 exhaust passage 12 air flow meter 13 water temperature sensor 14 crank angle sensor 15 vehicle speed sensor 16 Throttle opening sensor 17 Control unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02P 5/15 F02P 5/15 B

Claims (5)

[Claims] An accelerator opening detecting means for detecting an amount of depression of an accelerator pedal as an accelerator opening; a throttle valve controlling means for controlling an opening of an electronically controlled throttle valve based on the detected accelerator opening; Abnormality detection means for detecting the presence or absence of an abnormality between the accelerator opening detection means and the throttle valve control means; and a throttle opening for holding the electronically controlled throttle valve at a predetermined throttle opening when the abnormality is detected. Holding means; a vehicle engine control device comprising: an accelerator operation detecting means for detecting an operation state of the accelerator pedal; a vehicle speed detecting means for detecting a vehicle speed; and detecting the accelerator operation when the abnormality is detected. When the accelerator operation state detected by the means is in a predetermined state,
An engine control device for a vehicle, comprising: an output control unit configured to set at least one of a fuel injection amount and an ignition timing based on a vehicle speed detected by the vehicle speed detection unit and control an output of the engine. 2. The output control means increases the fuel injection amount as the vehicle speed detected by the vehicle speed detection means increases.
The engine control device for a vehicle according to claim 1, wherein the ignition timing is set to be advanced. 3. A vehicle speed change amount calculating means for calculating the vehicle speed change amount in a predetermined period; and output control for correcting a fuel injection amount and an ignition timing set by the output control means based on the vehicle speed change amount. The vehicle engine control device according to claim 1 or 2, further comprising: a correction unit. 4. The output control correcting means according to a magnitude of a target acceleration amount calculated based on a fuel injection amount and an ignition timing set by the output control means and a change amount of the vehicle speed. 4. The engine control device for a vehicle according to claim 3, wherein the set fuel injection amount and ignition timing are corrected. 5. An accelerator operation detecting means for detecting an operation state of an accelerator pedal based on an output of an idle switch for detecting a state where an operation amount of an accelerator pedal is substantially zero. An engine control device for a vehicle according to any one of claims 1 to 4.