JPS63134837A - Control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve the limp home function as ensuring the safety of a vehicle, by stopping the operation of an internal combustion engine when abnormality of valve opening/closing operation of a throttle valve is generated at a predeter mined opening angle or more. CONSTITUTION:A throttle valve control device 5 receives a detection valve from a throttle opening sensor 31 and determines abnormality of valve opening/ closing operation of a throttle valve 3 according to a program and data stored in a memory 25. An engine control device 7 stops or reduce fuel supply to an engine 1 according to an abnormality generation opening angle (lock opening angle) of the throttle valve 3. Accordingly, when the lock opening angle of the throttle valve 3 is an opening angle such that an output cannot be reduced to an appropriate value (operation stop opening angle or more), the operation of the engine 1 is stopped to avoid reckless running of a vehicle or the like. On the other hand, when the throttle valve 3 is locked at an opening angle less than the operation stop opening angle, a fuel injection quantity is reduced to thereby allow minimum running of the vehicle.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention provides a method for detecting abnormalities in opening/closing operation of a throttle valve.
The present invention relates to a control device for an internal combustion engine that enables the vehicle to run while ensuring safety.

[Prior Art] Conventionally, as a control technique when a throttle valve drive device fails, a device has been disclosed that stops fuel supply to an internal combustion engine when the opening/closing operation of a throttle valve is abnormal. (Japanese Unexamined Patent Publication No. 61-8436). This technology controls the internal combustion engine to prevent the engine speed from becoming abnormally high by stopping the fuel supply to the engine if the engine speed exceeds a predetermined level when the throttle valve becomes stuck in the open state. It is something to do.

[Problems to be Solved by the Invention] However, the above-mentioned conventional technology was developed with the main purpose of improving safety by preventing engine runaway in the event of a throttle valve failure. However, it was difficult to say that sufficient consideration had been given to the ability to drive to a service shop near R. In other words, when attempting to limp home using the above technique,
Regardless of the driver's will, the engine speed fluctuates significantly across the boundary speed, leading to a hunting condition and extremely poor drivability. Alternatively, if the throttle valve becomes stuck on an uphill slope with a large load, the engine speed will not rise to the above-mentioned boundary speed, and there is a risk that the fuel cut will not be performed.

The present invention can solve the above problems and improve the limp home function of the vehicle while ensuring the safety of the vehicle. The purpose is to provide a control device for an internal combustion engine.

[Means for Solving the Problems] A first invention made as a means for achieving the above object, as illustrated in FIG. 1, provides a throttle valve B for adjusting the amount of air supplied to an internal combustion engine A. and an abnormality detection means C1 for detecting that an abnormality has occurred in the opening/closing valve operation of the throttle valve B, and a means for detecting an abnormality in the opening/closing valve operation of the throttle valve B when the abnormality in the opening/closing valve operation of the throttle valve B is detected. and an operation stop means E1 that stops the operation of the internal combustion engine A when an abnormal opening/closing operation of the throttle valve B occurs at a predetermined opening or more. The main topic is control devices for internal combustion engines.

The second invention, which has been made as a means to achieve the object of the present invention, as illustrated in FIG. Abnormality detection means C2
and an abnormal opening determination means D2 that determines whether the throttle valve B is at a predetermined opening or more when the sticking of the throttle valve B is detected; an operation stop means E2 for stopping the operation of the internal combustion engine A when the throttle valve B is stuck at an opening less than a predetermined opening; The gist of the present invention is a control device for an internal combustion engine, which includes an output control means F2 that performs control accordingly.

The throttle valve B may be, for example, mechanically connected to the accelerator pedal, or may be of a linkless type that is controlled based on the opening degree of the accelerator pedal and the running state of the vehicle.

The abnormality detection means C1 detects, for example, a state in which the throttle valve B is stuck and does not operate, or a state in which the valve opens and closes abnormally without responding to commands from an accelerator pedal, a controller, etc. , an abnormality in the opening/closing valve operation of the thrower valves 1 to 1 is detected by means as exemplified below.

That is, ■ Based on the deviation between the target throttle opening and the actual throttle opening, ■ Based on the change value of the target throttle opening and the change in intake air, ■ The operation amount of the accelerator pedal and the actual throttle opening In the case of a linkless throttle valve, an abnormality in the opening/closing valve operation of throttle valve B is detected based on the current value of the motor.

The abnormality detection means C2 detects, for example, a state in which the throttle valve B is stuck and does not operate, and detects the sticking of the throttle valve B by the same means as the abnormality detection means C1 of the first invention. It is something.

Operation stop means E1. E2 may be to stop the operation of the internal combustion engine by stopping the fuel supplied to the internal combustion engine A, or may be to stop the operation of the internal combustion engine by stopping ignition, etc. Good too.

The output control means F2 increases or decreases the fuel supply level (controls the air-fuel ratio) to control the output to the internal combustion engine, or EGRf
The output of the internal combustion engine A may be controlled by increasing or decreasing i, or the control may also control the advance angle of the ignition timing, or control the opening of a bypass passage for controlling the idle speed. good.

[Operation] The control device for an internal combustion engine according to the first invention has a throttle valve B.
When the abnormality detecting means C1 detects an abnormality in the opening/closing valve operation, and the abnormal opening degree determining means D1 determines that the opening degree of the throttle valve B at the time of detection of the abnormality is equal to or higher than the predetermined opening degree,
The operation stopping means E1 stops the operation of the internal combustion engine A, and when the abnormal opening degree determining means D1 determines that the opening degree of the throttle valve B at the time of the abnormality detection is less than the predetermined opening degree, the operation of the internal combustion engine A is stopped. continue.

The control device for an internal combustion engine according to the second invention includes a throttle valve B.
When the abnormality detecting means C2 detects the sticking of the throttle valve B and the abnormal opening determining means D2 determines that the opening degree of the throttle valve B at the time of detecting the sticking is greater than or equal to the predetermined opening degree, the operation stopping means E
2 stops the operation of the internal combustion engine Δ, and on the other hand, when the abnormal opening determination means D2 determines that the opening degree of the throttle valve B at the time of the above-mentioned sticking detection is less than the predetermined opening degree, the output of the internal combustion engine A is stopped. Control is performed by the output control means F2 according to the opening degree of the valve B.

[Example] 1st. Each embodiment of the control device for an internal combustion engine according to the second invention will be described.

As shown in FIG. 3, the system to which this embodiment is applied includes an internal combustion engine (hereinafter referred to as engine) 1, a throttle valve 3 that adjusts the intake air amount of the engine 1, and a throttle valve that controls the throttle valve 3. The control device 5 and the fuel supply level and exhaust gas recirculation amount (hereinafter referred to as EG) of the engine 1
The engine control device 7 includes an engine control device 7 that controls the R amount (referred to as R amount) based on the operating state.

The engine control device 7 is composed of an input/output interface 9, a central processing section 11, a storage section 13, etc., and performs the following operations.

That is, the operating state of the engine 1 is input to the central processing unit 11 via the input/output interface 9, and
The central processing unit 11 calculates the fuel injection a=lffi and the EGR amount based on the program and data stored in the fuel injection valve 15 and the fuel injection valve 15 that supplies fuel to the engine 1 according to the calculated values. EGR valve 17
A control signal is output via the input/output interface 9 to a modulator 19 that controls the valve opening of the valve. By outputting the control signal to each part, the engine control device 7 optimally controls the combustion state of the engine 1. Note that the details of the control of the fuel injection valve 15 and the modulator 19 are well-known techniques, so a description thereof will be omitted here.

Like the engine control device 7, the throttle valve control device 5 includes an input interface 21, a central processing section 23,
and a storage section 25, etc., and performs the following operations.

(1) An intake m sensor 27 that detects the amount of intake air, a throttle opening sensor 31 that detects the opening of the throttle valve 3, and a rotational speed sensor 33 that detects the rotational speed of the engine 1.
, the detection values of the water temperature sensor 35 that detects the cooling water temperature (engine water temperature) of the engine 1 and the accelerator operation amount sensor 39 that detects the operation port of the accelerator pedal 37 are sent to the central processing unit 23 via the input/output interface 21. Process to input.

(2) According to the input data, it is recorded in advance and stored in the upper part 25)! Processing that calculates the opening degree of the throttle valve 3 (throttle opening degree), determines abnormality in opening/closing valve operation of the throttle valve 3, determines EGR supply stop, and determines the fuel supply amount based on the program and data etc. .

(3) In accordance with the decision, EG for EGR supply suspension
R stop valve 41, two throttle actuators that drive the throttle valve 3, and engine control device 7
Input/output interface 21 for each control signal to
A process of controlling the opening degree of the throttle valve 3 and controlling the output of the engine 1 by outputting the output through the .

The opening of the throttle valve 3 is controlled by the detection value of the throttle opening sensor 31 and the accelerator operation amount sensor 3.
It is executed based on the detected value of 9, etc. For example, the throttle valve control device 5 shown in FIG. 3 inputs detected values of the accelerator operation amount sensor 39, engine water temperature sensor 35, engine speed sensor 33, intake port sensor 27, etc. via its input/output interface 21, The optimum target throttle opening θ0 of the throttle valve 3 is calculated, and the throttle actuator 29 is operated so that the actual opening θr of the throttle valve 3 (opening detected by the throttle opening sensor 31) matches the opening θO. Drive. Incidentally, in this embodiment, the EGR supply is stopped by the EGR stop valve 41, but it may be configured to output an EGR supply stop signal to the modulator 19 as another means. Further, in this embodiment, the engine state is input to the engine control device 7 through the input/output interface 21 of the throttle valve control device 5, but this may be reversed. That is, the engine state may be input to the engine control device 7, and the engine state may be input to the throttle valve control device 5 through the input/output interface 9.

The output control of the engine 1 first detects an abnormality in the opening/closing operation of the throttle valve 3 (see Figures 4 to 6), then stops EGR or changes the basic fuel injection amount (see Figures 7 and 8). This is done by executing the internal combustion engine control routine shown in FIG.

First, the abnormality detection means (lock detection means) in the operation of the linkless throttle valve will be explained based on FIGS. 4 to 6.

The abnormality detection routine shown in FIG. 4 is executed, for example, every 50 m5ec apart from the throttle valve opening control described above.

In the abnormality detection routine shown in FIG. 4, it is determined based on the abnormality flag F whether or not the opening/closing operation of the throttle valve 3 has already been determined to be abnormal (step 100).

If the abnormality flag F has already been set, this routine is once terminated, and if the abnormality flag F has not been set, the process proceeds to step 110. In step 110, the opening difference Δθ between the target opening θO of the throttle valve 3 (command value from the throttle valve control device 5 to the throttle actuator 29) and the actual opening θr (detected value of the throttle opening sensor 31) is determined. Calculate. Next, the opening degree difference Δ
An integral value θi@ of θ is calculated (step 120). The integral value θi is the integral value θi of the opening difference Δθ calculated in the past four processes of this routine and the opening difference Δθ calculated in the current process.
It is calculated by adding . That is, θi ← θi ten △
A calculation of θ-Δθ5 is performed (Δθ5 is the value set in the previous step 140). For example, as shown in FIG. 5, when the current processing time is time TF, the integrated value θi of the opening difference Δθ between the target throttle opening θO and the actual throttle opening Or from time TA to TE. (=
ΔθA+ΔθB+ΔθC+ΔθD+ΔθE), add 〇F to the opening difference at the current time TF and add the opening difference Δ at the time TA.
The integral value θi at the current time is calculated by subtracting θA.

Next, it is determined whether the integral value θi of the opening degree difference Δθ is smaller than the lock determination value (step 130 in FIG. 4).

The lock determination value may be a predetermined value, or may be a function of the engine water temperature, the temperature near the bearing of the throttle actuator 29, the ambient temperature, etc., as shown in FIG. By making it a function of the engine water temperature, etc., locking of the throttle valve 3 can be determined more accurately.

Throttle valve 3 according to step 130 in FIG. 4 above
In the lock determination, if it is determined that the throttle valve 3 is not locked (θi <K), the previous value of the fourth opening difference memory Δθ4 is stored in the fifth opening difference memory Δθ.
5 (step 140), the previous third opening degree difference memory Δθ
3 to the fourth opening difference memory Δθ4 (step 150)
, the previous value of the second opening difference memory Δθ2 is stored in the third opening difference memory Δθ3 (step 160), and the previous value of the first opening difference memory Δθ1 is stored in the second opening difference memory Δθ2 (step 170). , the current opening difference Δθ is stored in the first opening difference memory Δθ
1 (step i s o > set. As a result, the fifth opening degree difference memory Δ set in step 140
It becomes possible to use the value of θ5 in the calculation performed in step 120 above.

As a result of the processing in steps 100 to 180, if it is determined in step 130 that the throttle valve 3 is locked (θi≧K), an abnormality flag F is set (step 190). This abnormality flag F is used to detect the locked state of the throttle valve in the internal combustion engine control routine shown in FIG.

Next, an embodiment of the first invention will be described. This embodiment is carried out by monitoring the set state of the abnormality flag F in the abnormality detection routine shown in FIG. 4 and executing the internal combustion engine control routine shown in FIG. 7, which changes the basic fuel injection amount. In this routine, first, the set state of the abnormality flag F is checked to determine whether or not the throttle valve 3 is in an abnormal (locked) state (step 200>. Based on this determination, it is determined that the throttle valve 3 is abnormal. In this case, the opening degree θ of the throttle valve 3 becomes the operation stop opening degree θ3 based on the detected value of the throttle opening degree sensor 31.
(Here, 30°) or more is determined in step 21.
0>, θ≧03, a fuel injection stop signal is output from the throttle valve control device 5 executing this routine to the engine control device 7 controlling the fuel injection amount, and the engine 1 (step 220).

By performing steps 200 to 220 described above, when the throttle valve 3 is locked at an operation stop opening degree of less than 03, the fuel supply to the engine 1 can be stopped before the engine speed increases abnormally.

Therefore, the fail-safe function for the throttle valve 3 is improved.

When the throttle opening degree θ is determined to be less than the operation stop opening degree 03 as determined in step 210, the process moves to the next determination of the abnormal opening degree (step 230). In step 230, it is determined whether the abnormal opening is less than the operation stop opening 03 and greater than or equal to the output reduction opening 02 (θ2≦θ×θ3), or less than the output reduction opening 02 (θ×θ2>). Then, based on this determination, the process is shifted to one of the next output control steps 240 to 250 for the engine 1.

The abnormal opening degree is θ2≦θ<θ3 (here, θ2 is 20'
), a fuel injection amount reduction signal is output to the engine control device 7 to reduce the engine output (step 24O). The above fuel injection amount is, for example, an air-fuel ratio at which the engine 1 can be operated without misfire,
For example, it may be set to 0.7 times the basic injection amount, or the basic injection amount may be decreased based on the throttle opening θ. By reducing the basic injection amount based on the throttle opening θ, the engine output can be controlled with high precision.

Above step 200. As a result of the processing in '210, 230, and 240, if an abnormality occurs when the throttle opening θ is relatively large, that is, if the throttle valve 3 is locked while a large engine output is being generated, the fuel to the engine 1 will be The feed rate can be reduced to reduce engine power. Therefore, even if the throttle valve 3 is locked at a relatively large throttle opening, by executing this process, the engine output can be reduced, making it possible to safely drive the vehicle by operating the clutch and brake. .

If it is determined in step 230 that the abnormal opening degree is θ2, the basic injection amount control signal is directly output to the engine control device 7 (step 250). This results in
The output of the engine 1 is controlled to a value calculated without an instruction to increase or decrease the injection amount from the throttle valve control device @5.

By the processing in steps 200, 210, 230, and 250, if the throttle opening θ at which the abnormality occurs is an opening that generates an engine output that enables emergency driving, the current engine output can be maintained.

As explained above, according to this embodiment, the fuel supply to the engine 1 is stopped or reduced according to the abnormal opening degree (lock opening degree) of the throttle valve 3, so that the engine can respond to the abnormal opening degree. Output characteristics can be obtained. Therefore, if the lock of the throttle valve 3 is at an opening where the output cannot be reduced to an appropriate value other than by limiting the intake air amount (operation stop opening 03 or more), the operation of the engine 1 is stopped and the vehicle is operated. This has an excellent effect of avoiding runaway behavior and greatly improving safety.

On the other hand, when the throttle valve 3 is locked at an operation stop opening degree of less than 03, by reducing the fuel injection amount,
This has the excellent effect of improving the so-called limp home function, in which the engine output can be controlled to enable the vehicle to run at a minimum.

As a result, this embodiment can provide an internal combustion engine control device with excellent fail-safe and limp-home functions.

Next, an embodiment of the second invention will be described based on FIG. In this embodiment, step 230 of the internal combustion engine control routine of FIG. 7 of the embodiment of the first invention is changed to step 235 of FIG. 8, and the process shown in step 260 is added.

Therefore, steps 200 to 240 are common to the embodiment of the first invention and have the same effects, so their explanation will be omitted here.

In step 235 of Fig. 8, the abnormal opening is 01≦θ and θ2
(here, θ1 is 10°), the basic injection master control signal is directly output to the engine control device 7 (step 250). As a result, as in the first embodiment, the vehicle can be driven while maintaining the current engine output.

Furthermore, in this embodiment, in step 235, the abnormal opening degree is θ.
1, a signal instructing the engine control device 7 to increase control of the basic injection amount and an EG
A signal for driving the R stop valve 41 is output (step 260). Thereby, the output generated by the engine 1 can be increased.

When an abnormality occurs at a small throttle opening θ by the processing in steps 200, 210, 235, and 260,
Increase the engine output to the level that allows the vehicle to run,
The vehicle can be driven.

As explained above, according to this embodiment, the engine output can be controlled according to the throttle opening degree as shown in FIG. can shut down the engine or reduce its power to improve the vehicle's fail-safe and limp-home capabilities.

Moreover, the thrower valve 3 has an extremely small opening (
When the throttle is locked at a throttle opening (less than θ1), the engine output can be increased to a value that allows the vehicle to travel.

As a result, the limp home function of the embodiment of the first invention can be greatly improved according to the embodiment of the second invention.

Note that the present invention is not limited to the above-mentioned embodiments, and various embodiments can be implemented without departing from the gist of the present invention.

[Effects of the Invention] The internal combustion engine control device of the first invention allows the throttle valve to be opened and closed at a throttle opening degree where the output of the internal combustion engine is too large and safe driving cannot be achieved by operating the vehicle's brakes or clutch. Since the operation of the internal combustion engine can be stopped when an abnormality occurs, the limp home function of the vehicle can be maintained and a high fail-safe function can be obtained, which is an excellent effect.

The internal combustion engine control device of the second invention provides a high fail-safe function while maintaining the limp home function as in the first invention, and further improves the limp home function by controlling the output of the internal combustion engine in the output control means. can be done.

Therefore, the internal combustion engine control device of the present invention has an extremely excellent effect of sufficiently improving the fail-safe and limp-home functions of the vehicle.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram illustrating the basic configuration of the first invention;
FIG. 3 is a configuration diagram illustrating the basic configuration of the second invention, FIG. 3 is a configuration diagram of an embodiment to which the first and second inventions are applied, and FIG.
The figure is a flowchart of the abnormality detection routine of the embodiment.
FIG. 6 is a graph showing the opening/closing valve control characteristics of the throttle valve according to the embodiment, FIG. 6 is a characteristic graph of the lock judgment value of the embodiment, and FIG. 7 is a flowchart of the control routine for the internal combustion engine according to the embodiment of the first invention. , FIG. 8 is a flowchart showing a part of the control routine of the internal combustion engine according to the embodiment of the second invention, and FIG. 9 is a graph of the engine output characteristics of the embodiment of the second invention. A... Internal combustion engine B... Throttle valves C1, C2... Abnormality detection means DI, D2... Abnormal opening degree judgment means E1. E2... Operation stop means F2... Output control means 1... Engine 3... Throttle valve 5... Throttle valve control device 7... Engine control device 15... Fuel injection valve 41...・EGR stop valve

Claims (1)

[Scope of Claims] 1. A throttle valve that adjusts the amount of air supplied to the internal combustion engine; An abnormality detection means that detects an abnormality in the opening/closing valve operation of the throttle valve; and Abnormality in the opening/closing valve operation of the throttle valve. is detected,
Abnormal opening determination means for determining whether the throttle valve is at a predetermined opening or more, and stopping operation of the internal combustion engine when an abnormal opening/closing operation of the throttle valve occurs at a predetermined opening or more. A control device for an internal combustion engine, comprising an operation stop means. 2. A throttle valve that adjusts the amount of air supplied to the internal combustion engine, an abnormality detection means that detects sticking of the throttle valve, and a means for detecting whether the opening of the throttle valve is at least a predetermined opening degree when sticking of the throttle valve is detected. abnormal opening determination means for determining whether the throttle valve is stuck at a predetermined opening or more; and operation stopping means for stopping the operation of the internal combustion engine when the throttle valve is stuck at a predetermined opening or more; and output control means for controlling the output of the internal combustion engine according to the opening degree of the throttle valve when the throttle valve is opened. 3. The internal combustion engine control device according to claim 2, wherein the output control means controls at least one of fuel supply amount, ignition timing, or exhaust gas recirculation amount in accordance with the opening degree of the throttle valve.