JPH0776540B2 - Slot valve control device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention has a function of adjusting the opening of a throttle valve that is provided in an internal combustion engine and is opened and closed by an actuator or the like without being mechanically connected to an accelerator pedal. The present invention relates to a throttle valve control device for an internal combustion engine, which is effective in detecting a failure.

[Prior Art] In recent years, a throttle valve of an internal combustion engine is not mechanically connected to an accelerator pedal, and a sensor for detecting the opening degree of the throttle valve, an actuator for changing the opening degree, and the like are provided. A technique for driving the actuator while adjusting the opening degree of the throttle valve and changing the output of the internal combustion engine while utilizing the detection result of the sensor based on the control signal according to the operating state of the internal combustion engine, a so-called linkless throttle It has been known. By the way, since the internal combustion engine for a vehicle is frequently operated in a transient state, it is necessary to accurately adjust the opening of the throttle valve. Therefore, when the linkless throttle is applied to such a vehicle internal combustion engine, high reliability is required.
Therefore, in order to confirm whether the linkless throttle normally operates and ensure its reliability, for example, the following techniques have been proposed. That is, (1) at the beginning of the operation of the ignition switch, a command signal for opening the throttle valve to a predetermined opening is output to the actuator, and the difference between the command throttle valve opening of the command signal and the actual throttle valve opening is detected. By checking the throttle valve control device from the state of the difference, it is possible to check beforehand whether or not the three members of the control system, the actuator, and the throttle valve operate correctly at the beginning of engine startup. Control device "(Japanese Patent Laid-Open No. 59-1190
No. 36).

(2) If the actual throttle valve opening is zero but the throttle valve opening zero signal is not output after a lapse of a predetermined time with a response delay when the accelerator pedal displacement is set to zero It is determined that there is an abnormality in the throttle valve opening detection means, and similarly, if the actual throttle valve opening has not become zero after the elapse of a predetermined time, it is determined that there is an abnormality in the other system. Abnormality diagnosis device in engine accelerator control device "
(Japanese Patent Laid-Open No. 61-8435).

[Problems to be Solved by the Invention] The conventional technique has the following problems. That is, (1) In the technique of determining the failure of the throttle valve control device at the initial stage of engine startup, once it is determined that there is no abnormality at the initial stage of engine startup, the failure determination is not performed until the next startup. However, in general, a failure of the throttle valve control device is highly likely to occur due to vibrations caused by traveling of the vehicle, entrapment of foreign matter, temperature increase, or the like during engine operation, not during engine stop. Therefore, even if the failure of the throttle valve control device is determined every time the engine is started, the failure that occurred during engine operation cannot be determined until the next start, and the delay of failure detection cannot ensure sufficient reliability. was there.

Further, in the technique of performing the abnormality determination by comparing the displacement amount of the accelerator pedal and the actual throttle valve opening during the engine operation, there is a high probability that the abnormality determination is performed while the vehicle is running as described above. However, for example, in a situation where bite occurs only when the throttle valve is driven to a position near the fully open state, there is also a problem that the abnormality cannot be detected until the fully open state.

The present invention determines abnormality in a so-called linkless throttle that mechanically controls a non-connected throttle valve based on an operation amount of an accelerator pedal, and in particular, controls an actual throttle opening largely during fuel cut. Also, paying attention to the fact that the driver does not feel uncomfortable, the throttle is forcibly driven to the fully open position during fuel cut to check the throttle operation, and the fuel cut operation state is the time required for the inspection time. The purpose of the present invention is to prevent the interruption of the operation check and to surely check the field of use in the operation industry by performing the operation check after previously determining the condition for continuing.

[Means for solving problems]

Therefore, in the present invention, as shown in FIG. 1, throttle valve opening detection means for detecting the opening of a throttle valve that is not mechanically connected to the accelerator pedal, and operating state detection means for detecting the operating state of the internal combustion engine are provided. An accelerator operation amount detecting means for detecting an operation amount of the accelerator pedal; a control means for controlling an opening degree of the throttle valve based on the operation amount of the accelerator pedal; and a fuel cut operation of the internal combustion engine. And a fuel cut execution detecting means for detecting that the internal combustion engine is in the fuel cut operation based on the detection result of the operating state detecting means when it is detected by the fuel cut execution detecting means. In this state, the determination means determines whether or not it is an inspection startable condition in which the inspection is continuously performed for a predetermined time or more, and the inspection start can be performed by the determination means. When it is determined that the situation, the inspection means for outputting a command for forcibly setting the opening of the throttle valve of the internal combustion engine to the maximum opening regardless of the operation amount of the accelerator pedal, and outputting the command to the control means, When the difference between the opening degree of the throttle valve detected by the throttle valve opening degree detecting means and the predetermined opening degree commanded by the checking means is out of a predetermined range after the command output of the checking means, the control is performed. The control device for the throttle valve of the internal combustion engine is provided with an abnormality determining means for determining that the means is abnormal.

[Action]

According to the above configuration, the fact that the internal combustion engine is in the fuel cut operation is detected by the fuel cut execution detection means, and further in the determination means, the internal combustion engine is continuously operated for a predetermined time or more in the fuel cut operation state. It is determined that the inspection enable condition is satisfied. After it is determined that the inspection startable condition is met, the inspecting means issues a command to force the throttle valve opening to the maximum opening regardless of the operation amount of the accelerator pedal detected by the accelerator operation amount detecting means. The difference between the throttle valve opening detected by the throttle valve opening detecting means and the predetermined opening commanded by the inspecting means is out of a predetermined range after output to the throttle valve control means. At this time, the abnormality determining means determines that the control means is abnormal.

As described above, according to the present invention, the throttle valve is forcibly driven to the fully open state during fuel cut when the accelerator pedal is rarely operated, so that the actual opening degree of the throttle valve and the predetermined opening degree commanded. By performing the operation check based on the difference between and, it is possible to reliably check whether or not the throttle valve operates in the entire region, and it is possible to frequently perform the operation check of the throttle valve during operation.

Furthermore, moving the throttle valve to full open during fuel cut takes a very long time, so if the time in the fuel cut operation area is too short, drive the throttle to a large opening during the operation check. Although there is a concern that fuel injection will be restarted in the middle of the process, and the engine output will rapidly increase when fuel injection returns,
In the present invention, during the fuel cut, in order to perform the operation check by driving the throttle valve to the maximum opening degree after determining the inspection startable condition that the fuel cut state continues for a predetermined time or more required for the inspection time. The operation check can be prevented from being interrupted while the throttle valve is open, so that the operation check can be performed more reliably and the safety is improved.

[Embodiment] Next, a preferred embodiment of the present invention will be described in detail with reference to the drawings. FIG. 2 shows the system configuration of an engine control device according to an embodiment of the present invention.

As shown in FIG. 2, an engine control device 1 is provided in the engine 2, an electronic control device (hereinafter simply referred to as an ECU) 3 for controlling a fuel injection amount and an ignition timing of the engine 2, and the engine 2. A throttle valve 4 for controlling the intake air amount and a throttle valve electronic control unit (hereinafter simply referred to as throttle valve ECU) 5 for controlling the opening of the throttle valve 4 are provided.

The engine 2 includes a combustion chamber 8 composed of a cylinder 6 and a piston 7.
And a spark plug 9 is disposed in the combustion chamber 8. The intake system of the engine 2 has an intake port 11 communicating with an intake pipe 12 via an intake valve 10. A surge tank 13 that absorbs pulsation of intake air is provided upstream of the intake pipe 12, a throttle valve 4 is provided upstream of the surge tank 13, and an air cleaner 14 is provided further upstream. .

The throttle valve 4 is biased in a direction to close the throttle valve 4 by a return spring 15 which is a torsion spring. Further, the throttle valve 4 changes its opening by being rotated by receiving the rotational force supplied from the motor 16.

On the other hand, in the exhaust system of the engine 2, an exhaust port 18 communicates with an exhaust pipe 19 via an exhaust valve 17, and a three-way catalyst 20 is provided downstream of the exhaust pipe 19. The fuel system includes a fuel supply source including a fuel tank and a fuel pump (not shown), a fuel supply pipe, and a fuel injection valve 21 disposed near the intake port 11. Also, the ignition system is an igniter 22 equipped with an ignition coil that outputs a high voltage necessary for ignition and a distributor that supplies the high voltage generated by the igniter 22 to the ignition plugs of each cylinder in conjunction with a crankshaft (not shown). It is composed of 23.

The engine control device 1 serves as a detector, which is provided in the air cleaner 14 and measures an intake air temperature by an intake air temperature sensor 31,
A throttle position sensor 32 that interlocks with the throttle valve 4 to detect the opening of the throttle valve 4, a motor
Motor stop position sensor 33 that detects the stop position of 16, intake pressure sensor 34 that detects the intake pipe pressure, water temperature sensor that is provided in the cooling system of the cylinder block and detects the cooling water temperature
35, an oxygen concentration sensor 36 provided in the exhaust pipe 19 for detecting the residual oxygen concentration in the exhaust as an analog signal, every 1/24 revolution of the camshaft of the distributor 23, that is, at a crank angle of 0 ° to 30 °. A rotation angle sensor 37 that also serves as a rotation speed sensor that outputs a rotation angle signal for each integral multiple, an accelerator sensor 38 that detects an operation amount of an accelerator pedal 38a and a fully closed command signal, and between the engine 2 and a transmission (not shown). A clutch sensor 39 is provided which detects an on / off state of the interposed clutch and outputs a clutch signal.

The detection signal from each of the above sensors is input to at least one of the ECU 3 and the throttle valve ECU 5, and the ECU 3 connects the fuel injection valve 21 and the igniter 22 to the throttle valve ECU 5.
The ECU 5 controls the opening degree of the throttle valve 4.

The ECU 3 is configured as a logical operation circuit centering on the CPU 3a, ROM 3b, RAM 3c, and backup RAM 3d, and is connected to the input / output unit 3f via the common bus 3e to perform input / output with the outside. The detection signals of the intake pressure sensor 31, the throttle position sensor 32, the intake pressure sensor 34, the water temperature sensor 35, the oxygen concentration sensor 36, and the rotation angle sensor 37 are sent to the CPU 3a via the input / output unit 3f.
Is input to the fuel injection valve 2 via the input / output unit 3f.
1. A control signal is output to the igniter 22 to perform fuel injection control and ignition timing control, and a fuel cut execution signal is transmitted to the throttle valve ECU 5 via the input / output unit 3f during fuel cut execution. The fuel cut is executed during deceleration with the throttle valve 4 fully closed.

On the other hand, the throttle valve ECU5 consists of CPU5a, ROM5b, RAM5c,
It is configured as a logical operation circuit centering on the backup RAM 5d, and is connected to the input / output unit 5f via the common bus 5e to perform input / output with the outside. Each of the detection signals of the intake pressure sensor 31, the throttle position sensor 32, the motor stop position sensor 33, the intake pressure sensor 34, the water temperature sensor 35, the rotation angle sensor 37, the accelerator sensor 38, and the clutch sensor 39 and the ECU 3
The fuel cut execution signal transmitted by the
It is input to the CPU5a, and the CPU5a uses the input / output unit 5f to
A control signal is output to control the throttle valve opening.

Next, the failure detection timing determination process executed by the throttle valve ECU 5 will be described based on the flowchart shown in FIG. This failure detection timing determination process is started with the activation of the throttle valve ECU 5, and is repeatedly executed at predetermined time intervals. First, at step 100 (fuel cut execution detection means), it is determined whether or not a fuel cut execution signal is transmitted from the ECU 3, and if an affirmative judgment is made, the routine proceeds to step 110 (judgment means), while if a negative judgment is made. This failure detection timing determination processing is once ended. In step 110, which is performed during fuel cut, the rotation angle sensor 3
Based on the detection result of 7, the rotation speed Ne of the engine 2 is 300.
It is determined whether or not it exceeds 0 [rpm], and if an affirmative judgment is made, the routine proceeds to step 120, while if a negative judgment is made, the main failure detection timing judgment processing is once terminated. At step 120 (determination means) executed when the current rotation speed Ne is high and there is sufficient time until fuel cut execution is interrupted due to the decrease in the rotation speed Ne, the clutch signal detected by the clutch sensor 39 is detected. Is at a high level (ON), and if an affirmative decision is made, the operation proceeds to step 200, while
When a negative determination is made, the main failure detection timing determination processing is once ended. In the engine braking state in which the clutch is connected, when it is determined that there is sufficient time for the rotation speed Ne of the engine 2 to decrease, step 200 (abnormality determination means) executes a failure described later. After the detection processing is performed, the main failure detection timing determination processing is once ended. After that, this failure detection timing determination processing is repeatedly executed at predetermined time intervals.

Next, the failure detection processing executed in the failure detection timing determination processing will be described based on the flowchart shown in FIG. First, at step 210, a fully closed inspection process described later is performed. In the following step 240, a fully open inspection process described later is performed. Then proceed to step 270
An intermediate opening degree inspection process described later is performed. Subsequent steps
At 295, after the full-closed inspection process similar to that at step 210 is performed again, the control shifts to the above-described failure detection timing determination process.

Next, the full-closed inspection process executed during the failure detection process will be described based on the flowchart shown in FIG. First, at step 215, a process of outputting a control signal for driving the throttle valve 4 to the fully closed position to the motor 16 is performed. In the following step 220, a process of inputting a detection signal of the throttle position sensor 32 is performed to detect the opening degree of the throttle valve 4 driven by the process of step 215. Next, the routine proceeds to step 225, where it is judged whether or not the throttle valve 4 is in the fully closed state based on the detection signal inputted at step 220. On the other hand, if a negative decision is made, the routine proceeds to step 230, where it is considered to be a function abnormality and the throttle valve abnormality flag XF is set to the value 1, and then this full-closed inspection processing is terminated. After that, the control shifts to the above-mentioned failure detection processing. The throttle valve abnormality flag XF has been reset to a value of 0 by an initialization process (not shown) performed when the throttle valve ECU 5 is started.

Next, the full-open inspection process executed during the failure detection process will be described based on the flowchart shown in FIG. First, at step 245, a process of outputting a control signal for driving the throttle valve 4 to the fully open position to the motor 16 is performed. In the following step 250, processing for inputting the detection signal of the throttle position sensor 32 is performed in order to detect the opening degree of the throttle valve 4 driven by the processing in step 245. Next, the routine proceeds to step 255, where it is judged whether or not the throttle valve 4 is in the fully open state based on the detection signal inputted in the above step 250, and if a positive judgment is made, it is considered that the function is normal and the full open inspection processing is ended. On the other hand, if a negative decision is made, the routine proceeds to step 260, where it is considered to be a functional abnormality and the throttle valve abnormality flag XF is set to the value 1, and then this full open inspection processing is terminated. After that, the control shifts to the above-mentioned failure detection processing.

Next, the intermediate opening degree inspection processing executed during the above-mentioned failure detection processing will be described based on the flowchart shown in FIG.
First, at step 275, a process of outputting a control signal for driving the throttle valve 4 to a predetermined opening degree to the motor 16 is performed. In the following step 280, a process of inputting the detection signal of the throttle position sensor 32 is performed in order to detect the opening degree of the throttle valve 4 driven by the process of the above step 275. Next, in step 285, based on the detection signal input in step 280, the opening error between the actual opening of the throttle valve 4 and the predetermined opening commanded in step 275 is within the tolerance (throttle position sensor It is a value that is determined based on the mounting accuracy of 32 and the motor 16, and is included in, for example, the range of 2 ° to 5 °). On the other hand, if the determination is negative, the routine proceeds to step 290, where it is considered to be a function abnormality and the throttle valve abnormality flag XF is set to the value 1, and then this intermediate opening degree inspection processing is terminated. After that, the control shifts to the above-mentioned failure detection processing.

As described above, in the present embodiment, when the engine 2 is operated in the engine braking state during the fuel cut, the throttle valve 4 is sequentially driven to the four states of fully closed, fully opened, intermediate opening and fully closed. Is output to the motor 16 and the opening of the throttle valve 4 that opens and closes in response to the output is detected by the throttle position sensor 32, and the detection result and the output command do not match or are outside the predetermined tolerance. The throttle valve abnormality flag XF is set to the value 1 when an error occurs. Therefore, the throttle valve opening adjustment function, for example, the motor 16
Alternatively, even when an abnormality occurs in the throttle position sensor 32 or the like, the abnormality can be detected promptly and accurately before the abnormality affects the traveling of the vehicle.
The reliability of the device can be improved.

Further, the value of the throttle valve abnormality flag XF is constantly monitored, and when the value is set to 1, for example, a warning light in the driver's seat is turned on to inform the driver of the abnormality, or
If the ECU 3 and the throttle valve ECU 5 perform a process such as executing a fail mode control process, there is an advantage that a road failure while the vehicle is traveling can be avoided.

Furthermore, in the failure detection process, the throttle valve 4 in the fully closed state is sequentially driven to the fully closed, fully opened, intermediate opening, and fully closed states for inspection, so that a smooth and quick inspection can be realized. After the inspection is completed, the initial fully closed state is restored, so that the inspection can be performed without affecting the operating state of the engine 2.

In the present embodiment, in the failure detection timing determination process, the determination that the fuel cut is being executed is made based on the fuel cut execution signal transmitted from the ECU 3.
However, the throttle valve ECU 5 may be configured to determine that the fuel cut is being performed directly based on the detection result of each sensor.

Further, although the ECU 3 and the throttle valve ECU 5 are used in the present embodiment, for example, the ECU 3 performs various controls of the engine 2 and the opening degree control of the throttle valve 4, and also executes a failure detection process. It can also be configured as follows.

Further, in this embodiment, the case where the engine 2 including the fuel injection valve 21 is used has been described. However, for example, even if the present invention is applied to a carburetor type engine that includes a rotation speed sensor and a throttle valve fully closed detection switch or a vacuum switch and performs fuel cut control, and the engine has a so-called linkless throttle, the present embodiment It has the same effect as the example.

Although the embodiments of the present invention have been described above, the present invention is not limited to such embodiments, and it goes without saying that the present invention can be implemented in various modes without departing from the scope of the present invention. .

EFFECTS OF THE INVENTION As described above, according to the present invention, the throttle valve is forcibly driven to fully open during fuel cut to check the operation. Is detected, and the operation check is executed after determining the inspection startable condition that the fuel cut state continues for more than the predetermined time required for the inspection time, so the operation check is interrupted without closing the throttle valve. It becomes possible to avoid the above, and thereby, the excellent effect that the certainty and safety of the check can be improved can be obtained.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram conceptually illustrating the content of the present invention, and FIG. 2 is a system configuration diagram of an embodiment of the present invention, and FIG.
FIG. 4, FIG. 5, FIG. 6, FIG. 6 and FIG. 7 are flowcharts showing the same control. 1 …… Engine control unit 2 …… Engine 3 …… Electronic control unit (ECU) 3a …… CPU 5 …… Throttle valve electronic control unit (Throttle valve ECU) 5a …… CPU 16 …… Motor 31 …… Intake temperature sensor 32 …… Throttle position sensor 34 …… Intake pressure sensor 35 …… Water temperature sensor 36 …… Oxygen concentration sensor 37 …… Rotation angle sensor 38 …… Accelerator sensor 39 …… Clutch sensor

Claims (2)

[Claims] 1. A throttle valve opening detecting means for detecting an opening of a throttle valve which is not mechanically connected to an accelerator pedal, an operating state detecting means for detecting an operating state of an internal combustion engine, and an operation of the accelerator pedal. Accelerator operation amount detecting means for detecting the amount, control means for controlling the opening degree of the throttle valve based on the operation amount of the accelerator pedal, and fuel cut execution for detecting that the internal combustion engine is in a fuel cut operation. When the fuel cut operation is detected by the detection means and the fuel cut execution detection means, based on the detection result of the operation state detection means, the internal combustion engine is in the fuel cut operation and continues for a predetermined time or more. Determination means for deciding that the inspection startable condition is to be operated in the following manner, and the determination means determines that the inspection startable condition is satisfied. When the throttle valve of the internal combustion engine is forcibly set to the maximum opening regardless of the operation amount of the accelerator pedal, the inspection means outputs a command to the control means, and after the command output of the inspection means, When the difference between the opening degree of the throttle valve detected by the throttle valve opening degree detecting means and the predetermined opening degree commanded by the inspecting means is outside the predetermined range, it is determined that the control means is abnormal. An apparatus for controlling a throttle valve of an internal combustion engine, comprising: an abnormality determining means. 2. The control device for the throttle valve of an internal combustion engine according to claim 1, wherein the inspection startable condition includes a condition that the engine speed is equal to or higher than a predetermined value.