JPS6235040A - Engine controller - Google Patents

Abstract

PURPOSE:To ensure the safety of control by providing a fuel supply blocking means for blocking fuel supply to an engine and a fuel supply stop confirming means for confirming the stoppage of fuel supply to the engine. CONSTITUTION:An amount of fuel supplied to an engine e is controlled by a fuel supply controlling means f. Any abnormalities in opening and closing control of a throttle valve c are detected by a valve opening and closing control abnormality detecting means g. When said abnormalities are detected, fuel supply to the engine e is blocked by a fuel supply blocking means h. Further, the stoppage of fuel supply to the engine e is confirmed by a fuel supply stoppage confirming means i. Thus, the safety of control of throttle valve opening and closing and fuel supply can be ensured.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides a throttle valve that is mechanically disconnected from an accelerator operator and is controlled to open and close in response to the operation of the accelerator operator. The present invention relates to an engine control device that simultaneously controls the supply amount.

(Background of the Invention) In this type of device, the amount of fuel supplied to the engine is controlled using an electronically controlled fuel injection device.
As shown by 31 and the like, a throttle valve is controlled to open and close by a motor or the like in accordance with the operation of an accelerator operator.

In this type of device, the engine's throttle valve control and fuel supply amount control are performed electronically, so ensuring control safety in the event of a problem with these controls is a major issue. was.

(Object of the Invention) The present invention has been made in view of the above problems, and its purpose is to provide an engine that can ensure control safety even when an abnormality occurs in the opening/closing control of the throttle valve. The purpose is to provide a control device.

(Configuration of the Invention) In order to achieve the above object, an apparatus according to the present invention is configured as shown in FIG.

In the figure, the operation amount of the accelerator operator a has already been detected by the accelerator operation amount detection means, and the throttle valve C is adjusted according to the operation amount of the accelerator operator a detected by the accelerator operation amount detection means. Opening/closing is controlled by opening/closing control means d.

Further, the amount of fuel supplied to the engine e is controlled by a fuel supply amount control means f, and an abnormality in the opening/closing control of the throttle valve C is detected by a valve opening/closing control abnormality detection means q.

When an abnormality in the opening/closing control of the throttle valve C is detected, the fuel supply to the engine e is blocked by the fuel supply blocking means, and furthermore, the stoppage of the fuel supply to the engine e is confirmed by the fuel supply stop confirmation means i. ing.

(Description of Embodiments) Hereinafter, preferred embodiments of the apparatus according to the present invention will be described based on the drawings.

In FIG. 2, the amount of depression of the accelerator pedal 10 is detected by an accelerator potentiometer 12, and the detection signal is supplied to a throttle valve control circuit 14.

The throttle valve control circuit 14 is mainly composed of a microcomputer, and a detection signal from the accelerator potentiometer 12 is supplied to an A/D converter 16 thereof.

The detection signal of the accelerator potentiometer 12, which is converted into a digital signal by the A/D converter 16, is supplied to the CPU 18, and the CPU 18 obtains a 4-bit valve opening/closing control signal.

The valve opening/closing control signal is supplied to the motor driver 22 via the latch 20, and the winding 2 of the step motor 24
4a and 24b are excited and controlled by the motor driver 22 in accordance with the valve opening/closing control signals.

The rotation axis of the throttle valve 26 is fixed by the step motor 24, and as a result, the throttle valve 26 is controlled to open and close in accordance with the operation of the accelerator pedal 10.

Further, the throttle valve 26 is always urged in the closing direction by a return spring 28, and the opening degree of the throttle valve 26 is detected by a throttle opening degree sensor 30.

The detection signal of the throttle opening sensor 30 is the A/D
The signal is supplied to the CPU 18 via the converter 16, and the engine rotation speed detection signal obtained by the crank angle sensor 32 is also supplied to the CPU 18.

The engine rotation speed detection signal from the crank angle sensor 32 and the control signal from the CPU 18 are supplied to a fuel injection control circuit 34, and the transistor 38 that drives the injector 36 is controlled by this fuel injection control circuit 34.

The emitter of this transistor 38 is grounded, and the output voltage on the collector side is sent to the CPU via the A/D converter 16.
1.8.

3 and 4 show the control routine of the CPU 18 in FIG. 2, and the process in FIG. 3 is a fixed-time interrupt process that is activated at a predetermined period by an operating system (not shown). The process in Figure 4 is oci
This is an interrupt process and is activated according to the motor speed set by the fixed time interrupt process.

In FIG. 3, the amount of depression of the accelerator pedal 10! is read (step 100), and the target opening degree of the throttle valve 26 (target step number 5TEP'') is determined based on the depression amount l of the accelerator pedal 10 (step 102).
).

Then, the actual step number STE,P (opening of the throttle valve 26 estimated and detected from the feed amount of the step motor 24) is subtracted from the target opening (target number of steps 5TEP''), so that the control deviation ε of the throttle valve 26 is calculated. Once calculated (step 104), the motor speed of the step motor 24 is calculated based on the deviation ε, and its normal rotation is
Judgment of reversal or holding, roughly setting of the activation cycle of oci interrupt, flag setting regarding the direction of rotation of the motor, etc. are performed (step 106).

Next, it is determined whether the accelerator pedal 10 is not operated using the detection signal of the accelerator potentiometer 12 (step 108), and it is also determined whether the actual step number 5TEP of the step motor 24 is 4 or less. It is determined whether the throttle valve 26 is at a position just before being fully opened (step 110).

At this time, if the accelerator pedal 10 is not operated or the throttle valve 26 is not in the position immediately before full opening, the non-excitation flag N0TRQ is reset (step 11'2).
Also, when the accelerator pedal 10 is not operated and the throttle valve 26 is in a position just before being fully opened, a non-excitation flag N0TRQ is set (step 114).

Next, the oci interrupt processing shown in FIG. 4 will be explained.

First, when it is confirmed that the non-excitation flag N0TRQ is not set (step 116), the step motor 2
It is determined whether the rotational position No. 4 should be maintained as it is, whether it should be rotated forward, or whether it should be reversed (step 1).
18).

At this time, when a forward rotation is determined, 1 is added to the actual step number 5TEP (step 120), and when a reverse rotation is determined, the actual step number 5TEP is added.
1 is subtracted from (step 122>), and when it is further determined to hold, the actual step number 5TEP remains unchanged.

Then the excitation pattern shown in Table 1 of 1.2.3.
4 are selected in a predetermined order, thereby controlling the step motor 24 in forward and reverse directions to drive the throttle valve 26 to open, close, or hold it (step 124).

4 is selected, the terminal A to terminal A corresponds to them.
to, terminal 100 to terminal B, terminal A to terminal, terminal B
Each rated excitation current flows from to terminal ■.

When pattern 1 changes to pattern 2, the rotation shaft of the step motor 24 is driven in the forward rotation direction, and when the pattern changes in the order of 3.4.1.2.3, the step motor 24 is sequentially stepped in the forward rotation direction. Driven.

Further, when the patterns are selected in the order of 1.4.3.2.1.4, the rotation shaft of the step motor 24 is sequentially driven step by step in the reverse direction.

In this way, by selecting the excitation patterns 1.2.3.4 in a predetermined order, the step motor 24 is fed in steps in the forward or reverse rotation direction, and the throttle valve 26 is opened and closed, for example, in 1.8° increments. When it is determined that it is held, it is controlled to stop at that position.

As described above, when the accelerator pedal 10 is being depressed or when the throttle valve 26 is not immediately before full opening and the non-excitation flag N0TRQ is reset, the step motor 24 is driven and controlled in response to the accelerator pedal 10 depression operation. This causes the throttle valve 26
is controlled to open and close in response to the depression of the accelerator pedal 10.

In addition, the non-excitation flag N0 indicates that the accelerator pedal 10 is not operated and the throttle valve 26 is about to be fully opened.
If confirmed from the set of TRQs (step 11
8), the non-excitation pattern in Table 1 is selected (step 126), thereby prohibiting excitation of the windings 24a and 24b of the step motor 24.

As a result, when the throttle valve 26 is at the position immediately before full opening and the accelerator pedal 10 is not operated, the step motor 24
The drive control of the throttle valve 26 is stopped, and the throttle valve 26 is then fully closed by the return spring 28.

Therefore, the throttle valve 26 is reliably closed without colliding with the throttle chamber at high speed, and the engine speed is rotated at the normal idle speed.

In addition, the actual driving step number of the step motor 24 is 5TEP.
The reason why it is determined that the throttle valve 26 is at the position just before full opening is made when is 4 or less is because, for example, when the system is powered on, the actual drive step number 5TEP is O and the first pattern 1 is selected. Sometimes the magnetic fields strengthen each other and the rotational position of the rotor, where it stops, does not always coincide with the fully open position of the throttle valve 26, and as in this embodiment, there are four patterns 1.
．． This is because in the method in which 2.3.4 is selected sequentially, an error occurs by a maximum of 3 steps, and the maximum error step number is 4 steps or less.

Further, when the non-excitation flag N0TRQ is set in the process shown in FIG. 3 (step 114), the crank angle sensor 3
The engine speed detected by 2 is 300 Orpm.
It is determined whether or not it exceeds (step 128).

At this time, if it is determined that the engine speed exceeds 3000 rl)m (affirmative determination at step 128), a control signal instructing the engine to stop fuel injection is sent to the fuel injection control circuit 34. (step 130), and then transistor 3 determines whether fuel injection was performed despite the fuel injection stop instruction.
8 (step 132).
).

When fuel injection is performed despite the instruction to stop fuel injection (affirmative determination at step 132),
The fuel control abnormality flag indicating an abnormality in fuel injection control is CERA 1.
- is performed (step 134).

Further, when it is confirmed that the fuel injection has been stopped in accordance with the instruction to stop the fuel injection (negative determination in step 132),
The fuel control abnormality flag is reset (step 136
).

Note that if the engine speed is 300 rpm or less when the non-excitation flag N0TRQ is set (negative determination in step 128), the instruction to stop fuel injection is prohibited (step 138).

As described above, in this embodiment, the accelerator pedal 10 is not operated, the throttle valve 26 is almost fully open, and the engine speed is approximately 300 or
pm or more, it is checked whether fuel injection to the engine is reliably stopped.

Here, in the next cycle of processing, it is determined whether or not the fuel control abnormality flag is set (step 1).
40).

At this time, if the fuel control abnormality flag is not set (negative determination in step 140), the drive amount of the step motor 24 (actual number of steps 5 TEP') and the throttle valve 26 detected by the throttle opening sensor 30 Based on the difference from the actual opening degree, it is determined whether or not there is an abnormality in the opening/closing control of the throttle valve 26 (step 142).

If there is no abnormality in the opening/closing control of the throttle valve 26, the opening/closing control is performed as described above (step 142 → step 100), but if an abnormality is found in the opening/closing control (step 142 is affirmative). (determination), the fuel supply to the engine continues to be stopped (step 144→step 140).

In this way, when the opening/closing control of the throttle valve 26 is stopped, the fuel injection control circuit 34 cuts the fuel supplied to the engine.
As a result, abnormal increases in engine speed are prevented and control safety is therefore ensured.

In order to ensure control safety in this manner, it is necessary that the fuel injection control circuit 34 reliably cut off the fuel supplied to the engine.

Therefore, in this embodiment, while normal throttle valve opening/closing control is being performed, it is always confirmed that fuel cut is being performed normally as described above.

If an abnormality is found in the fuel cut operation during that time, that is, if the fuel control abnormality flag is confirmed to be set (affirmative determination in step 140), the non-excitation flag N0TRQ is forcibly set ( Step 140→
Step 114).

As a result, the drive control of the step motor 24 is stopped.
The throttle valve 26 is fully closed by a return spring 28.

In this way, when the fuel injection control is abnormal, the throttle valve 26
is forcibly closed, and as a result, even in the event of this abnormality, an abnormal increase in engine speed is prevented and control safety is ensured.

As described above, according to this embodiment, control safety can be ensured even when there is an abnormality in the throttle valve opening/closing control or when there is an abnormality in the fuel injection control.

As a result, even if the throttle valve 26 becomes unable to open or close due to seizure of the bearing portion of the step motor 24, or even if the transistors 1 to 38 become inoperable, an increase in engine speed is reliably prevented.

In this embodiment, the throttle valve 26 was forcibly closed when an abnormality was detected in the fuel cut operation, but at that time, only a warning was given to the driver to prompt repair, and no such control was performed. It is also possible to configure the device so that it does not occur.

Additionally, the throttle valve control circuit 14 and the fuel injection control circuit 3
It is also possible to integrally configure 4 and 4 using one CPU.

(Effects of the Invention) As explained above, according to the present invention, when an abnormality is detected in the opening/closing control of the throttle valve, the supply of fuel to the engine is blocked, and the supply of fuel to the engine is reliably stopped. It will be checked whether there is
It is possible to ensure control safety of throttle valve opening/closing control and fuel supply amount control.

[Brief explanation of drawings]

FIG. 1 is a complaint correspondence diagram, FIG. 2 is a block diagram showing a preferred embodiment of the apparatus according to the present invention, and FIGS. 3 and 4 are flowcharts showing the processing procedure of the CPU 18 in FIG. Meter: Accelerator operator b: Accelerator operation amount detection means C:
Throttle valve d... Throttle valve opening/closing control means e...
・Engine f...Engine speed detection means q...
Fuel supply amount control means h...Abnormality detection means i...Fuel supply amount limiting means j...Fuel supply blocking means 10...Accelerator pedal 12...Accelerator potentiometer 14... Throttle valve control circuit 22... Motor driver 24... Step motor 26... Throttle valve 28... Return spring 30... Throttle opening sensor 32... Crank angle sensor 34...・Fuel injection control circuit 36...Injector 38...Transistor

Claims (1)

[Claims] (1) Accelerator operation amount detection means for detecting the operation amount of the accelerator operator; throttle valve opening/closing control means for controlling the opening and closing of the throttle valve according to the operation of the accelerator operator; and fuel supply for controlling the amount of fuel supplied to the engine. a valve opening/closing control abnormality detecting means for detecting an abnormality in opening/closing control of the throttle valve; a fuel supply blocking means for blocking fuel supply to the engine when an abnormality in opening/closing control of the throttle valve is detected; An engine control device comprising: a fuel supply stop confirmation means for confirming a stop of fuel supply.