JPS63159645A - Throttle controller - Google Patents

Abstract

PURPOSE:To speed up the detection of abnormalities by judging the abnormalities when the integrated value of step number to control a step motor for driving a throttle valve is in a predetermined relation with an actual throttle valve opening detected by an opening detecting means. CONSTITUTION:A throttle controller for opening and closing a throttle valve 4 with a step motor 3 calculates a valve opening-closing control signal with a controlling means 2 on the basis of the output signals of an accelerator operation amount detecting means 1, etc., to control the step motor 3 with said control signal. Then, the opening of the throttle valve 4 is detected by an opening detecting means 5 for feed-back. In this case, an abnormality detecting means 6 is provided which judges abnormalities when a signal detected by said detecting means 5 is in a predetermined relation with an integrated value of step number for driving the step motor 3. And in the detection of abnormalities, a fuel supply is limited by a fuel limiting means 7 to limit the rotational frequency of an engine to a predetermined value or less.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an accelerator operating means (for example, an accelerator pedal)
The present invention relates to fail-safe technology for a throttle control device in which the throttle valve and the throttle valve are mechanically disconnected and electrically controls the throttle valve opening of an internal combustion engine.

[Prior art]

As a conventional throttle control device, for example, JP-A-59
There is one described in No.-58131.

The above-mentioned throttle control device basically calculates the deviation between the accelerator signal (target value) corresponding to the amount of depression of the accelerator pedal and the throttle signal corresponding to the actual throttle opening, and drives to eliminate the deviation. This system operates the motor to perform feedback control so that the throttle valve opening matches the target value, and adds a correction function when the clutch is disengaged.

[Problem that the invention seeks to solve]

In the throttle control device as described above.

The accelerator pedal and the throttle valve are not mechanically connected, but are electrically controlled using an electronic control device.

Therefore, if an abnormality occurs in the control system or drive system.

The throttle valve may become uncontrollable. In internal combustion engines for vehicles, if the throttle valve becomes uncontrollable, it may become difficult to drive the vehicle safely.

In order to solve the above problem, the present applicant detects that the throttle valve is left open from the detection signals of the throttle opening detection means and the accelerator pedal position detection means, and in that case, adjusts the fuel injection amount. An application has already been filed for a device that forcibly controls the engine speed so that it does not exceed a predetermined value (Japanese Patent Laid-Open No. 8436/1983).

However, with the above device, it is not possible to detect that the throttle valve is stuck, that is, the throttle valve remains open, until a predetermined period of time has elapsed after the accelerator pedal is released. The problem remained that if the throttle valve became stuck while the driver was depressing the throttle, detection would be delayed.

The present invention has been made in order to solve the problems of the prior art as described above, and provides a throttle control device that can quickly detect an abnormality in throttle valve control and quickly activate a safety function in the event of an abnormality. The purpose is to

[Means to solve the problem]

FIG. 1 is a block diagram showing the functions of the present invention.

In FIG. 1, an accelerator operation amount detection means 1 detects an operation amount of an accelerator operation means (for example, the amount of depression of an accelerator pedal).

Further, the control means 2 calculates and outputs a valve opening/closing control signal for driving the step motor 3 based on at least the above operation amount. The step motor 3 rotates in the forward or reverse direction in accordance with the valve opening/closing control signal, thereby controlling the opening/closing of the throttle valve 4.

On the other hand, the abnormality detection means 6 detects the detection signal of the throttle valve opening detection means 5 which detects the throttle valve opening (that is, the signal corresponding to the actual throttle valve opening) and the number of steps by which the step motor 3 is driven. When the relationship with the integrated value (actual step number 5TEP described later) becomes a predetermined relationship, it is determined that there is an abnormality.

When the abnormality is detected, the fuel limiting means 7 limits the fuel supplied to the internal combustion engine to limit the engine speed to a predetermined value or less.

Note that the abnormality detection means 6 detects, for example, that the difference between the value obtained by converting the integrated value of the number of steps into the throttle valve opening and the actual throttle valve opening detected by the throttle valve opening detection means 5 is equal to or greater than a predetermined value. It is determined that there is an abnormality when , or when the actual throttle valve opening detected by the throttle valve opening detecting means 5 does not change even though the integrated value of the number of steps has changed.

As described above, in the present invention, an abnormality is determined when the relationship between the integrated value of the number of steps to control the step motor and the actual throttle valve opening detected by the throttle valve opening detection means becomes a predetermined relationship. Since it is configured like this,
When an abnormality such as a stuck throttle valve occurs, the abnormality can be detected promptly, and a safety function can be activated immediately in the event of an abnormality, thereby improving the safety of vehicle running.

[Embodiments of the invention]

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

FIG. 2 is a diagram showing an embodiment of the present invention.

In FIG. 2, the amount of depression of the accelerator pedal 10 is detected by an accelerator potentiometer 12.

The detection signal is supplied to the throttle valve control circuit 14.

The throttle valve control circuit 14 is configured mainly of, for example, 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 sent to the CPU 18.
The CPU 18 calculates and outputs a 4-bit valve opening/closing control signal.

The valve opening/closing control signal is supplied to the motor driver 22 via the latch circuit 20.

The motor driver 22 controls the excitation current of the windings 24a, 24b of the step motor 24 according to the valve opening/closing control signal.

The rotation shaft of the throttle valve 26 is connected to this step motor 24.
As a result, the throttle valve 26 is controlled to open and close in accordance with the operation of the accelerator pedal 10.

Note that the integrated value of the number of steps of the valve opening/closing control signal that drives the step motor 24 (the actual number of steps 5TE to be described later)
P) is stored in a memory (not shown) within the throttle valve control circuit 14.

Further, the throttle valve 26 is always urged in the closing direction by a return spring 28.

Next, the opening degree of the throttle valve 26 is detected by the throttle opening sensor 30.

The detection signal of the throttle opening sensor 30 is
is supplied to the CPU 18 via the D converter 16;
The engine speed detection signal obtained by the crank angle sensor 32 is also supplied to U18.

The CPU 18 calculates the fuel injection amount according to various operating variables of the internal combustion engine, such as the engine speed detection signal and the detection signal of the throttle opening sensor 30, and outputs a fuel injection control signal (fuel injection pulse) according to the engine speed detection signal and the detection signal of the throttle opening sensor 30. Output.

The above fuel injection pulse and engine speed detection signal from the crank angle sensor 32 are supplied to the fuel injection control circuits 3 and 4,
Fuel injection is performed by the fuel injection control circuit 34 controlling the opening and closing of the transistor 38 that drives the injector 36 in response to these signals.

Next, FIGS. 3, 4, and 5 show C in FIG.
It is a figure which shows the control routine of PU18.

The processing in FIGS. 3 and 4 is a fixed-time interrupt process, which is activated at a predetermined period by an operating system (not shown), and the process in FIG. 5 is an oci interrupt process, which is a fixed-time interrupt process. It is activated according to the motor speed set by .

First, in FIG. 3, the depression amount Ω of the accelerator pedal 10 is read (step 100), and the target opening degree of the throttle valve 26 (target number of steps 5TEP'') is determined based on the depression amount Q of the accelerator pedal 10. (Step 102).

Next, the actual step number 5TEP (the opening of the throttle valve 26 estimated from the feed amount of the step motor 24) is subtracted from the target opening (the target number of steps 5TEP"), so that the control deviation ε of the throttle valve 26 is calculated. is calculated (step 104), and based on the deviation ε, the motor speed of the step motor 24 is calculated, it is determined whether to rotate forward, reverse, or hold, and furthermore, the startup cycle of the oci interrupt is set, a flag regarding the motor rotation direction, etc. are performed. (Step 106).The above-mentioned actual step number 5TEP increases or decreases in accordance with forward or reverse rotation of the step motor, as will be explained in detail later in FIG. It becomes the cumulative value of the number.

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. As a result of the determination, 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 in an unoperated state or the throttle valve 26 is not in the position immediately before full opening, the unexcited flag N0TRQ is reset (step 11).
2), when the accelerator pedal 10 is not operated and the throttle valve 26 is in the position immediately before being fully closed, the non-excitation flag N0TRQ is set (step 114).
.

Next, in FIG. 4, the opening θ of the throttle valve 26 is read by the throttle opening sensor 30 (step 11).
6).

Next, it is determined whether the relationship between the actual step number 5TEP and the throttle valve opening θ is abnormal (step 118).
.

Here, step 11 shows how to determine whether or not there is an abnormality.
This will be explained based on the diagram shown in 8. The horizontal axis of this figure is the actual step number 5TEP, and in this example, 15TEP
is equivalent to 1.8@.

It changes from 08TEP to 138STEP (=fully open). The vertical axis is the throttle valve opening θ, and for example, the detected voltage value ranges from 0.5V (=fully closed) to 4.5V (
= fully open).

In the above characteristics, in the normal state, the actual step number 5TEP and the throttle valve opening degree θ have a corresponding relationship and move along the broken line in the figure.

However, if the throttle valve becomes stuck due to seizure of the step motor bearing, for example, and stops at point a in the figure,
When the accelerator pedal 10 is released, the relationship between θ and 5TEP moves to point b in the diagram, and deviates from the normal correspondence shown by the broken line. In other words, the diagonally shaded area in the diagram becomes an abnormal area, and the relationship between θ and 5TEP moves to point b in the diagram. If this happens, it can be determined that there is an abnormality.

That is, in this embodiment, the integrated value of the number of steps (
When the difference between the value obtained by converting the actual step number (5TEP value) into the throttle valve opening and the actual throttle valve opening detected by the throttle valve opening detection means is greater than or equal to a predetermined value, it is determined that there is an abnormality. There is.

Note that the reason why a margin is provided between the hatched part and the broken line in the diagram in step 118 is because variations in the throttle valve opening sensor 30 and mounting tolerances are taken into consideration.

Furthermore, in the diagram shown in step 118, when the abnormal range is provided only above the normal value indicated by the broken line, that is,
We have given an example where an abnormality is determined only when the actual throttle valve opening is larger than the number of steps to be controlled (when the throttle valve does not move in the closing direction even when the accelerator pedal is released), but the broken line indicates normality. Similarly, an abnormal range can be provided below the value.

Next, if it is determined in step 118 that the engine is not in the abnormal region, this routine is immediately terminated, and if it is determined that the engine is in the abnormal region, the engine speed does not exceed a predetermined value (for example, 2000 rpm). Carry out tuuniru cut and recovery to avoid this (steps 120 to 126)
.

This limits the fuel injection amount and controls the engine speed to be below a predetermined value.

Next, the oci interrupt processing shown in FIG. 5 will be explained.

First, when it is confirmed that the non-excitation flag N0TRQ is not set (step 216), the step motor 2
It is determined whether the rotational position No. 4 should be maintained as it is, whether it should be rotated in the forward direction, or whether it should be rotated in the reverse direction (step 2).
18).

At this time, when the forward rotation is determined, 1 is added to the actual step number 5TEP (step 220), and when the reverse rotation is determined, the actual step number 5TEP is added (step 220).
1 is subtracted from (step 222), and when it is further determined to hold, the actual step number 5TEP remains unchanged.

Thereafter, the excitation pattern 1.2. shown in Table 1 below.
3.4 is selected in a predetermined order, whereby the step motor 24 is controlled in forward and reverse directions, and the throttle valve 26 is driven to open/close or is held (step 224).

Table 1 In Table 1, when excitation patterns 1 and 2.3° 4 are selected, the current flows from terminal A to terminal A, from terminal B to terminal B, and from terminal A to terminal A in response to these selections.

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 sequentially steps in the forward rotation direction. Driven.

Further, when patterns are selected in the order of 1.4.3.2 and 1.4, the rotating shaft of the step motor 24 is sequentially driven step by step in the reverse direction.

By selecting the excitation patterns 1, 2, 3, and 4 in a predetermined order in this manner, the step motor 24 is fed in steps in the forward rotation direction or in the reverse rotation direction, whereby the throttle valve 26 is rotated one step at a time, for example, at each step. It opens and closes at 1.8° increments. Furthermore, when it is determined that the holding position is maintained, the stop control is performed 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 responds to the amount of depression of the accelerator pedal 10. The drive is controlled.

Thereby, the throttle valve 26 is controlled to open and close depending on the amount of depression of the accelerator pedal 10.

In addition, the non-excitation flag N0TR indicates that the accelerator pedal 10 is not operated and the throttle valve 26 is about to be fully opened.
If it is confirmed from the set of Q (affirmative determination in step 114), the non-excitation pattern in Table 1 is selected (step 226), and thereby the windings 24a and 24b of the step motor 24 are not energized. It is forbidden.

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 opened by the return spring 28. Therefore, the throttle valve 26 is reliably fully opened without colliding with the throttle chamber at high speed, and the engine speed becomes the normal idle speed.

Note that the actual number of steps 5TEP of the step motor 24 is 4.
It is determined that the throttle valve 26 is in the position immediately before fully closing when the following conditions are met: 1 For example, when the actual step number 5 TEP is O and the first pattern 1 is selected when power is turned on to the system. , the rotational position of the rotor where the magnetic fields strengthen each other and stop does not necessarily coincide with the fully open position of the throttle valve 26, and there are four patterns 1, 2,
This is because in the method in which 3.4 is selected sequentially, an error of up to 3 steps may occur, but the maximum error step number is 4 steps or less.

Next, another embodiment of the present invention will be described based on the flowchart shown in FIG.

The routine shown in FIG. 6 follows the routine shown in FIG. 3 above, and the portion in FIG. 3 is the same as above.

In FIG. 6, first, the opening θ of the throttle valve 26 is read by the throttle opening sensor 30 (step 31).
6).

Next, it is determined whether the actual step number 5TEP has changed (step 318), and if it has changed.

It is determined whether the throttle opening degree θ has changed (step 320). At this time, if the throttle opening degree θ is changing, it is determined to be normal and the flag NGFLG for abnormality determination is reset (step 322). on the other hand.

At this time, if the throttle opening degree θ is not changing, it is determined that the throttle valve is stuck and is abnormal, and a flag NGFLG is set (step 326).

Next, it is determined whether or not the flag NGFLG is set (step 326), and if it is set, the flag NGFLG is set to 2000.
When the throttle valve is stuck, the engine rotation is forcibly controlled to be 2000 rpm or less by performing a power cut when the rpm is higher than that and a power cut recovery when the speed is lower than 2000 rpm (steps 328 to 334).
.

That is, in this embodiment, the integrated value of the number of steps (
An abnormality is determined when the actual throttle valve opening detected by the throttle valve opening detecting means does not change even though the actual step number (value of 5TEP) is changing.

Other parts are the same as those shown in FIGS. 3 and 5 above.

〔Effect of the invention〕

As explained above, in the present invention, the relationship between the integrated value of the number of steps for controlling the step motor for driving the throttle valve and the actual throttle valve opening detected by the throttle valve opening detection means is a predetermined relationship. Since the structure is configured so that it is determined that an abnormality occurs when an abnormality occurs, such as a stuck throttle valve, it can be detected immediately, and safety functions can be activated immediately in the event of an abnormality, thereby preventing the vehicle from running. This has the excellent effect of improving safety.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the functions of the present invention, Fig. 2 is an overall configuration diagram of an embodiment of the invention, and Figs. 3, 4, and 5 show operations of an embodiment of the invention. Flowchart, No. 6
The figure is a flowchart showing calculations in another embodiment of the present invention. <Explanation of symbols> 1...Accelerator operation amount detection means 2...Control means 3...Step motor 4
...Throttle valve 5...Throttle valve opening detection means 6...Abnormality detection means 7...Fuel restriction means 10
...Accelerator pedal 12...Accelerator potentiometer 14...Throttle valve control circuit 16...A/D converter 18...CPU 20...
... Latch 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 (3)

[Claims] 1. A throttle control device comprising an accelerator operation amount detection means for detecting an operation amount of an accelerator operation means, a step motor for driving the opening and closing of a throttle valve, and a control means for controlling the step motor based on at least the operation amount, A predetermined relationship is established between a throttle valve opening detection means for detecting a throttle valve opening, an integrated value of the number of steps driven by the step motor, and an actual throttle valve opening detected by the throttle valve opening detection means. A throttle characterized by comprising: abnormality detecting means for determining an abnormality when the abnormality occurs; and fuel limiting means for restricting the fuel supplied to the internal combustion engine to limit the engine speed to a predetermined value or less when the abnormality is detected. Control device. 2. The abnormality detection means determines that an abnormality occurs when the difference between the integrated value of the number of steps converted into a throttle valve opening and the actual throttle valve opening detected by the throttle valve opening detection means is a predetermined value or more. 2. A throttle control device according to claim 1, wherein the throttle control device is characterized in that: 3. The abnormality detection means is characterized in that it determines that there is an abnormality when the actual throttle valve opening detected by the throttle valve opening detection means does not change even though the integrated value of the number of steps has changed. Claim 1
Throttle control device as described in section.