JPH0531248Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electronic fuel injection device that electronically controls the opening degree of a throttle valve in accordance with the depression angle of an accelerator pedal.

[Conventional technology]

As this type of electronic fuel injection device, one shown in FIG. 4 has been proposed. i.e. accelerator pedal 9
The pedal position detector 1 detects the depression angle as an accelerator pedal signal. On the other hand, the valve opening degree of the throttle valve 10 is detected by the valve position detector 2 as a throttle valve signal. The accelerator pedal signal and throttle valve signal detected by these position detectors 1 and 2 are input to the control circuit 11, which drives the actuator 12 according to the amount of deviation between these two signals. The valve opening degree is controlled so that both input signals of the control circuit 11 become equal, that is, the valve opening degree of the throttle valve 10 corresponds to the depression angle of the accelerator pedal 9. In this manner, this device controls the opening degree of the throttle valve using a servo mechanism.

In such a device, the actuator 12 may fail for some reason, or the throttle valve 10 may malfunction, making it impossible to control the opening of the throttle valve 10 in response to the accelerator pedal signal. be. If the throttle valve 10 remains in the fully open position due to such a failure, the vehicle speed will increase, which is dangerous if the vehicle is running, and the engine rotational speed will increase if the vehicle is stopped. will rise and there is a danger that the engine will be destroyed.

Therefore, an electronic fuel injection system has been proposed that is equipped with a fail-safe device to prevent such a dangerous situation. FIG. 3 shows a conventional structure of such a fail-safe device. In the figure, an accelerator pedal signal Va from a pedal position detector 1 and a throttle valve signal Vb from a valve position detector 2.
is supplied to the differential amplifier 3, and these two signals Va,
Deviation of Vb is detected. If the gain for each input of the differential amplifier 3 is R ₂ /R ₁ , then the differential amplifier 3
The output V ₁ of is R ₂ /R ₁ (Vb−Va). This deviation signal V ₁ is full-wave rectified by a full-wave rectifier circuit 7, and an absolute value signal V ₂ of the deviation signal V ₁ is obtained.

The absolute value signal V ₂ of this deviation is the set value in comparator 4.
It is compared with _VR , and if it is equal to or higher than _VR , the output of the comparator 4 becomes a low level L and is detected. When the comparator 4 detects that the absolute value signal V ₂ of the deviation is greater than or equal to the set value _VR , and this detection state continues for longer than the set time _TR , the set time detection circuit 5 detects this.
For example, the output of the comparator 4 is input to each clear terminal CL of the counter CT and the D-type flip-flop FF. A clock signal from the clock oscillator CK is input to the clock terminal CK of the counter CT.
A high level H is applied to the data terminal D of the D-type flip-flop FF, and a counter signal is applied to the clock terminal CK.
CT set count value output is supplied.

While the output of comparator 4 is at H level, counter CT,
The flip-flop FF is in a clear state,
The Q output of the flip-flop FF outputs a low level. However, when the absolute value of the deviation amount becomes larger than the set value _VR , the counter CT is cleared and starts counting the clocks of the clock oscillator CK, and the clearing of the flip-flop FF is also released. Therefore, when the counter CT counts the clock to the design value, the high level H is set in the flip-flop FF by the output of the counter CT, the Q output of the flip-flop FF becomes a high level, and the absolute value of the deviation V ₂ exceeds the set value _VR . It is detected that the time for which the fuel injection device has been running has exceeded the set time T _R , that is, that the electronic fuel injection device has become abnormal.

The abnormality detection output from the set time detection circuit 5 is input to the stop circuit 6, and fuel injection is stopped.
That is, when the output of flip-flop FF becomes high level, transistor Q is made conductive by that output, and the relay inserted in series with transistor Q is activated.
RL ₁ operates and its junction SW ₁ is turned off. A main relay RL ₂ is connected between the terminal T connected to the battery of the vehicle and ground via a contact SW ₁ , and the contact SW ₂ of this relay RL ₂ is connected to the terminal T and the operating power source of the control circuit 8 of the fuel injection device. inserted between the terminals. Therefore, when an abnormality is detected in the time detection circuit 5, the relay RL ₁ operates, and the operating circuit of the relay RL ₂ is interrupted by the relay contact SW ₁ , and the relay contact
SW ₂ is turned off, the control circuit 8 becomes inoperable, and fuel injection is stopped. The stop circuit 6 may stop ignition of the engine instead of stopping fuel injection based on the abnormality detection output.

In the normal state, the opening and closing of the throttle valve 10 is controlled by the device shown in FIG.

In this way, conventional fail-safe circuits detect when the deviation between the accelerator pedal signal and the throttle valve signal exceeds a set value, and the time that the difference continues to exceed the set value exceeds the set time. The detection output is configured to stop fuel injection or engine ignition.

[Problem that the invention attempts to solve]

In such a conventional device, the full-wave rectifier circuit 7 outputs the absolute value of the deviation between the accelerator pedal signal and the throttle valve signal, and the comparator 4 outputs the absolute value of the deviation amount between the accelerator pedal signal and the throttle valve signal.
is input. Therefore, regardless of whether the actuator 12 is locked in the opening or closing direction of the throttle valve 10, the deviation amount is the reference set value.
If it is greater than the set value corresponding to V _R and the time T _R set by the set time detection circuit 5,
The stop device 6 is driven to stop fuel injection or engine ignition.

Therefore, when the actuator 12 is locked only in the opening direction of the throttle valve 10, that is, for example, when the actuator 12 is locked at a certain position between the fully closed position and the fully open position of the throttle valve 10, the locked position When the throttle valve 10 cannot be opened more than that, but the valve 10 can be returned to the closing direction, the throttle valve 10 will follow the accelerator pedal 9 from the fully closed position to its locked position. Even though the valve opening degree of the throttle valve 10 can be controlled by the throttle valve 10 (the valve is not locked in the closing direction), the accelerator pedal 9 cannot be controlled from the locked position.
If the driver depresses the button further, fuel injection or engine ignition will stop when the deviation exceeds a predetermined amount, which poses a safety problem.

Therefore, in view of the above-mentioned conventional problems, the present invention detects the amount of deviation between the depression angle of the accelerator pedal and the valve opening of the throttle valve, and uses this detected amount of deviation to drive the actuator to open the throttle valve. In a device in which the opening degree is controlled to a value corresponding to the depression angle, fuel injection or engine ignition is stopped only when the actuator locks the throttle valve in the closing direction, and the actuator locks the throttle valve in the direction in which it opens. An object of the present invention is to provide an electronic fuel injection device that does not stop fuel injection or engine ignition regardless of the amount of deviation when the engine is locked.

[Means for solving problems]

In order to solve the above problems, the electronic fuel injection system of the present invention detects the depression angle of the accelerator pedal as an accelerator pedal signal using a pedal position detector, and detects the valve opening degree of the throttle valve using a valve position detector. Detects the throttle valve signal as a throttle valve signal, inputs each signal to a control circuit, drives an actuator based on the output of the control circuit, and sets the opening degree of the throttle valve to a value corresponding to the depression angle by the actuator. a differential amplifier that outputs a deviation signal by calculating the difference between an accelerator pedal signal from the pedal position detector and a throttle valve signal from the valve position detector; The deviation signal output by the differential amplifier is compared with a preset standard deviation amount, and the deviation signal when the opening degree of the throttle valve in the closing direction does not follow the depression angle of the accelerator pedal is determined to be less than the standard deviation amount. a comparison means that outputs a signal when the signal is larger; a set time detection means that detects that the comparison means continues to output a signal for a set time or more; and a set time detection means that determines whether fuel injection or The engine is characterized by comprising a stop means for stopping ignition of the engine.

[Effect]

In the above configuration, the differential amplifier calculates the difference between the accelerator pedal signal from the pedal position detector and the throttle valve signal from the valve position detector and outputs a deviation signal. The comparison means compares this deviation signal with a preset standard deviation amount, and outputs a signal when the deviation signal when the opening degree of the throttle valve in the closing direction does not follow the depression angle of the accelerator pedal is larger than the standard deviation amount. Output.

The set time detection means detects that the comparison means continues to output a signal for the set time or more, that is, the throttle valve is locked in the closing direction and its opening does not follow the depression angle of the accelerator pedal. The stopping means is adapted to stop fuel injection or ignition of the engine when the period continues for a set period of time.

On the other hand, when the actuator is locked in the direction of opening the throttle valve, the comparison means does not generate any signal even if the accelerator pedal is further depressed from the locked position and the deviation from the throttle valve opening exceeds the set value. Therefore, even if this state continues for longer than the set time, the stop means will not be activated to stop fuel injection or engine ignition.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. 1st
In the figures and FIG. 2, the same parts as in FIG. 3 are denoted by the same reference numerals. 1 and 2, the full-wave rectifier circuit 7 in FIG. 3 is removed and the output of the differential amplifier 3 is directly connected to the negative phase input of the comparator 4,
The other configurations are the same as in FIG. 3. Also, the differential amplifier 3 outputs a deviation amount, which is the difference between the output of the pedal position detector 1 (accelerator pedal signal) and the output of the valve position detector 2 (throttle valve signal). The polarity of the deviation amount is (+) when the throttle valve 10 is locked in the closing direction, and (-) when it is locked in the opening direction.
The magnitude is the absolute value of the amount of deviation.

In this configuration, the output signal of the pedal position detector 1 is 0 when the accelerator pedal is fully closed.
(v), Vs(v) is output when fully open. Regarding the output signal of the valve position detector 2,
It is assumed that 0 (v) is output when the throttle valve is fully closed, and Vs (v) is output when it is fully open. Therefore, when the accelerator pedal 9 is in the fully closed position, the output of the differential amplifier 3 is zero, and the output of the comparator 4 is at H level. When the accelerator pedal 9 is fully depressed, the actuator 12 is driven by the action of the control circuit 11 and the throttle valve 1 is activated.
0 rotates from the fully closed position to the open direction following the depression angle of the accelerator pedal 9, but is locked at a certain position corresponding to the depression angle (fully open position) of the accelerator pedal 9. If the output of the valve position detector 2 at this locked position is Va, the output V _OUT of the differential amplifier 3 is V _OUT =R ₂ /R ₁ ·(Va-Vs) (1). In equation (1), Vs is the pedal position detector 1
This is the output at the fully open position, and since Va < Vs, V _OUT < 0, and the polarity of the output V _OUT is (-)
becomes. Therefore, the output of the comparator 4 is the differential amplifier 3
The output level, that is, the H level is always maintained regardless of the absolute value of the deviation amount. Therefore, the count CT and flip-flop FF of the set time detection circuit 5
maintains the reset state, and since the detection circuit 5 is not driven, the transistor Q of the stop circuit 6 is turned off, and fuel injection and engine ignition are not stopped. That is, when the actuator 12 is locked in the direction of opening the throttle valve 10, the stop circuit 6 is not driven regardless of the magnitude of the deviation obtained from the output of the differential amplifier 3. That is, when the accelerator pedal 9 is depressed at an arbitrary depression angle, the vehicle continues to travel.

On the other hand, assume that the actuator 12 has locked the throttle valve 10 in the closing direction. That is, when the throttle valve 10 is at a predetermined valve opening position, when the accelerator pedal 9 is returned to the fully closed position, the throttle valve 10 does not fully close, and the throttle valve 10 does not fully close, but returns to the predetermined position between the valve opening position and the fully open position. Assume that the actuator 12 is locked in the locked position (the actuator 12 can be driven in the opening direction from the locked position).
Valve position detector 2 in this locked position
Letting the output of the differential amplifier 3 be Vb, the V _OUT of the differential amplifier 3 is V _OUT = R ₂ /R ₁ · (Vb-0) = R ₂ /R ₁ Vb (2). Here, 0(v) in equation (2) is the output for the fully closed position of the pedal position detector 1,
The polarity of V _OUT is (+). This output V _OUT is input to the negative phase input of the comparator 4 and compared with the set value V _R applied to the positive phase input. At this time V _OUT
>V _R , the output of the comparator 4 becomes L level, the counter CT is cleared, the clock oscillator CK starts counting the clocks, and the flip-flop FF is also cleared. Therefore, when the counter CT counts the clock to the set value, the output of the counter CT causes the flip-flop FF to go high.
The level is set, the Q output becomes H level, and when the time during which the output V _OUT is equal to or higher than the set value V _R becomes equal to or longer than the set time T _R , the transistor Q is turned on and the stop circuit 6 is driven to start fuel injection or Engine ignition is stopped.

Note that the set value V _R is generally the accelerator pedal signal from the pedal position detector 1 or the valve position detector 2.
This is a very small value of several percent of the signal change width of the throttle valve signal (the difference between the signals at the fully closed and fully open positions). As described above, the actuator 12 is connected to the throttle valve 10.
When locked in the closing direction, the stop circuit 6 is driven if the deviation amount is greater than a set value and the deviation amount greater than the set value continues for a set time or longer.

Even with the conventional configuration shown in FIG. 3, when the actuator 12 is locked in the opening direction of the throttle valve 10, the control circuit 11 prevents the accelerator pedal 9 from being depressed within the range from the locked position to the valve fully closed position. The throttle valve 10 opens and closes depending on the angle, and ignition of the fuel injection device or the engine does not stop. However, since the driver of the vehicle cannot recognize the lock position,
It is not possible to recognize whether the vehicle will not stop no matter how far the accelerator pedal 9 is depressed. Therefore, when the accelerator pedal 9 is continuously depressed by more than the deviation amount from the lock position, the stopping means 6 is driven and the vehicle is stopped. In other words, in the conventional configuration, when the actuator 9 is locked in the direction of opening the valve, the driver must always be careful about the depression angle of the accelerator pedal 9 so that the stopping means 6 is driven and the vehicle does not stop. Therefore, it is virtually impossible to drive the vehicle safely.

Also, compared to the conventional configuration shown in FIG.
Since it is no longer necessary, the number of parts can be reduced.

〔effect〕

As described above, according to the present invention, when the actuator is locked in the opening direction of the throttle valve, the ignition of the fuel injection device or the engine is not stopped regardless of the amount of deviation, so the vehicle can continue to run, and the vehicle You can move to a safe place.

[Brief explanation of the drawing]

1 and 2 are block diagrams and circuit diagrams respectively showing an embodiment of the fail-safe device according to the present invention, FIG. 3 is a circuit diagram showing a conventional fail-safe device, and FIG. FIG. 2 is a block diagram showing a fuel injection device. 1...Pedal position detector, 2...Valve position detector, 3...Differential amplifier, 4...Comparator, 5...
Set time detection circuit, 6... Stop circuit, 9... Accelerator pedal, 10... Throttle valve, 11...
...control circuit, 12...actuator.

Claims (1)

[Claims for Utility Model Registration] The depression angle of the accelerator pedal is detected as an accelerator pedal signal by a pedal position detector, the valve opening of the throttle valve is detected as a throttle valve signal by a valve position detector, and each of the above-mentioned signals is input into a control circuit, an actuator is driven by the output of the control circuit, and the actuator controls the opening degree of the throttle valve to a value corresponding to the depression angle, the electronic fuel injection device comprising: a differential amplifier that calculates the difference between an accelerator pedal signal from a pedal position detector and a throttle valve signal from the valve position detector and outputs a deviation signal; and a deviation signal outputted by the differential amplifier is set in advance. a comparison means that outputs a signal when the deviation signal when the opening degree of the throttle valve in the closing direction does not follow the depression angle of the accelerator pedal is larger than the reference deviation amount; A set time detection means for detecting that the comparison means continues to output a signal for a set time or more; and a stop means for stopping fuel injection or engine ignition upon detection by the set time detection means. An electronic fuel injection device featuring: