JPH04203447A - Throttle valve opening control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent vehicle speeds from being changed as well as to prevent a vehicle from being jerky in running by providing a second throttle valve opening control means which suspends control by a first throttle opening control means when it is judged that an accelerator sensor is abnormal so as to control the vehicle to run at a speed set in advance. CONSTITUTION:A device is equipped with an accelerator sensor 100 detecting the stroke of accelerator pedal footing, a first throttle valve opening control means 101 controlling throttle valve opening based on the result of detection by the accelerator sensor 100, a vehicle speed detecting means 102 detecting vehicle speeds, and with an abnormality judging means 103 judging whether or not the accelerator sensor 100 is abnormal. And when it is judged by the abnormality judging means 103 that the accelerator sensor is abnormal, control by the first throttle valve opening control means 101 is suspended, and throttle valve opening is concurrently controlled by the second throttle valve opening control means 104 based on the vehicle speed in such a way that the vehicle speed is equal to one set in advance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a throttle valve opening control device for an internal combustion engine.

[Conventional technology]

Japanese Unexamined Patent Publication No. 59-53135 discloses an input circuit with high input impedance that manually inputs a signal from an accelerator sensor that outputs an electric signal corresponding to the amount of operation of the accelerator, and a circuit in which the rate of change of the output signal of the input circuit is greater than a predetermined value. An abnormality detection circuit outputs a switching signal when
A signal processing circuit for an accelerator sensor is disclosed, which includes a switching circuit that sends out the output of a holding circuit when a switching signal is given, and sends the output of the switching circuit to a subsequent circuit as an accelerator sensor signal. .

On the other hand, Japanese Patent Application Laid-open No. 60-50248 discloses an idling switch, an intermediate switch, and a fully closed switch that are provided in an accelerator position sensor and turn ON or OFF when the armature of the accelerator position sensor crosses them.
When the accelerator position sensor is determined to be malfunctioning, the accelerator is composed of a computer that determines the desired driving state from the combination of ON-OFF signals of each switch and controls the injector without accepting the signal from the accelerator position sensor. A position sensor acting device is disclosed.

[Problem to be solved by the invention]

However, the former signal processing circuit for the accelerator sensor has a problem in that it gives the driver a sense of anxiety because the vehicle speed changes depending on the road condition, for example, the degree of inclination of the road.

On the other hand, the latter accelerator position sensor substitute device controls the throttle valve from a combination of signals from the idling switch, intermediate switch, and full-open switch, resulting in jerky driving.

[Means to solve the problem]

In order to solve the above problems, according to the present invention, as shown in the configuration diagram of the invention in FIG. a first throttle valve opening control means 10 for controlling the throttle valve opening;
1 and vehicle speed detection means 1 for detecting vehicle speed.
02, abnormality determination means 103 that determines whether or not the accelerator sensor 100 is abnormal, and when the abnormality determination means 103 determines that the accelerator sensor 100 is abnormal, the control by the first throttle valve opening control means 101 is stopped. and second throttle valve opening control means 104 for controlling the throttle valve opening based on the vehicle speed so that the vehicle speed reaches a predetermined speed.

[For production]

When the accelerator sensor becomes abnormal, the throttle valve opening degree is controlled based on the vehicle speed so that the vehicle speed becomes a predetermined vehicle speed.

〔Example〕

Referring to FIG. 2, 1 is an intake passage of an internal combustion engine, 2 is a throttle valve disposed within the intake passage 1, and 3 is a step motor for driving the throttle valve 2. As shown in FIG.

The electronic control unit 20 consists of a digital computer and has R(I) connected to each other by a bidirectional bus 2I.
It includes an M (read only memory) 22, a RAM (random access memory) 23, a CPIJ (microprocessor) 24, an input port 25, and an output port 26.

A throttle sensor 5 for detecting the opening degree of the throttle valve 2 is connected to the input port 25 via an AD converter 27. First and second accelerator sensors 6 and 7 for detecting the amount of depression of an accelerator pedal (not shown) are
Input port 25 via AD converters 28 and 29, respectively
connected to. A crank angle sensor 8 for detecting the engine speed, a vehicle speed sensor 9 for detecting vehicle speed, and a brake switch 10 that is turned on when the brake pedal is depressed are each connected to the input port 25.

On the other hand, the output boat 26 is connected to the step motor 3 via a drive circuit 3G.

When the accelerator sensor is normal, the opening degree of the throttle valve 2 is calculated from a map based on the detected value of the accelerator sensor, and the throttle valve 2 is controlled based on this. However, when the accelerator sensor becomes abnormal, the detected value of the accelerator sensor no longer corresponds to the amount of depression of the accelerator pedal, so the opening degree of the throttle valve 2 cannot be controlled, and therefore the engine operation cannot be controlled. Therefore, a problem arises in that the vehicle cannot be driven.

Therefore, in this embodiment, when it is determined that the accelerator sensor is abnormal, the opening degree of the throttle valve 2 is not controlled based on the detected value of the accelerator sensor, and the opening degree of the throttle valve 2 is controlled based on the vehicle speed and engine speed. I'm trying to control the intensity.

FIG. 3 shows a routine for calculating the opening degree of the throttle valve 2. This routine is executed by interrupts at regular intervals.

Referring to FIG. 3, first, in step 40, the accelerator pedal depression amounts AI and A2 detected by the first and second accelerator sensors 6 and 7 are read. Next, in step 41, it is determined whether the absolute value of the difference between A1 and A2 is greater than or equal to the reservation window value As. That is, in this step, it is determined whether one of the first and second accelerator sensors 6 and 7 has become abnormal. lA
If it is determined that 1-A2 t <As, that is, if it is determined that the first and second accelerator sensors 6 and 7 are normal, the process proceeds to step 42, and the detected values of the first and second accelerator sensors 6 and 7 are determined. The average value of (A
, +A2)/2, the throttle valve opening θ is calculated from the map.

On the other hand, in step 41, l At A2 l
If ≧As, that is, if it is determined that either one of the first and second accelerator sensors 6 and 7 has become abnormal, the process proceeds to step 43 and the brake switch 10
It is determined whether or not is on. When the brake switch 10 is on, that is, when the brake pedal is depressed, the process proceeds to step 44, where the throttle valve opening degree θ is 0, that is, fully closed. If the brake pedal is not depressed, the process proceeds to step 45, where the engine speed NE and vehicle speed V are read. Next, in step 46, the engine speed NE is set to a predetermined speed NEI, for example 3000r.
It is determined whether or not it is smaller than pm. If NE≧NEI, the process proceeds to step 47, where the throttle valve opening degree θ is decreased by B. That is, while NE≧NEI, the throttle valve is closed in steps of B.

On the other hand, if NE<NEI, the process proceeds to step 48 and it is determined whether the vehicle speed V is smaller than a predetermined speed v1, for example 50 b/h. If ■≧■1, step 4
The process proceeds to step 9, where the throttle valve opening degree θ is reduced by C. That is, during V2V5, the throttle valve θ is closed by C.

On the other hand, if V<V1, the process proceeds to step 50 and the throttle valve opening θ is increased by D. That is, NE<
While NEI and V<V1, the throttle valve is opened by D. Note that C and D are sufficiently small values, and B and C are larger than D. Also, B and C
may be equal.

As described above, when the accelerator sensor is determined to be abnormal and the brake pedal is depressed, the throttle valve is fully closed. On the other hand, if the accelerator sensor is determined to be abnormal and the brake pedal is not depressed, the throttle valve opening is controlled so that the engine speed NE becomes NEI or the vehicle speed V becomes Vl. , NE and V reach NE1 and V1, the throttle valve opening is controlled so as to maintain the value at that value.

Therefore, since the throttle valve opening degree is controlled so that the vehicle speed V becomes the predetermined vehicle speed v1, the vehicle can be driven safely, and changes in vehicle speed and jerky running can be prevented.

Furthermore, since the throttle valve opening degree is controlled so that the engine speed NE becomes the preset engine speed NEI, acceleration shock during downshifting can be prevented. That is, even when downshifting, the engine speed increases in order to bring the vehicle speed to vl, and unless the engine speed is controlled as described above, an acceleration shock will occur.

Note that in this embodiment, two accelerator sensors 6.
7 is used to detect an abnormality in the accelerator sensor, but it is also possible to detect an abnormality using only one accelerator sensor.

Further, in step 50 of FIG. 3, the throttle valve opening degree θ is increased by D, but as shown in FIG.
The throttle valve opening may be controlled so that the acceleration is small up to m/h and the acceleration is increased from v2 to Vl.

〔Effect of the invention〕

If the accelerator sensor becomes abnormal, the throttle valve opening degree is controlled so that the vehicle speed becomes the vehicle speed set in the reserved window, so changes in vehicle speed and jerky driving can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the invention, FIG. 2 is a diagram showing an embodiment of the throttle valve opening control device for an internal combustion engine according to the invention, FIG. 3 is a flowchart for calculating the throttle valve opening, and FIG. FIG. 4 is a diagram showing changes in vehicle speed during acceleration. 2...Throttle valve, 6.7...Accelerator sensor, 9...Vehicle speed sensor. Figure 1 Figure 4

Claims (1)

[Claims] an accelerator sensor for detecting the amount of depression of the accelerator pedal; a first throttle valve opening control means for controlling the throttle valve opening based on the detection result of the accelerator sensor; and a first throttle valve opening control means for detecting the vehicle speed. control by the vehicle speed detection means, the abnormality determination means for determining whether or not the accelerator sensor is abnormal, and the first throttle valve opening control means when the abnormality determination means determines that the accelerator sensor is abnormal; and a second throttle valve opening control means for controlling the throttle valve opening based on the vehicle speed so that the vehicle stops and the vehicle speed reaches a predetermined speed. Control device.