JP3069870B2 - Car engine abnormality detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting an abnormality in an engine, and more particularly to a method for detecting an abnormality in a vehicle used for diagnosing and alarming an abnormality in a motorcycle in which ignition timing is controlled using a microcomputer. .

[0002]

2. Description of the Related Art An ignition timing control device using a microcomputer (hereinafter referred to as a CPU) is generally known.
The configuration as shown in FIG. 4 is used. That is, a waveform shaping circuit 1 for inputting information on the rotation angle of the engine, a gear input circuit 2 for inputting the state of the gear position of the transmission, a throttle input circuit 3 for detecting the throttle opening, and an optimal ignition of the engine connected to these circuits. And a CPU 4 for calculating timing.

[0003] However, the conventional ignition timing control device does not have an alarm circuit for automatically detecting an abnormality of the engine and informing the driver of the abnormality. Therefore, there has been no method of diagnosing the engine abnormality except for the driver detecting the abnormality of the engine speed or the engine sound by hearing.

[0004]

However, such a method of diagnosing an engine abnormality based on human hearing has a problem in that the driver erroneously determines whether or not the engine is abnormal. For example, in a motorcycle with multiple spark plugs, if one of the spark plugs fails and there is no output, the engine speed will not increase as expected, but if the driver is unfamiliar The engine may not be noticed. Or, conversely, there is a case where the driver tries to repair a motorcycle having no failure anywhere by illusion that the engine is abnormal because the engine sound is abnormal even though the engine has no abnormality.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an engine abnormality diagnosis function and an alarm function are added to an ignition timing control device so that a driver can correctly diagnose an engine abnormality. It is an object of the present invention to provide a method of detecting a vehicle engine abnormality which can be performed.

[0006]

According to the present invention, a program for diagnosing the presence or absence of an engine abnormality is added to a program for a CPU for calculating ignition timing control, and an alarm is issued when an engine abnormality is detected. Things. That is, when the transmission is in the neutral state or the clutch is disengaged, and when the state where the engine speed is not within the predetermined range corresponding to the throttle opening occurs more than the predetermined number of times within the predetermined time, It is determined that the engine is abnormal.

[0007]

According to the present invention, the abnormality of the engine is detected when the transmission is in the neutral state or the clutch is disconnected. In such a state, the engine speed is detected, and it is determined whether or not the detected engine speed is within a predetermined range according to the throttle opening. If the detected engine speed is not within the predetermined range, the number is counted up. Then, if such a state occurs a predetermined number of times or more within a predetermined time, it is determined that the engine is abnormal. Thereby, the driver can detect the engine abnormality without depending on the hearing.

[0008]

FIG. 2 is a block diagram showing a configuration of a relevant portion of an engine control device for realizing an engine abnormality detecting method according to the present invention. The same portions as those of the configuration of the conventional ignition timing control device shown in FIG. 4 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In order to detect the rotation angle information of the engine,
A rotating body 7 that rotates coaxially with the crankshaft of the engine is provided.
Eight and one projections are provided at 0-degree intervals, respectively. The rotation angle information is detected by an electromagnetic pickup 8 provided in the vicinity of detecting these convex portions, and the waveform shaping circuit 1
As an input signal of the CPU 4a.

The CPU 4a controls the optimal energization ignition timing from this input signal. The CPU 4a is connected to a gear input circuit 2 for determining whether the gear position is neutral and whether the clutch is connected or disconnected, and an input circuit 3 for a throttle sensor indicating the throttle opening TH. Have been.

On the basis of the input signals from these circuits 1 to 3, the CPU 4a performs an ignition timing control and an engine abnormality diagnosis and an alarm operation at the same time. When an abnormality is detected, the lamp 5 for warning the engine abnormality is turned on by the drive circuit
The warning is given to the driver by turning on the LED.

In order to make these diagnoses, it is necessary to calculate the engine speed NE. For this purpose, a pickup signal detected by the electromagnetic pickup 8 is converted into a waveform shaping circuit 1.
And input to the CPU 4a. In synchronization with this input signal, the CPU 4a jumps to an interrupt program, calculates the time between each input signal, and calculates the engine speed NE.

Further, the CPU 4a determines whether the gear position of the transmission is neutral or whether the clutch is engaged based on a signal from the gear input circuit 2. The CPU 4a converts the signal from the throttle sensor input circuit 3 by a built-in AD converter to convert the throttle opening TH into a digital value.

FIG. 1 is a flowchart showing a processing procedure of an engine abnormality detecting method performed by the CPU 4a.

The CPU 4a first determines whether the gear position is in neutral according to an input signal from the gear input circuit 2.
Alternatively, it is determined whether the clutch is connected (step 101). If the neutral or clutch is disconnected, the process proceeds to step 102. Step 10
2, the upper limit value (hereinafter referred to as normal NEMAX) and the lower limit value (hereinafter referred to as normal NE)
MIN). Normal NEMAX and normal N
As shown in FIG. 3, EMIN has a predetermined range determined in advance corresponding to the throttle opening TH. For example, when the throttle opening TH is TH = TH1, the respective values can be calculated based on Expression 1 described later.

[0016]

(Equation 1)

Here, the throttle openings THa and THb and the engine speeds NE1, NE2, NE3 and NE4 are both data previously written in the data area of the program of the CPU 4a. This is the section data of TH and the engine speed NE.

Next, when the engine speed NE is normal NEMI
It is determined whether or not the engine speed is in the range of N or more and the normal NEMAX or less. If not, it is determined that the engine speed is abnormal, and the counter X is incremented (steps 103 and 104).

Next, the count value of the counter X is compared with the comparison data N registered in the program memory in advance, and an alarm is output when it exceeds the comparison data N (steps 104 to 106). . However, counter X
Is cleared to zero by the timer interrupt processing that occurs at a constant time period (step 107).
An alarm is output only when the engine speed is abnormal for N times or more of the comparison data within a predetermined time.

When such an engine abnormality is detected, FIG.
Outputs an alarm output to the drive circuit 6. The drive circuit 6 operates to turn on the lamp 5 in response to the alarm output. By turning on the lamp 5, the driver can know the abnormality of the engine.

[0021]

As described above in detail with reference to the embodiment, in the present invention, the CPU compares the engine speed within a predetermined normal range according to the gear position state and the throttle opening. To determine if there is an engine abnormality. When the engine is abnormal, a warning is issued to the driver by a warning device such as a lamp, so that the engine abnormality can be easily detected by simply adding a part of the program to the conventional ignition timing control device and adding a warning device. Can be.

[Brief description of the drawings]

FIG. 1 is a flowchart for explaining an engine abnormality detection procedure according to the present invention.

FIG. 2 is a block diagram showing a part of an engine control device for realizing the engine abnormality detection method of the present invention.

FIG. 3 is a characteristic diagram showing a relationship between a throttle opening and an engine speed.

FIG. 4 is a block diagram showing a configuration of a conventional ignition timing control device.

[Explanation of symbols]

 1 Waveform shaping circuit 2 Gear input circuit 3 Throttle input circuit 4a CPU 5 Lamp 7 Rotating body 8 Electromagnetic pickup TH Throttle opening NE Engine speed

Claims (1)

(57) [Claims] A means for detecting whether a vehicle transmission is in a neutral state or a clutch disengaged state; a means for detecting a throttle opening;
Means for detecting an engine speed, wherein an engine abnormality is determined when the state in which the engine speed is not within a predetermined range according to the throttle opening occurs a predetermined number of times or more within a predetermined time. Car engine abnormality detection method.