JPH0560005A - Malfunction detecting device for electronic controller for engine - Google Patents

Abstract

(57) [Summary] [Purpose] In an electronic controller used for a starter engine, it is possible to easily detect malfunction of the central processing unit due to poor ground connection. [Configuration] An input terminal 6 of an electronic controller 5 and a central processing unit 8 are sequentially connected to an output terminal 2a of a battery 2 of an engine. An engine abnormality detection circuit 12 is connected to the central processing unit 8. A first timer 14 for delaying the output signal of the abnormality detection circuit 12 is provided. The controller input terminal 6 is connected in series with the light emitting element 17 of the photocoupler 9 and the emergency stop switch 18. A second timer 21 for delaying the output signal of the light receiving element 20 of the photocoupler 9.
To provide. The set delay time ΔT ₂ of the second timer 21 is set to a value shorter than the set delay time ΔT ₁ of the first timer 14 described above.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting malfunction of an electronic controller used for a starter engine.

[0002]

2. Description of the Related Art Generally, an engine abnormality detecting apparatus having an electronic controller has a controller input terminal and a central processing unit which are sequentially connected to an output terminal of a battery for supplying electric power to a starter motor. It is configured by connecting an abnormality detection circuit that outputs an abnormality signal such as high engine cooling water temperature.

In the above structure, the inventor, prior to the present invention, connects the light emitting element of the photocoupler and the emergency stop switch to the controller input terminal in series,
First, the one in which the engine is stopped by the output signal of the light receiving element of the photo coupler is considered. In this case, the output signal of the light receiving element and the output signal of the engine abnormality detection circuit are delayed by a single timer for a set time (about 100 mS) to activate the engine stop alarm circuit.

[0004]

In the above prior invention example,
When the engine was started, the alarm circuit was activated and the engine stopped even though the engine was not abnormal. The reason for this is that if the ground of the central processing unit has a poor connection due to loose terminals, etc., the voltage at the controller input terminal will drop by the amount of the poor ground connection. It is considered that this is because the voltage at the controller input terminal becomes lower than the required voltage. Therefore, the operation of the starter relay controlled by the central processing unit becomes unstable, and the rotation of the starter motor becomes unstable. As a result, the voltage at the controller input terminal fluctuates significantly, the light emitting element of the photocoupler is switched to the non-conductive state, and the light receiving element outputs an emergency stop signal to stop the engine.

However, in the above-mentioned prior invention example, since the output signal of the emergency stop circuit and the output signal of the engine abnormality detection circuit are processed by one timer, it is detected which cause causes the engine to stop. I couldn't. An object of the present invention is to make it possible to easily detect a malfunction of the central processing unit due to a defective ground connection.

[0006]

In order to achieve the above-mentioned object, the present invention comprises a malfunction detecting device for an electronic controller for an engine as follows, as shown in FIGS. 1 and 2, for example.

A battery 2 for supplying electric power to a starter motor 4 attached to the engine, an input terminal 6 of an electronic controller 5 connected to an output terminal 2a of the battery 2,
A central processing unit 8 connected to the input terminal 6, an engine abnormality detection circuit 12 that outputs an engine abnormality signal to the central processing unit 8, and a first timer 14 that delays the output signal of the engine abnormality detection circuit 12. A first alarm circuit 15 activated by the output signal of the first timer 14,
The light emitting element 17 and the emergency stop switch 18 of the photocoupler 9 connected in series to the input terminal 6 of the electronic controller 5, the second timer 21 for delaying the output signal of the light receiving element 20 of the photocoupler 9, and its second 2 timer 21
And a second alarm circuit 22 which is activated by the output signal of the second timer 21 is provided, and the set delay time ΔT ₂ of the second timer 21 is set to a value shorter than the set delay time ΔT ₁ of the first timer 14. ..

[0008]

The present invention operates as follows. When starting the engine, the ground terminal 10 of the electronic controller 5
When the connection between the ground line 11 and the ground line 11 is poor or the ground line 11 is about to be broken, the input voltage of the central processing unit 8 becomes lower than the required voltage due to the voltage drop due to the start of the starter motor 4. The operation of the starter relay 3 becomes unstable, and the rotation of the starter motor 4 becomes unstable. As a result, the voltage of the input terminal 6 of the electronic controller 5 becomes unstable, the light emitting element 17 of the photocoupler 9 is switched to the non-conductive state, and the light receiving element 20 outputs the emergency stop signal to the second timer 21.

The above emergency stop signal is set delay time ΔT.
_When continuously input for ₂ (50 mS in this case), the second timer 21 activates the second alarm circuit 22. Therefore, before the engine abnormally stops due to the abnormal signal of the engine abnormality detection circuit 12, the engine can be brought to an emergency stop or the emergency stop warning lamp can be turned on.

[0010]

According to the present invention, when the ground of the central processing unit is not properly connected, the second alarm circuit for emergency stop is activated before the first alarm circuit for engine abnormality detection is activated. Therefore, the malfunction due to the ground connection failure can be easily known. Moreover, in order to obtain the above effect, since the emergency stop circuit including the photocoupler and the emergency stop switch can be used, the configuration of the device for detecting a malfunction can be simplified.

[0011]

In the block diagram of FIG. 1, a starter motor 4 is connected to an output terminal 2a of a battery 2 mounted on an engine via a contact 3b of a starter relay 3 and an input terminal of an electronic controller 5 is provided. 6 is connected. This input terminal 6 has a central processing unit 8 and a photo coupler 9
And are connected. The coil 3a for opening and closing the contact 3b of the relay 3 is operated by the output signal of the central processing unit 8. Reference numeral 10 is a ground terminal of the central processing unit 8, and reference numeral 11 is a ground line.

An engine abnormality detection circuit 12 that outputs an engine abnormality signal (here, a high temperature signal of the engine cooling water temperature) is connected to the central processing unit 8. The abnormality detection circuit 12 is provided with a water temperature switch 13 that opens at a high temperature of the engine cooling water, and a first water temperature switch 13 is used to control the first temperature via a first timer 14.
It is connected to the alarm circuit 15. The first timer 14 is
The first alarm circuit 15 is activated when an abnormal signal is continuously input for a set delay time ΔT ₁ (here, 100 mS).

The light emitting element 17 of the photocoupler 9 and the emergency stop switch 18 are connected in series to the input terminal 6 of the electronic controller 5. The photo coupler 9
The light receiving element 20 is connected to the second alarm circuit 22 via the second timer 21.

During normal operation of the engine, since the emergency stop switch 18 is closed, the light emitting element 17 is energized and the light receiving element 20 outputs an engine operating signal to the central processing unit 8. .. When the switch 18 is opened while the engine is running, the light emitting element 17 of the photocoupler 9 is switched to the non-energized state, and the light receiving element 20 outputs an emergency stop signal to the second timer 21.

If the connection between the ground terminal 10 and the ground wire 11 of the electronic controller 5 is poor at the time of starting the engine, in addition to the voltage drop due to the start-up of the starter motor 4, the ground connection failure is caused. However, since the input voltage of the central processing unit 8 further decreases, the operation of the starter relay 3 becomes unstable and the rotation of the starter motor 4 becomes unstable. As a result, the voltage at the input terminal 6 of the electronic controller 5 becomes unstable, and the photocoupler 9
The light emitting element 17 of the
0 outputs an emergency stop signal to the second timer 21.

The second timer 21 is provided with a second alarm circuit when an abnormal signal is continuously input for a delay time ΔT ₂ (here, 50 mS) shorter than the delay time ΔT ₁ of the first timer 14. 22 is activated.

The operation of the central processing unit 8 will be described mainly with reference to FIG. When the operation of the starter motor 4 is started
(S1), the engine abnormality detection circuit 12 determines whether or not an engine abnormality signal is input (S2). If the abnormal signal is input, the signal is 100mS
Determine whether or not the input is continuous over the time
(S3). Outputs an alarm when input continuously
(S4).

Simultaneously with the operation of the starter motor 4, it is determined whether or not an emergency stop signal is input from the light receiving element 20 of the photocoupler 9 (S5). When the emergency stop signal is input, it is determined whether or not the signal is continuously input for a time of 50 mS (S6).
When continuously input, an alarm is output (S7) to stop the engine in an emergency and turn on the alarm lamp.

As the engine abnormality signal,
In addition to the high engine cooling water temperature signal, a lubricating oil pressure drop signal or the like may be provided. Further, the set delay time ΔT ₂ of the second timer 21 is not limited to 50 mS and may be shorter than the delay time ΔT ₁ of the first timer 14.

[Brief description of drawings]

FIG. 1 is a block diagram of a malfunction detection device of an electronic controller.

FIG. 2 is a flowchart of a main part of the malfunction detection device.

[Explanation of symbols]

2 ... battery, 2a ... output terminal, 4 ... starter motor,
5 ... Electronic controller, 6 ... Input terminal, 8 ... Central processing unit, 9 ... Photocoupler, 12 ... Engine abnormality detection circuit,
14 ... First timer, 15 ... First alarm circuit, 17 ... Light emitting element, 18 ... Emergency stop switch, 20 ... Light receiving element, 21 ...
Second timer, 22 ... Second alarm circuit, ΔT ₁ ... Set delay time of first timer 14, ΔT ₂ ... Set delay time of second timer 21.

Claims (1)

[Claims] 1. A starter motor attached to an engine (4)
A battery (2) for supplying electric power to the battery, an input terminal (6) of an electronic controller (5) connected to an output terminal (2a) of the battery (2), and a central processing connected to the input terminal (6) A device (8), an engine abnormality detection circuit (12) for outputting an engine abnormality signal to the central processing unit (8), and a first timer (14) for delaying the output signal of the engine abnormality detection circuit (12). A first alarm circuit (15) which is activated by the output signal of the first timer (14), and a photocoupler connected in series to the input terminal (6) of the electronic controller (5).
Light emitting element (17) and emergency stop switch (18) of (9)
A second timer (21) for delaying the output signal of the light receiving element (20) of the photocoupler (9), and the second timer (2)
The second alarm circuit (22) which is activated by the output signal of (1), and the set delay time (Δ) of the second timer (21).
T ₂ ) is set delay time (ΔT ₁ ) of the first timer (14) above
A malfunction detection device for an electronic controller for an engine, which is set to a value shorter than the above.