JP2660778B2 - Malfunction detection device for engine electronic controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In general, an abnormality detecting device for an engine having an electronic controller has a controller input terminal and a central processing unit connected to an output terminal of a battery for supplying power to a starter motor in order, and the central processing unit is connected to the central processing unit. An abnormality detection circuit that outputs an abnormality signal such as a high temperature of the engine cooling water is connected and configured.

[0003] In the above configuration, prior to the present invention, the inventor connected a light emitting element of a photocoupler and an emergency stop switch to the controller input terminal in series,
A device for emergency stop of the engine by the output signal of the light receiving element of the photocoupler was considered first. 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-mentioned 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 cause is that if the ground of the central processing unit becomes loose due to loose terminals, etc., the voltage at the controller input terminal will decrease by the amount of ground connection failure. This is probably because the voltage at the controller input terminal is 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 greatly, the light emitting element of the photocoupler is switched to a non-energized state, and the light receiving element outputs an emergency stop signal to stop the engine.

However, since the above-mentioned prior-art example has a configuration in which 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 possible to detect which cause caused the engine to stop. I couldn't. SUMMARY OF THE INVENTION An object of the present invention is to make it possible to easily detect a malfunction of a central processing unit due to a ground connection failure.

[0006]

According to the present invention, in order to achieve the above object, a malfunction detecting device for an electronic controller for an engine is constructed as follows, for example, as shown in FIGS.

A battery 2 for supplying power to a starter motor 4 attached to an 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 for outputting an engine abnormality signal to the central processing unit 8, a first timer 14 for delaying an output signal of the engine abnormality detection circuit 12, A first alarm circuit 15 activated by an output signal of the first timer 14,
A light emitting element 17 and an emergency stop switch 18 of the photocoupler 9 connected in series to the input terminal 6 of the electronic controller 5; a second timer 21 for delaying an output signal of the light receiving element 20 of the photocoupler 9; 2 timer 21
And a second alarm circuit 22 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 the engine is started, the ground terminal 10 of the electronic controller 5
If the connection between the ground line 11 and the ground line 11 is poor, or if 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 switches to the non-energized state, and the light receiving element 20 outputs an emergency stop signal to the second timer 21.

The above emergency stop signal has a set delay time ΔT.
_When input is continuously performed for ₂ (here, 50 ms), the second timer 21 activates the second alarm circuit 22. Therefore, before the engine is abnormally stopped by the abnormality signal of the engine abnormality detection circuit 12, the engine can be emergency stopped or the emergency stop alarm lamp can be turned on.

[0010]

According to the present invention, when the ground of the central processing unit is poorly connected, the second alarm circuit for emergency stop is activated before the first alarm circuit for engine abnormality detection is activated. Therefore, a malfunction due to the ground connection failure can be easily known. Moreover, in order to obtain the above-described effects, an emergency stop circuit including a photocoupler and an emergency stop switch can be used, so that the configuration of a device for detecting a malfunction can be simplified.

[0011]

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. A central processing unit 8 and a photocoupler 9
Are connected. The coil 3a for opening and closing the contact 3b of the relay 3 is operated by an output signal of the central processing unit 8. Reference numeral 10 denotes a ground terminal of the central processing unit 8, and reference numeral 11 denotes a ground line.

The central processing unit 8 is connected to an engine abnormality detection circuit 12 which outputs an engine abnormality signal (here, a high temperature of the engine cooling water). The abnormality detection circuit 12 includes a water temperature switch 13 that opens when the temperature of the engine cooling water is high.
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).

A light emitting element 17 of the photocoupler 9 and an emergency stop switch 18 are connected in series to the input terminal 6 of the electronic controller 5. The photo coupler 9
Are 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 operation signal to the central processing unit 8. . When the switch 18 is opened during the operation of the engine, the light emitting element 17 of the photocoupler 9 is switched to a non-energized state, and the light receiving element 20 outputs an emergency stop signal to the second timer 21.

When the connection between the ground terminal 10 of the electronic controller 5 and the ground line 11 is defective at the time of starting the engine, the above-mentioned ground connection failure is added to the voltage drop due to the starter motor 4 starting. 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 of the input terminal 6 of the electronic controller 5 becomes unstable, and the photocoupler 9
Is switched to the non-energized state, and the light receiving element 2
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 operated.

The operation of the central processing unit 8 will be described mainly with reference to FIG. When the operation of the starter motor 4 starts
(S1) The engine abnormality detection circuit 12 determines whether an engine abnormality signal is input (S2). If the abnormal signal is input, the signal is 100 ms
Whether input has been performed continuously for a period of time
(S3). Outputs an alarm when input is continuous
(S4).

At the same time as the operation of the starter motor 4, it is determined whether an emergency stop signal is input from the light receiving element 20 of the photocoupler 9 (S5). If the emergency stop signal has been input, it is determined whether or not the signal has been input continuously for a time of 50 ms (S6).
If they are continuously input, an alarm is output (S7), and the engine is stopped immediately and the alarm lamp is turned on.

The above-mentioned engine abnormality signal includes:
In addition to the high temperature signal of the engine cooling water temperature, a lubricating oil pressure drop signal or the like may be provided. The set delay time ΔT ₂ of the second timer 21 is not limited to 50 ms, but may be any value as long as it is shorter than the delay time ΔT ₁ of the first timer 14.

[Brief description of the 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)

(57) [Claims] A starter motor attached to an engine (4)
(2) for supplying 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 unit 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) activated by an output signal of the first timer (14); and a photocoupler connected in series to the input terminal (6) of the electronic controller (5).
(9) Light emitting element (17) and emergency stop switch (18)
A second timer (21) for delaying an output signal of the light receiving element (20) of the photocoupler (9); and a second timer (2)
1) a second alarm circuit (22) that is activated by the output signal, and the second timer (21) set delay time (Δ
T ₂ ) is set to the delay time (ΔT ₁ ) set by the first timer (14).
A malfunction detecting device for an electronic controller for an engine, wherein the malfunction is set to a shorter value.