JPH0232833Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an abnormal operation display device for a diesel engine.

Unmanned operation of diesel engines, which are used as prime movers to drive generators, etc., is widespread, but the operation control requires that the output be set to the rated output value or lower than the rated output value, and the fuel supply to the engine is The maximum amount of is also set at approximately 115% of the rated output.
When an abnormal overload exceeding the normal operating range occurs due to a malfunction or accident in the load equipment, such a diesel engine cannot maintain its rotation speed if the overload exceeds the amount of fuel supplied. This causes the engine to rotate at a low speed below the rated speed (stall) and even stop completely.

By the way, this type of diesel engine is equipped with several protection devices for the purpose of protecting against abnormalities.These protection devices automatically stop the engine in case of abnormal operation of the engine, and also detect abnormalities by abnormality item. This makes it easy to identify the cause of the abnormality.

Conventional automatic stop control is configured in an engine stop circuit 1 shown in FIG. This engine stop circuit 1
The stop operation contact 3, which closes when a stop operation is performed manually or automatically (such as when automatic stop is performed when commercial power is restored in an emergency), and abnormality detection (engine overload) from each of the protection devices described above. The closing contact 4, which closes with its detection output when the engine speed increases, the cooling water temperature increases, the lubricating oil pressure decreases, etc., the limit switch 5 on the engine body side, and the self-holding contact (self-auxiliary contact) 2A of the engine stop detection relay 2 are connected to each other. A timer relay 6 is connected in parallel to the parallel circuit, and a series circuit of the operating contact 6A of the timer relay 6 and the engine stop detection relay 2 is connected in parallel to the timer relay 6.

The operation of this engine stop circuit 1 is such that when the contact 4 is turned on due to the detection of an abnormality in each protection device, the engine stop detection relay 2 is activated, and the output contact controls the fuel delivery to the engine using a solenoid or the like for a predetermined period of time (until the engine is completely time until it stops). This time becomes the time limit of the timer relay 6. When the engine is stopped due to this operation, the cause of the abnormality can be determined by displaying abnormality information for each abnormality item by each protection device.

However, it has been difficult to detect and display the cause of engine stalling or engine stoppage due to non-operation of the protection device itself, which is caused by causes other than the above-mentioned abnormality items. In particular, there is no established detection method for engine stalling due to abnormal overload, and the operator must individually inspect the load connection status and the operating status of each load at the time of engine stalling to determine the results. At this time, in the event of an engine stall, once the engine stops and power supply from the generator stops, the load status of each load may also be restored, which tends to result in unclear judgments and makes it difficult to obtain quick judgments. It was hot.

An object of the present invention is to provide an abnormal operation display device that can accurately detect and display engine stalls and operation stoppages due to other causes.

In this invention, as conditions for determining engine stalling due to abnormal overload, the engine speed has fallen below the rated value without a stop operation or stop protection operation while the engine is running, and abnormal output is also added to the conditions. Features.

FIG. 1 is a circuit diagram showing an embodiment of the present invention. The engine stop circuit 1 is constructed in the same manner as the conventional circuit, and the engine stop detection relay 2 has a stop operation contact 3 that closes when a manual or automatic stop operation is performed as an operation input circuit, and a stop operation contact 3 that closes when a stop operation is performed due to an abnormality. A parallel circuit of the closing contact 4, the limit switch 5 on the engine body side, and the self-auxiliary contact 2A is connected in series, and the operating contact 6A of the timer relay 6 is interposed in this series connection.
Timer relay 6 has the same operation input circuit as relay 2.

Engine stall display relay 8 of engine stall display circuit 7
is a normally closed contact 2B of the engine stop detection relay 2 as its operation input circuit, and a breaker contact 9 that is closed by the tripping operation of the breaker provided between the engine-driven generator and the load; a power detection device contact 10 that closes upon overload from the generator to the load;
A series circuit is connected to a low-speed relay contact 11 that closes when the engine (generator) speed drops to 70% or less of the rated speed, and a normally closed button switch 12 for display recovery and a self-normalization switch are connected in parallel to this series circuit. Open contact 8
A series circuit is connected. The operation output contact 8B of the engine stall indicator relay 8 is made a normally open contact and is connected in series with the engine stall indicator 13 together with its current limiting resistor 14.

In this configuration, the engine stop circuit 1 operates the relay 2 and starts the timer relay 6 when the contact 3 closes when an automatic or manual stop operation is performed, the contact 4 closes when an abnormality occurs, or the limit switch 5 closes. The timer relay 6 continues to operate due to the self-holding of the relay 2, and when the time limit (for example, 20 seconds) is reached, the contact 6A is opened to release the self-holding of the relay 2.

The engine stall display circuit 7 is connected to the power detection device contact 1 due to overload, except during the self-holding period of the relay 2.
The engine stall display relay 8 operates when the following three conditions are met: 0 closing/shutoff contact 9 is closed and contact 11 is closed due to a decrease in engine speed, and self-holding operation is also performed by closing contact 8A. Due to this operation, the engine stall indicator 13 displays the engine stall.

Therefore, the stop operation (contact 3) and stop protection operation (contacts 4 and 5) are the operating conditions for stop relay 2.
In the absence of engine speed, the engine stall indication is performed by reducing the engine speed (contact 11), including the abnormal output of the breaker operation and overload (contacts 9 and 10) as conditions. This engine stall display is restored by the restoration switch 12.

In addition, in the embodiment, the engine stall display relay 8
In some cases, the operating condition circuit shown in FIG. 2a, b, c, and d may be used to form an engine stall display circuit. Figure 2 a shows the output voltage relay contact 1 of the generator.
5 is provided in place of the closing contact 9, and the second
Fig. 2b shows the case where the power detection device contact 10 is omitted, Fig. 2c shows the case where the contact 10 is omitted and an output voltage relay contact 15 is provided in place of the closing contact 9, and Fig. 2d shows the case where the power detection device contact is replaced. This is a case where an engine fuel supply restriction position limit switch 16 is provided. In either case, the abnormal output condition is added or omitted, and the engine stall is displayed with a decrease in rotational speed as an absolute condition.

As described above, the present invention has the effect of reliably detecting and displaying the cause of engine stoppage in unmanned operation equipment, since the engine stall display is displayed when the engine speed drops without engine stop operation or stop protection operation. .

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the present invention;
2a, 2b, 2c and 2d are circuit diagrams showing other embodiments of the operating condition circuit for the display relay in FIG. 1. 1...Stop circuit, 2...Stop detection relay, 3...
...stop operation contact, 4...blocking contact, 5...limit switch, 6...timer relay, 7...engine stall display circuit, 8...engine stall display relay, 9...
Power breaker contact, 10...Power detection device contact, 11
...Low speed relay contact, 12...Display return button switch, 13...Engine stall indicator, 15...
Voltage relay contact, 16...Fuel supply limit position limit switch.

Claims (1)

[Scope of utility model registration request] An engine stop circuit that operates an engine stop detection relay for a certain period of time in response to an automatic stop signal caused by a diesel engine stop operation or the operation of an abnormality detection protection relay, and an engine stop circuit that displays an engine stall when the engine speed decreases and stops the engine. An abnormal operation display device for a diesel engine, comprising an engine stall display circuit that prohibits display when a detection relay is operating.