JPS58195039A - Device for stopping gas fuel engine upon abnormal operation - Google Patents

Abstract

PURPOSE:To make it possible to prevent the leakage of fuel gas from an engine mixer, by detecting the condition of abnormal operation with the use of a detecting circuit attached to an engine, for generating an abnormal detecting signal so that an electro-magnetic shut-off valve is automatically closed. CONSTITUTION:When an abnormal signal is issued from at least one of detecting circuits 17, 20, 23, 26 during engine running, a relay switch circuit 25 is energized in accordance with a signal delivered from an OR circuit 31, for opening a drive power source circuit 54 for an electro-magnetic shut-off valve 5 which is therefore automatically closed. Thus, the engine 1 comes to a stop and the leakage of fuel gas through a mixer 4 may be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an abnormal operation stop device attached to a gas fuel engine, and when an abnormality such as a gas leak occurs in the fuel gas, the engine cannot be started or operated, and the leaked fuel gas is stopped. The purpose is to prevent gas from igniting from the engine and causing a gas explosion.

In gas fuel engines, fuel gas, unlike liquid fuels such as gasoline, easily leaks, and the leaked fuel gas diffuses into the air, creating an explosive atmosphere. If the engine was operated in this condition, there was a danger that the heat of the engine could cause a gas explosion.

The present invention was proposed to solve the above problems, and
Based on at least one parameter of lubricating oil amount, lubricating oil supply pressure, engine temperature, and rotation speed, abnormal engine operation is detected and the engine is stopped.In addition, a gas leak detection circuit is attached. When a fuel gas leak is detected, the fuel gas supply path is blocked to prevent a gas explosion.

Hereinafter, the structure and operation of the present invention will be explained through illustrated embodiments.

FIG. 1 is a complete schematic diagram of the abnormal operation stop device for a gas fuel engine, where 1 is the engine, 2 is the intake manifold,
Reference numeral 5 indicates a fuel gas supply path.

The fuel gas supply path 5 is connected to a fuel gas supply source G to the mixer 4, and along the way there are two electromagnetic on-off valves 5, an integrated gas meter 6, and a regulator (1::).

A zero governor) 7 is interposed in series.

In this example, the electromagnetic on-off valve 5 is formed of a port type valve, so in order to substantially eliminate the influence of internal leakage, two
Although the electromagnetic on-off valves are connected in series, if the electromagnetic on-off valve is configured with sheet valves with almost no internal leakage, only one electromagnetic on-off valve may be used.

A float type oil level sensor 9 is attached to the oil sump 8 of the engine 1, an oil pressure switch 11 is connected to the lubricating oil supply pressure oil passage 10, and a temperature switch 1 is connected to the water jacket (not shown).
2, and a rotational speed setter 14 consisting of a pickup coil is made to face the large starting gear 15 of the engine 1.

Further, a gas sensor 15 is placed near the mixer 4 where fuel gas leakage is likely to occur.

oil level sensor 9, oil pressure switch 11, temperature switch 12,
The rotation speed sensor 14 and the gas sensor 15 are connected to a control circuit 16.

The control circuit 16 includes a chattering removal circuit 18 and knot circuit 19 of the oil amount abnormality detection circuit 17, and a chattering removal circuit 21 and knot circuit 22 of the oil pressure abnormality detection circuit 20.
, the chattering removal circuit 24 and knot circuit 25 of the overheat detection circuit 25, the rectification circuit 27 of the rotation abnormality detection circuit 26,
A frequency/voltage conversion circuit 28, a low-speed comparison circuit 29, and a high-speed comparison circuit 60 are wired, and each detection circuit 17°20.25
Each output terminal of .degree. 26 is connected in parallel to an OR circuit 51.

Incidentally, the oil level abnormality detection circuit 17 has an oil level sensor 9, a chattering removal circuit 18, and a knot circuit 19 connected in series, and an oil level abnormality detection monitor lamp 62 made of a light emitting diode is attached to the power end of the knot circuit 19. 'fr, all input voltage setting resistors '56 are connected to the input terminal of the chattering removal circuit 18, respectively.

The oil pressure abnormality detection circuit 20 is connected in series to the oil pressure switch 11, the chattering removal circuit 21, and the knot circuit 22', and a oil pressure abnormality detection monitor lamp 54 made of a light emitting diode is connected to the output end of the knot circuit 22. An input voltage setting resistor 55 is connected to the input terminal of each of the input terminals.

The overheating detection circuit 26 has the temperature switch 12 , the chattering removal circuit 24 , and the knot circuit 25 connected in series, and an overheating detection monitor wrap 66 made of a light emitting diode is connected to the output terminal of the knot circuit 25 and is input to the input terminal of the chattering elimination circuit 24 . A voltage setting resistor S7 is connected respectively.

In the rotation abnormality detection circuit 26, the rotation speed sensor 14 is connected to the input terminal of the rectification circuit 27, and the high speed comparison circuit 60 is connected to the output terminal of the rectification circuit 27 via the frequency/voltage conversion circuit 28.
A comparison circuit including a positive input terminal of and a negative feedback circuit 58! +9
The output terminal of the comparison circuit 69 is connected to the negative input terminal of the low-speed comparison circuit 29. Low speed comparison circuit 2
A voltage dividing point of a voltage dividing circuit 40 for setting a low speed reference voltage is connected to the positive input terminal of 9, and an abnormal low speed detection monitor lamp 42 consisting of a light emitting diode is connected to the output terminal thereof. Connected in parallel, a normal operation detection monitor lamp 4 consisting of a light emitting diode is connected at the output end of the knot circuit 41.
Connect 6.

The voltage dividing point of the high speed reference voltage 1° voltage setting voltage dividing circuit 44 is connected to the negative input terminal of the high speed comparator circuit 60, and its output output,
, i, □-'ri-h"yowa・1・(:'・reya□wa.

Nitara knob 45 is connected.

The output terminal of the OR circuit 61 is connected to the input terminal of the AND circuit 46, and the output terminal of the AND circuit 46 is connected to another OR circuit 47, and the other input terminal is connected to the key switch 48.
The starting contact is connected via a one-shot trigger pulse generation circuit 49, so that even if there is an output from the OR circuit 51 at the time of starting, it is not output from the AND circuit 46 to the OR circuit 47.

The output terminal of the gas leak detection circuit 56 is connected to the other input terminal of the second OR circuit 47 .

The gas leak detection circuit 56 includes the gas sensor 5, a knot circuit 57 connected in series with the gas sensor 5, and a gas leak detection monitor lamp 58 made of a light emitting diode connected to the output terminal of the gas leak detection circuit 56. The output terminal of the second OR circuit 47 is amplified. Transistor 50・
51 to a relay switch circuit 52, this relay coil 52a excites a relay switch 53 consisting of a B contact switch, opens the power supply port 4 of each on-off valve 5, and closes each on-off valve 5 fully automatically. do. ″□ When the oil level 55 in the oil reservoir 8 falls below a predetermined height, the oil level sensor 9 opens the input circuit of the chattering elimination circuit 18, stops the output of the chattering elimination circuit 18, and drains oil from the knot circuit 19. An abnormality detection signal consisting of a quantity shortage signal is output.

The oil pressure switch 11 is opened when the supplied oil pressure falls below a predetermined value, stops the output of the chattering removal circuit 20, and causes the knot circuit 22 to output an abnormality detection signal consisting of an oil pressure shortage signal.

Further, the temperature sensor 12 stops the input to the chattering removal circuit 24 when the coolant temperature of the engine 1 exceeds a predetermined value, and causes the knot circuit 25 to output an abnormality detection signal consisting of an overheating signal.

A rotation speed signal consisting of a voltage signal that increases or decreases in proportion to the engine rotation speed is obtained via the rotation speed sensor 14, the rectifier circuit 27, and the frequency/voltage conversion circuit 28, and this rotation speed signal is set by the voltage dividing circuit 40. When the rotation speed signal is lower than the reference voltage set by the voltage dividing circuit 44, an abnormality detection signal consisting of an abnormally low speed signal is sent from the low speed comparison circuit 29, and when the rotation speed signal exceeds the reference voltage set by the voltage dividing circuit 44, the high speed comparison circuit 60
An abnormality detection signal consisting of an abnormal high-speed signal is output from each of them.

At least one detection circuit 17.20 during engine operation
．． When an abnormal signal is output from 25.26, the OR circuit 6
Relay switch circuit 5 based on the signal output from 1
2 to open the drive power circuit 54 of the electromagnetic on-off valves 5, each on-off valve 5 is automatically closed, the engine 1 is stopped, and fuel gas is prevented from leaking through the mixer 4. .

FIG. 3 shows an hour meter circuit 60 connected to the generator 59 driven by the engine 1, where 61 is a light emitting diode, 62 is a resistor whose resistance value changes in response to the light emitted, and 66 is an hour meter. show.

By providing the hour meter 65 and the cumulative gas meter 6 in this way, the user can check the maintenance period from the table on the hour meter 6S and the gas usage needle from the display on the cumulative gas meter 6.

In addition, in the above embodiment, when each detection circuit 17.20, 25.26 outputs 4 abnormalities, the fuel gas supply is cut off based on the signal. As shown, each detection circuit 17°20.25°26
The abnormality detection signal is used to operate the electronic gas (as shown in FIG. 5). The engine 1 may be stopped immediately by cutting off power supply to the ignition device 65.

Furthermore, as shown in FIG. 4, if the starting circuit 68 to the cell starter 67 is opened when the gas processor 15 detects a gas leak abnormality, the cell starter 68 can be exposed to the explosive atmosphere formed by the leaked fuel gas. It is possible to prevent ignition and explosion due to the start-up of the tank 67 or the start-up of the engine 1.

As described above, at least one detection circuit attached to the engine detects an abnormal operating state of the engine and outputs an abnormal power detection signal, and based on this abnormality detection signal, the relay switch circuit is The system is designed to automatically close the electromagnetic on-off valve interposed in the fuel gas supply path, so if the engine goes into abnormal operation for some reason, the fuel gas supply is stopped and the engine is stopped. - Not only can the engine be protected from seizure, but also fuel gas can be prevented from leaking from the mixer after the engine is stopped, and explosion accidents caused by this leaked fuel gas can be effectively prevented.

In addition, abnormal operation of the engine is detected using the oil amount or oil pressure, engine temperature, and rotation speed as parameters, and if an abnormal signal is detected based on at least one parameter, the relay circuit is activated and the on-off valve is closed. This makes it possible to detect all abnormal operations of the engine and reliably protect the engine from abnormal operations.

In addition, if a fuel gas leak occurs while the engine is running, the gas sensor detects this and immediately stops the engine, causing the leaked fuel gas to form a discharge explosion! ,, ``゛'''''' can be prevented from exploding with one fire bow.

If the configuration is such that the on-off valve is closed and the cell starter starting circuit is opened at the same time based on the detection of an abnormality in the gas sensor, making it impossible to start the engine, the leakage of fuel gas while the engine is stopped is possible. Even if an explosive atmosphere is formed around the engine, the gas sensor detects this and disables the cell starter to start, preventing the explosive atmosphere from causing a gas explosion due to sparks from the cell starter or engine during startup. can.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic diagram of a device for stopping abnormal operation of a gas fuel engine, FIG. 2 is a circuit diagram thereof, FIG. 3 is a circuit diagram of an hour meter circuit, and FIGS. 6th
The figures are circuit diagrams of main parts showing all different embodiments. 1. Engine, 6. Fuel gas supply path, 5. Solenoid on-off valve, 8. Oil reservoir, 17. Oil amount abnormality detection circuit, 20
・・Hydraulic pressure abnormality detection circuit, 25・・Overheat detection circuit, 52・
・Relay switch circuit, 54 ・・Drive power supply circuit, 56・
・Gas leak detection circuit, 67... Sul starter, 68...
67 Starting Circuit Patent Applicant Kubota Iron Works Co., Ltd. Agent Hisashi Chatan H1., J.

Claims (1)

[Claims] 1. Is the electromagnetic on-off valve 5 interposed in the fuel gas supply path 6 of the engine 1 such that the oil level 55 in the oil reservoir 8 of the engine 1 is at a predetermined height? An oil quantity abnormality detection circuit 17 that detects an oil quantity shortage state in which the oil quantity falls below and outputs an abnormality detection signal consisting of an oil quantity shortage signal; A hydraulic abnormality detection circuit 20 that outputs an abnormality detection signal consisting of an insufficient signal; an overheating detection circuit 25 that detects an overheating state in which the temperature of the engine 1 exceeds a predetermined value and outputs an abnormality detection signal consisting of an overheating signal; Each detection circuit 17.20.23. of the rotational abnormality detection circuit 26 detects the rotational speed and outputs an abnormality detection signal consisting of an abnormal rotational signal in an abnormal rotational state in which the rotational speed is out of a predetermined rotational speed range.
The command input terminal t'- of the relay switch circuit 52 is connected to the at least one detection circuit 11, 20, 23, 26, and the relay switch circuit 52 is provided with at least one of the detection circuits 11, 20, 23, 26. The drive power supply circuit 54 can be fully opened and closed, and the above-mentioned '
The relay switch circuit 52 is excited by the abnormality detection signal outputted from at least one of the detection circuits 17.20.2!1.26, and the drive power supply circuit 54 is switched on and off to open and close the drive power supply circuit 54. Magnetic opening/closing well 5
The valve is configured to close automatically, and also prevents fuel gas leakage.
The output end of the gas leak detection surface path 56 for all detection is connected to the relay switch circuit 52! Connected to the 1j command input terminal, the relay switch circuit 52 is excited by the gas leak detection signal output from the gas leak detection circuit 56, the drive power supply circuit 54 is switched on and off, and the electromagnetic on-off valve 5 is fully automatically closed. In the abnormal operation stop device 2 for a gas fuel engine characterized by having the following structure, in the abnormal operation stop device +t for a gas fuel engine described in claim 1, the lock switch circuit 52 opens and closes. The driving power supply circuit 54 of the valve 5 is switched on and off, and in conjunction with this, the starting circuit 6 of the cell starter 67 is switched on and off.
8 to open and close the relay switch circuit 52.
is energized and opens the drive power circuit 54 of the on-off valve 5, the starting circuit 68 is opened in synchronization with this.