JPS6337485Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a safety device against gas leakage occurring in the gas supply system of an engine using gas as fuel.

Gas fuel engines that use LPG, LNG, etc. as fuel have already been installed in vehicles and are in widespread use, but recently, their use as a driving source for air conditioning systems is being considered. However, with conventional gas fuel engines, the only measure taken is to stop the engine when a gas leak is detected, and the safety measures against explosions caused by gas leaks are not perfect, and in the unlikely event that a gas leak occurs, In some cases, there was a risk of a major accident.

The purpose of the present invention is to provide a gas fuel engine safety device that has a safety measure that stops the engine when a gas leak is detected and makes it impossible to start the starter motor, which can be a source of ignition of the leaked gas. There is a particular thing.

In order to achieve the above object, the present invention provides a gas supply valve control device that closes a gas supply valve when a gas leak detection signal is input, and a gas supply valve control device that closes a gas supply valve when a gas leak detection signal is input, and that operates an engine when the gas leak detection signal is input. an engine stop circuit that stops the operation of the ignition system;
A gas leak detection signal is input between the switch that is closed when the engine is started and the starter motor, and when the detection signal is generated, it becomes non-conducting and prevents energization to the starter motor. A starter motor start prevention switch is provided to prevent the start of the starter motor.

The present invention will be explained in detail below with reference to the illustrated embodiments.

The figure is a block diagram showing one embodiment of the gas fuel engine safety device according to the present invention. In the figure, 1 is a gas fuel engine (internal combustion engine), 2 is an engine 1.
3 is a gas supply source that supplies gas fuel such as LPG, LNG, etc.
The gas is supplied to the engine 1 via the gas supply valve 4. 5 is a starter drive circuit that drives a starter motor 6 that starts the engine 1; 7 is a power source; 8 is a switch that is closed to operate the engine; this switch has a movable contact a and first and second fixed contacts b; and c, and when the switch is switched to the starting position when starting the engine, the movable contact a contacts both the first and second fixed contacts b and c, and after the engine has started, the switch is released. The movable contact a is held in a position away from the second fixed contact c and in contact with only the first fixed contact b. The output of the power source 7 is supplied to the starter drive circuit 5 via the second fixed contact c of the switch 8, the delay circuit 9, and the starter motor start blocking switch 20. The delay circuit 9 is a circuit that provides a delay time of several seconds, and when the movable contact a of the switch 8 is switched to the starting position where it contacts the first and second fixed contacts, the output of the power source 7 is sent to the starter drive circuit 5 with a delay of several seconds. is applied, and the starter motor 6 rotates. Reference numeral 10 denotes a gas leak detection device that detects a gas fuel leak and outputs an electrical detection signal, and this detection device is placed at a location in the gas supply system from the gas supply source to the engine where there is a risk of gas leakage. The amplification circuit 13 consists of a gas leak detection sensor 11 that has been detected, a gas leak detection circuit 12 that converts the detection result of the sensor 11 into an electrical signal, and an amplification circuit 13 that amplifies the output of the detection circuit 12 and outputs a detection signal Er. The detection signal Er obtained from the detection signal Er is in a state of "1" when no gas leak occurs, and becomes a state of "0" when a gas leak occurs. In this embodiment, this "0" state detection signal Er is used as the gas leak detection signal. The detection signal Er is input to the engine stop circuit 14, the starter motor start prevention switch 20, and the comparison circuit 15. The engine stop circuit 14 detects the ignition device 2 when the detection signal Er (gas leak detection signal) in the "0" state is input.
By disabling the operation of part of the circuit, the ignition operation is stopped and the engine is stopped.
This engine stop circuit is configured, for example, to short-circuit a part of the circuit of the ignition device 2 when the detection signal Er in the "0" state is input. The comparison circuit 15 also receives the drive signal Es given from the power supply 7 when the movable contact a of the switch 8 is in contact with the first fixed contact b.
The output is input to the valve drive circuit 16. The output of the valve drive circuit 16 is supplied to the valve opening/closing device 17,
The gas supply valve 4 is opened and closed by a valve opening/closing device 17. Comparison circuit 15, valve drive circuit 1
6 and the valve opening/closing device 17 constitute a gas supply valve control device 18. Further, the amplifier circuit 13
A gas leak detection signal obtained from the gas leak detection signal is supplied to an alarm means 19 consisting of a lamp and a buzzer, and when a gas leak is detected, this alarm means 19 is activated to notify the gas leak. Incidentally, the alarm means 19 may be provided with only one of a light emitting body such as a lamp and a sounding body such as a buzzer.

The starter motor start prevention switch 20 is composed of a switching element triggered by the detection signal Er. The switch 20 conducts only when there is no gas leakage and the detection signal Er is in the state of "1", allowing power to be supplied to the starter motor 6,
When a gas leak is detected and the detection signal Er becomes "0", it becomes non-conductive and prevents the starter motor 6 from being energized, thereby preventing the starter motor 6 from being driven. The starter motor 6 is provided with a brush, and sparks are generated from the brush during startup. However, according to this embodiment, when a gas leak is detected, the starter motor start blocking switch 20 becomes non-conductive, and even if the starting switch 8 is switched to the starting position, the starter motor 6 does not rotate, so that no spark occurs. It is possible to prevent ignition of gas that leaks without being generated.

In the above embodiment, when there is no gas leak, the output signal Er of the gas leak detection device 10 is in the state "1" indicating that there is no gas leak, and this signal is transmitted to the comparison circuit 15 and the starter motor start prevention switch 20. has been entered. When switch 8 is switched to the starting position in this state, comparison circuit 1
5, the start signal Es in the state of "1" is input.
The comparator circuit 15 in this embodiment is a type of AND gate, and outputs a signal in the "1" state (signal for opening the valve) when both input signals Es and Er are in the "1" state. As a result, the valve drive circuit 16 generates an output, and the valve opening/closing device 1 such as a motor or a solenoid valve
Drive 7. Therefore, the gas supply valve 4 opens,
Fuel gas is supplied to the engine 1 from the gas supply source 3 . On the other hand, when a certain delay time elapses after the switch 8 is closed, power is supplied to the starter drive circuit 5 through the delay circuit 9 and the switch 20 which is in a conductive state, thereby driving the starter 6 and rotating the engine. As a result, a magnet generator (not shown) attached to the engine generates an output to operate the ignition device 2, which ignites the engine 1 and starts the engine. When a gas leak occurs while the engine is rotating, the output signal Er of the gas leak detection device 10 becomes "0", so the output of the comparator circuit 15 becomes "0", and the valve drive circuit 16 outputs Stop, valve opening/closing device 17
Release the bias. As a result, the gas supply valve 4 is automatically closed by the biasing force of the spring, etc., and the supply of gas to the engine 1 is stopped. In addition, the detection signal Er (gas leak detection signal) in the state of "0" indicating that a gas leak has occurred is also supplied to the engine stop circuit 14, so this engine stop circuit operates and immediately stops the operation of the ignition device 2. make it stop. In this way, when a gas leak occurs, the engine stops immediately because the gas supply stops and the ignition operation also stops at the same time. Also, at this time, a signal is given to the alarm means 19, so that the buzzer sounds and the lamp lights up to notify that a gas leak has occurred.

In addition, if a gas leak occurs before starting the engine, the movable contact a of the starting switch 8 contacts the first fixed contact b, and at the same time the gas leak detection device 10 sends a detection signal in the "0" state. Since Er is input to the comparator circuit 15, even if the start signal Es in the "1" state is input from the switch 8 side, the output of the comparator circuit 15 remains in the "0" state. The valve drive circuit 16 therefore produces no output and the gas supply valve remains closed. At this time, the detection signal Er in the "0" state is also input to the engine stop circuit 14, so that the operation of the ignition device is blocked.

Furthermore, since the detection signal Er in the "0" state is also input to the starter motor activation prevention switch 20, activation of the starter motor 6 is prevented. Therefore, even if the starting switch 8 is switched to the starting position, the starter motor 6 will not rotate and the engine will not start.

In the above embodiment, the switch 20 for inhibiting starter motor activation is provided between the delay circuit and the starter drive circuit 5, but it goes without saying that the switch 20 may be provided before the delay circuit 9.

Although a DC power source is used as the power source 7 in the above embodiment, an AC power source can also be used as the power source 7 if an AC power source can be used.

In the above explanation, the detection signal Er becomes "0" when a gas leak occurs, but depending on the configuration of each part, the detection signal may become "1" when a gas leak occurs. In this case, the comparator circuit 15 is configured to output a signal to open the gas supply valve 4 only when the input signals Es and Er are "1" and "0", respectively, and the engine stop circuit 14 is It is configured to stop the operation of the ignition device when the signal Er is "1". Also, comparison circuit 1
5 is equipped with a circuit that generates a reference voltage from the signal Es, and also generates a detection signal Er when a gas leak occurs.
is set to be higher than the reference voltage, and when the detection signal Er becomes higher than the reference voltage, the comparator circuit 1
5 outputs a signal to close the gas supply valve 4, each part can be operated using analog signals. In this case, engine stop circuit 1
4, the ignition operation of the ignition device 2 is stopped when the detection signal Er exceeds a predetermined value.

The present invention is of course applicable to gas fuel engines installed in vehicles, but is also fully applicable to gas fuel engines that drive home heating and cooling systems.

As described above, according to the present invention, when a gas leak occurs, the gas supply is stopped and the engine's ignition operation is also stopped, so the leaked gas ignites and explodes during operation. This has the advantage of being able to reliably prevent accidents from occurring and improving safety. In addition, according to the present invention, a starter motor start prevention switch is provided, which becomes a non-conducting state when a gas leak is detected and prevents electricity from flowing to the starter motor, thereby preventing the starter motor from starting. Even if a leak occurs, it is possible to prevent the leaked gas from being ignited by the spark generated from the brush of the starter motor and cause an explosion, thereby improving safety during starting.

[Brief explanation of the drawing]

The drawing is a block diagram showing one embodiment of the present invention. 1...Gas fuel engine, 2...Ignition device, 3
... Gas supply source, 4 ... Gas supply valve, 10 ... Gas leak detection device, 14 ... Engine stop circuit, 1
8...Gas supply valve control device, 20...Starter motor start prevention switch.

Claims (1)

[Scope of Claim for Utility Model Registration] A sensor that detects gas leakage in a gas fuel engine safety device that aims to prevent explosions of gas leaking from the gas supply system of an engine to which gas fuel is supplied from a gas supply source through a gas supply valve. a gas leak detection device that outputs a gas leak detection signal when a gas leak is detected by the sensor; and a gas leak detection device that outputs a gas leak detection signal when a gas leak is detected by the sensor; a gas supply valve control device that opens a supply valve and closes the gas supply valve when the switch is opened and when the gas leak detection signal is input; and the gas leak detection signal is input and the detection signal is generated. an engine stop circuit that sometimes stops the operation of the engine's ignition device; and an engine stop circuit that is provided between the switch and the starter motor and receives the gas leak detection signal as an input, and when the detection signal is generated, becomes non-conductive and starts the starter motor. 1. A gas fuel engine safety device comprising a starter motor start prevention switch that prevents energization to the motor and prevents the starter motor from starting.