JPH0355657B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a starting device for an internal combustion engine, and for example, to a starting device for an internal combustion engine that uses alcohol fuel such as methanol.

<Prior Art> Alcohol fuels such as methanol have poor ignition performance compared to gasoline, making low-temperature starting difficult. Some systems attempt to improve low-temperature startability by converting alcohol fuel into hydrogen or the like. Such a conventional example is shown in FIG. 3 (see Japanese Patent Laid-Open No. 113426/1983).

That is, methanol is supplied to the combustion device 2 via the first on-off valve 1, and the methanol is ignited and burned by the spark plug 3. Then, the reactor 4 is heated by the combustion operation of the combustion device 2, and the inside of the reactor 4 is raised to the reaction temperature of methanol. Thereafter, methanol is supplied to the reactor 4 via the second on-off valve 5 and converted into a flammable gas containing a large amount of hydrogen.The methanol is then supplied to the engine 7 via the vaporizer 6. This improves low-temperature startability.

Note that 8 is a battery, and 9 is an engine key switch.

<Problems to be Solved by the Invention> However, in such a conventional starting device, the combustion device 2 and the reactor 4 are provided separately,
Since methanol fuel and combustion air are controlled respectively, the structure becomes complicated and the cost increases. Further, there was a problem in that it took time to heat the reactor 4 and raise it to the reaction temperature, and it took time to start the engine.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a starting device for an internal combustion engine that has a simple structure and can generate flammable gas in a short time.

<Means for Solving the Problems> For this reason, the present invention provides a hollow reactor body that generates flammable gas, a fuel injection valve device that injects liquid fuel into the reactor body, and a fuel injection valve device that injects liquid fuel into the reactor body. an ignition device that ignites fuel; an air supply passage that supplies air into the reactor body; a flammable gas supply passage that supplies flammable gas generated within the reactor body to the engine; A temperature sensor that detects the temperature of the gas, and a combination of fuel and air that is supplied into the reactor body in order to increase the fuel concentration as the detected temperature increases and maintain the flammable gas temperature approximately constant. A control means for controlling the ratio is provided.

<Function> In this way, after the injected droplet-shaped fuel is ignited in a short time, the supply ratio of fuel and air is controlled according to the flammable gas temperature, and the flammable gas is quickly ignited with a simple structure. It generates in time and improves the starting performance of the engine.

<Example> An example of the present invention will be described below based on FIGS. 1 and 2.

In FIG. 1, a reactor 12 for converting methanol as a liquid fuel into a flammable gas containing hydrogen is located near an intake manifold 11 of an engine (not shown).
is provided.

A hollow reactor main body 13 is formed in this reactor 12, and inside this reactor main body 13, a main body 1 is formed.
3 A cylindrical member 1 that forms a predetermined gap between the inner wall and the inner wall.
3a is installed. The reactor main body 13 is provided with a fuel injection valve 14 for injecting methanol into the cylindrical member 13a. Further, the reactor main body 13 is provided with a glow plug 15 as an ignition device for igniting droplet-shaped methanol injected from the fuel injection valve 14. Said cylindrical member 13
An air supply passage 17 for introducing intake air upstream of the intake throttle valve 16 is provided in the air supply passage 1.
A diaphragm type air flow control valve 18 is interposed in the valve 7 .

In addition, the upper space inside the reactor main body 13 and the intake throttle valve 1
A flammable gas supply passage 19 communicating with the interior space of the intake manifold 11 located one downstream is provided, and a gas temperature sensor 20 for detecting the temperature of the combustible gas is provided at the entrance of the flammable gas supply passage 19.
A cooling water passage 21 through which engine cooling water flows is formed in the outer wall of the reactor main body 13, and a water temperature sensor 22 for detecting the temperature of the cooling water is provided in the cooling water passage 21. The water temperature sensor 22 is formed of a bimetal or the like and is configured to turn on when the cooling water temperature is below a predetermined value (for example, 60° C.) and turn off when it exceeds a predetermined value, that is, after warm-up is completed.

A negative terminal of the water temperature sensor 22 is connected to a positive terminal of a battery 24 via an ignition switch 23, and the other terminal of the water temperature sensor 22 is connected to one end of a relay coil 25a of a normally open first relay 25. . The other end of the relay coil 25a is connected to the control device 2.
6 with a grounded emitter transistor 27
is connected to the collector terminal of. The + terminal of the battery 24 is connected to one end of the glow plug 15 via the relay contact 25b of the first relay 25, and the other end of the glow plug 15 is grounded.

Further, one end of the relay coil 28a of the normally open self-holding type second relay 28 provided in the control device 26 is connected to the + terminal of the battery 24 via the starter motor switch 29.
The other end is grounded. One end of the relay contact 28b of the second relay 28 is connected to one end of the relay coil 25a of the first relay 25, and the relay contact 28b is connected to one end of the relay coil 25a of the first relay 25.
The other end of 8b is connected to an input terminal of an electromagnetic on-off valve 30 interposed in a fuel supply passage 29 that supplies methanol to the fuel injection valve 14. Further, the other end of the relay coil 28a of the second relay 28 is grounded via a resistor 31 and a Zener diode 32, and the cathode terminal of the Zener diode 32 is connected to the - terminal of the control circuit 33.
Apply constant voltage to the terminal.

Further, the output voltage of the gas temperature sensor 20 is applied to the other terminal of the control circuit 33. This gas temperature sensor 20 is configured so that its output voltage increases as the temperature of the combustible gas increases.
The output voltage of the control circuit 33 is applied to a servo valve 35 via an amplifier 34, and the servo valve 35 controls the operating negative pressure of the diaphragm air flow control valve 18 according to the applied output voltage. .

Note that 36 is a diode, and 37 is an inverting amplifier.

Next, the operation will be explained according to the time chart shown in FIG.

When the engine starts, the coolant temperature sensor 22 is on because the coolant temperature is low, so when the ignition switch 23 is turned on, the battery 2 is sent to the relay coil 25a of the first relay 25 via the water temperature sensor 22.
Voltage is applied from 4. At this time, the temperature inside the combustible gas supply passage 19 is low and the gas temperature sensor 20
Since the output voltage of the inverting amplifier 37 is low, this voltage is
The base current of transistor 27 increases. This turns on transistor 27.
Since the relay coil 25a of the first relay 25 is excited, the relay contact 25b is closed. Then, the glow plug 15 is energized from the battery 24 and the glow plug 15 is preheated.

Then, when the starter motor switch 29 is turned on to start cranking, the relay coil 28a of the second relay 28 is energized via the starter motor switch 29, the relay coil 28a is energized, and the relay contact 28b is closed. This results in
Electricity is supplied from the battery 24 to the electromagnetic on-off valve 30 via the water temperature sensor 22 and the relay contact 28b, and the electromagnetic on-off valve 30 opens. Therefore, methanol is supplied to the fuel injection valve 14, and a constant amount of methanol is injected and supplied from the fuel injection valve 14 into the cylindrical member 13a.

Also, at the same time as the electromagnetic on-off valve 30 is energized, the battery 24 is connected via the relay coil 28 and the resistor 31.
A constant voltage is applied to the + terminal of the control circuit 33 from . At this time, since the output voltage of the gas temperature sensor 20 is low, the output of the control circuit 33 becomes large, and the servo valve 35 is fully opened. As a result, the operating negative pressure of the diaphragm air flow control valve 18 increases, and the air flow control valve 18 is fully opened.

Therefore, droplets of methanol and air are supplied into the cylindrical member 13a, the mixture thereof is ignited by the glow plug 15, and the temperature inside the reactor body 13 rises. When this heated combustible gas flows into the combustible gas supply passage 19, the output voltage of the gas temperature sensor 20 increases as the gas temperature increases. Then, when the output voltage of the gas temperature sensor 20 reaches a predetermined value, the output of the inverting amplifier 37 becomes "L", the transistor 27 is turned off, the relay contact 25a of the first relay 25 opens, and the supply of electricity to the glow plug 15 is stopped. be done.

Further, as the output voltage of the gas temperature sensor 20 increases, the output voltage of the control circuit 33 gradually decreases, and the output to the servo valve 35 decreases. As a result, the operating negative pressure of the air flow control valve 18 becomes smaller, and the amount of air supplied into the cylindrical member 13a via the air flow control valve 18 decreases. Therefore, the methanol concentration within the cylindrical member 13a increases, and the hydrogen concentration in the generated combustible gas increases. In this way, the air flow rate is controlled so that the temperature of the flammable gas is maintained at a temperature where the concentration of combustible gas containing sufficient hydrogen is achieved.

The generated combustible gas is then supplied to the engine via the intake manifold 11, and the engine is started. Furthermore, since the cooling water temperature is low immediately after the engine starts, the water temperature switch 22 is maintained in the ON state, so that the relay coil 28a is energized from the relay contact 28b via the diode 36, and the relay contact 28 is energized.
a is closed. A constant voltage is applied to the control circuit 33 via the water temperature switch 22 and the relay contact 28b of the second relay 28, and the fuel and air are supplied to the cylindrical member 13.
supplied to a. As a result, flammable gas is supplied to the engine immediately after the engine is started, so that engine operation during warm-up is stabilized. Then, when the cooling water temperature rises due to completion of warm-up, the water temperature switch 20 is turned off, power supply to the relay coil 28a of the second relay 28 is stopped, and the relay contact 28b is opened. As a result, the electromagnetic on-off valve 30 is de-energized, the injection operation of the fuel injection valve 14 is stopped, and the control circuit 3
The constant voltage application to servo valve 35 is stopped.
The supply of electricity to the air is stopped and the air supply operation is stopped.

As explained above, after the droplet-shaped methanol injected into the cylindrical member 13a is ignited, the air supply amount is controlled to maintain the temperature of the generated combustible gas substantially constant, so that the combustible gas containing sufficient hydrogen can be heated. Since flammable gas is supplied to the engine, flammable gas can be generated in a short time after droplets of methanol are ignited in a short time, and the engine can be started in a short time. In addition, flammable gas can be generated without particularly providing a combustion device as in the past, and the structure is extremely simple and costs can be reduced. Furthermore, since the cooling water is passed through the outside of the reactor main body 13a, the cooling water is heated by the heat of reaction, so that the warm-up time can be significantly shortened.

In this embodiment, the methanol concentration was increased by changing the air supply amount, but the methanol injection amount may be controlled to be changed instead.

<Effects of the Invention> As explained above, the present invention generates flammable gas by controlling the ratio of fuel and air to increase the fuel concentration after igniting the injected droplet fuel. Flammable gas can be generated in a short period of time, thereby greatly reducing engine starting time. In addition, flammable gas can be generated without particularly providing a conventional combustion device, making it possible to simplify the device and reduce costs.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIG.
The figure is a time chart same as the above, and FIG. 3 is a configuration diagram showing a conventional example of a starting device for an internal combustion engine. 12...Reactor, 13...Reactor main body, 14...
...Fuel injection valve, 15...Glow plug, 17...
Air supply passage, 18... Air flow control valve, 19...
...Flammable gas supply passage, 20...Gas temperature switch, 26...Control device.

Claims (1)

[Claims] 1. In a starting device for an internal combustion engine that converts liquid fuel into flammable gas and supplies the flammable gas to the engine at startup, it includes a hollow reactor body that generates flammable gas, and a liquid inside the reactor body. A fuel injection valve device that injects fuel, an ignition device that ignites the injected fuel, an air supply device that supplies air into the reactor main body, and a combustible gas generated in the reactor main body. A combustible gas supply passage that supplies the engine, a temperature sensor that detects the temperature of the combustible gas,
a control device that controls the ratio of fuel and air supplied into the reactor body in order to increase the fuel concentration as the detected temperature increases and maintain the flammable gas temperature substantially constant; A starting device for an internal combustion engine characterized by the following.