JPS62178771A - Ignition timing control device for engine using different kind of fuel by changeover - Google Patents

Abstract

PURPOSE:To make operation with ignition characteristics suitable for fuel actually supplied when the fuel is changed, by providing a delay means for effecting an actual ignition timing change by an ignition control device in a prescribed period of timing after fuel change means has operated. CONSTITUTION:First and second switch valves 7, 10 are so actuated by a fuel changeover switch 11 to be operated by a driver that when any one of them is opened, the other is closed so that any selected kind of fuel of gasoline or LPG is supplied to a suction passage 2. An ignition timing delay unit 15 is interposed between an ignition advance angle changeover switch 12 and a distributor 13 and the delay unit 15 permits the ignition advance angle changeover switch 12 to effect a change of an actual ignition timing after a prescribed period of time has elapsed. Therefore, when the kind of fuels to be supplied to an engine is changed, it is possible to operate the engine with advancing characteristics suitable for the fuel actually supplied to the suction passage 2, whereby the engine can be operated securely.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an ignition timing control device for an internal combustion engine, and in particular to a device for switching between different fuels (Ia) that switches between liquid fuel such as gasoline and gaseous fuel such as LPG. This invention relates to a leap ignition timing control device.

(Prior art) As is well known, gasoline and LP are used as a type of internal combustion engine.
There has been provided an engine that can switch between different types of fuel, and in this type of engine, a carburetor for atomizing gasoline and a mixer for supplying LPG are provided in the intake passage.

By the way, the optimum value for the ignition timing of the internal combustion engine 11 differs depending on the fuel used, and generally gaseous fuels such as LPG are advanced considerably more than liquid fuels such as gasoline.

For this reason, in the above-mentioned engine that uses different types of fuel, it is necessary to set an advance angle suitable for each fuel. Ignition timing control devices with several advance angle characteristics have been proposed.

The device shown in U11 in the same issue has a fuel switching device that selects the fuel to be supplied to the engine, and an ignition timing control device that has multiple advance angle characteristics corresponding to the selected fuel type. It is said that the ignition timing is automatically switched in conjunction with the ignition timing and that the ignition timing is always matched to the fuel used, but the following problem occurred directly when the fuel was switched to 1q.

(Problem to be Solved by the Invention) In other words, when the fuel used is switched from gasoline to 1-PG during another operation, it takes until the gasoline in the flow 1-chamber of the carburetor is completely consumed. , which requires a certain amount of time.

However, the device disclosed in the above-mentioned publication is operated during this time with advance angle characteristics suitable for the switched side, that is, LPG.

Therefore, even though gasoline is being supplied to the engine, the engine is operated with the LPG advance characteristic, which greatly increases the advance angle, resulting in problems such as knocking.

On the other hand, when switching from LPG to gasoline, it takes a certain amount of time to fill the float chamber of the carburetor with gasoline, and even though LPG is used as fuel, the advance angle characteristics are not suitable for gasoline. and operated with characteristics outside the engine's requirements.

This invention was made in view of these problems, and its purpose is to provide an engine that uses different fuels and can be operated with advance angle characteristics that meet the requirements of the engine even when the fuel is changed. Ignition timing control 211S! The aim is to provide a

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a fuel switching means for selecting one of different types of fuel and supplying it to the engine;
In a different fuel switching engine comprising an ignition timing control device that switches ignition timing in accordance with the type of fuel selected by the fuel switching means, the ignition control device It has a U extension means that performs substantial ignition timing switching.

(Function) According to the ignition timing control device having the above configuration, the ignition timing is switched to the one corresponding to the selected fuel after a predetermined time after the VJ conversion of the fuel is performed, so that the ignition timing is changed to the one corresponding to the selected fuel. You can operate reliably with advance angle characteristics that match the fuel.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 to 3 show an embodiment of an ignition timing control device for an engine that uses different fuel switching according to the present invention.

FIG. 1 is an overall explanatory view showing how the device of the present invention is installed in an engine. Although detailed illustration is omitted, an intake passage 2 through which air purified by an air cleaner 1 of the engine is taken in is filled with gasoline. a vaporizer 3 for atomizing;
A mixer 4 for supplying LPG is also provided.

Gasoline is supplied from gasoline 5 to the float chamber of the carburetor 3 via a fuel pump 6, and a first on-off valve 7 is provided in a passage connecting the fuel pump 6 and the carburetor 3. It is being

Further, a vaporizer 9 is connected to the mixer 4, and a vaporizer 9 is connected to adjust the pressure of the LPG filled in the LPG tank 8 and supply it to the mixer 4. is the second on-off valve 1
0 is set.

The first on-off valve 7.10 and the first on-off valve 7.10 are controlled by a fuel changeover switch 11 operated by the driver so that when either one of the on-off valves opens, the other closes. 2 is supplied with a selected type of fuel from gasoline or LPG.

The fuel changeover switch 11 is interlocked with the ignition advance changeover switch 12, and when one fuel is selected by the fuel changeover switch 11, the ignition advance changeover switch 12 is also driven, thereby changing the advance angle as shown in FIG. The characteristics of the selected fuel type of the distributor 13 with two advance angle characteristics compatible with gasoline and LPG are selected so as not to show the characteristics,
The engine is configured to be operated via the ignition coil 14 in accordance with its characteristics.

The basic configuration as described above is the same as that of the conventional ignition timing control device.
′? Although not exclusive, the device of the present invention is characterized by the following points.

That is, in this embodiment, the ignition advance changeover switch 1
2 and the ignition timing delay device 1 between the distributor 13
5 is interposed, and the ignition advance changeover switch 12 is operated by the delay device 15 to selectively change the ignition timing after a predetermined period of time has elapsed.

FIG. 2 is a block diagram showing the operating state of the engine using different fuel switching shown in FIG. , the selector switch 11 is set to L.
Assume that the switch is made to the PG side. By operating the fuel changeover switch 11, the first on-off valve 7 is closed and the second on-off valve 7 is closed.
The on-off valve 10 is opened, and the intake passage 2 is ready to be supplied with LPG. In this case, ignition advance selector switch 1
2 is also switched to the LPG side, but the characteristic of the distributor 13 does not immediately become the LPG advance characteristic, and only switches to the LPG advance characteristic after the time set by the ignition timing delay device 15 has elapsed.

On the other hand, contrary to the above, even if the engine is operated on LPG and the fuel selector switch 11 is switched to the gasoline side, the 1h characteristic of the distributor 13 does not immediately change to the gasoline advance 1) characteristic by the switching operation. Similarly to the above, after the delay time set by the ignition timing ill'i device 15, the characteristic is switched to the gasoline advance characteristic.

As the ignition timing delay device 15, for example, the fuel switching device 1
An electric or mechanical timer is used that is started by the switching operation in step 1, and during the delay period, taking into account the float capacity of the carburetor 3, when switching from gasoline to LPG, the gasoline in the float chamber is This is set to the time during which fuel is consumed, or the time during which gasoline can be supplied into the float chamber when switching from LPG to gasoline.

Now, with the ignition timing control device configured as described above, when switching the fuel type supplied to the engine, the engine is operated with advance characteristics that match the fuel actually supplied to the intake passage 2. This makes it possible to prevent problems such as knocking.

Note that the implementation of the present invention is not limited to the embodiments described above, and it is only necessary that the ignition advance changeover switch 12 substantially switches the ignition timing after a predetermined time, and the ignition timing delay device 154 and the fuel F31 Off (between the moxibustion switch 11 and the ignition advance switch 12, or between the distributor 1
3 and the ignition coil 14.

(Effects of the Invention) As described above in detail in the embodiments, according to the ignition timing control device for an engine that uses different fuel switching according to the present invention, when the fuel to be used is switched, the fuel that is actually supplied is The engine can be operated reliably with ignition characteristics 'C that are suitable for the engine.

[Brief explanation of drawings]

Figure 1 is an overall explanatory diagram of an engine that uses different fuel switching to which the present invention is applied, Figure 2 is a block diagram showing the operation of the engine, and Figure 3 is a block diagram showing the operation of the engine.
The figure is a graph showing the advance angle characteristics of the distributor. 1... Air cleaner 2... Intake passage 3... Carburetor 4... Mixer 5... Gasoline tank 6... Fuel pump 7...First opening/opening valve 8...
・LPG tank 9...Vaporizer 10・
...Second on-off valve 11...Fuel selector switch 12...Ignition advance selector switch 13...Distributor 14...Ignition coil 15...Ignition timing delay device patent applicant Mazda Corporation Agent
Person Patent Attorney - Color Ken Shaft Circumference
Patent Attorney Masatoshi Matsumoto Figure 1 Figure 3

Claims (1)

[Claims] A different fuel switching device comprising: a fuel switching device that selects one of the different fuels to supply the engine; and an ignition timing control device that switches the ignition timing in accordance with the type of fuel selected by the fuel switching device. An ignition timing control device for an engine using different fuel switching, characterized in that the engine includes a delay means for substantially switching the ignition timing by the ignition control device after a predetermined period of time has elapsed after activation of the fuel switching device.