JPS62111173A - Ignition detecting device - Google Patents

Abstract

PURPOSE:To enable an explosion condition in a cylinder to be observed as a quantity change of light, by providing a path of light from in the vicinity of a discharge electrode of a spark plug while the other end of said path of light in the vicinity of a high voltage connection part. CONSTITUTION:If high voltage from a distributor is applied to an electrode 2, an electric discharge is generated in a discharge electrode 5 to perform ignition of fuel in a cylinder inside 7 and introduce an explosion. Here an optical fiber 3 transmits the state of ignition in the cylinder inside 7 as a quantity of light to be fed from an end face in the vicinity of the discharge electrode 5 to a part in the vicinity of the electrode 2. This quantity of light, being transmitted to an optical fiber 9 through a connector 8, is transmitted to an ignition detecting circuit 10. This quantity is converted into an electric signal by a photodiode 12, and its output, after being amplified by an amplifier 13, is compared with a reference value 15 by a comparator 14. If an output from the amplifier 13 exceeds the reference value 15, it is decided ignition of the fuel is performed, and a detection signal is fed to an output terminal 16.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device for detecting the presence or absence of ignition, which is used when performing fuel control, ignition control, etc. of an engine.

(Prior Art) FIG. 3 shows the configuration of a conventional ignition detection device. In the figure, when a high voltage is applied from a high voltage generating coil 31 to a spark plug 33 via a distributor 32, a discharge occurs in the spark plug 33, and the current flowing at this time is detected by an ignition detection coil 34. be.

(Problem to be Solved by the Invention) In the above configuration, it is assumed that the current flowing between the cables connecting the high-voltage generating coil to the spark plug causes a discharge in the spark plug, causing ignition in the cylinder. It does not actually observe the ignition inside the cylinder. Therefore, even if a discharge occurs somewhere else rather than at the spark plug in the cylinder due to deterioration of the istoripulator, there is a drawback that it cannot be detected.

Further, there was a drawback that fuel was not supplied into the cylinder and it was not possible to detect whether or not the fuel was ignited.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ignition detection device which overcomes the drawbacks of the prior art and is capable of actually detecting ignition of fuel within an engine cylinder.

(Means for Solving the Problem) The ignition detection device of the present invention provides an optical path from near the discharge electrode of one spark plug, and the other end of the optical path is provided near the high voltage connection part, and detects the explosion situation in the cylinder. can be observed as changes in light intensity.

In addition, there is an optical fiber and connector that guides the amount of light in the optical path provided on the spark plug, a photodiode and connector that receives the amount of light from this optical fiber, an amplifier that outputs electrical power according to the amount of light from the photodiode, and an amplifier that outputs electrical power according to the amount of light from the photodiode. It is equipped with a comparator that detects whether the electrical output exceeds a certain value, and a reference power source, and uses the output voltage from the photodiode to determine whether or not discharge from the spark plug transfers to the fuel in the cylinder and ignites it.

(Function) According to the present invention, it is possible to actually detect the ignition of fuel in the engine cylinder, and the above-mentioned drawbacks of the conventional method of estimating from the current flowing through the cable to the spark plug can be avoided. I can do it.

(Example) An example of the present invention will be described based on FIGS. 1 and 2.

FIG. 1 is a block diagram of the ignition detection device of the present invention.

In the figure, 1 is a spark plug with an optical fiber for observing inside the cylinder, 2 is an electrode for connecting high voltage from a distributor, 3 is an optical fiber, and 4 is a ceramic material that holds the optical fiber 3 and electrode 2. and 5 is a discharge electrode for insulation from the surroundings. 6 is the engine body, and 7 is the inside of the cylinder within the engine body 6.

Every time high voltage from the distributor is applied to the electrode 2, a discharge occurs at the discharge electrode 5, igniting the fuel in the cylinder and causing an explosion. At this time, the optical fiber 3 transmits the ignition state inside the engine cylinder 7 from the end surface near the discharge electrode 5 to near the electrode 2 as the brightness of light, that is, the amount of light. This amount of light is transmitted to the optical fiber 9 via the connector 8, and this amount of light is transmitted to the ignition detection circuit 10.In the ignition detection circuit 10, 11 is a connector that transmits the amount of light transmitted to the optical fiber 9 to the ignition detection circuit 10. Connecting. A photodiode 12 converts the amount of light transmitted to the ignition detection circuit 10 into an electrical signal. The output of the photodiode 12 is amplified by an amplifier 13, and then compared with a reference value 15 by a comparator 14. If the output from the amplifier 13 exceeds the reference value, it is determined that fuel has been ignited, and the output terminal is A detection signal is sent to 16. An example of signals at each portion during this period is shown in FIG. In the figure, (a) is the amount of light inside the cylinder, (b) is the amount of light output from the optical fiber 3, (c) is the output from the photodiode 12, (d) is the output from the amplifier 13, and (e) is the reference value 15.
, and (f) shows the detection signal of the output terminal 16.

The third waveform in FIG. 2 shows a state in which light from only the discharge of the spark plug was detected, but no explosion occurred within the cylinder.

As described above, it is possible to reliably detect whether or not the spark plug discharges within the cylinder and ignites the fuel.

In addition, in Fig. 1, the optical path provided in the spark plug is
Although an example has been shown in which the optical path is provided in the ceramic material 4 using the optical fiber 3, the entire ceramic material 4 may be made of a Si-based material that transmits light, and may also be used for this purpose.

Further, in the embodiment shown in FIG. 1, one cylinder has been described as an example, but the optical fiber 9 can be branched, and the amount of light from, for example, four cylinders can be detected by one ignition detection circuit 10.

(Effects of the Invention) According to the present invention, since the explosion of fuel within the engine cylinder can be directly detected, there is an effect that ignition within the cylinder can be accurately detected.

Furthermore, by measuring the temperature by optically analyzing the color at the time of ignition inside the cylinder, which travels from the inside of the engine cylinder through an optical path called a glass fiber, it is also possible to detect whether or not the explosion is occurring properly.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an ignition detection device according to an embodiment of the present invention, FIG. 2 is a diagram of signal waveforms of various parts in the same embodiment, and FIG. 3 is a configuration diagram of a conventional ignition detection device. 1...Spark plug, 2...Electrode, 3,9...
Optical fiber, 4...Ceramic material, 5...Discharge electrode, 6...Engine body, 7...Cylinder interior, 8, 11...Connector, lO...Ignition detection circuit, 12...・Photodiode, 13...Amplifier,
14...Comparator, 15...Reference value, 16...
・Output terminal. Patent applicant Matsushita Electric Industrial Co., Ltd. Figure 2 Figure 3

Claims (1)

[Claims] (1) An ignition device characterized in that an optical path is provided from the vicinity of the discharge electrode of the spark plug, and the other end of the optical path is provided near the high voltage connection part, so that the explosion situation inside the cylinder can be observed as a change in the amount of light. Detection device. (2) An optical fiber and a connecting connector that guide the amount of light in the optical path provided in the ignition plug, a photodiode and connector that receive the amount of light from the optical fiber, and an electrical output according to the amount of light from the photodiode that exceeds a certain value. An ignition detection device comprising a comparator and a reference power source for detecting whether or not the spark plug is activated, and determining whether or not the discharge of the spark plug has transferred to the fuel and ignited the fuel in the cylinder based on the output voltage from the photodiode.