JPS5818564A - Engine ignition system - Google Patents

Abstract

PURPOSE:To improve combustion efficiency by boosting a battery voltage to accumulate its electric charge in a capacitor and by starting discharge at an ignition plug by a high voltage from an ignition coil and thereafter feeding the energy of the capacitor into the ignition plug. CONSTITUTION:At start of ignition operation a voltage of a battery 1 is boosted by a booster 7 to charge a capacitor C1. On the other hand, when a contact point 4 is switched off in association with operation of a crankshaft of an engine, a high voltage is developed at the secondary coil of an ignition coil 3, fed to a rotor electrode 8 of a distributor 5 via a diode D1, and discharged to opposed one among peripheral electrodes 9A through 9D. The energy of 0.1J- 0.5J accumulated in the capacitor C1 is thereafter supplied between electrodes of one of ignition plug 6A through 6D via a diode D2 and said electrodes 8 and 9. Accordingly, within a short period after start of ignition an intense energy may be supplied for the ignition plugs 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition device for a spark-ignition engine, and more particularly to an ignition device with improved combustion efficiency.

As a conventional ignition device, there is one shown in FIG. 1, for example.

In the circuit shown in FIG. 1, the output of the battery 1 is applied to the ignition coil 30 through the resistor 2 to the primary coil L1. When the contact port 4 is turned off at the ignition timing, the current flowing through the primary coil L1 is cut off. At this time, a high voltage pulse with a peak value of minus several tens of kV is generated in the secondary coil L2, and this is transmitted to the ignition stroke of the spark plugs 68 to 6D of each cylinder via the distributor 5 and the high voltage cable. Sent to compatible spark plugs.

A high-voltage pulse is applied to the spark plug, and when its peak value reaches the breakdown voltage between the center electrode and the side electrodes of the spark plug, a discharge begins 17, followed by the induction stored in the spark coil 6. The energy causes the electric discharge to continue, igniting and burning the air-fuel mixture.

In the conventional ignition system as described above, the energy stored in the ignition coil as inductive energy is injected into the ignition plug, so even if the ignition energy is increased (for example, by increasing the capacity of the ignition coil), the discharge continues. The problem is that it is difficult to improve the combustion efficiency because the time only becomes longer and the energy closely related to combustion immediately after the start of ignition tends to increase too much.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an ignition device that can improve combustion efficiency.

In order to achieve the above object, the present invention boosts the battery voltage to store charge in a capacitor, and connects the output of the ignition coil and the output of the capacitor to the spark plug via a distributor having noble metal electrodes. Let's give,
After discharge starts at the spark plug due to high voltage from the ignition coil, when the discharge sustaining voltage decreases, 0.1 to 0.5 J of energy stored in the capacitor is injected into the spark plug.

The present invention will be described in detail below based on the drawings.

FIG. 2 is a diagram showing an embodiment of the present invention, and FIG. 6 is a voltage waveform diagram of the circuit shown in FIG. In Figure 6, ■ and v
A to {circle around (2)} indicate voltage waveforms at locations designated by the same reference numerals in FIG. 2, respectively.

In FIG. 2, 7 is a booster composed of, for example, a DC-DC converter, and the output voltage of battery 1 (12V
) to -i, 5kV and output. Further, C1 is a capacitor having a value of, for example, 0.2 μF. Further, Dl and D2 are high voltage diodes, which are used to prevent the output of the ignition coil B and the output of the capacitor C1 from flowing to the other side.

In addition, the distribeater 5 has a rotor electrode 8 and a side electrode 9A so as to withstand the influence of large current on the electrodes.
At least the spark discharge part (tip part) of ~9D is formed of a noble metal such as platinum or palladium, or an alloy mainly composed of these noble metals.

Next, the operation will be explained.

The booster 7 boosts the voltage of the battery 1 to -1.5 kV, and charges the coil capacitor C1. At this time, for example, 0.2 J of energy is stored in the capacitor C1.

On the other hand, the contact point 4 is linked to the engine crankshaft and turns off every time the crankshaft rotates 180 degrees.

When the contact point 4 is turned off, a high voltage (for example -20 kV peak) is generated in the secondary coil of the ignition coil 6. Then, it is guided to the rotor electrode 8 of the distributed beater 5 via the diode D1, and the side electrodes 9A to 9
Among the electrodes D, the discharge occurs to the one facing the rotor electrode 8, and is further guided to the spark plug connected to that side electrode, and discharge is started between the electrodes of the spark plug.

Once the discharge starts, the discharge voltage drops to about -1 kV. At this time, the energy stored in the capacitor C1 has a potential of -1.5 kV, and the diode D
2. Injected between the electrodes of the spark plug via the rotor electrode 8 and the side electrodes.

Due to this large current discharge from the capacitor C1, the discharge form becomes an arc between the electrodes of the distribeater and between the electrodes of the spark plug. When the charge in the capacitor C1 is completely injected, the discharge pressure rises again, and the energy stored in the ignition coil 6 is injected into the spark plug.

As mentioned above, not only the energy stored in the ignition coil but also the energy of about 0.2 J stored in the capacitor C1 is rapidly injected, so the energy can be injected. Therefore, combustion conditions can be significantly improved and fuel consumption can be saved.

FIG. 4 is a diagram showing the relationship between the energy injected from the capacitor C1 and the fuel efficiency improvement ratio.

As can be seen from FIG. 4, if the implantation energy is less than 0.1 J, the effect will be significantly reduced, so it is necessary to set it to 0.1 J or more.

Moreover, if the injection energy exceeds 0.5 J, the electrodes of the distributor 5 will be severely worn out, so this is not suitable for practical use.

Therefore, the energy stored in capacitor C1 is 0,1
It is necessary to keep it in the range of J or more and 0.5 J or less.

Note that the capacitor C1 is always -1,5 except when igniting.
Although a kV voltage is applied, the configuration is such that the power is distributed to each spark plug via a distributor, so
There is a danger that the voltage will be applied to a spark plug other than the spark plug at the ignition timing, and therefore an irregular discharge that occurs at a time other than the ignition timing will not occur.

As explained above, according to the present invention, a large amount of energy can be injected into the spark plug in a short time after ignition starts, so combustion efficiency can be significantly improved, thereby greatly improving fuel efficiency. I can do it. Furthermore, there is no risk of irregular discharge occurring due to a spark plug that is not at the ignition timing, and the durability of the distributor can be made to a level that does not pose a practical problem.

[Brief explanation of the drawing]

Fig. 1 is a diagram of an example of a conventional ignition system, Fig. 2 is a diagram of an embodiment of the present invention, Fig. 6 is a voltage waveform diagram of the circuit of Fig. 2, and Fig. 4 is a diagram of the relationship between injected energy and fuel efficiency improvement ratio. It is a relationship diagram. Explanation of symbols 1... Battery 2... Resistor 6... Ignition coil 4... Contact point 5... Distributor 68-6D... Spark plug 7... Booster 8... Rotor Electrode 9A~
9D... Side electrodes D, D... Diode C1... Capacitor 1) 2 Agent patent attorney Junnosuke Nakamura procedural amendment (voluntary) Indication of the September 9, 1980 incident Patent application filed in 1982 No. 11531, Title of Invention Person who corrects engine ignition system Shin Marunouchi Building 3rd floor, 44th Ward (〒100) ('
Telephone 214-0502) Target of correction Drawing large size - 〇 0

Claims (1)

[Claims] The ignition coil outputs a high voltage at the ignition timing, the booster boosts the battery voltage, the capacitor charged by the output of the booster, and at least the spark discharge parts of the rotor electrode and side electrodes are made of platinum. and a distribeater formed of palladium or an alloy mainly composed of these metals, and the output terminal of the ignition coil and the terminal of the capacitor are connected to the rotor electrode of the distribeater through diodes, respectively. , and connect the spark plugs of each cylinder to each side electrode of the distribeater, respectively.
After the spark plug starts discharging by the high voltage applied from the ignition coil at the ignition timing, the energy of 0.1 to 0.5 J stored in the capacitor is injected into the spark plug. Configured engine ignition system.