JP4726940B2 - Ignition device for internal combustion engine - Google Patents

Description

  The present invention relates to an internal combustion engine ignition device having a function of detecting a combustion state of an internal combustion engine by detecting ions during combustion of the vehicle internal combustion engine.

  As a means for detecting the combustion state of an internal combustion engine, a method is known in which ions generated when fuel is burned in a cylinder are drawn into an ignition coil and detected as an ion current. In such an ignition coil, that is, an ion current detection ignition coil, it is difficult to detect the ion current due to noise or ignition current at the time of ignition coil ignition. There is a method of detecting (see, for example, Patent Document 1).

JP-A-4-140478

  However, when such a method is adopted, two ignition coils are required, which is costly, and there is a problem that the layout is deteriorated because a large space is required for installing the ignition coils.

  The present invention has been proposed to solve the above-described problem, and an ignition device for an internal combustion engine that can be detected by a single ignition coil without deteriorating the detectability of ion current due to noise or ignition current during ignition. Is to provide.

An ignition device for an internal combustion engine according to the present invention includes a primary coil, a secondary coil, the primary coil, and the secondary coil, one end of which is connected to a battery and the other end is connected to a switching element for energizing / cutting off a primary current. In an ignition device for an internal combustion engine that includes an ignition coil including an iron core that is magnetically coupled to a secondary coil, and the ignition coil is housed in an insulating case and cast with an insulating resin, the ignition coil includes: The output plug is connected to the secondary coil, and the output plug is connected to the spark plug in order to apply a high voltage generated when the current flowing through the primary coil is cut off to the spark plug. Connected to the high voltage output terminal to be connected and an ion current detection circuit including at least a bias capacitor, and is generated as the fuel in the internal combustion engine burns. Consists of a ion current detecting terminal connected to a probe for detecting an ion current, in the ion current detecting terminal only outputs of the switching element is connected, one end of the ion current detection circuit in the primary coil It is connected.

  The internal combustion engine ignition device according to the present invention has an effect of being compact because it is housed in an insulating case and casted by an insulating resin, and uses a voltage generated in the primary coil as a bias voltage for detecting an ionic current. It is possible to suppress the increase in cost without impairing the layout.

Embodiment 1 FIG.
1 is a circuit diagram of an internal combustion engine ignition device according to Embodiment 1 of the present invention. FIG. 2 is a view showing a state in which the internal combustion engine ignition device according to Embodiment 1 of the present invention is attached to the internal combustion engine.
In the ignition device for an internal combustion engine according to Embodiment 1 of the present invention, as shown in FIGS. 1 and 2, one end 31 of the primary coil 30 is connected to the battery 10, and the other end 32 energizes and interrupts the primary current. Is connected to the switching element 20 for the purpose. One end of the secondary coil 40 that is magnetically coupled via the iron core 50 is connected to a high voltage output terminal 71, and a spark plug 110 attached to the internal combustion engine is connected to the high voltage output terminal 71. The primary coil 30, the secondary coil 40, and the iron core 50 are built in the insulating case 60, and the gap is cast with an insulating resin.
A primary coil 30 having one end 31 connected to the battery 10 and the other end 32 connected to the collector of the switching element 20; a switching element 20 having a collector connected to the other end of the primary coil 30 and an emitter grounded; Are collectively referred to as a bias circuit.

  In addition, the internal combustion engine ignition device according to Embodiment 1 of the present invention includes an ion current detection circuit 90, and the ion current detection circuit 90 detects the ion current so as to output a bias voltage to the ion current detection terminal 72. Capacitor 80 connected to terminal 72, Zener diode 81 for determining the upper limit of the voltage applied to capacitor 80, diode 91 and resistor 92 for charging capacitor 80 with a voltage generated in primary coil 30, and current for detecting ion current And a detector 93. The anode of the diode 91 is connected to the collector of the switching element 20 (and the other end 32 of the primary coil 30), and the cathode of the diode 91 is connected to the capacitor 80 via the resistor 92. An ion current detection circuit 90 is also built in the insulating case 60.

  An ion current detection probe 120 is attached to the internal combustion engine, and the probe 120 and an ion current detection terminal 72 of the ion current detection circuit 90 are connected by an output line 130. The elements through which the ionic current flows and the path through which the bias current of the capacitor 80 flows are connected by soldering or welding. The ion current detection terminal 72 employs a plating material or a corrosion resistance preventing material.

Next, the operation principle of the internal combustion engine ignition device according to Embodiment 1 of the present invention will be described.
When an energization signal input from an ECU (not shown) is turned on, a primary current is energized to the primary coil 30. Thereafter, when the energization signal is turned off, a voltage of about several hundred volts is generated on the primary side (the collector of the switching element 20). This voltage charges the capacitor 80 of the ion current detection circuit 90 via the primary coil 30.
Further, when the primary current is cut off, a voltage of several tens of kV is generated in the secondary coil 40, and a high voltage is applied to the spark plug 110 connected via the high voltage output terminal 71 by this voltage. Cause dielectric breakdown. As a result, the fuel in the internal combustion engine burns.
In addition, it is possible to detect a combustion state by detecting ions generated by combustion as an ion current by the bias voltage charged in the capacitor 80 of the ion current detection circuit 90.

The internal combustion engine ignition device according to Embodiment 1 of the present invention is housed in an insulating case 60 and cast by an insulating resin, and generates a bias voltage for detecting an ionic current in the primary coil 30 when energization is cut off. Since the voltage is used, it can be configured in a small size, the layout property is not impaired, and the cost increase can be suppressed.
Further, since the capacitor 80 for the bias voltage is connected to the switching element 20 via the diode 91 and the resistor 92, it is possible to suppress a decrease in the charged voltage, so that the ionic current generated by the ignition at the normal ignition timing is Of course, the ion current can be detected even when the fuel burns due to erroneous ignition, or when the inside of the cylinder becomes hot during the discharge and self-ignites.

In the internal combustion engine ignition device according to Embodiment 1 of the present invention, what is housed in one insulating case 60 is referred to as a package, and one high voltage output terminal 71 and one ion from one package. Although the current detection terminal 72 is provided, as shown in FIG. 3, it may be a coil having a simultaneous ignition type in which a high voltage output is taken out from both ends of the secondary coil 40B, and the ion current detection terminal 72 is also provided. Two of them may be connected to another cylinder together with the two high voltage output terminals 71 as shown in FIG.
In addition, as shown in FIG. 5, one high voltage output terminal 71 and four ion current detection terminals 72 may be used to detect ion currents generated in a plurality of cylinders by one ignition coil.

Further, since the ion current detection terminal 72 and the terminal of the probe 120 connected thereto are made of plating or corrosion resistance prevention material, increase in contact resistance and conduction failure can be prevented to improve the reliability of ion current detection. You can also.
Further, the connection of the path through which the ionic current flows and the path through which the bias current flows is made of solder or welding, so that an increase in contact resistance and conduction failure can be prevented and the reliability of the ionic current detection can be improved.
In addition, since the ion current detection circuit 90 is not connected to the high voltage side of the ignition coil, that is, the secondary coil 40, the superposition of noise at the time of ignition and the deterioration of the detectability of the ion current due to the ignition current do not occur.
In addition, since the bias voltage for detecting the ion current can be stably supplied from the primary coil 30, the necessity of a separate power source and the detectability of the ion current due to the decrease in the bias voltage are not deteriorated.

Embodiment 2. FIG.
FIG. 6 is a view showing a state where the internal combustion engine ignition device according to Embodiment 2 of the present invention is attached.
The ignition device for an internal combustion engine according to Embodiment 2 of the present invention is different from the ignition device for internal combustion engine according to Embodiment 1 of the present invention in that an ignition plug 110B is provided instead of the probe 120 for detecting ionic current, Since other than that is the same, the same code | symbol is attached | subjected to the same thing and description is abbreviate | omitted.

In the ignition device for an internal combustion engine according to Embodiment 2 of the present invention, since the ignition plug conventionally used in the internal combustion engine as an ion current detection probe is provided, reliability such as durability can be secured, It can be cheaper than a dedicated probe.
In addition, the detection can be improved by eliminating the side electrode of the spark plug 110B or increasing the center electrode.
Further, by plating the terminal of the spark plug 110B or using a corrosion resistance preventing material, it is possible to prevent an increase in contact resistance and poor conduction and improve the reliability of ion current detection.

Embodiment 3 FIG.
FIG. 7 is a view showing a state in which the internal combustion engine ignition device according to Embodiment 3 of the present invention is attached to the internal combustion engine.
The internal combustion engine ignition device according to Embodiment 3 of the present invention is different from that of the internal combustion engine ignition device according to Embodiment 2 of the present invention in that the plug boot 150 is attached to the ignition plug 110B for ion current detection. Since other than that is the same, the same code | symbol is attached | subjected to the same thing and description is abbreviate | omitted.
In the internal combustion engine ignition device according to Embodiment 3 of the present invention, the plug boot 150 is mounted between the ion current detection terminal 72 for detecting the ion current and the ignition plug 110B, so that the ion current detection path is reliably connected. The ion current can be reliably detected.
In addition, unlike the plug boot used for a general ignition coil, the plug boot 150 does not need to be insulated, so an inexpensive material having a low withstand voltage is used , or a structure for insulation is not required, and the plug boot 150 is inexpensive. Can be produced.

Embodiment 4 FIG.
FIG. 8 is a view showing a state where the internal combustion engine ignition device according to Embodiment 4 of the present invention is attached to the internal combustion engine.
In the internal combustion engine ignition device according to Embodiment 4 of the present invention, the ignition plug 110 for ignition of the internal combustion engine ignition device according to Embodiment 3 of the present invention is connected to the high-voltage output terminal 71 by the H / T cord 160. Since the connection is different and the rest is the same, the same components are denoted by the same reference numerals and the description thereof is omitted.
In the internal combustion engine ignition device according to Embodiment 4 of the present invention, since the ignition spark plug 110 is connected using the H / T cord 160, the connection is simple and the cost increase can be suppressed. In addition, since the H / T cord 160 is used, the same spark plug 110 can be used even when it is attached to an internal combustion engine having a different bore diameter, for example, so that parts can be shared and cost reduction can be achieved.

1 is a circuit diagram of an internal combustion engine ignition device according to Embodiment 1 of the present invention. FIG. It is a figure which shows the state which attached the internal combustion engine ignition device which concerns on Embodiment 1 of this invention to the internal combustion engine. It is a circuit diagram of the ignition device for other internal combustion engines which concerns on Embodiment 1 of this invention. It is a figure which shows the state which attached the ignition device for other internal combustion engines which concerns on Embodiment 1 of this invention to the internal combustion engine. It is a circuit diagram of the ignition device for other internal combustion engines which concerns on Embodiment 1 of this invention. It is a figure which shows the state which attached the internal combustion engine ignition device which concerns on Embodiment 2 of this invention to the internal combustion engine. It is a figure which shows the state which attached the internal combustion engine ignition device which concerns on Embodiment 3 of this invention to the internal combustion engine. It is a figure which shows the state which attached the internal combustion engine ignition device which concerns on Embodiment 4 of this invention to the internal combustion engine.

Explanation of symbols

  10 battery, 20 switching element, 30 primary coil, 31 (primary coil) one end, 32 (primary coil) other end, 40, 40B secondary coil, 50 iron core, 60 insulation case, 71 high voltage output terminal, 72 ions Current detection terminal, 80 capacitor, 81 Zener diode, 90 ion current detection circuit, 91 diode, 92 resistance, 93 current detection unit, 110, 110B ignition plug, 120 probe, 130 output line, 150 plug boot, 160 H / T code.

Claims (9)

A primary coil having one end connected to a battery and the other end connected to a switching element for energizing / cutting off a primary current, a secondary coil, and an iron core that magnetically couples the primary coil and the secondary coil; In an ignition device for an internal combustion engine comprising an ignition coil composed of:
The ignition coil has a plurality of output ends,
The output terminal is connected to the secondary coil and a high voltage output terminal connected to the spark plug for applying a high voltage generated when the current flowing through the primary coil is interrupted to the spark plug. An ion current detection circuit including at least a bias capacitor and an ion current detection terminal connected to a probe for detecting an ion current generated when the fuel in the internal combustion engine burns,
Only the output of the switching element is connected to the ion current detection terminal,
One end of the ion current detection circuit is connected to the primary coil.   The bias circuit is connected to the bias capacitor via a diode for preventing discharge of charge voltage and a resistor, the cathode side of the diode is connected to the collector side of the switching element, and the voltage generated in the primary coil when the primary current is cut off The ignition device for an internal combustion engine according to claim 1, wherein the bias capacitor is charged and used as a power source for detecting an ionic current.   The ignition device for an internal combustion engine according to claim 1 or 2, wherein the probe is similar to an ignition spark plug.   4. The internal combustion engine ignition device according to claim 3, wherein a plug boot is attached to the spark plug as the probe.   The ignition device for an internal combustion engine according to any one of claims 1 to 4, wherein elements of a path through which an ion current flows and a path through which the bias current of the capacitor flows are connected by soldering or welding.   6. The ignition device for an internal combustion engine according to claim 1, wherein the ion current detection terminal connected to one end of the capacitor is made of a plating material or a corrosion resistance preventing material.   7. The internal combustion engine ignition device according to claim 1, wherein the high voltage output terminal connected to the secondary coil is connected to an ignition spark plug by an H / T cord.   The ignition device for an internal combustion engine according to any one of claims 1 to 7, wherein the terminal of the probe is made of a plating material or a corrosion resistance preventing material.   The ion output portion including the ion current detection probe and the ion current detection terminal employs a material or a structure having a lower withstand voltage than a high voltage output portion including the high voltage output terminal. 2. An ignition device for an internal combustion engine according to 1.

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