JPH04134183A - Ignition device for internal combustion engine - Google Patents

Abstract

PURPOSE:To eliminate diode assembly installed in each cylinder to reduce the number of parts, and simplify the structure, and reduce a cost, and improve layout characteristic and reliability by building an ion current detecting diode in a cap of a distributor. CONSTITUTION:Ion current detecting diodes corresponding to each air cylinder are built-in a cap 1A of a distributor. When a power transistor 14 is controlled for turn-off by a computer unit 13 synchronously with the rotation of an internal combustion engine, namely, in response to the output from a signal generator 10, the counter-electromotive force is generated in the primary side of an ignition coil 15, and the negative high voltage is generated in the secondary side in response to the counter-electromotive force of the primary side, and this negative high voltage is supplied to an ignition plug 8 through a central electrode 2, side electrodes 3 and a high voltage cord 5. When the air-fuel mixture in the cylinder of an engine 9 is burned, the ion current is generated, and this ion current is supplied to an ion current detecting unit 11 and the computer unit 13, and the combustion condition is judged.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ignition device for an internal combustion engine, and more particularly to an ignition device for an internal combustion engine in which an ion current detection diode is built into a power distributor cap.

[Prior Art] FIG. 4 is a configuration diagram showing a conventional ignition device for an internal combustion engine. In the figure, (1) is a power distributor cap, (2) is a central electrode provided in the center of this power distributor cap (1), (
3) is a plurality of side electrodes provided around the power distributor cap (1) corresponding to each cylinder of the engine; (4) is a center electrode (2) rotatably in sliding contact with the center electrode (2); is selectively connected to the side electrode (3), (5) is the high voltage cord connected to the side electrode (3), (6) is the ionic current detection diode, and (7) is the diode ( This diode assembly (7) is molded around the diode and electrode with a resin material, and is prepared as many times as the number of cylinders. (8) is a signal extraction diode assembly that includes the high voltage cord (5) and the diode assembly (7). ), (9) is the engine to which this spark plug (8) is attached, (10) is a signal generator that detects the rotation angle of the engine (9), 11) is the ion current detection unit connected to the ion current detection diode (6), (12) is the ion flow path, and (13) is the signal generator (10) and the ion current detection unit (11). A computer unit for ignition timing control etc. to which an output is supplied; (14) a power transistor whose drive is controlled by the output of the computer unit (13); (15) a primary side connected to the collector of the power transistor (14); The secondary side is the center electrode (
2) is the ignition coil connected to.

Next, the operation of the conventional ignition system for an internal combustion engine shown in FIG. 4 will be explained. The computer unit (13) operates in synchronization with the rotation of the internal combustion engine, that is, in response to the output from the signal generator (10), and when the power transistor (14) is controlled and turned off by the output, the ignition coil (15) A back electromotive force is generated on the primary side of the 5), etc., to the ignition plug (8), whereby the ignition plug 8) ignites. At this time, since the negative high voltage is in the opposite direction of the diode (6), the ion current detection unit
11).

When the air-fuel mixture in the cylinder of the engine (9) is ignited by the spark plug (8), an ionic current is generated, and this ionic current is biased to a negative voltage by the negative power source of the ionic current detection unit (11). The ion current is supplied through the ion current path (12) to the ion current detection unit (11), where it is processed and sent to the computer unit (13).
). Since the computer unit (13) detects the rotation angle of the internal combustion engine using the signal generator (10), it is possible to determine whether or not each cylinder is combusting normally using the signal transmitted from the liquid detection unit (11). I can know.

[Problems to be Solved by the Invention] The conventional ignition system for an internal combustion engine is refined as described above, and the diode assembly (7) must be prepared for each cylinder, so the refinement is complicated and the cost is high. Furthermore, it is necessary to secure a space for the diode assembly (7), which makes layout difficult in modern narrow engine compartments, and there are also problems in that reliability is poor due to the large number of parts.

This invention has been made to solve the above-mentioned problems, and aims to provide an ignition device for an internal combustion engine that is easy to refine, inexpensive, and has improved layout and reliability.

[Means for Solving the Problems] An ignition device for an internal combustion engine according to the present invention has a central electrode connected to an ignition coil, connected to a spark plug of each cylinder, and selectively connected to the central ti. A plurality of side electrodes, a diode connected to the side electrode, a terminal connected to the diode to take out an ion detection signal, and the center electrode, the side electrode, the diode, and the terminal are separated from each other. The device is equipped with a power distributor cap made of a resin material that is held in place.

[Operation] In the present invention, a diode for extracting ions from liquid is built into the power distributor cap, and the diode assembly provided for each cylinder is removed to reduce the number of parts.

Embodiment] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1st
The figure is a configuration diagram showing one embodiment of the present invention, and (2) to
(6), (8) to (15) are the same as described above.

In this embodiment, an ionic current detection diode (6) corresponding to each cylinder is built into the power distributor cap (IA). That is, here, as an example, four diodes (6) are prepared for four side electrodes (3) provided corresponding to four cylinders, and the anode of each diode (6) is connected to the corresponding side electrode ( 3), the cathodes are connected in common and connected to the signal extraction terminal (16), and this terminal (6) is connected to the ion current detection unit (11). Therefore,
The previously required diode assembly (7) is now eliminated.

Next, the operation of the embodiment of the present invention shown in FIG. 1 will be explained. When the power transistor (14) is controlled and turned off by the computer unit (13) in synchronization with the rotation of the internal combustion engine, that is, in response to the output from the signal generator (10), a reverse voltage is applied to the primary side of the ignition coil (15). An electromotive force is generated, and in response, a negative high voltage is generated on the secondary side, and this negative high voltage is applied to the center electrode (2) and the side electrodes (
3) is supplied to the spark plug (8) via the high voltage cord (5), which causes the spark plug (8) to ignite. At this time, the negative high voltage does not affect the ion current detection unit (11) because the diode (6) is in the opposite direction. When the air-fuel mixture in the cylinder of the engine (9) is ignited by the spark plug (8), a flow of ions is generated, and this ion current is biased to a negative voltage by the negative power supply of the ion current detection unit (11). Since the ionic current path (
12) (Here, only the ion current path of the lower right diode (6) is shown as a representative) to the ion current detection unit (11), where it is processed and sent to the computer unit (13). Supplied. Since the computer unit (13) detects the rotation angle of the internal combustion engine using the signal generator (10), the ion current detection unit (13) detects whether or not combustion is normal in each cylinder.
1) It can be known from the signal transmitted from the source.

FIG. 2 shows an example of a specific structure of a power distributor to which the present invention is applied, and in FIG. 2, parts corresponding to those in FIG. 1 are designated by the same reference numerals. In Figure 2, (17
) is a connector for external connection with a terminal (16) attached, and (18) is a resin material that separates and holds the center electrode (2), side electrodes (3), diode (6), and terminal (16). , (1) is the power distributor housing that engages with the power distributor cap (IA) and is screwed, (2o) is the engine (9
) (Figure 1). The power distribution rotor (4) is attached to one end of this shaft (20).The shaft (20) rotates in synchronization with the rotation of the engine (9), and the signal generator (]
0) to detect the rotation of the engine (9). Further, the negative high voltage for ignition inputted to the center electrode (2) is distributed to the side electrodes (3) of predetermined cylinders by the power distribution rotor (4).

FIG. 3 shows another example of a specific structure of a power distributor to which the present invention is applied, and in FIG. 3, parts corresponding to those in FIG. 2 are designated by the same reference numerals.

Figure 2 shows the case where the cathodes of the diodes (6) are connected in common and connected to a single signal extraction terminal (13), that is, the structure corresponds to Figure 1, but in Figure 3, each This is a case where a signal extraction terminal (13) is provided corresponding to each diode (6).

[Effects of the Invention] As described above, according to the present invention, the central electrode is connected to the ignition coil, and the plurality of side electrodes are connected to the spark plugs of each cylinder and selectively connected to the central electrode. and,
A diode connected to the side electrode, a terminal connected to the diode to take out an ion detection signal, and a resin material that separates and holds the center electrode, the side electrode, the diode, and the terminal, respectively. Since the power distributor cap is provided, it is possible to obtain an ignition device for an internal combustion engine with a reduced number of parts, a simple structure, low cost, and improved layout and reliability.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing one embodiment of the present invention, Fig. 2 is a sectional view showing the main part of the invention, Fig. 3 is a sectional view showing another example of the main part of the invention, and Fig. 3 is a sectional view showing another example of the main part of the invention. FIG. 1 is a configuration diagram showing a conventional ignition device for an internal combustion engine. In the figure, (IA) is the distributor cap, (2) is the center electrode, (3) is the side electrode, (6) is the ionic current detection diode, (8) is the spark plug, (15) is the ignition coil, (16) is a terminal for signal extraction, and (18) is a resin material. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] A center electrode connected to an ignition coil, a plurality of side electrodes connected to spark plugs of each cylinder and selectively connected to the center electrode, and a plurality of side electrodes connected to the side electrodes. A power distributor cap comprising: a diode connected to the diode; a terminal connected to the diode to take out an ion detection signal; and a resin material that separates and holds the center electrode, the side electrode, the diode, and the terminal, respectively. An ignition device for an internal combustion engine characterized by: