JPS6018835B2 - Ignition system for multi-cylinder internal combustion engine - Google Patents

Description

[Detailed description of the invention] The present invention relates to an ignition system for a multi-segment internal combustion engine.

In order to obtain good drivability and good fuel efficiency in prior art automobiles, it is necessary that the ignition timing of the internal combustion engine is well matched. As a result of fully adapting the ignition timing under all operating conditions, the earliest ignition start timing is approximately 60o before top dead center (BTDC) in terms of crankshaft rotation angle (crank angle), and the latest ignition end timing is approximately 60o before top dead center (BTDC). It will be about 40o after dead center (ATDC). Therefore, in a distributor, its rotor has a crank angle between the center electrode and one side electrode.
000, it is necessary to secure a rotation angle (disangle) of the shaft of the distributor for 50 degrees. If the internal combustion engine is composed of six cylinders, six side electrodes of the distributor are required at equal intervals, and the period when the rotor is not connected to any side electrode is 36 days angle.
Pi/6-50o only 1oo. If the internal combustion engine is configured with eight cylinders, this period does not exist, in which case the rotor may be connected across two side electrodes, and the high voltage for the spark is then supplied. For example, it is not determined which side electrode this high voltage will be directed to, and therefore it is not known in which cylinder the ignition spark will occur, making it difficult for the internal combustion engine to operate smoothly.

Even in the case of a 6-cylinder engine, it is sufficient if the pitch circle of the side electrode is large, but if not, the pitch circle of the side electrode is 10.
The gap at 0 is not large, and it is similarly unclear in which cylinder the spark will occur.

Sparks in such undesired gaps without proper distribution are called flashovers. To prevent this flashover, it is common practice to increase the pitch circle of the side electrodes and, by extension, the diameter of the distributor, but in cases such as all-electronic advance control ignition systems, the possibility of flashover occurring increases. and
It is no longer possible to simply increase the diameter. For the reasons mentioned above, there is a method of installing two distributors in one internal combustion engine and distributing half of the cylinders in each, and to further simplify this, basically two distributors are installed. A method of unifying the rotor shaft with a single rotor shaft is being considered.
However, the former has the problem of doubling the cost and also requires a large space. The latter, i.e. 1 by one rotor shaft.
Although this method is advantageous in terms of space, it requires two ignition coils, which leaves a problem in terms of cost. Furthermore, since essentially two distributors are integrated, the internal structure becomes complicated, which increases the possibility of flashover. In addition, as the latter method, for example, the side electrodes are arranged on the distributor cap by two large and small pitch circles, and the amount of downward protrusion of the side electrode arranged by the large pitch circle is reduced. So-called two-stage distributors are beginning to appear, in which the rotor is provided with two brushes that are larger than the downward protrusion of the side electrodes arranged by the pitch circle, and that face each other. .

Although the diameter of this type of distributor cap can be reduced, the problem is that the height becomes too large. If sufficient height is not provided, the lower metal body or drive can be removed from the side electrode arranged by a large pitch circle and protruding downwardly, or from the brush for distributing high voltage to that side electrode. This is because flashover to the shaft is likely to occur. Purpose of the Invention The purpose of the present invention is to supply a high voltage whose phase is reversed every time to one center electrode, and to appropriately distribute this high voltage to two brushes using diodes with mutually different polarities. Based on this concept, the separation distance between the side electrode of the distributor cap or the rotor arm or brush and the metal body is reduced to reduce the height of the distributor, while preventing the risk of flashover and improving the operation of the internal combustion engine. To obtain a compact ignition device for a multi-cylinder internal combustion engine that can be smoothly operated.

Structure of the Invention In the present invention, a high voltage whose phase is inverted every time is supplied to the center electrode 2 of the distributor cap, and the rotor 9 directly electrically connected to the center electrode 2 has two sizes: one large and one small.
Two brushes 10 each facing two groups of side electrodes provided on the distributor cap with a pitch circle of
, 11, and the two brushes 10, 11 are connected to the center electrode by arms 13, 15 sealed in an insulator through diodes 14, 17 having mutually different polarities, and at least have a large pitch circle. The arm 15 on the brush side facing the side electrode group extends outward in the radial direction of the rotor while being enclosed in an insulator, and further extends upward in the axial direction of the rotor in the opposite direction from the distributor body while being enclosed in the insulator. An ignition device for a multi-cylinder internal combustion engine is provided, characterized in that the brush 11 extends from the insulator and is exposed toward the side electrode.

Embodiment A distributor used in an ignition system for a multi-cylinder internal combustion engine is shown in FIGS. 1 to 3 as an embodiment of the present invention. This distributor is an embodiment for use in a six-cylinder internal combustion engine. The distributor cap 102 is provided with one center electrode 2 and six side electrodes 3, 4, 5, 6, 7, 8. The side electrodes 3, 5, and 7 are arranged in a 4-diameter pitch circle around the center electrode 2, and the side electrodes 4, 6, and 8 are arranged in a large pitch circle. Side electrodes 3, 4, 5, 6
, 7 and 8 are earth. 1. Earth. 6, M. 3, M. 4. Shame.
2 and no. The spark plug of cylinder No. 5 is connected to a high tension cord (not shown), respectively. The metal fittings of the side electrodes are molded on the distributor cap 102 and are exposed to the inside and outside of the distributor cap 102. The externally exposed part is connected to the high tension cord, and the internally exposed part is periodically connected to the brush of the lower rod 9. Here, the metal fittings of the side electrodes 3, 5, and 7 are longer than the metal fittings of the side electrodes 4, 5, and 8, and are exposed inside the distributor cap lc at a position that projects further downward. Therefore, the brushes of the rotor 9 also include two brushes: a brush 11 located at a high position to face the side electrodes 4, 6, 8, and a brush 10 located at a low position to face the side electrodes 3, 5, 7. ing. The power distribution fitting molded inside the rotor 9 includes two arms 13 and 15 whose exposed parts form brushes, and one center fitting 12 to which a high voltage is directly supplied from the center electrode. , the arm and the center metal fitting are connected via diodes 14 and 17.

The arm 13 having the brush 10 located at a lower position and the center metal fitting 12 are connected through a diode 14 whose direction is oriented with the center metal fitting 12 as the positive electrode. Further, the arm 15 having the brush 11 located at a high position and the center metal fitting 12 are connected via a diode 17 whose forward direction is the direction in which the center metal fitting 12 is the negative electrode. Note that the rotor 9 is disk-shaped, and a concentric recess 16 is provided from above. The metal fittings of the side electrodes 3, 5, and 7 are exposed in this recess, and the arm 13 protrudes from the bottom of the rotor recess 16 so as to face the exposed side electrode metal fittings.
A brush 10 is formed. The brush 10 faces upward and is exposed in an arc shape, and its opening angle is 500 degrees. As the rotor 9 rotates, this brush 10 faces the side electrodes 3, 5, and 7 in sequence, and is capable of applying a high voltage during each 50° facing period. Further, a brush 11 is exposed upward in an arc shape at the upper end of the outermost circumference of the rotor 9, and its opening angle is 50 degrees. This brush 11 faces the side electrodes 4, 6, and 8 in sequence as the rotor 9 rotates, and is capable of supplying a high voltage during each 50° facing period. Note that the brushes 10 and 11 have an opening angle of 120 degrees. The main body of the rotor 9 is made of resin with high withstand voltage, and the two arms 1 are made of this resin.
3, 15, 1 center metal fitting 12, 2 diodes 1
4 and 17 are molded and fixed. The inside of the rotor 9 is fixed to a shaft, and the shaft is driven in synchronization with the crankshaft of the internal combustion engine at half the rotational speed. A center metal fitting 12 is exposed at the upper end of the rotor 9, and a carbon brush 18 provided on the center electrode 2 contacts and slides on the exposed surface of the center metal fitting 12. Also, the distributor cap 102 has screws 19a, 19b, 19
It is fixed to the distributor body 01 by the screws c. The distributor body 101 is made of metal and is fixed to the internal combustion engine, and houses therein a shaft, a play force contact, a cam, a reference position disk, and the like. An ignition circuit of an ignition system for a multi-cylinder internal combustion engine as an embodiment of the present invention is shown in FIG.

The distributor assembly 1 is for 6 cylinders, and includes a cam la that opens and closes the play force contact 22, and a reference position disc lb.
and the rotor arm rotate coaxially. The negative electrode of the battery 20 is grounded. One end of the key switch 21 is connected to the positive electrode of the battery 20. One end of a play force contact 22 built into the distributor 1 is grounded, and the other end is connected to one end of a resistor 23. The other end of the resistor 23 is connected to the base of a PNP transistor 24. The emitter of the transistor 24 is connected to the key switch 2.
It is connected to the other end of 1. Resistor 25 is transistor 24
It is connected between the base and the base. The collector of transistor 24 is connected to one end of resistor 51, and the terminals of resistor 51 are connected to the clock input of D-flip-flop 26 and one ends of AND gate 27 and AND gate 28, respectively. ○-For the flip-flop 26, use RCA product number CD4013, and the D-input is Q.
It is connected to the output to operate as a flip-flop.

The Q output is connected to the other input of the AND gate 27, and the Q output is connected to the other input of the AND gate 28. The disk lb changes to 1 when the distributor 1 rotates once.
It is a rotating disc made of magnetic material with a protrusion at one point. The magnet detector 29 is a well-known commercially available magnet detector that generates a signal every time the protrusion of the disk lb passes. A shaping circuit 30 is connected to the output of the magnet detector 23 and shapes the signal of the magnet detector 29. The output of the shaping circuit is connected to the reset terminal of the O flip-flop 26. The output of the asodo gate 27 is connected to the base of the power transistor 32, and the output of the AND gate 28 is connected to the base of the power transistor 33.

The other end 31 is a current limiting resistor, and one end is connected to the key switch 21.
The other end is the intermediate terminal 34a of the primary sequential coil of the ignition coil 34.
is connected to one end of the secondary sequential coil.

One end 34a of the primary coil of the ignition coil 34 is connected to the collector of the power transistor 32 via a diode 36, and the other end 34c is connected to the collector of the power transistor 33 via a diode 36. . The emitters of power transistors 32 and 33 are grounded. The other end of the secondary coil of the ignition coil 34 is electrically connected to the center portion 12 and the center portion 15 of the rotor 9 via the center electrode 2 of the high voltage divider of the distributor. The relationship between the center electrode, diodes and side electrodes of the high voltage divider has been explained with reference to FIGS. 1 to 3, and will therefore be omitted. The spark plug is designated by reference numeral 37.

The specifications of the winding between the terminals 34a and 34b of the primary coil of the ignition coil 34 and the winding of the secondary coil are equivalent to the winding specifications of a conventional ignition coil. The specifications of the primary winding between terminals 34a and 34c are the same as the specifications of the primary winding between terminals 34a and 34b except that the winding direction is reversed. When the primary coil terminals 34a and 34b of the ignition coil 34 are energized and cut off, a positive high voltage is generated in the secondary coil, and the ignition coil 34 is energized and cut off between the primary coil terminals 34a and 34c. When this happens, a high negative voltage is generated in the secondary coil. Next, the operation of the above-mentioned ignition circuit will be explained.

First, the key switch 21 closes and the distributor 1
The cam rotates to open or release the play force contact 22. Thereby, when the play force contact 22 is opened, the transistor 24 is turned on, and when it is opened, the transistor 24 is turned off. The waveform is shown in FIG. On the other hand, the reference position disk lb also rotates, and a pulse as shown in FIG. 6 is obtained at the output of the shaping circuit 30. The outputs Q and Q of the D-flip-flop 26 output voltage waveforms as shown at 3 and 4 in FIG. Therefore, the output waveform of the AND gate 27 is as shown in FIG. 5, and the output waveform of the AND gate 28 is as shown in FIG. When the output of the AND gate 27 is at a high level, the power transistor 32 is conductive, and when the output is at a low level, it is cut off.
Similarly, when the output of the AND gate 28 is at a high level, the power transistor 33 is conductive, and when the output is at a low level, it is cut off. 2 when the power transistor 32 conducts and shuts off.
A high positive voltage as shown in FIG. 5 is generated in the next coil, and a negative high voltage as shown in FIG. 8 is generated when the power transistor 33 is turned on and cut off. The diode 35 prevents the power transistor 32 from being destroyed by the high voltage generated in the primary coil when the power transistor 33 is cut off.
This prevents the power transistor 33 from being destroyed by the high voltage generated when the transistor 2 is cut off. As described above, the high voltage distributor 1 generated on the secondary side of the ignition coil 34 distributes the high voltage to the spark plugs of each cylinder.

However, a high voltage diode 14 is disposed between the center metal fitting 12 of the rotor 9 and the brush 10 with the positive electrode facing the center metal fitting 12 side and the negative electrode facing the brush 10 side. In between, there is a high voltage diode 1 with the negative electrode on the center metal fitting 12 side and the positive electrode on the brush 11 side.
7, only a positive high voltage is transmitted to the brush 10 of the rotor 9, and only a negative high voltage is transmitted to the brush 11 of the rotor 9. Therefore, when the power transistor 32 is activated, a spark is discharged to the spark plugs for the first, third and second cylinders, and when the power transistor 33 is activated, the spark is discharged to the spark plugs for the fifth, sixth and fourth cylinders. Sparks can be discharged. Therefore, each cylinder of an internal combustion engine has an M. 1,M. 5,M
．． 3, No. 6, No. 2, M. Ignition is ensured in the order of 4.

In the structures shown in Figures 1 to 3, in a so-called two-stage distributor, the amount of downward protrusion of the side electrodes provided on the distributor cap that are arranged by the small pitch circles is equal to that of the side electrodes arranged by the large pitch circles. The lower protrusion amount is larger than that of the lower end, and its tip is disposed within an annular recess provided in the disc-shaped outer row D.

Side electrodes arranged by small pitch circles (3 in the figure)
, 5, 7) or a storage brush (
In order to flashover from 10) to the lower metal body (lb in the figure), it is necessary to go over the rotor concavity (16 in the figure), but in the structure shown in Figures 1 to 3, this is not realistic. Actually, such a thing cannot happen. Effects of the Invention According to the present invention, a high voltage whose phase is inverted every time is supplied to one center electrode, and this high voltage can be appropriately distributed to two brushes using diodes with mutually different polarities. It is possible to reduce the height of the distributor by reducing the separation distance between the side electrode of the distributor cap or the rotor arm or brush and the metal body.
It is possible to obtain a compact ignition device for a multi-cylinder internal combustion engine that prevents the risk of flashover and allows smooth operation of the internal combustion engine.

[Brief explanation of drawings]

FIG. 1 is a top view of a distributor used in an ignition system for a multi-cylinder internal combustion engine as an embodiment of the present invention;
1 is a partial sectional view of the distributor shown in FIG. 1, FIG. 3 is a sectional view taken along line m-m of the distributor shown in FIG. 2, and FIG. FIG. 5, a circuit diagram of the ignition device, is a waveform diagram showing voltage waveforms in the circuit of FIG. 4. 1: Distributor assembly, 102: Distributor cap, 101: Distributor body, 2: Center electrode, 3, 4, 5, 6, 7, 8: Side electrodes.
9: Rotor, 10, 11: Brush, 12: Center metal fitting,
13: Arm, 14: Diode, 15: Arm, 16
:dent, 17: diode, 18: carbon brush, 1
9a, 19b, 19c: screw, 20: battery, 21:
Key switch, 22: Play force contact, 23: Resistance, 24
: Transistor, 25: Resistor, 26: Flip-flop circuit, 27, 28: AND gate, 29: Magnet detector, 30: Shaping circuit, 31: Resistor, 32, 33: Power transistor, 34: Ignition coil, 35, 36: Diode, 37: Spark plug. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. A high voltage whose phase is inverted every time is supplied to the center electrode 2 of the distributor cap, and the rotor 9, which is directly electrically connected to the center electrode 2, has two pitches, large and small. It includes two brushes 10 and 11 each facing two groups of side electrodes provided on the distributor cap in a circle,
The two brushes 10 and 11 are connected to the center electrode by arms 13 and 15 enclosed in an insulator through diodes 14 and 17 of different polarity, respectively, and are connected to at least the side electrodes of the large pitch circle. The arm on the opposing Bratz side is enclosed in an insulator and extends outward in the radial direction of the rotor, and is further enclosed in an insulator and extends upward in the axial direction of the rotor in the opposite direction to the distributor body. An ignition device for a multi-cylinder internal combustion engine, characterized in that the brush is exposed on the side electrode side of the insulator. 2 The base of the rotor 9 is a thick disc-shaped insulator, and is provided with a concentric ring-shaped recess 16 that opens toward the side electrodes, and an arm for the brush 11 facing the side electrode group of the large pitch circle. A brush 15 is sealed in the bottom of the insulator of the rotor 9 and extends outward in the radial direction of the rotor, and is further sealed in the outer peripheral wall of the rotor 9 and extends toward the side electrodes, and is exposed from the upper part of the outer peripheral wall to extend the brush 11. An arm 1 for the brush 10 is formed and faces the side electrode group of the small pitch circle.
3 is sealed in the bottom of the insulator of the rotor 9, extends outward in the radial direction of the rotor, and is further exposed in the recess 16 to form the brush 1.
Claim 1 characterized in that it forms 0.
An ignition system for a multi-cylinder internal combustion engine as described in 2.