JPS59138772A - Ignitor for internal-combustion engine - Google Patents

Abstract

PURPOSE:To provide an ignitor with low cost and in small size, which does not require to use any distributor, by incorporating a single winding construction, in which the direction of primary current to a single primary coil is switched over alternately to cause generation of bi-directional high voltage on the secondary side. CONSTITUTION:The primary coil 2 of an ignition coil 1 is in single winding construction, and a micro-computer 20 calculates the optimum ignition timing and dwell angle. An ignition control signal actuates transistors 33, 26, and when these are deactuated, a high voltage with opposite polarity is impressed on ignition plug 10, 14. Then another ignition control signal actuates transistors 32, 27, and when they are deactuated, a high voltage is impressed on ignition plugs 15, 11. Therby the primary coil can be made in single winding construction, that ensures to manufacture the devices with low cost and in small size.

Description

DETAILED DESCRIPTION OF THE INVENTION 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.

An ignition system for an internal combustion engine generates sparks by applying high voltage to the spark plugs installed at the top of each cylinder in synchronization with the rotation of the crankshaft.11 These sparks start combustion in the cylinders during the compression stroke. It ignites the gas. In this case, conventionally commonly used internal combustion Il
A high voltage is generated in the secondary coil by cutting off the current flowing through the primary coil of the ignition coil at the optimum ignition point, and this high voltage is then dissipated.

However, in the device with the above configuration, the contactor 1 for intermittent the primary current of the ignition coil is
- Sparks are generated at the point and the distributor that distributes high voltage, and the sparks generate noise, which causes various disturbances to televisions, radios, and electronic control circuits. Furthermore, the generation of sparks in this way causes problems such as a relatively large power loss occurring in that part.

In contrast, in recent years, this problem has been solved by replacing the =l contact point with a switching transistor. For distributors, this problem is solved by using a distributor-less ignition system.

FIG. 1 is a circuit diagram showing a conventional example of an ignition system for an internal combustion engine based on an ice triputer-less system.

In the same figure, 1 is an ignition coil (consisting of primary coils 2a, 2b and a secondary coil 3).
2b are connected in series, and their connection point is drawn out as a midpoint to connect to the power source -1v.

4.5 is a semiconductor switch connected between each other end of the primary coils 2a, 2b and ground, and is alternately opened at the optimum ignition point. 6.7 and 8.9 are series bodies of a resistor and a capacitor, and are connected in parallel to the semiconductor switch 4.1). to and ii are spark plugs connected to one end of the secondary coil 3 constituting the ignition coil 1 through diodes 12 and 13 having opposite directions, respectively, and the spark plug 10
．． 11 is installed in the first and third cylinders in a four-cylinder internal combustion engine, in which the pistons operate 180 degrees apart from each other. 14.15 are diodes 16 that are oriented in opposite directions.
The second cylinder, which is a spark plug connected to the other end of the secondary coil 3 through the angle 17, operates at a 180° offset from each other. ! 'It is installed in 14 cylinders.

In the ignition device configured as described above, after the semiconductor switch 4.5 is turned on at a predetermined dwell angle as the crankshaft rotates, the first. 3rd and 2nd
．． They are turned off at the optimum ignition time for the fourth cylinder J'. In this case, when the semi-isolated switch 4 is turned off, the primary current is cut off in the primary coil 2a of the ignition coil 1, and a high voltage is generated in the secondary coil 3. This high voltage is applied to diodes 12, 13. The shed flowing through IL 17 is selected as it flows through the light path shown by the solid line at tll. This F! N, spark plug 1 (1, 14
This JJ will only cause sparks to be selectively generated in the opposite direction! 4-cylinder internal combustion II! If you are on A3 in the open,
The first GJ where the plugs 10 and 14 are installed. Although the pistons of the second cylinder are moving at the same time, the stroke of the 4-cycle operation is a reverse stroke. In other words, when the first cylinder is in the contraction stroke, the second cylinder is in the exhaust stroke. Therefore, even if sparks are generated at the spark plugs 10 and 14 simultaneously, only one Only the cylinder located on one compression stroke will be ignited.Next, when the crankshaft rotates 180' When the semiconductor switch 5 is turned off, the 1 of the ignition coil 1
Since the direction of the current flowing through the secondary coil 21 is opposite to the direction of the current flowing through the primary coil 2a, the polarity of the high voltage generated in the secondary coil 3 is also opposite. As a result, as shown by the dotted line, a high voltage current flows through the two spark plugs 13 and 15, which are different from the case described above, and sparks are generated in both plugs in opposite directions. Even if the spark plugs 13. and 15 are installed in the 3rd and 4th cylinders,
Since only one of them is the compression stroke,
Ignition occurs and the internal combustion engine continues to rotate.

Here, the polarity of the high voltage generated in the secondary coil 3 is determined by the direction of the winding of the primary coil, etc., but in any case, it is as shown by the solid line and dotted line in Figure 1. The polarity changes at intersection 77.

In the ignition device configured as described above, a primary current in opposite directions is alternately passed through the two primary coils 2a and 2b, thereby generating high voltage in two directions in the forward and reverse directions in the secondary coil. Since the spark plug, which is polarized by a diode, is divided into two wires ( ) to generate sparks alternately, there is no need for a distributor to distribute the +1%i voltage to each plug. Accordingly, generation of sparks is prevented, thereby preventing power loss and adverse effects on various devices.

However, in the above configuration, since the primary coil of the ignition coil has a two-winding structure, it is large and expensive, and magnetic force cancellation and leakage occur when the primary voltage is generated, reducing the high voltage generation efficiency. Decrease - have the problem right.

In addition, as a prior art of the one shown in Fig. 1, for example,
There is Utility Model Application Publication No. 55-135161.

This invention was made to eliminate the above-mentioned problem, and alternately switches the primary current direction for one primary coil, so that the secondary side receives electricity in two directions: forward and reverse. It is something that is generated.

Hereinafter, the ignition device for an internal combustion engine according to the present invention will be explained in detail using the drawings.

FIG. 2 is a circuit diagram of an embodiment of the ignition system for an internal combustion engine according to the present invention, and the same parts in the figures rat' and m1 are indicated using the same symbols and months. In the figure, reference numeral +5 and 2 indicate the primary coil of the ignition-1 coil 1, which has a single-winding structure. 18 is a multiplexer that takes in various analog signals necessary for ignition timing control, such as the intake pipe negative pressure signal Δ and water temperature signal B, in a time-division manner; 19 is a multiplexer that converts the output signal of this multiplexer 1a into a digital value; A digital converter 20 is a microphone converter for controlling ignition timing, and a crank position signal C, a crank angle signal supplied from a crank (not shown), a crank angle sensor, and a crank angle sensor. 41 No. 1) and af1 cog/f
Digital number E output from digital converter 19
Input interface circuit 21. Microprocessor 4) (CPU) 22. Read-only memory ((
riMO)23. Random address memory (RAM) 24
and an output interface circuit 2 (i). 26 and 27 are connected in parallel between the power supply V and the ground, and are supplied from the microphone 1 combination 20 through resistors 28 and 29. Ignition control n signal F11°F 2
A transistor that is turned on by 1, and both 1-
A connection point between the transistors 2G and 27 is connected to one end of the primary coil 2. ff30.31 is transistor 26
, 27 and its transistor 26°27
Transistor protection diodes 32 and 33 are connected in a direction opposite to the polarity of the transistor, and are connected in one row between the power source and ground, and are supplied from the microcomputer 20 through resistors 34 and 35. Ignition control signal 8Fx
, 36.37 is a 1-transistor that is turned on by F+a, and the connection point of both transistors 32 and 33 is connected to the other end of the primary coil 2.
．． This is a diode that protects 33.

In the ignition system configured in this way, the microcomputer 20 outputs a crank position signal C, a crank angle signal, an intake pipe negative pressure signal B, and a water temperature signal B, which are expressed as time-division digital values. 'Igital death jU
The optimal ignition timing and dwell angle are determined by executing various mathematical processes that incorporate It's on. Next, the ignition control signal
F: Time T1 for , , C] After a delay, the ignition control signal F11 shown in FIG. 3 is generated from the microcombicoater 20, and the transistor 2G is turned on. In this case, since the ignition control signal FIlIF+2 has the same width, 713
This becomes the opening through which the current flows in the direction shown by arrow G to the primary winding 2 of the ignition-1 coil 1, and this time 1-1 becomes the dwell angle. Then, when the previously generated ignition control signal "is turned off at the injury time t1,
The current in the secondary coil 3 is cut off, a high voltage is generated in the secondary coil 3, and the spark plug 10.14 is connected to the J shown in FIG.
High voltages of opposite polarity are applied to generate a spark discharge.

Next, time point 1. ．． 1. As shown in FIGS. 3e and 3f, the ignition control signal F21 is sent from the microcombi coater 20.
．． When F22 is generated, the transistors 32 and 27 are turned on, and a current flows in the primary coil 2 in the opposite direction to the arrow G. Then, at time t4, the ignition control signal F
When 21 is turned off, the 1-transistor 32 is turned off and the primary current is cut off. As a result, a high voltage having a polarity opposite to that in the case described above is generated in the secondary = 1 ile 3, and is applied to the ignition plug 15.degree. 11, generating a spark.

In this case, the high voltages applied to the spark plugs 15.11 have opposite polarities, as shown in FIGS. 9 and 11.

In this case, if the transistor on the ground side is controlled to become A earlier than the transistor on the power supply side, the primary coil current will be energized by the switching time of transistors 1 to 2G and 32 on the power supply side. Delays are prevented. This is because the current flowing through the coil is blocked due to the principle of self-induction, making it easier to conduct electricity. However, the same effect can be obtained by 1!7 even if the 1- transistor on the power supply side is turned off earlier than the 1- transistor on the ground side.

As explained above, according to the ignition system for an internal combustion engine according to the present invention, a distributor-less ignition control system can be constructed using one primary ignition coil. Along with this, when two primary coils are used, there is an excellent effect of reducing the efficiency of J3G and reducing the cost and size of the ignition coil.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a circuit diagram showing an example of a conventional distributor-less ignition system, and Fig. 2 is a circuit diagram showing an embodiment of an ignition system for an internal combustion engine according to the present invention. Figure 3 a-h
FIG. 2 is an operational waveform diagram of each part of the circuit. 1...Ignition coil, 2...Primary coil,
3...2nd order = 1 il, 10.11.14.15...
Spark plug, 12, 13.16.17...Diode, 2G, 27.32.33...Transistor, 2
8.29.34.35...Resistance, 30.31°36,
37...Diode. Characteristics Applicant: Fuji Heavy Industries 1. Nobuyuki Kobashi, Patent Attorney, Agent for Gyo Co., Ltd.

Claims (1)

[Claims] An ignition coil, each having one primary coil and one secondary coil, and a first coil connected in series between a power source and ground, the connection point of which is connected to one end of the primary coil. a second transistor, and a third transistor connected in series between the power supply and ground, the connection point of which is connected to the other end of the primary coil. a fourth transistor, and a first... A third spark plug connected between the second spark plug and the other end of the secondary coil and ground via diodes having opposite polarities. An ignition device for an internal combustion engine, comprising: a fourth spark plug, and generating eight voltages in two directions, forward and reverse, in a secondary coil of an ignition coil by controlling the first to fourth transistors.