JPH0128305Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to an ignition signal detection device for a multi-cylinder engine that extracts and detects an ignition signal for fuel injection from an ignition device provided in the multi-cylinder engine. be.

(Prior Art) Generally, an electronic fuel injection device or an engine tachometer of an engine is configured to perform a predetermined operation based on an ignition signal from an ignition device of the engine. For example, in the case of an electronic fuel injection system for a four-cylinder engine, as shown in FIG. In addition to providing a quantity detection circuit e, the detection circuit e
output and the crankshaft of engine a (not shown)
An injection pulse generation circuit f is provided which generates an injection pulse corresponding to the amount of fuel supplied per rotation based on the ignition signal from the ignition device X that is output four times during two rotations. Fuel corresponding to the amount of intake air is injected by injection pulses from fuel injection valves _g1 to _g4 disposed downstream of the throttle valve c in the intake passage b in response to an ignition signal.

As shown in FIG. 2, the ignition device X has a power transistor i for primary current intermittent control connected to the primary winding _h1 of the ignition coil h, and
Four spark plugs _k1 to _k4 are connected to the next winding _h2 via a distributor j, and the crank rotation is detected by a pick-up 1 that detects the rotation of the crankshaft (not shown) of the engine a. A pulse signal having one period with an angle of 180° is generated, and this pulse signal is outputted to the power transistor i at a predetermined timing by the ignition timing adjustment circuit m, so that the transistor i is connected to the crankshaft (not shown). The spark plugs are turned ON and OFF four times during the two rotations of step (1), and the spark plugs _k1 to _k4 sequentially start discharging through the power distribution of the distributor j. As the ignition signal, a collector voltage (primary induced voltage due to primary current interruption) signal of the power transistor i is taken out and output to the injection pulse generation circuit f. Note that n is an air cleaner.

Incidentally, in recent years, so-called electronic power distribution type ignition devices using diodes have been adopted in place of the so-called mechanical power distribution type ignition devices using the distributor j as described above. This device connects two power transistors for primary current intermittent control to both ends of the primary winding of the ignition coil, and connects the same number of spark plugs as the number of engine cylinders to the secondary winding via diodes. By making each of the above power transistors shift from ON operation to OFF operation with a phase difference of the engine crank angle (for example, 180 degrees in a 4-cylinder engine), one period is 360 degrees of the engine crank rotation angle. , the corresponding predetermined spark plugs are discharged to sequentially ignite each cylinder during two revolutions of the crankshaft.
(See Publication No. 20759, etc.)

(Problem to be solved by the invention) However, in the case of a four-cylinder engine, for example, with a conventional mechanical power distribution type ignition system, the ignition signal is output four times during two revolutions of the crankshaft. On the other hand, in the case of the electronic power distribution type ignition system mentioned above, the ignition signal from each power transistor is output only twice, half of the time, during two revolutions of the crankshaft. When adopting this, various improvements are required in extracting the ignition signal for each cylinder. For example, it is conceivable to provide a device for frequency doubling the ignition signal, but this would have the disadvantage of a complex circuit and high cost.

In view of this, the present invention has been developed by detecting the operating state of each power transistor in parallel in a multi-cylinder engine equipped with an electronic power distribution type ignition device as described above. It is an object of the present invention to make it possible to detect an ignition signal corresponding to the number of cylinders during rotation, thereby easily detecting an ignition signal for each cylinder.

(Means for solving the problem) In order to achieve the object, the present invention includes an ignition coil, two power transistors for primary current intermittent control connected to the primary side of the ignition coil,
An ignition device comprising a plurality of spark plugs connected to the secondary side of the ignition coil via diodes, and discharges a predetermined spark plug when each of the power transistors transitions from ON operation to OFF operation. In a multi-cylinder engine equipped with a multi-cylinder engine, the collector voltage signal of each of the power transistors is taken out and detected through an OR circuit, and the detected signal is supplied to the fuel supply amount control means. It is designed to detect the ignition signal of the

In addition, in the present invention, as described above, the collector voltage signal of each power transistor is taken out and detected through the OR circuit, but the detection of this ignition signal is also performed by detecting the base voltage signal of each power transistor. It is also possible to detect the secondary induced voltage signal of the ignition coil. however,
In the former case, the signal voltage is low, so the S/N ratio is poor, and there is a strong possibility of malfunction due to external noise, while in the latter case, the insulation of the spark plug is required to obtain a good ignition condition. However, with the above configuration, a predetermined voltage value can be obtained and an ignition signal for each cylinder with high noise resistance can be detected.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 shows an embodiment in which an ignition signal is extracted and detected from an ignition device as a rotational speed signal to an electronic fuel injection device of an engine, and 1 is a cylinder 4 having first to fourth cylinders 1a to 1d. cylinder engine, 2
3 is an intake passage, 3 is a throttle valve disposed in the intake passage 2, and 4a to 4d are branch passages 2a to 2 to each cylinder 1a to 1d downstream of the throttle valve 3 in the intake passage 2.
d is the first to fourth fuel injection valves arranged, 5 is an air flow meter arranged upstream of the throttle valve 3 in the intake passage 2, and 6 is an intake air amount whose intake air amount is detected by the air flow meter 5. A detection circuit 7 injects fuel corresponding to the amount of fuel supplied per revolution according to the amount of intake air based on the output from the detection circuit 6 and the ignition signal output four times during two revolutions of the crankshaft. This is an injection pulse generation circuit that generates a pulse, and as described above, fuel injection is configured to inject fuel according to the amount of intake air from each fuel injection valve 4a to 4d based on the injection pulse from the pulse generation circuit 7. This constitutes device A.

Further, 8 is an ignition coil, and the ignition coil 8 has a primary winding 8b divided into two by an intermediate terminal 8a connected to a power source (not shown) of voltage Vb,
A secondary winding 8c is provided at each end of the primary winding 8b.
Two power transistors 9a, 9b are connected at their collector terminals, and both transistors 9a, 9b are connected at their collector terminals.
The emitter terminals of b are each grounded.
On the other hand, at both ends of the secondary winding 8c of the ignition coil 8, first to fourth spark plugs 11a to 11a are respectively disposed in each cylinder 1a to 1d of the engine 1 via high voltage diodes 10a to 10d. 11d is connected. As described above, when the first power transistor 9a shifts from ON operation to OFF operation, this OFF operation interrupts the primary current and causes the secondary winding 8c of the ignition coil 8 to move in the direction of the arrow shown by the solid line in the figure. A high voltage is induced in the first and fourth
While the spark plugs 10a and 10d start discharging at the same time, the second power transistor 9b is turned on.
When transitioning from operation to OFF operation, a high voltage is similarly generated in the secondary winding 8c of the ignition coil 8 in the direction of the arrow shown by the broken line in the figure, and the second and third spark plugs 11b and 11c discharge simultaneously. An electronic power distribution type ignition device 12 is configured to start the ignition system.

Reference numerals 13 and 14 are first and second pickups for detecting the rotation of the crankshaft (not shown) of the engine 1, respectively.
The second pickup 14 generates a pulse signal corresponding to the second and third cylinders 1a and 1d of the engine 1, with one cycle being one revolution of the crankshaft (not shown). Corresponding to the cylinders 1b and 1c, the phase is different from that of the first pickup 13.
It generates pulse signals that differ by 180°. Furthermore, 15 is an ignition timing adjustment circuit that receives the outputs of the pickups 13 and 14, and the adjustment circuit 15 adjusts each pulse signal of the pickups 13 and 14 to the optimum ignition timing that has been measured and corrected each time. Accordingly, each power transistor OFF operation signal is converted into a power transistor OFF operation signal, and each power transistor OFF operation signal is transmitted to the power transistor 9a, 9b.
It is output as a base voltage. Therefore, the first power transistor 9a is switched from ON to OFF based on the output of the first pickup 13.
When the engine is activated, among the discharge ignition at the first and fourth spark plugs 11a and 11d, if the crank rotation angle is 180 degrees, the first spark plug 1
The air-fuel mixture in the first cylinder 1a is ignited and exploded by the discharge ignition of the spark plug 1a, and when the crank angle is 540 degrees, the air-fuel mixture in the fourth cylinder 1d is ignited and exploded by the discharge ignition of the fourth spark plug 11d. Second
When the second power transistor 9b is shifted from ON operation to OFF operation based on the output of the pickup 14, the second and third spark plugs 11
Of the discharge ignition at b and 11c, the crank angle is
When the crank angle is 360 degrees, the air-fuel mixture in the third cylinder 1c is ignited by discharge from the third spark plug 11c, and when the crank angle is 720 degrees, the mixture in the second cylinder 1b is ignited by discharge from the second spark plug 11b. It is configured to ignite and explode each air-fuel mixture.

And each of the power transistors 9a, 9b
A diode 1 is connected to each collector terminal of
6, 17 and two signal detection paths 2 interposed with resistors 18, 19 for protecting the diodes 16, 17.
One end of an OR circuit 20 consisting of 0a and 20b is connected, and the other end of the OR circuit 20 is collectively connected to the injection pulse generation circuit 7 of the fuel injection device A. Therefore, the OR circuit 20 extracts and adds the collector voltage signals of the respective power transistors 9a and 9b in parallel, detects it as an ignition signal, and outputs this ignition signal to the injection pulse generation circuit 7 as a rotation speed signal. It is composed of still,
21 is an air cleaner.

Next, to explain the operation of the above embodiment,
When the crank rotation angle reaches 180 degrees due to rotation of the crankshaft (not shown) of the engine 1, the first power transistor 9a shifts from ON operation to OFF operation, and as a result, the first and fourth spark plugs 1
Although discharge ignition is started at 1a and 11d,
Among them, the first spark plug 11a ignites the first spark plug 11a.
Ignition and explosion occur only within the cylinder 1a. At the same time, the collector voltage (primary induced voltage of 200 to 300 V due to primary current interruption) signal of the first power transistor 9a is taken out and detected as an ignition signal via the signal detection path 20a of the OR circuit 20. Similarly, when the crank rotation angle reaches 360 degrees, the second power transistor 9b shifts from ON operation to OFF operation, and as a result, the second and third spark plugs 11
Discharge ignition is started at points b and 11c, and the third cylinder 1 is ignited by the ignition of the third spark plug 11c.
The ignition explosion takes place only within c. At the same time, the collector voltage (primary induced voltage) signal of the second power transistor 9b is taken out and detected as an ignition signal via the signal detection path 20b of the OR circuit 20. Thereafter, each time the crank rotation angle increases by 180 degrees, the first and second power transistors 9a and 9b alternately shift from ON operation to OFF operation, and the ignition explosion changes from the 4th cylinder 1d to the 2nd cylinder 1b to the 1st cylinder. Cylinder 1a
→This is carried out in the order of the third cylinder 1c, and the collector voltage (primary induced voltage) signals of the respective power transistors 9a and 9b are taken out and detected in parallel as an ignition signal via the OR circuit 20, which is repeated. . As a result, the number of ignition signals detected via the OR circuit 20 is increased for each cylinder 1a to 1.
d, there are four during two revolutions of the crankshaft (not shown).

Therefore, the OR circuit 2 is connected to the electronic power distribution type ignition device 12.
0 can be easily applied to the fuel injection control device A corresponding to the mechanical power distribution type ignition device.
The versatility of 2 can be easily and inexpensively increased. Furthermore, since the ignition signal is extracted using the collector voltage signals of the power transistors 9a and 9b, a predetermined voltage value can be obtained, and an ignition signal for each cylinder with high noise resistance can be detected.

In addition, in the above embodiment, the case where it was applied to a four-cylinder engine equipped with an electronic power distribution type ignition system was explained, but it can also be applied to a multi-cylinder engine with a plurality of cylinders. Of course.

(Effect of the invention) As explained above, according to the invention, in a multi-cylinder engine equipped with an electronic power distribution type ignition device, the collector voltage signals of two power transistors for primary current control are connected to an OR circuit. By detecting the fuel taken out through the fuel tank and supplying the detected signal to the fuel supply amount control means,
Since the ignition signal for each cylinder can be easily detected as a signal with high noise resistance, this greatly contributes to improving the versatility of the electronic power distribution type ignition system and improving the fuel control accuracy.

[Brief explanation of the drawing]

FIG. 1 is an overall schematic diagram showing an embodiment of the present invention, and FIG. 2 is an overall schematic diagram showing a conventional example. 1...Engine, 1a-1d...Cylinder, 8...
Ignition coil, 8b...Primary winding, 8c...Secondary winding, 9a, 9b...Power transistor, 10a
~10d...Diode, 11a-11d...Spark plug, 12...Electronic power distribution type ignition device, 20
...OR circuit.

Claims (1)

[Scope of utility model registration request] an ignition coil, two power transistors for primary current intermittent control connected to both ends of a primary winding of the ignition coil, and a plurality of ignitions connected to a secondary winding of the ignition coil via diodes. In a multi-cylinder engine equipped with an ignition device that discharges a predetermined spark plug when each of the power transistors transitions from ON operation to OFF operation, the collector voltage signal of each of the power transistors is connected to an OR circuit. 1. An ignition signal detection device for a multi-cylinder engine, characterized in that the ignition signal detection device for a multi-cylinder engine is configured to extract and detect the signal via the fuel supply amount control means and to supply the detected signal to fuel supply amount control means.