JPH0249969A - Electronically controlled advance timing device for multicylinder internal combustion engine - Google Patents

Abstract

PURPOSE:To contrive the smallness of a memory capacity with overlapping eliminated of a preset data by individually setting an ignition timing setting amount in common to all the cylinders and one used only for the specific cylinder, of the ignition timing setting amounts corresponding to a change of an engine operative condition. CONSTITUTION:An electronically controlled timing control device 30, in order to control each ignition timing in many cylinders, applies primary voltage respectively to many ignition coils 31 being based on each detection signal from a throttle valve opening sensor 18, crank angle sensor 24 and many pulser coils P1 to P6. Here the basic ignition timing for all the cylinders is set in accordance with a change of an engine operative condition by a section 32, while an advance timing correction amount of the specific cylinder for the basic ignition timing is set by a section 33. In the point of time a crank angle is positioned in the basic ignition timing, a basic ignition signal is output from a section 38. While the basic ignition timing of the specific cylinder is corrected by a section 40 outputting a correction ignition signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronically controlled advance angle device for a multi-cylinder internal combustion engine suitable for use in outboard motors, inboard/outboard motors, and the like.

[Prior Art] Conventionally, the ignition timing of an internal combustion engine is electronically controlled in response to changes in operating conditions such as the rotational speed and throttle valve opening of the internal combustion engine.
An electronically controlled advance device has been proposed that controls the ignition timing to a predetermined optimum ignition timing.

At this time, the conventional electronically controlled advance device records the optimal ignition timing corresponding to changes in the operating state of the engine in the ignition timing setting section using setting data expressed by mathematical formulas, tables, charts, etc. .

[Problem to be solved by the invention] However, in the above-mentioned conventional electronically controlled advance angle device,
The setting data set in the ignition timing setting section is only data for the engine, that is, data that is common to all cylinders even in a multi-cylinder internal combustion engine.

Therefore, the above setting data is determined on the premise that a specific cylinder in a multi-cylinder internal combustion engine can be operated without trouble, such as under severe thermal conditions where it is necessary to avoid piston melting or knocking. The other cylinders will also be subjected to advance angle control based on this data.

This means, for example, that the ignition timing of other cylinders that are not thermally severe cannot be set to an advanced state sufficient for that cylinder to obtain high output, resulting in insufficient output from that cylinder, and as a result, the total engine output means that it is insufficient.

In addition, when setting the optimum ignition timing for each cylinder in the ignition timing setting section, the storage capacity becomes enormous and is not appropriate.

It is an object of the present invention to provide an electronically controlled advance device that can optimize the ignition timing of each cylinder and allow all cylinders to output sufficient output without increasing the storage capacity that the ignition timing setting section should have. purpose.

[Means for Solving the Problems] The electronically controlled advance timing device for a multi-cylinder internal combustion engine according to the present invention has a basic ignition timing setting that determines a common basic ignition timing for all cylinders in response to changes in the operating state of the engine. a correction advance angle setting section that determines an advance angle correction amount for a specific cylinder with respect to the basic ignition timing in response to changes in the engine operating state; an engine operating state detection means that detects the engine operating state; and a crankshaft. While obtaining the detection results of the crank angle detection means for detecting the angular position of the engine operating state detection means and the detection results of the crank angle detection means, using the setting data of the basic ignition timing setting section,
an ignition timing main control section that outputs a basic ignition signal when the angular position of the crankshaft is at the basic ignition timing of each cylinder;
Obtaining the detection result of the engine operating state detection means and the detection result of the crank angle detection means, and using the setting data of the correction advance angle setting section, correct the basic ignition timing of the specific cylinder determined by the ignition timing main control section, The ignition timing correction control section outputs a corrected ignition signal.

[Function] According to the present invention, (1) the ignition timing of multiple cylinders is controlled by the basic data of the basic ignition timing setting section, and (2) a difference in the ignition timing setting amount between the cylinders and other cylinders due to severe thermal conditions is provided. For the specific cylinder that should be used, the basic ignition timing determined in (2) above is corrected using the setting data (advance correction amount) of the correction advance setting section. At this time, it is sufficient for the correction advance angle setting section to store the advance angle correction amount corresponding to the change in the operating state only for the range of required operating states in which the above-mentioned correction (2) is to be performed for the specific cylinder.

That is, according to the present invention, (1) the ignition timing setting amount common to all cylinders corresponding to changes in the operating state of the engine is set in the basic ignition timing setting section using unique data; Regarding the ignition timing setting amount that is different from that of other cylinders in the range of operating conditions, this is set in the correction advance angle setting section as the advance angle correction amount for the specific cylinder.

Therefore, there is no duplication of setting data in the basic ignition timing setting section and the corrected advance angle setting section, and the storage capacity that they should have is not unnecessarily increased. Further, the ignition timing of all cylinders can be optimized by the above-mentioned methods (1) and (2), and as a result, an ignition state in which all cylinders can produce sufficient output can be realized.

[Embodiment FIG. 1 is a block diagram showing an electronically controlled advance angle device of the present invention,
FIG. 2 is a sectional view of essential parts of an example of an internal combustion engine to which the present invention is applied.

The internal combustion engine 10 is an example of a V-type 4-cylinder two-stroke internal combustion engine for outboard motors, and in FIG. 2, 11 is a crankshaft;
2 is a flywheel magneto, 13 is a spark plug, 14
is a carburetor, and 15 is an intake box.

In the internal combustion engine 10, the throttle valve 17 of the carburetor 14 can be opened and closed by a link mechanism as shown in the drawing, which is connected to a throttle operation cable 16. 18 is a throttle valve opening sensor.

The internal combustion engine 10 includes a permanent magnet 19 and a power generation coil 20 inside a flywheel magnet 12, as well as six permanent magnets 21, first to sixth, and a balsa coil 22 corresponding to each cylinder. ing. The pulsar coil 22 opposes each permanent magnet 21 once for each rotation of the crankshaft 11, and generates first to sixth balsa signals P1 corresponding to each cylinder.
~ Output P6.

The internal combustion engine 10 includes a ring gear 23 for starting operation that is attached to the flywheel magneto 12 and a crank angle sensor 24 that faces the ring gear 23 . The crank angle sensor 24 outputs an electric pulse corresponding to the meshing teeth of the ring gear 23.

The internal combustion engine 10 is equipped with an electronically controlled advance angle device 30 comprising a microcomputer as shown in FIG. The electronically controlled advance device 30 obtains the outputs of the throttle valve opening sensor 18, pulser coil 22, and crank angle sensor 24, and controls the ignition timing of each of the first to sixth cylinders. Each of the first to sixth ignition coils 3
Apply a primary voltage to 1.

The electronically controlled advance angle device 30 includes a basic ignition timing setting section 32, a correction advance angle setting section 33, a rotation speed calculation section 34, a throttle opening A/D conversion section 35, a cylinder discrimination calculation section 36, a pulse input section 37, The ignition timing main control section 38 includes an ignition timing main control section 38, a basic ignition timing calculation section 39, an ignition timing correction control section 40, and a CDI control section 41 attached thereto.

The basic ignition timing setting section 32 stores a basic map in which the basic ignition timing common to all the first to sixth cylinders is determined in response to changes in engine rotational speed and throttle valve opening (operating state). ing.

The correction advance angle setting unit 33 is configured to set a specific cylinder (for example, the sixth cylinder, which is considered to be thermally severe
It stores inter-cylinder advance angle difference data in which advance angle correction amounts for cylinders are determined in response to changes in engine rotational speed and throttle valve opening (operating state).

The rotation speed calculation section 34 constitutes one of the engine operating state detection means together with the crank angle sensor 24, and calculates the rotation speed of the engine based on the number of output pulses of the crank angle sensor 24 per unit time.

The throttle opening A/D converter 35 constitutes one of the engine operating state detection means together with the throttle valve opening sensor 18, and outputs the throttle valve opening of the engine.

The cylinder discrimination calculation section 36 constitutes a crank angle detection means together with the pulser coil 22 and the crank angle sensor 24. The cylinder discrimination calculation unit 36 uses the output signal of the crank angle sensor 24 as a reference signal for cylinder discrimination when outputting the sixth balsa signal P6 corresponding to, for example, the sixth cylinder determined as the reference cylinder, and the pulser coil 22 subsequently outputs the signal. It is determined which cylinder the balsa signal corresponds to. The first output that the pulsar coil 22 outputs corresponding to each cylinder
~Sixth balsa signals P1 to P6 indicate the cylinder to be ignited this time, and indicate the crank angle position that should be the reference timing for setting the ignition timing in the cylinder.

The pulse human power 37 transfers the balsa signals P1 to P6 output by the pulser coil 22 to the ignition timing main control section 38.

The basic ignition timing calculation unit 39 obtains the outputs of the rotational speed calculation unit 34 and the throttle opening A/D conversion unit 35, and also uses the setting data of the basic ignition timing setting unit 32 to optimize the current engine operating state. Calculate the basic ignition timing,
This is transferred to the fire timing main control section 38. The ignition timing main control section 38 receives the balsa signal P1 from the pulse input section 37.
~P6, the calculation result of the calculation unit 39 is obtained, and a basic ignition signal is output when the angular position of the crankshaft 11 is at the basic ignition timing of each cylinder.

The ignition timing correction control section 40 controls the ignition timing main control section 38.
At the same time, the outputs of the rotational speed calculation section 34, the throttle opening A/D conversion section 35, and the cylinder discrimination calculation section 36 are obtained. Further, the ignition timing correction control section 40 uses the setting data of the correction advance angle setting section 33 to determine whether or not the cylinder to be ignited this time is the above-mentioned specific cylinder. The basic ignition timing of the specific cylinder determined by the timing main control section 38 is corrected, and a corrected ignition signal is output.

The CDI control section 41 obtains the output of the power generation coil 2o, and also obtains the outputs of the ignition timing main control section 38 and the ignition timing correction control section 40, and controls the ignition coil 31 corresponding to each cylinder to adjust the output to the appropriate value for each cylinder. Apply the primary voltage at the correct ignition timing.

Next, the operation of the above embodiment will be explained.

According to the above embodiment, (1) the ignition timing of the cylinder is controlled by the basic data of the basic ignition timing setting section 32;
■For example, for a specific cylinder that is thermally severe and requires a difference in ignition timing setting amount from other cylinders, the basic ignition timing determined in step ) will be corrected. At this time, it is sufficient for the correction advance angle setting unit 33 to store the advance angle correction amount corresponding to the change in the operating state only for the range of required operating states in which the above-mentioned correction (2) is to be performed for the specific cylinder.

That is, according to the above embodiment, (1) the ignition timing setting amount common to all cylinders corresponding to changes in the operating state of the engine is set in the basic ignition timing setting section 32 using unique data;
Regarding the ignition timing setting amount that is different for a specific cylinder from that of other cylinders within a certain operating state range, this is set in the correction advance angle setting section 33 as an advance angle correction amount for the specific cylinder.

Therefore, there is no duplication in the setting data of the basic ignition timing setting section 32 and the corrected advance angle setting section 33, and the storage capacity they should have is not unnecessarily increased. Further, the ignition timing of all cylinders can be optimized by the above-mentioned methods (1) and (2), and as a result, an ignition state in which all cylinders can produce sufficient output can be realized.

[Effects of the Invention] As described above, according to the present invention, the ignition timing of each cylinder can be optimized without increasing the storage capacity that the ignition timing setting section should have, and the golden cylinder can output sufficient output. It is possible to construct an electronically controlled advance angle device that obtains the following results.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an electronically controlled advance angle device of the present invention, and FIG. 2 is a sectional view of essential parts of an example of an internal combustion engine to which the present invention is applied. DESCRIPTION OF SYMBOLS 10... Internal combustion engine, 11... Crankshaft, 18... Throttle valve opening sensor, 22... Balsa coil, 24... Crank angle sensor, 30... Electronically controlled advance angle device, 32 ...Basic ignition timing setting section, 33...Correction advance setting section, 34...Rotational speed calculation section, 35...A/D conversion section for throttle opening, 36...
Cylinder discrimination calculation section, 38... Ignition timing main control section, 39... Basic ignition timing calculation section, 40... Ignition timing correction control section.

Claims (1)

[Claims] (1) A basic ignition timing setting section that determines the basic ignition timing common to all cylinders in response to changes in engine operating conditions, and a basic ignition timing setting section that sets advance angle correction amounts for specific cylinders relative to the basic ignition timing in response to changes in engine operating conditions. A correspondingly defined correction advance angle setting section, an engine operating state detecting means for detecting the operating state of the engine, a crank angle detecting means for detecting the angular position of the crankshaft, a detection result of the engine operating state detecting means and the crank. An ignition timing main control section that obtains the detection result of the angle detection means and uses the setting data of the basic ignition timing setting section to output a basic ignition signal when the angular position of the crankshaft is at the basic ignition timing of each cylinder. Then, in addition to obtaining the detection results of the engine operating state detection means and the crank angle detection means, the basic ignition timing of the specific cylinder determined by the ignition timing main control section is corrected using the setting data of the correction advance angle setting section. and an ignition timing correction control section that outputs a corrected ignition signal.