JPS5937268A - Electronic controlled ignition advancing device of internal-combustion engine - Google Patents

Abstract

PURPOSE:To ignite at the optimum ignition timing by a method wherein the optimum ignition timing is obtained by an ignition timing setting device in accordance with the speed and the amount of suction air of the engine. CONSTITUTION:The engine speed is detected by a pulser coil 32. The opening degree of a throttle valve or the amount of suction air is detected by a throttle opening degree detector 46. The ignition timing setting device 51 reads out the optimum ignition timing in accordance with the speed and the amount of suction air of the engine from a map. An abnormal combustion detector 49 delays the ignition timing by sending a signal to the ignition timing setting device 51 when the knocking of the engine is detected. Obtained optimum ignition timing is compared with a crank angle, obtained by the pulser coil 32, a crank rotating angle signal generator 36 and a crank angle detector 52, and an ignition signal is outputted when they are coinciding with each other. According to this method, the optimum ignition timing without generating knocking may be obtained for the ignition of the engine.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronically controlled advance angle device for an internal combustion engine suitable for use in outboard motor engines and the like.

In conventional internal combustion engines, a support stand that supports the ignition signal generator is rotatably attached to the engine body, and the ignition timing is changed by rotating the support stand in conjunction with a throttle operating mechanism. ing. Here, the maximum ignition advance angle is set below an angle that does not cause abnormal combustion in the maximum torque rotational speed range of the engine. That is, up to a predetermined opening of the throttle valve, the ignition timing is advanced to the maximum advance angle corresponding to the opening, and above the predetermined opening, the ignition timing is held constant.

However, the engine's advancing angle in the throttle valve partial opening range, which is the economic fuel consumption speed range in actual operation, is extremely extreme compared to the angle that does not cause abnormal combustion in the maximum torque rotation speed range. It is on the advance side. Furthermore, even when the throttle valve is fully open, in a rotational speed range outside the maximum torque rotational speed range, the possibility of abnormal combustion occurring is small, and the engine can advance up to the required advance angle of the engine.

In other words, with conventional mechanical advance devices, it is necessary to advance the ignition timing to the optimum ignition timing required by the engine in a rotation speed range outside of the economical fuel efficiency speed range and the maximum torque rotation speed range in a high load range. has become incapacitated.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electronically controlled advance angle device that enables ignition at the optimum timing for all load conditions and rotational speed conditions of an engine, thereby improving fuel efficiency and output.

In order to achieve the above object, an electronically controlled advance angle device for an internal combustion engine according to the present invention includes an engine speed detector that detects engine speed, an intake air amount detector that detects intake air amount, and an engine speed and intake air amount detector that detects engine speed. The optimum ignition timing for each combination of air amounts is determined in advance, and an ignition timing setter that sets the optimum ignition timing corresponding to the detection results of an engine speed detector and an intake air amount detector, and a crank angle position can be detected. It consists of a crank angle detector and an ignition signal generator that generates an ignition signal when the crank angle position reaches 61 the optimum ignition timing based on the detection results of the ignition timing setter and the crank angle detector. It is.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 shows an example of a V-type 4-cylinder two-stroke internal combustion engine for an outboard motor to which the present invention is applied, partially cut away.
Figure 2 shows the internal combustion engine for the outboard motor.
, is a cutaway plan view. A V'' crankshaft 12 is vertically disposed in the engine body 11, and a piston 14, which is accommodated in each horizontally disposed cylinder, is connected to the crankshaft 12 via a connecting rod 13. A V↓ is drawn at the rear of the main body 11 in one row of the machine, and a combustion chamber 15 is drawn in each cylinder. i. The controller 16 is fixed. At the front of the main body 11 of the machine 1 (
is connected to a carburetor 20° intake box 21 that supplies air-fuel mixture to the crank chamber 19 of each cylinder via a reed valve 18 provided in the intake +4i 17 corresponding to each cylinder. In addition, 22 indicates a spark plug, 23 indicates a throttle valve, and a magneto' is located at the upper end of the crankshaft 12.
A boss portion 25 of the L-shaped through rotor 24 is fixed by a half-moon key 26 and a nut 21. A permanent magnet 28 is fixed to the inner surface of the rotor 24.

29 is a power generation coil, and ll1i of the permanent magnet 28
Multiple pieces are arranged in a ring to correspond to the

These power generation coils 29 are fixed to a plurality of legs 30 provided on the engine body 11.

31A, 31B, 31C, 31D (31C,
31D (not shown) is a permanent magnet fixed to the outer peripheral surface of the boss portion 25 of the rotor 24.

Reference numeral 32 denotes a pulser coil, which is fixed to the inner surface of an annular holder 34 that is integrated with a support base 33 supported by the engine body 11. Each permanent magnet 31A to 31D is
Each of them faces the pulsar coil 32 once during one rotation of the crankshaft 12 .

Therefore, as shown in FIG.
For each rotation of the crankshaft 12, one pulse of electric pulse PX is induced for each of the N-1 cylinder and the N cylinder. Further, a ring gear 35 is provided on the outer periphery of the rotor 24 and receives rotational force from a starter (not shown) when the engine is started.
is fixed, and the engine body 1 is fixed to the outer periphery of the ring gear 35.
A crank rotation angle signal generator 36, which is fixedly arranged at 1, is arranged opposite to the crank rotation angle signal generator 36. Crank rotation angle signal generator 36
As shown in FIG. 3, as the crankshaft rotates 120 times, a corresponding electric pulse PY is induced in each meshing tooth of the ring gear 35.

That is, the pulsar coil 32 rotates the crankshaft 120 by the number of cylinders corresponding to each fixed angular position of the crankshaft 12 in one rotation of the crankshaft 12.
Generates a reference angle signal. Therefore, pulsar coil 3
2 functions as a reference angle signal generator for the crankshaft 120, and the angular position of the crankshaft 12 can be detected by counting the number of pulses generated by the crank rotation angle signal generator 36 after the pulse generation point of the Lusa coil 32. In addition, when detecting the angular position of the crankshaft 120, it is assumed that the pulse generated by the Lusa coil 32 (corresponding to the N-1 cylinder) is used as the reference angle signal regarding the crank angular position of the N cylinder. Compared to the case where the pulses generated by the Lunar coil 320 (corresponding to the N cylinder) are used as the reference angle signal, the angles before the pulses generated by the Lunar coil 320 corresponding to the N cylinder can be calculated with a smaller angle difference. Hata: Accurately indexed to 5J performance.

The pulsar coil 32 also functions as an engine speed detector. That is, since the balsa coil 32 generates pulses equal to the number of cylinders per revolution of the crankshaft 12, the rotational speed of the crankshaft 12 can be determined by counting the number of pulses generated by the balsa coil 32 within a unit time. In other words, it becomes possible to detect the engine speed.

Further, an intermediate lever 37 is rotatably supported on the side of the engine body 11, an end of a throttle tire 38 is connected to one end of the intermediate lever 37, and a link 39 is connected to the other end of the intermediate lever 37. A cam lever 40 is connected via. The lower end of the cam lever 40 is rotatably supported by the engine body 11 via a fulcrum 41 . 42 is a lever that rotates together with the throttle valve 23;
2 is provided with a cam follower 43 that comes into contact with the cam lever 40. Throttle valve 23 of each upper and lower carburetor 20
The upper and lower levers 42 facing each other are operatively connected by a link 44. That is, when the middle (16 lever 37 is rotated clockwise in FIG. 1, the link 3
The cam lever 40 also rotates in the same direction via 9fc, and the lever 42 also rotates in the same direction together with the cam follower 43, so that the throttle valves 23 in the upper and lower carburetors 20 are opened in conjunction with each other.

Further, the link 44 is connected to an actuation lever 47 of a potentiometer serving as an intake air # detector and a throttle opening detector 46 via a link 45. That is, the throttle opening degree detector 46 detects the throttle valve 23 which rotates according to the operation solution of the throttle wire 38.
It is possible to detect the opening degree of the throttle valve 23 and, therefore, the amount of intake air into each cylinder. In addition, as an intake air amount detector for detecting the total amount of intake air to each intake, an intake air flow meter, an intake negative pressure needle, a crankcase internal pressure gauge, etc. are used instead of the throttle opening degree detector 46. Furthermore, the cylinder head 1 fixed to the engine body 11
6 is provided with a temperature detector 48 made of, for example, a thermistor type. The temperature detector 48 is capable of detecting the temperature of the engine. Note that the engine cooling water temperature may be used as a means for detecting the engine temperature.Also, the cylinder head 16 is provided with an abnormal combustion detector 49 of a vibration detection type such as a piezoelectric element type or a magnetostrictive type. It is being The abnormal combustion detector 49 detects vibrations occurring in the engine above a certain level, and detects harmful knocking,
It is possible to detect the occurrence of abnormal combustion such as pre-ignition or run-on.The abnormal combustion detector 49 is located in the cylinder head 16 at a position where it can detect the imaging occurring in the engine with the highest sensitivity. In a multi-cylinder engine like the one in this embodiment, it is provided near the cylinder where abnormal combustion is most likely to occur. The abnormal combustion detector 49 detects the propagation of pressure waves to the cylinder head 16 that occur in the combustion chamber when abnormal combustion occurs and is completely different in terms of frequency components and levels from those during normal combustion. It is possible to convert the magnitude of the movement into the magnitude of the voltage and output it. The frequency component of the pressure wave inside the combustion chamber when abnormal combustion occurs is:
Due to the cylinder inner diameter and combustion temperature of the existing engine, the overall strength becomes extremely large compared to normal combustion. Therefore, the method for detecting abnormal combustion may be either a method of looking at the overall vibration level or a method of looking at the level of vibration at a previously known knocking frequency of the engine.

Next, the controller 50 comprising a microcomputer that performs advance angle control in the internal combustion engine will be explained.

The controller 50 is fixed to the engine body 11, and includes an ignition timing setter 51, a crank angle detector 52, and an ignition signal generator 53, as shown in the control system diagram of FIG. All installations are operational. Note that the CDI ignition device rectifies the voltage generated in the power generation coil 29 of the magneto using the diode 54 to start charging the ignition capacitor 55, and then uses the signal current generated by the ignition signal generator 53 to activate the SCR 56. At the same time that the gate becomes conductive, the electric charge stored in the ignition capacitor 55 is strongly applied to the primary side of the ignition coil 57, generating a high voltage on the secondary side of the ignition coil 570, and the ignition plug is activated. 22 is capable of generating electric discharge.

First, the ignition timing setter 51 of the controller 50 records the engine speed N and the throttle valve opening [6] as the intake air amount.
The optimal ignition time 14AOs for each combination of v is the fifth
It is predetermined in the form of a map or function formula shown in the figure. That is, in FIG. 5, region I corresponds to the idle link state of the engine, and the optimum ignition timing is set in consideration of combustion stability. Region (3) corresponds to the speed range before the vessel is planed during actual cruising, and the optimum ignition timing is set to be more retarded than in conventional mechanical advance angles, with emphasis on the feeling of boarding. Region (2) is the region where the best fuel efficiency is achieved during cruising, and the possibility of knocking is low, so the optimal ignition timing is advanced to near the engine's required advance angle.

Region ■ is the maximum torque rotational speed region where the throttle valve opening is 30% to 40%, which is a dangerous region where knocking is likely to occur, so the optimal ignition timing should be set to an extent that can suppress the occurrence of knocking. It is said to be the advance angle of Area■
For example, throttle valve high opening L (maximum torque rotation yti
In areas where knocking is less likely to occur outside of area II,
The optimum ignition timing is set near the engine's required advance angle.

Region (2) assumes a transient state such as sudden acceleration n, 4, etc. and advances the angle, and is set slightly on the starting side than in region (2). Therefore, ``Niki Nairiranm i:s'J
During operation, engine speed 1 distortion, throttle opening 1 ((detector 4
When the throttle valve opening degree, that is, the amount of intake air detected as described above by 6 is transmitted to the ignition timing setter 51, the ignition timing setter 51 performs the following based on the map t or the function equation shown in FIG. Set the appropriate ignition timing corresponding to the above transmission result.

Next, as described above, the crank angle detector 52 of the controller 50 uses the crank angle coil 3 as a reference angle signal generator.
Crank rotation angle 1,1 after the pulse generation point of 2
The number of pulses i'kMl generated by the signal generator 36 is calculated, and the angular position of the crankshaft 120 is detected.

The ignition timing setter 51 and crank angle detector 52
Each detection result is transmitted to the ignition +4 generator 53.

The ignition signal generator 53 generates an ignition signal when the crank angle (i?) position is at the optimum ignition timing based on the detection results of the ignition timing setter 51 and the crank angle detector 52, and generates an ignition signal corresponding to each cylinder. The gate of 5CR56 is set to the oil-conducting state, and discharge is generated in the spark plug 22 of each cylinder.f That is, according to the advance control by the controller 50, the ignition timing is selected in advance by the ignition timing setting device 51. This makes it possible to ignite at the optimal ignition timing without causing abnormal combustion in each operating state of the engine.

Here, the effects of the l-correlation detector 48 and the abnormal combustion detector 49 on the angle control by the controller 50 will be explained as follows.

First, the temperature detector 48 detects the engine temperature as described above, and transmits the detection result to the ignition timing setting device 51. The ignition timing setter 51 presets the optimal ignition timing O8 when the engine temperature 'r is a constant temperature D, for example, 3 () degrees Celsius or less, as shown in FIG. 496, for example. That is, When starting when the engine temperature is 30°C or less (during cranking by starter motor), the optimal ignition timing is set to 7° before top dead center, and when the engine is cold after starting and the engine temperature is 5°C or less,
The optimum ignition timing is 5 degrees before top dead center, and the engine temperature is 5 degrees Celsius to 3 degrees Celsius.
When the engine is cold after starting at 0 degrees Celsius, the optimum ignition timing is set to 0 degrees. Therefore, when the engine temperature is below 30°C, the ignition timing setter 51 sets the advance angle value based on the engine speed 11fN and the throttle valve opening 6v shown in FIG. Advance angle values based on the temperature T are compared, and a larger advance angle value can be set as the optimum ignition timing. For example, if the throttle valve opening is 8 degrees and the engine speed is 11,000 RP, the advance angle value based on Figure 5 is 2 degrees before top dead center, and the engine temperature at that time is -5 degrees Celsius. Since the advance angle value based on FIG. 6 is 5 degrees before top dead center, the ignition timing setter 51 adopts 5 degrees before top dead center. The ignition timing setter 51 is
In this way, the lead angle value based on Figure 5 and the lead angle value based on Figure 6 are constantly compared, but considering the characteristics of the engine, the lead angle value based on Figure 6 is always compared.
The advance angle control based on the engine temperature as shown in the figure is substantially employed only in the low load and low rotational speed region.

That is, by using the detection result of the temperature detector 48 as a setting element of the ignition timing setter 51, the ignition timing is advanced from the normal ignition timing according to the engine temperature at the time of starting and when the engine is cold after the start νI. By doing so, it is possible to make starting and warm-up operations easier and more practical, and to stabilize the rotation of the engine when cruising in the cold engine low load Ir11 rotation speed range.

Next, the abnormal combustion detector 49 detects vibrations occurring in the engine at a certain level or higher as described above, and the ignition timing setter 51
It can be transmitted to The ignition timing setter 51 sets the ignition timing to 2 as shown in FIG. 7 based on the detection of abnormal combustion.
The retard angle setting is set to "d" in stages. In other words, in Fig. 7, when abnormal combustion is detected at point A, the combustion is retarded by a degree and
Set the ignition timing of the point. During the elapse of time from point B to point C, if abnormal combustion is detected again, the retard angle is further a degree, and the retard angle is set by a total of 2a degrees. After retarding the angle by 2a degrees above, point B to E
After the specified time has elapsed, the initial ignition timing is returned to the original ignition timing by performing the steps reverse to those described above. At this time, if abnormal combustion is detected again between point F and point G, the angle is retarded by a degree at that point. Note that the retardation width of 2a degrees in FIG. 7 is set to a value that can sufficiently suppress abnormal combustion. In addition, by adopting a two-stage retardation system as shown in Figure 7 above, the engine rotation speed and hull speed can be prevented from rapidly decreasing, causing physical shock to the driver and passengers, or causing mental stress. It is possible to avoid the occurrence of anxiety.

That is, by using the detection result of the abnormal combustion detector 49 as a setting element of the ignition timing setter 51, when abnormal combustion occurs during steady running of the engine, the ignition timing is intentionally delayed and the required time is Normal ignition timing after
This makes it possible to return to normal state. In other words, internal combustion engines used in outboard motors, etc., have vast differences in their nature, applications, and operating environments, so there may be carbon buildup on the combustion chamber or piston, mismatching of spark plugs, use of low-octane gasoline, etc. In consideration of the occurrence of abnormal combustion caused by the engine, it is normal to set the maximum ignition advance range of the engine to the retarded side of the required advance angle, but there may be cases where it is not possible to bring out the best performance of the engine by prioritizing safety. be. According to advance angle control using the abnormal combustion detector 49,
In addition to protecting the engine, it is possible to fully utilize the performance of the engine under operating conditions in which abnormal combustion does not occur.

In the above embodiments, the case where the present invention is applied to an internal combustion engine with multiple cylinders has been described, but the present invention can be similarly applied to an internal combustion engine with a single cylinder.

As described above, the electronically controlled advance angle device for an internal combustion engine according to the present invention includes an engine speed detector that detects the engine speed;
An intake air amount detector detects the amount of intake air, and the optimum ignition timing for each combination of engine speed and intake air amount is determined in advance, and the optimum ignition timing corresponds to the detection results of the engine speed detector and the intake air amount detector. Based on the detection results of the ignition timing setter that sets the ignition timing setter, the crank angle detector that can detect the crank angle position, the ignition timing setter, and the crank angle detector, when the crank angle position is at the optimal ignition timing. Since it consists of an ignition signal generator that generates an ignition signal, by selecting the ignition timing that is added to the ignition timing setting device in advance, ignition can be performed at the optimal ignition timing that will not cause abnormal combustion in each operating state of the engine. This makes it possible to improve the fuel efficiency and output of the engine.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of an embodiment of an internal combustion engine for an outboard motor to which the present invention is applied; FIG. 2 is a partially cutaway plan view of the internal combustion engine for an outboard motor; Fig. 3 is an explanatory diagram showing the respective generated values of the reference angle signal generator and the crank rotation angle signal generator in the same embodiment, Fig. 4 is a control system diagram showing the advance angle control procedure in the same embodiment, and Fig. 5 Figure 6 is a map showing the optimum ignition timing for the combination of engine speed and throttle valve opening in the same example, Figure 6 is a diagram showing the optimum ignition timing for the engine temperature in the same example, and Figure 7 is a diagram showing the Luli control state at the time of ignition when abnormal combustion occurs in the same embodiment. 12...Crankshaft, 22...Ignition plug, 23...
・Throttle valve, 32... Balsafil, 36...
Crank rotation angle signal generator, 46... Throttle opening detector, 48... Temperature detector, 49... Abnormal combustion detector,
50... Controller, 51... Ignition timing foot device,
52...Crank angle detector, 53...Ignition signal generator. Agent Patent attorney Osamu Shiokawa Figure 5 Figure 6 S Procedural amendment (spontaneous) May 77, 1980 Commissioner of the Japan Patent Office Kazuo Wakasugi1, Indication of case 1982 Patent Application No. 1462682, Invention Name of Electronically Controlled Advancement Device for Internal Combustion Engines 3, Relationship to the Amendment Case Patent Applicant Name Sanshin Kogyo Co., Ltd. 4, Agent 105 Address No. 23 Mori Building, 23-7 Toranomon-chome, Minato-ku, Tokyo Column 6 of detailed explanation of the invention in the 8th floor specification, contents of amendment

Claims (1)

[Claims] (1) An engine speed detector detects engine speed, an intake air amount detector detects intake air amount, and the optimum ignition timing for each combination of engine speed and intake air amount is determined in advance. An ignition timing setter that sets the optimum ignition timing corresponding to the detection result of the intake air amount detector, a crank angle detector that can detect the crank angle position, and a and an ignition signal generator that generates an ignition signal when the crank angle position is at the optimum ignition timing.