JPH07243373A - Ignition system of engine for motorcycle - Google Patents

Abstract

PURPOSE:To prevent knocking at the time of quick acceleration by delaying ignition timing at the time when an increasing rate of engine speed is higher than a previously specified value in a medium speed rotating region. CONSTITUTION:Ignition control of a CPU 14 is carried out as an ignition timing setting means 23 outputs an ignition signal to a CDI ignition unit 16 for each ignition timing. The CPU 14 detects engine speed, a crank angle and motorcycle speed, and when the engine speed is judged to be in a medium speed rotating region, an ignition timing control means 24 compares an increasing rate of the engine speed with a set value. Consequently, when the increasing rate is higher than the set value, the ignition timing is delayed from T1 to T3. This ignition timing T3 is set at an angle delayed later than an ignition timing T2 at the time when the engine speed is in a high speed rotating region. After this delay angle of the ignition timing, the ignition timing is spark-advanced from T3 to T2 at the time when the engine speed reaches the high speed rotating region. Consequently, knocking is hardly caused at the time when the engine speed reaches the high speed rotating region.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle engine ignition device for controlling the ignition timing of a motorcycle engine according to the engine operating condition.

[0002]

2. Description of the Related Art Conventionally, many scooter engine ignition devices have a structure in which the arrival of a piston at an ignition position is detected from the rotational position of a crankshaft and the spark plug is energized at that time.

In detecting that the piston has reached the ignition position, a pulsar rotor having a magnet embedded therein is mounted on a crankshaft, and when the pulsar rotor rotates and passes near the pulsar generator, the coil of the pulsar generator is rotated. It was used to generate electric current. That is, the structure is such that a spark is blown to the spark plug every time the crankshaft rotates by a certain angle, and the ignition timing is constant regardless of the engine speed.

[0004]

However, in the ignition device constructed as described above, setting the ignition timing is a problem. This is because it is desirable to set the ignition timing so that the engine output and thermal efficiency are high in order to improve fuel efficiency in the medium speed range that is frequently used during driving in engines such as scooters. This is because there is a demand to advance the ignition timing from the ignition timing.

However, if the ignition timing is advanced as described above, knocking will occur if the throttle valve is opened rapidly to accelerate rapidly even when the engine is running steadily in the medium speed range. Is likely to occur.

The present invention has been made to solve the above problems, and an object thereof is to obtain an ignition device capable of controlling the ignition timing in accordance with the engine operating state.

[0007]

An engine ignition device for a motorcycle according to the present invention controls an ignition timing based on a detecting means for detecting an engine speed and an engine speed detected by the detecting means. With a control device,
This control device advances the ignition timing when the engine speed is at least in the middle speed range with respect to the ignition timing at the idling speed, and the increase rate of the engine speed in the middle speed range is When the ignition timing is larger than a predetermined value, the ignition timing is retarded.

[0008]

According to the present invention, even if the ignition timing is set to achieve high fuel consumption when the engine speed is in the medium speed range, the ignition timing is retarded when the vehicle is suddenly accelerated. It's never too early.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS. FIG. 1 is a block diagram showing a schematic configuration of an ignition device for a motorcycle engine according to the present invention, FIG. 2 is a flowchart for explaining the operation of the ignition device for a motorcycle engine according to the present invention, and FIG. 3 is a scooter. 4 is a graph showing the relationship between the vehicle speed and the engine speed, FIG. 4 is a graph showing the relationship between the engine speed and the ignition timing when the ignition device for a motorcycle engine according to the present invention is used, and FIG. 6 is a graph showing a relationship between ignition timing and engine speed with respect to time.

In these figures, 1 is a scooter, and this scooter 1 has the same construction as a conventional one except for an ignition device which will be described later. Reference numeral 2 is a front wheel, 3 is a rear wheel, 4 is a steering handle, 5 is a seat, and 6 is a unit swing type engine (hereinafter, simply referred to as an engine) for rotationally driving the rear wheel 3.

This engine 6 is of a two-cycle single cylinder type. A carburetor 7 is connected to the upper part of a cylinder 6a and an exhaust pipe 8 is connected to the lower part thereof, and a crankshaft (not shown) is provided.
A power generator 9 is mounted on the shaft of the generator, and the power of the crankshaft is transmitted to the rear wheels via a V-belt type continuously variable transmission 10 and a centrifugal clutch (not shown).

The power transmission characteristic of the crankshaft of the engine 6 is shown in FIG. In the figure, the characteristics when the throttle valve is fully opened and accelerated from the vehicle speed 0 to the maximum speed are shown by thick lines, and the characteristics when the engine is braked from the maximum speed to the vehicle speed 0 are shown by the one-dot chain line. The chain line shows the characteristic when the throttle valve is suddenly fully opened while the vehicle is running at the vehicle speed V1. The above characteristics are those when traveling on a flat road surface that is not inclined.

In FIG. 3, a range indicated by a indicates an idling state (a state in which the centrifugal clutch is not engaged), and a range indicated by b indicates a state in which the centrifugal clutch is rubbing and transmitting power to shift to a connected state (so-called). Stall speed)
In the range indicated by c, the centrifugal clutch is completely engaged and the V-belt type continuously variable transmission is transmitting power with the maximum reduction ratio. The range indicated by d is V
The state in which the weight roller of the belt type continuously variable transmission is moved by centrifugal force to change gears is shown. The range indicated by e indicates that the weight roller moves to the final movement position and the V belt type continuously variable transmission is the most It shows a state in which power is transmitted in a state where the reduction ratio is small.

Further, in FIG. 3, the engine speed when the centrifugal clutch is completely engaged is indicated by NS, the engine speed during idling is indicated by N0, and the engine speed when traveling at a vehicle speed V1. Is represented by N1, and the engine speed at which the V-belt type continuously variable transmission starts shifting is represented by N2. Further, in the figure, the ignition timing at idling is indicated by T0, and the hatched area consisting of parallel lines descending to the right indicates the fuel consumption-oriented ignition timing (T1).
Indicates the engine rotation range set to, and the hatched range consisting of parallel lines descending to the left indicates the ignition timing T1.
The engine rotation range set to the ignition timing (T2) with a more retarded angle is shown. The switching of the ignition timings T0, T1 and T2 is performed by an ignition device described later.

An ignition device according to the present invention is designated by reference numeral 11 in FIG. The ignition device 11 includes a pulsar generator 12 provided in the generator 9, a vehicle speed sensor 13 for detecting a vehicle speed, and a CPU 14 as a control device.
And a ROM 15 in which ignition timing is stored, a CDI ignition unit 16, an ignition coil 17, an ignition plug 18, and the like. A reference numeral 19 in FIG. 1 is a regulator, and 20 is a battery.

The pulsar generator 12 has a structure for outputting a crank angle signal to the CPU 14 every time the pulsar rotor 21 axially mounted on the rotor (not shown) of the generator 9 rotates. This crank angle signal is configured to be generated when the crank shaft rotates by a predetermined crank angle. In this embodiment, the crankshaft is 1
A signal for one pulse is generated each time it rotates. That is, the pulsar generator 12 constitutes the engine speed detecting means according to the present invention.

The vehicle speed sensor 13 in this embodiment is configured to detect the rotation of the front wheel 2, and is composed of an electromagnetic pickup supported and fixed to the front fork 22 and a gear wheel that rotates together with the front wheel 2. It is well known in the art. In addition, as the vehicle speed sensor 13,
In addition to detecting the rotation of the front wheels 2 as shown in this embodiment, a configuration may be adopted in which the rotation of the rear wheels 3, the transmission gear (not shown), etc. is detected.

The CPU 14 is connected to the pulsar generator 12, the vehicle speed sensor 13, the ROM 15, the CDI ignition unit 16 and the regulator 17, and comprises an ignition timing setting means 23 and an ignition timing control means 24. The ignition timing setting means 23 uses the crank angle signal output from the pulsar generator 12 for the engine 6
Of the front wheel 2 output from the vehicle speed sensor 13, the vehicle speed is detected, and these data are collated with the ignition timing map of the ROM 15 to determine the engine operating state at that time. Is set to the most suitable ignition timing, and when the piston position obtained from the crank angle reaches the ignition position, the CDI ignition unit 1
6 is configured to output an ignition signal.

The ignition timing map stored in the ROM 15 is constructed by assigning the ignition timing required by the engine 6 to the crank angle, the engine speed and the vehicle speed. That is, by reading the ignition timing from the ignition timing map from time to time, it is possible to set it to the most suitable ignition timing for the engine operating condition. The ignition timing shown in the ignition timing map is set as shown in FIG.

The ignition timing is set to T0 when the engine 6 is in the idling state, and is set to T1 advanced from T0 when the engine speed is in the medium speed range, and the engine speed is in the high speed range. At some time it is set to T2 between T0 and T1. Here, the medium speed rotation range is the engine rotation from when the centrifugal clutch of the V-belt type continuously variable transmission 10 starts transmitting power to when the weight roller starts to move by centrifugal force as shown in FIG. Refers to a range of numbers. Further, the high rotation speed range means a range of engine rotation speed in which the engine rotation speed is higher than that in the medium speed rotation range.

Further, the ignition timing T0 is set to an angle at which the engine 6 is started and idling is most stable. The ignition timing T1 is set to an angle that maximizes the output and thermal efficiency of the engine 6. That is,
High fuel efficiency is achieved by setting this ignition timing T1. The ignition timing T2 is set at an angle such that the engine 6 is not overheated or knocked even if the engine speed is large. Here, depending on the case, the ignition timing may remain T1 even in the high engine speed range.

When the engine speed is in the medium speed range (when the ignition timing is T1), the ignition timing control means 24 increases the crankshaft angular acceleration from the crank angle and the engine speed (engine rotation speed). The rate of increase of the number is calculated, and the ignition timing is retarded from T1 to T3 (FIG. 5) when the rate of increase is larger than a predetermined value. In the present embodiment, the ignition timing T3 is set to an angle that is further retarded than the ignition timing T2 when the engine speed is in the high speed range.

The CDI ignition unit 16 includes a generator 9
A part of the electric power generated by is charged, and when the ignition timing setting means 23 outputs an ignition signal, the charged electric power is supplied to the primary coil of the ignition coil 17. Also, the ignition coil 1
Reference numeral 7 is a conventionally well-known structure, and a large voltage is generated in the secondary coil when the primary coil is energized, and this large voltage is applied to the ignition plug 18 of the engine 6.

Next, the operation of the ignition device 11 configured as described above will be described with reference to FIGS. 2 and 5. First,
When a main switch (not shown) is turned on, the CPU 14 detects the engine speed, the crank angle and the vehicle speed as shown in step S1 in FIG. 2, and then, in step S2, the ignition of the ROM 15 is performed based on the data. The optimum ignition timing for the engine operating condition at that time is read from the timing map.

The ignition timing is set to T0 as shown in FIG. 4 at the time of starting or when the engine speed is equal to or less than the idling speed N0. Further, when the engine speed becomes higher than N0, it is set to T1, and when the engine speed is in the high speed range, it is set to T2.

After reading the ignition timing from the ignition timing map in this way, the CPU 14 controls the ignition in step S3. This ignition control is performed by the ignition timing setting means 23.
Is output to the CDI ignition unit 16 at each ignition timing.

Thereafter, the ignition timing control means 2 of the CPU 14
4 determines in step S4 whether the engine speed is in the medium speed range. If it is determined that the engine is in the medium speed rotation range, the process proceeds to step S5. If not, the ignition is performed at the set ignition timing and the process returns to step S1 to repeat the above-described flow.

In step S5, the ignition timing control means 24
Compares the rate of increase in engine speed with the set value. As a result, when the rate of increase is smaller than the set value, ignition is performed at the set ignition timing, and the process returns to the step S1 to repeat the above-described flow. When it is larger than the set value, the process proceeds to step S6, as shown in FIG. The ignition timing is retarded from T1 to T3. FIG. 5 shows a change in the ignition timing and a change in the engine speed when the throttle valve is fully opened rapidly while the engine is running at a constant speed such that the engine speed is N1 (the ignition timing is T1) and the vehicle speed is V1. There is. The relationship between the vehicle speed and the engine speed under the same conditions is shown by the chain double-dashed line in FIG.

That is, as shown in FIG. 5, the ignition timing is T
When the vehicle is traveling in the state of 1 and the throttle valve is rapidly opened at the time indicated by the symbol t in FIG. 5, the engine speed also rapidly increases in response to the throttle operation. If the increase rate of the engine speed at this time is larger than the set value, the ignition timing is retarded from T1 to T3. After the ignition timing is retarded, the engine is advanced from T3 to T2 when the engine speed reaches the high speed range. In this way, step S6 of FIG.
The retard angle control ends in. After that, the process returns to step S1 and the above-described flow is repeated.

Therefore, since the ignition device 11 described above is constructed so that the ignition timing is retarded when the engine speed is in the high rotation speed range than in the medium speed rotation speed range, the ignition timing is set to the middle speed rotation speed when the engine rotation speed is in the middle speed rotation speed. Even if the fuel economy is set to be high when the engine is in the range, it will not be too early because the ignition timing is retarded when the engine speed reaches the high engine speed range. Therefore, in order to improve fuel efficiency in the engine 6 that uses a lot of medium-speed rotation range such as for scooters, the engine 6 is not overheated even when the engine speed reaches the high rotation range, and moreover, knocking is achieved. Is unlikely to occur.

Even if the throttle valve is opened rapidly with a large opening when the engine speed is in the medium speed range, at this time, the ignition timing is retarded, the combustion start timing is delayed, and the combustion time is delayed. Is relatively short,
Knocking is less likely to occur. In addition, at this time, the engine output temporarily decreases, so that the drive ratio of the rear wheels 3 gradually increases, and it is possible to suppress the progress of tire wear and reduce the frictional resistance of the road surface. Can move the car body smoothly.

Further, since it is detected from the rate of increase of the engine speed that the throttle valve is opened rapidly with a large opening, it is not necessary to dispose a special sensor around the carburetor, and the ignition timing can be adjusted. A controllable ignition device can be realized very easily. For example, the following advantages can be obtained as compared with the case where a position sensor such as a potentiometer is attached to the throttle valve to detect that the throttle valve is opened rapidly with a large opening, and the position sensor detects the position.

That is, it is possible to prevent the structure of the carburetor from becoming complicated because the position sensor is connected to the throttle valve. Further, it is not necessary to secure a space for disposing the position sensor around the carburetor, and it is not necessary to change the arrangement of electrical components and the like around the carburetor. In order to reliably perform ignition timing control using the position sensor, it is necessary to use an expensive position sensor with high durability, detection accuracy, and reliability.
The cost will increase, but it does not exist.

In the present embodiment, the example in which the ignition device according to the present invention is applied to the scooter has been shown, but the same effect as that of the present embodiment can be obtained even when applied to a motorcycle other than the scooter. Further, since the vehicle speed sensor 13 is provided and the detected value is stored as data, more detailed control can be performed, but the vehicle speed sensor 13 is not necessary.

[0035]

As described above, the ignition system for a motorcycle engine according to the present invention controls the ignition timing based on the detecting means for detecting the engine speed and the engine speed detected by the detecting means. And a control device for controlling the ignition timing when the engine speed is at least in the medium speed range, the control device advances the ignition timing with respect to the ignition timing at the idling speed, and Since the ignition timing is retarded when the rate of increase in engine speed is greater than a predetermined value, the ignition timing is set to achieve high fuel consumption when the engine speed is in the medium speed range. However, when the vehicle is suddenly accelerated, the ignition timing is retarded so that it is not too early.

Therefore, in order to improve fuel efficiency in an engine such as a scooter that uses a lot of medium speed range, the engine is not overheated even when the engine speed reaches a high speed range, and moreover, knocking is achieved. Is unlikely to occur.

Further, even if the throttle valve is opened rapidly with a large opening when the engine speed is in the medium speed range, at this time, the ignition timing is retarded, the combustion start timing is delayed, and the combustion time is delayed. Becomes relatively short.

Therefore, knocking is less likely to occur at the time of sudden start or sudden acceleration. In addition, since the engine output temporarily decreases, the drive ratio of the rear wheels will gradually increase, which can suppress the progress of tire wear and smooth the vehicle body even if the road friction resistance is small. Can be advanced to.

Further, since it is detected from the rate of increase of the engine speed that the throttle valve is opened rapidly with a large opening, it is not necessary to dispose a special sensor around the carburetor, so that the ignition timing can be improved. There is also an effect that an ignition device capable of controlling the ignition can be realized very easily.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an ignition device for an engine for a motorcycle according to the present invention.

FIG. 2 is a flow chart for explaining the operation of the ignition device for a motorcycle engine according to the present invention.

FIG. 3 is a graph showing the relationship between vehicle speed and engine speed on a scooter.

FIG. 4 is a graph showing the relationship between the engine speed and the ignition timing when the ignition device for a motorcycle engine according to the present invention is used.

FIG. 5 is a graph showing the relationship between the ignition timing and the engine speed with respect to the elapsed time when the motorcycle engine ignition device according to the present invention is used.

[Explanation of symbols]

6 ... Engine, 11 ... Ignition device, 12 ... Pulsar generator, 13 ... Vehicle speed sensor, 14 ... CPU, 15 ... R
OM, 16 ... CDI ignition unit, 23 ... Ignition timing setting means, 24 ... Ignition timing control means.

Claims (1)

[Claims] 1. A detection means for detecting an engine speed,
And a control device for controlling the ignition timing based on the engine speed detected by the detection means, and the control device controls the ignition timing when the engine speed is at least in the medium speed range to the ignition speed at the idling speed. A motorcycle for which the ignition timing is retarded when the engine speed is increased in this medium speed range and the increase rate of the engine speed is larger than a predetermined value Engine ignition system.