JP4772729B2 - Ignition control device for internal combustion engine - Google Patents

Description

The present invention relates to an ignition control device used for an internal combustion engine such as a motorcycle, and more particularly to an apparatus capable of improving drivability.

Unburned gas that may be generated when the internal combustion engine is started may affect drivability. This unburned gas can be reduced by multipoint ignition, and a multipoint ignition is known on the advance side only at the time of start (Patent Document 1).
JP-A-2-207180

By the way, when multipoint ignition is performed only at the time of starting, it is considered that a repulsive force is generated by combustion before top dead center with respect to rotation in the starting direction.
In addition, during high-speed rotation, there is a concern that the ignition coil may rise in temperature due to heat generation due to multipoint ignition on the advance side.
SUMMARY OF THE INVENTION Accordingly, the present invention aims to improve the occurrence of the above situation at the time of starting and at high speed rotation, and an ignition control device suitable for an internal combustion engine for a motorcycle.

In order to solve the above-mentioned problem, the invention of claim 1 according to an ignition control device for an internal combustion engine is a full-transistor ignition control device for a four-stroke internal combustion engine for controlling the ignition timing by a spark plug .
Perform first ignited by the previous compression stroke top dead center of the piston, the on a combustion stroke after the dead point, and the second in front of the next coming exhaust stroke of the combustion stroke While igniting ,
This ignition is performed twice when the engine speed Ne is within a predetermined low Ne range except at the start,
Otherwise, it is configured to perform only the first ignition ,
A second energization start position search means for determining a discharge time from the first ignition position to the start of energization for performing the second ignition is provided, and the discharge time becomes shorter as the engine speed increases. Is set to be
A second ignition position search means for determining an energization time from the start of energization for performing the second ignition to the second ignition is provided, and the energization time becomes shorter as the engine speed increases. It is set so that it may become .

According to a second aspect of the present invention, in the first aspect of the invention, it is provided with a stroke discriminating unit that discriminates whether or not it is the combustion stroke, and the discharge by the second energization start position searching unit after being determined to be the combustion stroke The time and the energization time by the second ignition position search means are searched .

According to a third aspect of the present invention, in the first aspect of the invention, the throttle opening is in a low throttle opening range smaller than the predetermined throttle opening, and the change rate of the throttle opening is a predetermined throttle opening change rate. When it is less than the above, the second ignition is performed .
According to a fourth aspect of the present invention, in the third aspect of the invention, there is provided ignition timing determining means for determining whether or not the ignition timing of the first ignition is within a predetermined range. The second ignition is performed.
A fifth aspect of the present invention is the ignition control device for an internal combustion engine of a motorcycle according to the first aspect.

  According to the first aspect of the present invention, in addition to the normal ignition on the advance side, in addition to the normal ignition on the advance side, only on the retard side for the purpose of combustion of the unburned gas, only in the predetermined low Ne region where combustion is unstable, except during starting The second ignition is performed before the exhaust stroke, and the ignition is performed twice from the compression stroke to the combustion stroke (hereinafter referred to as “double ignition”). Driveability can be improved. In addition, the ignition coil can be prevented from generating heat.

According to the invention of claim 3, since the double ignition is performed only when the throttle opening is in the predetermined low throttle opening range in addition to the condition of the predetermined rotation speed range, the above effect can be further increased. .

Hereinafter, an embodiment of an ignition control device for an internal combustion engine configured in a motorcycle will be described with reference to the drawings. Figure 1 is a block diagram of an ignition control device, the ignition control device, ECU (controller) 1, power transistor 2, a full-transistor type, which is composed of a computer controlled by an ignition coil 3 and the spark plug 4.

  Various signals such as the engine speed Ne, the intake negative pressure PB, the throttle opening θth, and the water temperature TW are input to the ECU 1 from the sensor. The ECU 1 calculates energization time and ignition timing for the ignition coil 3 based on these signals, and controls energization and ignition by turning the power transistor 2 on and off. The energization time is determined by a table built in the ECU 1. The ignition timing is also determined from a built-in map. The map uses a combination of the rotational speed Ne, the throttle opening degree θth, or the intake negative pressure PB.

  The ignition coil 3 includes a primary coil 5 and a secondary coil 6, energizes the primary coil 5 for a predetermined time by turning on the power transistor 2, and then turns off the power transistor 2 to cut off the energization to the primary coil 5. Then, a high voltage current is generated in the secondary coil 6 by the inductive power, and this is applied between the electrodes of the spark plug 4, so that a spark discharge is generated between the electrodes of the spark plug 4 and the combustion gas in the combustion chamber of the engine is generated. Ignited.

FIG. 2 is an ignition timing chart in the ECU 1 and here is based on 1800 rpm. As shown in this figure, first ignition, when the TDC (top dead center) and 0 deg, the advance side to become energized by -126deg is started, is energized between 10m · sec (109deg), -17deg And then discharged for 1.5 msec. The first ignition is a normal ignition. Moreover, it is a calculation ignition by ECU1, and as mentioned above, each timing of an energization start and ignition is determined based on the table and map which are built-in data.

After the first ignition, energization is started for 10 msec (109 deg) for the second ignition at -1 deg, the second ignition is performed at 108 deg before the exhaust stroke, and the unburned gas is completely burned. Do not carry over unburned gas in the process.
The crank angle is calculated based on the pulsar signal. The pulser signal is generated at intervals of 30 degrees, and the pulse immediately before TDC is set to rise 11 degrees before.

The conditions for performing the double ignition control are as follows.
Condition 1: Upper and lower limits of rotation speed Ne; 1000 to 5000 rpm
Condition 2: Upper and lower limits of throttle opening θth; 0 to 10%
Condition 3: Upper and lower limits of water temperature TW; -10 ° to 100 °
Condition 4: Upper and lower limits of intake air temperature TA; -10 ° to 100 °
Condition 5: Rate of change DTH of throttle opening DTH: Forced termination at 5% / 20 msec Condition 6: Double ignition control only in the arithmetic ignition 720 deg mode, that is, the above conditions 1 to 5 represent a low speed region where combustion is unstable. Yes, condition 6 means that the normal ignition is performed only once in 4 strokes, that is, the state where other multipoint ignition is not performed.

  FIG. 3 is a flowchart of ignition timing control in the ECU 1. A is a timer setting process for determining the output of the ignition coil 3 performed for each compression stroke, and includes four subroutines S1 to S4. S1 is a subroutine for energization start timer setting in the first ignition, which is set based on a predetermined table, counts down the timer from the reference position, and starts energization at 0. S2 is the first ignition timer set. The ignition timer is set according to a predetermined map, counted down from the reference position, and ignited at zero.

S3 is an energization start timer set for the second ignition, and starts counting at 0 after counting down the timer from the first ignition position. S4 is a second ignition timer set, and the timer is counted down from the second energization start position and ignited at 0.
As a result, the timer setting for one double ignition control is terminated.

  B is the contents of a subroutine in the double ignition control. In the case of a multi-cylinder engine, B is processed for each ignition coil. First, when starting, it is determined whether or not the combustion stroke is based on the intake negative pressure PB (S10). Since the double ignition control is performed only before the exhaust stroke in the combustion stroke, the process proceeds to the next S11 with YES (1), and the subroutine is terminated with NO (0).

  In S11, it is determined whether or not it is a calculation ignition. If it is a calculation ignition (1), since the double ignition control is possible, the process proceeds to the next S12. Otherwise (0), the subroutine is terminated because the double ignition control by the calculated ignition cannot be performed.

  In S12, it is determined whether or not the rotational speed Ne is within a predetermined range. The predetermined range is a low rotation range excluding start-up, and is, for example, idle rotation 1800 rpm and 1000 to 5000 rpm below the idle rotation. In this case, the lower limit Ne1 is 1000 rpm, and the upper limit Ne2 is 5000 rpm. If it is within the predetermined range (Y), it is a low rotation range to be controlled, and the process proceeds to S13. If NO (N), it is outside the control target, and the subroutine is terminated.

  In S13, it is determined whether or not the throttle opening θth is within a predetermined range. This is because it is performed only when the throttle opening is low and the vehicle is running at a low speed. In this case, for example, 0 to 10% is set as the low throttle opening range. In this case, the lower limit value θth1 is 0% and the upper limit value θth2 is 10%. If it is within the predetermined range (Y), it is the low rotation range of the controlled object, so the process proceeds to S14. If NO (N), it is out of the controlled object, and the subroutine is terminated.

  In S14, it is determined whether or not the water temperature TW is within a predetermined range. This is a case of a water-cooled engine, except for a case where the water temperature is not sufficiently increased immediately after starting and the engine is cold. In this case, the lower limit value TW1 is −10 ° C., and the upper limit value TW2 is 100 ° C. If it is within the predetermined range (Y), since it is the low rotation range of the controlled object, the process proceeds to S15. If NO (N), it is out of the controlled object and the subroutine is terminated.

  In S15, it is determined whether or not the intake air temperature Ta is within the set region. This is because the combustion immediately becomes unstable immediately after the instruction where the intake air temperature Ta is low. In this case, the lower limit value Ta1 is −10 ° C., and the upper limit value Ta2 is 100 ° C. If it is within the predetermined range (Y), it is the low rotation range of the controlled object, so the process proceeds to S16. If NO (N), it is out of the controlled object, and the subroutine ends.

  In S16, it is determined whether or not the first ignition timing is within a predetermined range. If the first ignition timing is outside the set range, the second ignition timing cannot be controlled based on the first ignition timing, so that it is confirmed whether the second ignition timing is in the normal position. If it is within the set range (Y), it is a low rotation range to be controlled, so the process proceeds to S17. If NO (N), it is out of the control target, and the subroutine is terminated.

  In step S17, it is determined whether or not the setting DTH is exceeded. DTH is the rate of change of the throttle opening, and if it is equal to or greater than the set value, it is accelerating, so it is forcibly terminated and the subroutine is terminated. The reference value at this time is 5% / 20 msec. If the reference value is not reached, the control is continued and the process proceeds to S18.

  In S18, it is determined whether or not the ignition timing is under acceleration control. If the ignition timing is at the time of acceleration, there is no need to control in the low speed range, so this is to be excluded. If the control is in progress (1), the subroutine ends. If not (0), the control is performed. Continue to S19.

  In S19, it is determined whether or not traction control is being performed. If the control is in progress (1), the double ignition control is stopped in order not to disturb the traction control and the subroutine is terminated. If not (0), the control is continued and the process proceeds to S20.

  In S20, the energization start position data for the second ignition is obtained by searching the table. FIG. 4 shows an Ne table used for the second energization start position data search. The Ne table is given as a correlation table between the waiting time from the first ignition position to the second energization start and the rotation speed, and the waiting time is obtained from this table.

  In step S21, the second ignition position is obtained by searching the table. FIG. 5 is a second ignition position table, which is given as a correlation table between the time from the second energization start position to the second ignition and the number of revolutions, and the second ignition time is obtained from this table.

  Subsequently, a second energization start timer is set according to the determined time (S22), and a second ignition timer is set (S23). S22 and S23 are the same as S3 and S4, respectively.

  In this way, by performing double ignition consisting of normal ignition on the advance side with TDC and ignition after the timing before the exhaust stroke on the retard side, unburned gas is removed by the second ignition. The drivability can be improved by sufficient combustion, and the unburned gas can be completely burned by the exhaust stroke so that it does not carry over to the next stroke. In addition, since the double ignition is performed only in the low rotation range except at the start, the generation of repulsive force at the start, the heat generation of the ignition coil 3 at the high speed range, and further the heating of the driver inside the ECU 1 are prevented. Thus, it is possible to effectively double-ignite only in a low speed range where unburned gas needs to be burned, and the ignition control device is suitable for an internal combustion engine for a motorcycle. However, the application object of the present invention is not limited to motorcycles, but is applicable if it is started by a kick.

The present invention is not limited to the above-described embodiments, and various modifications and applications can be made within the principle of the invention. For example, the double ignition is not necessarily a total of two ignitions with the TDC interposed therebetween, and may be two or more times as long as it is before the exhaust stroke after the TDC.

Block diagram of ignition control device Ignition timing chart in ECU Flow chart of ignition timing control in ECU Table used for second energization start position data search Table used for second ignition position data search

Explanation of symbols

1: ECU, 2: Power transistor, 3: Ignition coil, 4: Spark plug, 5: Primary coil, 6: Secondary coil

Claims (5)

In a full-transistor ignition control device for a four-stroke internal combustion engine for controlling ignition timing by a spark plug ,
Perform first ignited by the previous compression stroke top dead center of the piston, the on a combustion stroke after the dead point, and the second in front of the next coming exhaust stroke of the combustion stroke While igniting ,
This ignition is performed twice when the engine speed Ne is within a predetermined low Ne range except at the start,
Otherwise, it is configured to perform only the first ignition ,
A second energization start position search means for determining a discharge time from the first ignition position to the start of energization for performing the second ignition is provided, and the discharge time becomes shorter as the engine speed increases. Is set to be
A second ignition position search means for determining an energization time from the start of energization for performing the second ignition to the second ignition is provided, and the energization time becomes shorter as the engine speed increases. Set to be
An ignition control device for an internal combustion engine. A stroke discriminating unit that discriminates whether or not the combustion stroke is being performed, and after being determined to be the combustion stroke, a discharge time by the second energization start position search unit and an energization time by the second ignition position search unit ignition control system for an internal combustion engine according to claim 1, characterized in that to search for. When the throttle opening is in a low throttle opening range smaller than the predetermined throttle opening and the change rate of the throttle opening is less than the predetermined throttle opening change rate, the second ignition is performed. The ignition control device for an internal combustion engine according to claim 1. The ignition timing determining means for determining whether or not the ignition timing of the first ignition is within a predetermined range, and when the ignition timing is within the predetermined range, the second ignition is performed. 3. An ignition control device for an internal combustion engine according to 3. 2. The ignition control device for an internal combustion engine according to claim 1, which is an ignition control device for an internal combustion engine of a motorcycle.

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