JP2548648Y2 - Ignition timing control device for internal combustion engine - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an ignition timing control device for an internal combustion engine, and more specifically, to an ignition timing control device which retards ignition timing during acceleration to reduce rocking vibration caused by sudden torque fluctuation. Regarding improvement.

[0002]

2. Description of the Related Art During acceleration of a vehicle, the vehicle body may not be able to follow a sudden change in the output torque of the engine. In such a case, the transmission of the torque is delayed, and the output is reduced by the drive wheels. The drive system, especially the drive shaft, which transmits the vibration to the drive shaft, may generate torsional vibration. This deteriorates the feeling of acceleration and is not preferable in terms of running stability. In order to solve this problem, the present applicant has disclosed in Japanese Utility Model Laid-Open Publication No. 3-30576 that the ignition timing is retarded by a predetermined amount at the time of acceleration, and the ignition timing is retarded after the engine speed is increasing. Is proposed to gradually return the angle in the advance direction.

[0003]

According to the above-mentioned prior art, it is possible to effectively reduce a sudden torque fluctuation at the time of acceleration, and as a secondary effect, the occurrence of knock due to a delay in following the ignition timing at the time of acceleration. However, in the above-described prior art, the retard amount is set to be larger as the vehicle speed is lower, so that when the vehicle starts or accelerates from an extremely low vehicle speed, a misfire occurs and the engine stalls. Was invited. That is, since the moment of inertia becomes smaller as the vehicle speed becomes lower, the retard amount is set to be larger on the lower vehicle speed side in order to compensate for it. However, at extremely low vehicle speeds, the engine output is inherently small. When starting, accelerating, there was a case where the engine was misfired and stopped.

Accordingly, the purpose of the present invention is to improve it, and it is possible to start and accelerate effectively even at an extremely low vehicle speed, and to prevent sudden fluctuations in torque during acceleration to reduce rocking vibration. An object of the present invention is to provide an ignition timing control device for an internal combustion engine.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned object, the present invention provides, for example, a method for delaying the ignition timing by a predetermined amount at the time of accelerating the running of a vehicle.
Thereafter, when the engine speed is in the increasing direction, the ignition timing control device of the internal combustion engine is configured to perform the retard correction while decreasing the predetermined amount, thereby reducing a sudden engine output fluctuation during acceleration. Vehicle running speed detecting means for detecting a speed , and engine speed detecting for detecting the engine speed
Means is provided, the front Kisho quantitative, the running speed of the vehicle is small rather set as a low speed, the engine speed is predetermined
When the engine speed is lower than the engine speed,
The engine speed is set to increase, and the engine speed
If it exceeds, it will decrease as the engine speed increases
It was configured to be set as follows.

[0006]

[Action] retard correction amount at the time of acceleration rather small enough in a low vehicle speed
Since the set, when starting from very low speed, accelerate
Even when the output torque of the engine is inherently small, the engine can be started and accelerated without misfiring and stalling the engine. In addition, during acceleration, the ignition timing is retarded, and thereafter, when the engine speed is increasing, it is gradually corrected in the advance direction. this to improve the ring
Can be. In addition, the retard correction amount is set to a predetermined
When the engine speed is lower than the engine speed, it increases as the engine speed increases.
And the engine speed exceeds the predetermined speed.
When the engine speed increases
, I.e., in the constant speed region where the engine output is relatively low,
As the output increases, the degree of output decrease increases,
In the speed range, the output decrease due to the large moment of inertia
Is set to be smaller, so the retard correction amount is output from the engine.
It can be set optimally according to the power and engine stall
Avoiding and effectively avoiding shaking vibrations
it can. Further, it is also possible to prevent the occurrence of knock due to a delay in following the ignition timing at the time of acceleration.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an overall view of a knock control device for an internal combustion engine according to the present invention. Referring to FIG. 1, reference numeral 10 indicates a multi-cylinder internal combustion engine for a vehicle including six cylinders. The internal combustion engine 10 is provided with an intake air passage 12, and the air flowing from the air cleaner 14 reaches an intake manifold 18 connected to the intake air passage while being controlled in flow rate by a throttle valve 16, and is supplied by an injector 20. When the intake valve (not shown) is opened through an intake port (not shown) after being mixed with the fuel, the combustion chamber 22 of the cylinder (only one cylinder is shown)
Introduced within. In the cylinder combustion chamber 22, the air-fuel mixture is ignited by a spark plug 24 and burns, and the combustion gas passes through an exhaust port (not shown) from an exhaust manifold 26 to an exhaust pipe (not shown) when an exhaust valve (not shown) is opened. ), Is purified by a catalyzer (not shown) attached thereto, and is discharged outside the engine.

Here, the intake air passage 12 has a throttle valve 1
At an appropriate position downstream of the engine 6, an intake pressure sensor 28 for measuring the pressure of the intake air as an absolute value to detect the engine load is provided, and a water temperature sensor 30 is provided in the vicinity of the cooling water passage of the internal combustion engine 10. Detect the temperature of the cooling water.
A throttle position sensor 32 for detecting the opening degree of the throttle valve 16 is provided near the throttle valve 16 in the intake air passage 12, and an intake air temperature sensor 34 for detecting the temperature of the intake air is also provided. Further, a distributor 36 is provided near the internal combustion engine 10, and inside the distributor 36, a pulsar that rotates in synchronization with the rotation of a crankshaft (not shown) that rotates as the piston 38 moves up and down, and a pulsar that faces the pulsar. A crank angle sensor 40 for detecting an angle, which is composed of a pickup member arranged in a position, is housed, and outputs a pulse signal at every predetermined crank angle. In the vicinity of a drive shaft (not shown) of a vehicle on which the internal combustion engine 10 is mounted,
A vehicle speed sensor 42 for detecting the running speed of the vehicle through the rotation speed is provided. Furthermore, piezoelectric knock sensor 46 at an appropriate position of the cylinder block of the internal combustion engine 10 for detecting the vibration based on knocking generated from the cylinder combustion chamber 2 2
Is provided. A sensor 28 such as the above-described intake pressure sensor,
The outputs of 30, 32, 34, 40, 42, 46 are sent to the control unit 50.

FIG. 2 shows the details of the control unit 50. Referring to FIG. 2, an analog output from the intake pressure sensor 28 and the like is input to a level conversion circuit 52 in the control unit and converted to a predetermined level. Are input to the microcomputer 54. The microcomputer 54 includes an A / D conversion circuit 54a, an I / O 54b,
A CPU 54c, a ROM 54d, a RAM 54e, an operation counter and a timer (the counter and the timer are not shown) are provided.
After being converted into a digital value by the A / D conversion circuit 54a in accordance with the command of 54c, it is temporarily stored in the RAM 54e. The digital output of the crank angle sensor 40, etc.
After the waveform is shaped in the waveform shaping circuit 56, the I / O 5
4b, and is input into the microcomputer.
The output of the knock sensor 46 is transmitted to the control unit 5.
After being transmitted to 0, it is input to knock detection circuit 60.
The knock detection circuit 60 includes a filter means 60a, a comparator means 60b, and a D / A conversion means 60c. In the comparator means 60b, a reference value sent from the microcomputer through the D / A conversion means 60c and sent out through the filter means 60a. The detected knocking state is detected by comparing the detected value with the sensor output value.

As is well known, the CPU 54c of the microcomputer 54 calculates the engine speed from the output of the crank angle sensor 40,
The basic ignition timing is calculated by judging the engine load state from the output of the engine, and the final ignition timing is determined by appropriately correcting the knock generation state detected from the knock sensor 46, and is formed by an igniter and the like via an output circuit 62. An ignition command is issued to the ignition device 64, and the ignition plug 24 of a predetermined cylinder is ignited via the distributor 36 to ignite the air-fuel mixture in the cylinder combustion chamber 22. Further, in the microcomputer 54, C
The PU 54c similarly calculates the fuel injection control value, sends it out to the fuel injection device 68 via the second output circuit 66, and regulates the supply of fuel through the injector 20.

Next, the operation of the control device will be described with reference to the flowchart of FIG. This program is started by interruption at an appropriate crank angle.

First, in S10, it is determined whether an acceleration correction condition is satisfied. This condition includes, for example, that the warm-up has been completed and the vehicle speed and the engine speed are not extremely high.

When it is determined in S10 that the acceleration correction condition is satisfied, the process proceeds to S12, in which the NE / θthACCR table stored in the ROM 54d is searched from the engine speed NE, and this acceleration correction is targeted. Search throttle opening θthACCR. FIG. 4 shows the characteristics of the table. Then, the process proceeds to S14, where the previously detected actual throttle opening is compared with the searched throttle opening. If the previously detected actual value is smaller than the search value, the process proceeds to S16, where acceleration correction described below is performed. . That is, the opening and closing of the throttle valve is accompanied by an increase in the amount of intake air, that is, from a region with a relatively low opening (the hatching region) equal to or less than θthACCR to a region with a high opening (the non-hatching region) above it as indicated by the arrow. Since a sudden change in torque occurs when the throttle valve is depressed, such a state is set as an acceleration correction target in the present invention.

When the process proceeds to S16, it is determined whether or not the acceleration correction retard amount θIGACCR of the ignition timing is zero. Since the initial value of this value is zero, the answer is naturally affirmed and the routine jumps to S18, where the amount of change in the throttle opening Δθ Th (first-order difference value per predetermined time or predetermined crank angle) is calculated and the predetermined value is obtained. It is compared with the DTh ACCR to determine whether or not the vehicle is in a rapid acceleration state. That is, the predetermined value D
The value of Th ACCR is appropriately set, and a rapid acceleration state with a sudden change in torque is detected instead of a gentle acceleration state in which the throttle valve is gently depressed.

If it is determined in S18 that the vehicle is in the acceleration state, S
20 and the detected vehicle speed V is set to a predetermined value VACCRL,
For example, it is compared with a minimum value of about 5 km / h, and if it exceeds the value, the routine proceeds to S22, where the engine speed NE is calculated from NE / θIGAC.
The retard correction amount θIGACCR is determined by searching the CR1 table. FIG. 5 shows the characteristics of the table. On the other hand, if the detected vehicle speed is equal to or less than the predetermined value, the process proceeds to S24, and similarly, a similar NE / θIGACCR2 table is searched from the engine speed to determine the retard correction amount θIGACCR. FIG. 6 shows the characteristics of the table. As is clear from FIGS. 5 and 6, the retardation correction amount θIGAC
Both CRs are set with different characteristics with the middle speed range (specifically around 3000 rpm) as a boundary, and in the lower range where the engine output is relatively low, the output is made in direct proportion to the engine speed and increases with the increase in the engine output. The degree of decrease is set to be large, and in a high-speed range exceeding the set degree, it is set to be inversely proportional to the number of revolutions. That is, in this high-speed range, it is expected that the value of the vehicle speed, which is substantially proportional to the engine speed, increases and the moment of inertia becomes sufficiently large, so that the amount of retard correction is reduced in inverse proportion to the engine speed. Set as follows.
Further, the characteristic of FIG. 6 applied to an extremely low vehicle speed range is set smaller than the characteristic of FIG. 5 applied to various vehicle speed ranges, so that engine stall does not occur due to misfire. Like

Subsequently, the process proceeds to S26, where the down counter CA
The CCR is set, and it is determined in S28 whether the value of the counter has reached zero. Since this counter has just been set, the judgment here is naturally denied and S30
And the value of the counter is decremented by one,
To the unit amount DθAC from the retard correction amount θIGACCR.
CR is subtracted and corrected, and the routine proceeds to S34, where the ignition timing θ IG
Is subtracted from the ignition timing to obtain the current ignition timing θ IG ,
The ignition timing is commanded with this value, and the program is once ended. The ignition timing θ IG is a value obtained by adding another correction such as knock correction to the basic ignition timing described above. Also S
Unit quantity mentioned in 32 DishitaACCR may slow the vehicle speed, medium speed, and divided into a high speed, it may be made different accordingly. Note that in this flowchart, the ignition timing θ
Subtraction from IG means retard correction, and addition means advance correction (however, subtraction in S32 means correction in the advance direction).

In the next and subsequent program loops, the program proceeds to S14 via S10 and S12, where the throttle opening is set to a predetermined opening θthAC indicated by hatching in FIG.
It is determined that CR has been exceeded, and the flow proceeds to S38. If it is determined in S14 that the previously detected throttle opening is still less than the predetermined opening θthACCR, the process proceeds to S36 via S16, and the result is NO in the same manner, and the process similarly proceeds to S38. Then, in S38, it is determined that the retard correction amount θIGACCR is not zero, and the ignition timing is determined and commanded while decrementing the counter CACCR through S28 to S34. That is, as shown in FIG.
During the period CACCR defined by the counter, the retard correction of the ignition timing is continued while the retard correction amount is gradually reduced.

If it is determined in step S28 that the value of the counter CACCR has reached zero in some program loops, the process proceeds to step S40, where the variation Δ 機関 in the engine speed Δ
It calculates the N e (1-order difference value per predetermined time or a predetermined crank angle) is compared with a predetermined value DNACCR. As the predetermined value DNACCR, a value that can detect a change in the increase or decrease direction of the engine speed is selected and used. If it is determined in S40 that the change amount of the engine speed exceeds the predetermined value and the engine speed is increasing, the process proceeds to S32, and the retard correction amount θIGACCCR
Is reduced (advance correction), and the routine proceeds to S34, in which the ignition timing is determined. If it is determined in S40 that the amount of change in the engine speed is equal to or less than the predetermined value and the engine speed is decreasing, the process proceeds to S34.
42, the ignition timing θ IG becomes the advance correction amount DI
GACCA is added to advance the ignition timing. The advance correction amount DIGACCA divides the intake air temperature into two levels, and sets the unit amount at a high temperature to be smaller than that at a low temperature. Here, the reason why the ignition timing is advanced is to correct the fluctuation of the engine output by performing the retard correction when the engine speed increases and the advance correction when the engine speed decreases. The reason why the advance correction unit amount is determined based on the intake air temperature is to consider the knock margin, and the reason why the value on the high temperature side is made smaller is that the knock margin is smaller than that on the low temperature side.
Incidentally, the ignition timing θ IG referred to here also means a value obtained by adding other corrections other than the acceleration correction to the basic ignition timing as necessary, similarly to the ignition timing θ IG described in S34.

In the flowchart of FIG.
If the determination in step S18 is negative, or if it is determined in step S18 that the vehicle is not accelerating, the process advances to step S44 to set the retard correction amount θIGACCR to zero. If it is determined in S38 that the retard correction amount θIGACCR has reached zero, the program is immediately terminated.

As described above, in the present embodiment, the value of the retardation correction amount in the retard correction for preventing a sudden torque fluctuation during acceleration is different from that in the case where the vehicle speed is at an extremely low vehicle speed. As a result, the engine will not misfire and stall even when starting and accelerating from an extremely low vehicle speed. Further, the value of the retard correction amount is set appropriately for the engine speed, and when the engine output increases in accordance with the increase or decrease of the engine speed, the retard correction is performed so that the engine output decreases, and the engine When the output is reduced, the advance angle is corrected so that the engine output increases, so that the engine output can be smoothly increased, and the shaking vibration can be reduced to give a good feeling of acceleration. . Further, by performing the retard correction at the time of acceleration, it is possible to effectively prevent knocking that frequently occurs at the time of acceleration.

Although the acceleration is detected from the throttle opening in the above embodiment, it may be detected from the intake pressure or the engine speed. Although the value of the counter CACCR is decremented every time the program is started, that is, at every predetermined crank angle, it may be decremented at every predetermined time.

[0023]

[Effect of the invention] According to claim 1, wherein, even with never stalling the engine inviting misfiring, sudden torque during acceleration over the entire operating range when starting, accelerating from a very low vehicle speed The engine speed can be smoothly increased by preventing the fluctuation, and a good feeling of acceleration can be given while effectively avoiding the shaking vibration . Further, knocking due to a delay in following the ignition timing during acceleration can be effectively prevented as a secondary effect.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an entire ignition timing control device for an internal combustion engine according to the present invention.

FIG. 2 is a block diagram showing details of a control unit in FIG. 1;

FIG. 3 is a flowchart showing the operation of the control unit shown in FIG. 2 and showing the features of the present invention.

FIG. 4 is a characteristic diagram showing an acceleration correction throttle opening area used in the flowchart of FIG. 3;

FIG. 5 is an explanatory diagram showing characteristics of a retard correction amount table used in the flowchart of FIG. 3;

FIG. 6 is an explanatory view similar to FIG. 5 and showing characteristics of a retard correction amount table at an extremely low vehicle speed.

FIG. 7 is a timing chart illustrating the operation of the flow chart of FIG. 3;

[Explanation of symbols]

 Reference Signs List 10 internal combustion engine 28 intake pressure sensor 32 throttle position sensor 34 intake temperature sensor 40 crank angle sensor 42 vehicle speed sensor 50 control unit

Claims (1)

(57) [Scope of request for utility model registration] An ignition timing is retarded by a predetermined amount when the vehicle is accelerating, and when the engine speed is increasing, the retardation is corrected while decreasing the predetermined amount. the ignition timing control apparatus for an internal combustion engine so as to reduce the engine output fluctuation, a. Vehicle traveling speed detecting means for detecting the traveling speed of the vehicle; and b . Engine speed detecting means for detecting the engine speed, the provided pre Kisho quantitative, the running speed of the vehicle is set rather small as in a low traveling speed, engine speed predetermined rotation
If the engine speed is lower than
And the engine speed exceeds the predetermined speed.
When the engine speed increases,
An ignition timing control device for an internal combustion engine, which is set .