JPH0555711B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to an ignition timing control device that avoids knocking of an engine of an automobile or the like. (Prior technology) Knocking is mainly caused by compression ignition of unburned gas, and if it occurs violently, it can cause energy loss (lower output), shock to various parts of the engine, and even lower fuel efficiency, so it cannot be avoided. desirable. Conventional devices that control ignition timing to suppress such knocking include, for example, the "VG
System engine maintenance manual 1983” Nissan Motor Co., Ltd. Showa
Published in 1958, there is something written on page 35, and there is a
〜10 It is shown as in FIG. In Figure 7, 1
is an engine, in which intake air is supplied from an air cleaner 2 to each cylinder through an intake pipe 3, and fuel is injected by an injector 4 based on an injection signal Si. A spark plug 5 is installed in each cylinder,
A high voltage pulse Pi from an ignition coil 7 is supplied to the ignition plug 5 via a distributor 6.
The spark plug 5, distributor 6 and ignition coil 7 serve as an ignition means 8 for igniting the air-fuel mixture.
The ignition means 8 generates and discharges a high voltage pulse Pi based on the ignition signal Sp. Then, the air-fuel mixture in the cylinder is ignited and exploded by the discharge of the high-pressure pulse Pi, and is discharged as exhaust through the exhaust pipe 9. The intake air flow rate Qa is detected by an air flow meter 10 and controlled by a throttle valve 11 in the intake pipe 3. The vibration Ve of the main body of the engine 1 is detected by a knock sensor 12, and the output of the knock sensor 12 is input to a knock vibration detector 13. The knock vibration detector 13 is composed of a BPF (band pass filter) that passes only the frequency band of vibrations caused by knocking and an integrator, and detects a voltage proportional to the intensity of the knocking vibrations generated per combustion stroke.
Generates Vn (Vn=0 to 5V) and detects the knock
Output to. The knock judgment device 14 compares the output Vn of the knock vibration detector 13 with the judgment reference value Vo, and determines that Vn
When ＞Vo, it becomes [H], and when Vn≦Vo, it becomes [L]
A knock judgment signal Sn is output. Further, the rotation speed N of the engine 1 is detected by a crank angle sensor 15 built into the distributor 6. Signals from the air flow meter 10, knock determiner 14, and crank angle sensor 15 are input to the control unit 16, and the control unit 16 performs ignition timing control (there is also other injection amount control) based on these sensor information. (omitted below). FIG. 8 shows a block diagram of the part of the control unit 16 that realizes the ignition timing control function, and the control unit includes the correction amount calculator 21,
It is composed of a corrector 22, an ignition signal generator 23, an ignition timing calculator 24, and a Tp calculator 25.
Signals from the air flow meter 10 and crank angle sensor 15 are input to the Tp calculator 25, and the Tp calculator 25 calculates the basic injection amount according to the following formula.
Tp is calculated and output to the ignition timing calculator 24. Tp=K・Qa/N... However, K: Constant A signal from the crank angle sensor 15 is further input to the ignition timing calculator 24, and the ignition timing calculator 24 calculates Tp and Tp as shown in FIG. The basic advance angle value SAo is looked up from a three-dimensional table map with N as a parameter and output to the corrector 22.
The basic advance value SAo corresponds to the optimal ignition timing depending on the driving condition, and is expressed as the crank angle before top dead center. The corrector 22 further includes a correction amount calculator 21.
The retard angle correction amount SAk from is input. The correction amount calculator 21 calculates a retard angle correction amount SAk that corrects the basic advance angle value SAo to the retard side depending on whether or not knocking occurs.
(SAk≦0), and the initial value of SAk is
When the temperature is 0° and the knock judgment signal Sn reaches the [H] level (when knocking occurs), SAk is calculated at each ignition timing according to the following formula. SAk=SAk′−ΔSAr... However, SAk′: Retardation correction amount at the previous ignition timing SAk: Retardation correction amount at the current ignition timing ΔSAr: Correction value toward the retard side for each ignition timing On the other hand, the same signal When Sn is at [L] level (knocking does not occur), SAk is updated according to the following formula at each ignition timing. SAk=SAk'+ΔSAa... However, ΔSAa: Correction value to the advance side for each ignition timing The upper limit value of SAk when updating to the advance side is 0°, and a positive value exceeding 0° It won't be. The corrector 22 converts the basic retard value SAo into a retard correction amount.
Final advance angle value SA corrected by SAk and expressed by the following formula
is determined and output to the ignition timing calculator 24. SA=SAo+SAk... The ignition timing calculator 24 outputs the ignition signal Sp to the ignition means 8 at a timing corresponding to the final advance value SA, and the ignition means 8 generates a high pressure pulse Pi at the same timing to ignite the air-fuel mixture. do. Therefore, when the occurrence of knocking is detected, the ignition timing is sequentially retarded to suppress knocking, and when knocking no longer occurs, the ignition timing is gently advanced again to maintain optimal combustion conditions. In this case, the correction value ΔSAr is a value around 1°,
ΔSAa is set to a value of approximately ΔSAa=ΔSAr×(1/10 to 1/15). This is because, while knocking is suppressed immediately, the return from retard angle (advance angle) is done slowly to avoid rapidly approaching the knocking region again. (Problems to be Solved by the Invention) However, such conventional ignition timing control devices are configured to actually detect knocking and delay the ignition timing. Deterioration in sexuality, etc. (e.g.
It is difficult to avoid a decrease in torque (decreased torque), and there is room for improvement from the perspective of higher driving performance that is required these days. Here, we will explain in detail (a) the deterioration of drivability etc. due to the first occurrence of knocking, and (b) the required high drivability. First, (a) will be explained. FIG. 10a is a graph showing changes in the amount of fuel (note that this is the amount of fuel actually supplied to the engine) and the amount of intake air during rapid operation. When acceleration is started (depressing the throttle pedal) at time _t1 , the amount of intake air increases, and after a slight delay, the amount of fuel increases. This is because, as shown in the previous equation, the basic fuel injection amount Tp is determined by the intake air amount Qa and the engine speed N, and after a "predetermined time delay" according to this calculated value (Tp). This is because fuel is supplied to the engine. The delay time is generally determined by the fuel transfer delay time or the fuel injection valve (injector).
is given by the response delay time. Therefore, as shown in FIG. 10b, immediately after the start of acceleration, the amount of fuel is insufficient relative to the amount of intake air and the air-fuel ratio becomes lean, making knocking more likely to occur. In particular, the time t ₂ when the engine speed starts to increase is the actual acceleration start time (note that the time t ₁ is the time when the acceleration operation starts), so from this time t ₂ onwards, , the engine load increases rapidly and high-energy knocking becomes more likely to occur. The conventional technology retards the ignition timing when knocking of a predetermined value or more (ie, high-energy knocking) is detected. This means that no measures are taken against the first occurrence of knocking, and that it is impossible to prevent knocking from occurring once or several times during sudden acceleration. Although this is extremely short-term, it is impossible to avoid abnormal combustion in the engine, which goes against the technical requirement of fully demonstrating the operating performance of the engine. Next, regarding (a) "required high drivability", the first knocking occurs, for example, at the time of acceleration operation.
This can be avoided by retarding the ignition timing (estimated correction) in advance at _t1 . However, such estimated correction of the ignition timing at the start of the acceleration operation results in a decrease in engine torque during acceleration, resulting in deterioration of acceleration response. Therefore, due to the lack of engine torque, even if the amount of fuel is actually increased at time _t2 , the rise in engine speed is delayed. (Objective of the Invention) Therefore, the present invention accurately grasps the point in time when the engine speed starts to rise during acceleration, and uses this point as the starting point for knocking estimation control.
The purpose is to effectively suppress initial knocking while ensuring acceleration response. Here, the period Tn shown in FIG. 10 is a period in which knocking is likely to occur immediately after acceleration, and is referred to as a knocking induction period in this specification.
The knocking induction period Tn shown in the figure starts from time _t1 and continues until a predetermined time after _t2 , but this is just an example and may vary depending on the engine type and operating condition. Needless to say.
Furthermore, although an example of knocking that occurs during the knock inducing period Tn is shown in c of the same figure, knocking between time points t ₁ and t ₂ actually hardly occurs, or even if it does occur, it is extremely small. It's just a light knocking. This means that between time t ₁ and t ₂ the actual amount of fuel does not increase and therefore
This can be understood from the fact that the engine is in a state before high-load operation. (Structure of the Invention) The combustion control device for a vehicle engine according to the present invention has a basic conceptual diagram shown in FIG.
In addition to calculating the amount of fuel supplied to the engine (Tp) based on In a vehicle engine combustion control device that calculates a correction amount (SAk) for correcting the advance angle value (SAo), the amount of change (ΔTp) in the fuel supply amount (Tp) is calculated, and the amount of change (ΔTp) is calculated. If the amount of change (ΔTp) starts to decrease within a predetermined period from the time when it exceeds a predetermined value, it is determined that the transition to the knock induction period has started,
The present invention is characterized in that the transient retard correction amount (SAm) is immediately calculated, and the retard correction is performed using the transient retard correction amount (SAm) as the correction amount (SAk). (Example) Hereinafter, the present invention will be explained based on the drawings. FIG. 2 is a diagram showing a first embodiment of the present invention.
In explaining this embodiment, the same components as those of the conventional example are given the same reference numerals, and the explanation thereof will be omitted. First, the configuration will be explained. In Figure 2, 31
is a control unit, and the control unit 31 has a new transient detector 3 compared to the conventional example.
2. A transient control section detector 33 and a memory 34 are additionally configured. The transient detector 32 detects the engine load change amount ΔTp from the output Tp of the Tp calculator 25.
(For example, the amount of change in Tp for each ignition timing (IGN) or for each predetermined time), and calculate ΔTp>2msec/
If ΔTp becomes negative within a predetermined rotation (for example, two rotations) after IGN, a transient discrimination signal Sk that becomes [H] and [L] otherwise is output to the transient control section detector 33. That is, when a predetermined initial state of acceleration is detected, the signal Sk is set to [H],
When not detected, the signal Sk is set to [L]. In addition,
Detection of the initial state of acceleration is not limited to changes in Tp; for example,
It may also be performed based on changes in the throttle valve opening, suction negative pressure, etc. The transient control period detector 33 detects the knock induction period Tn caused by lean air-fuel ratio during acceleration, and starts from the time when the transient discrimination signal Sk becomes [H] at a predetermined rotation (for example, 10 rotations). The period is detected as the knock inducing period Tn, and the detection result is output to the correction amount calculator 21. Correction amount calculator 21
In addition to the same function as the conventional example, the retard angle correction amount SAk when knocking is suppressed is output to the memory 34. The memory 34 learns this SAk as corresponding to the driving state at that time, and stores it in the corresponding area as a corrected storage value SAm. Note that the memory 34 is constituted by, for example, a nonvolatile memory, and retains the corrected storage value SAm even after the engine 1 is stopped. Furthermore, when the knock inducing period Tn is detected, the correction amount calculator 21 changes the knock judgment signal Sn to [H].
Memory 34 without waiting for the level to change
Read out the correction memory value SAm in the area corresponding to the same driving condition at that time, and use this as the retard correction amount.
It is adopted as SAk and output to the corrector 22. Also,
When the notk induction period Tn ends, SAk is immediately
Update to SAk=0°. Therefore, the retardation correction amount SAk at the end of the knock inducing period Tn is stored in the memory 34 as the correction storage value SAm. It should be noted that each sensor and circuit in this embodiment constitutes the following means, and corresponds to the structural requirements for embodying the present invention. Operating state detection means 41: Air flow meter and crank angle sensor 15 Knock detection means 42: Knock sensor 12, knock vibration detector 13, and knock determination device 1
4 Knock induction period detection means: transient detector 32 Correction amount calculation means 43: correction amount calculation unit 21 and transient control interval detector 33 Storage means: memory 34 Advance angle value setting means 44: corrector 22, ignition timing calculation unit and Tp calculator 25 Ignition signal generating means: Ignition signal generator 23 Next, the operation will be explained. Generally, ignition timing control is performed as one method to avoid knocking. This aims to optimally control the combustion state while avoiding knocking as much as possible by advancing the ignition timing when knocking is not occurring and retarding the ignition timing when knocking occurs. However, since such control is based on the premise of detecting the occurrence of knocking, it is difficult to eliminate the adverse effects of knocking in the initial stage of knocking suppression. Therefore, in this embodiment, we focus on the point that knocking can be avoided if such a situation can be predicted before knocking occurs, and by detecting the situation where knocking occurs as a transient state, we reliably predict the knocking induction period Tn. In addition, the retardation correction amount SAk at the end of the knock inducing period Tn is learned,
By using this learned value from the next time onwards, the occurrence of knocking can be prevented and its negative effects can be eliminated. That is, when an acceleration operation is performed, the transient detector 3
2, the initial state of acceleration is detected and a transient judgment signal is generated.
Sk becomes [H]. Therefore, the correction amount calculation means 43 determines that the knock inducing period Tn has started, reads out the correction stored value SAm from the memory 34, and employs this as the retard correction amount SAk. As a result, the basic advance value SAo is immediately advanced according to the above formula, and the ignition timing is retarded. Therefore, in practice, the ignition timing is immediately retarded following the acceleration operation, and knocking can be avoided without causing knocking even once, regardless of the transition to the knock inducing period Tn. . This means that the occurrence of knocking can be prevented even during the knock inducing period Tn compared to the conventional engine, and it is possible to avoid the adverse effects of knocking occurrence and to significantly improve engine drivability. Furthermore, since the update correction (advance correction) is made to SAk=0° immediately after the knock inducing period Tn ends, there is an effect that a decrease in the output of the engine 1 can be minimized. Note that this advance angle correction is not limited to immediately setting SAk to 0°, but it can also be used to advance the angle by a predetermined amount (for example, 1° or a larger value that does not result in SAk = 0° at once) at each ignition timing. It may be updated. FIG. 3 is a diagram showing a second embodiment of the present invention,
This embodiment is an example in which the present invention is implemented by applying a microcomputer. The hardware configuration of this embodiment is the same as that shown in FIG. 7 presented as a conventional example, so a description thereof will be omitted, except that the control unit is constituted by a microcomputer. The control unit in this embodiment has the functions of a knock induction period detection means, an advance angle value setting means, a correction amount calculation means, a storage means, and an ignition signal generation means. is also held. FIG. 3 is a flowchart showing the ignition timing control program, and _P1 to _P20 in the figure indicate each step of the program. Note that this program is executed once for each ignition timing. First, at _P1 , a basic advance angle value SAo is calculated according to the operating state of the engine 1. This calculation is performed, for example, by looking up the appropriate optimal value from the table map of N and Tp, as in the first embodiment. Next, in P ₂ , it is determined whether the value of the change amount ΔTp of the basic injection amount Tp for each routine is greater than or equal to 2 msec/IGN, and when ΔTp≧2 msec/IGN, it is determined that it is a _transient state, and the 1 counter count value C _1
C1 is set to 4, the knock zone flag NF is reset (NF=0), and the process proceeds to _P4 .
On the other hand, if ΔTp<2msec/IGN, proceed directly to _P4 . The first counter is used together with the second counter described later to determine the knock triggering period Tn.
The set value C ₁ =4 means determination of two engine revolutions. The knock zone flag NF is a flag that indicates whether or not the engine 1 is within the knock inducing period Tn, and when it is set (NF=1), it is reset (NF= 0) indicates that the same period is not within Tn. Next, check the count value _C1 of the first counter at _P4 , and if _C1 = 0 (for example, when the first counter was cleared in the previous routine),
At _P5 , reset the knock zone flag NF and proceed to _P6 . Also, when C≠0, the knock zone flag NF is determined in P ₇ , and when NF = 1, the process advances to P ₈ and NF is determined.
When = 0, the count value of the first counter C ₁ at P ₉
Subtract [1] from (decrement) and proceed to P ₁₀ . At P ₁₀ , it is determined whether the amount of change ΔTp is negative or not, and when ΔTp<0, it is the time to start transitioning to a predetermined transient state (i.e. knock induction period Tn) (hereinafter referred to as zone start timing). After making a judgment, the ignition timing is retarded in steps _P11 to _P14 . On the other hand, when ΔTp≧0, it is determined that it is not the zone start timing, and the process jumps to step _P6 . When it is time to start the zone, first press P ₁₁ .
At P12, the knock zone flag NF is set, and the count value _C2 of the second counter is set to _C2 =20, and at _P12 , the correction stored value SAm is read from the memory and used as the retard correction amount SAk. Then,
At _P13 , calculate the final advance angle value SA according to the above formula,
_P14 outputs the ignition signal Sp at the timing corresponding to SA. Therefore, the ignition timing is immediately retarded by the value SAm, and knocking can be avoided even though the knocking inducing period Tn has started. On the other hand, if the above steps _P5 , _P10 branch to _P6 , the knocking zone flag NF is determined in _P6 , and if NF=1, the second counter is decremented in _P8 , and the process proceeds to _P15. . Further, when NF=0, it is determined that it is not within the knock inducing period Tn, and the normal knocking control (knocking control based on the output of the knock detecting means 42) following _P16 is executed. At P ₁₅ , the count value C ₂ of the second counter is

[0], and if C ₂ ≠0, it is determined that the knocking triggering period Tn is still within the knocking triggering period Tn, and the process proceeds to _P16 , where normal knocking control similar to the above is executed. When C ₂ = 0, it is determined that the same period Tn has ended, and in P ₁₇ the knock zone flag NF is reset and the first counter is cleared, and in P ₁₈ the retard angle correction amount SAk at this time is set as SAm. The lead angle value is stored in the memory and updated to SAk=0 for lead angle correction to return to the basic lead angle value SA, and then the process proceeds to _P13 . When it is determined from P ₆ and P ₁₅ to shift to normal knocking control in accordance with the NO command, it is first determined at P ₁₆ whether or not knocking is occurring due to the current ignition. If knotking occurs, P ₁₉
Then, a retard angle correction is performed according to the above formula, and if no occurrence has occurred, an advance angle correction is performed according to the above formula at P ₂₀ , and the process then proceeds to P ₁₃ . Note that the lower limit value of the lead angle correction is limited to -15°, and the upper limit value of the lead angle correction is limited to 0°. FIGS. 4a to 4c are timing charts showing ignition timing control based on the above program. When an acceleration operation is performed at timing t ₁₁ , the fourth
As shown in Figure a, the basic injection amount Tp increases and ΔTp increases.
2msec/IGN or more. Therefore, as shown in FIG. 4b, the first counter is set to [4],
Thereafter, it is decremented at each ignition timing. Then,
The count value C ₁ of the first counter is

Before it becomes [0],
In other words, the timing is before engine 1 rotates twice.
When Tp changes in the negative direction at t ₁₂ , the knock-induced period
It is determined that the transition is to Tn, and the second counter is set to [20], and thereafter is decremented at every ignition timing. Therefore, _t12 is the zone start timing, and as shown in FIG. 4c, SAm is adopted as the retardation correction amount SAk at _t12 , and the ignition timing is immediately retarded to a value that can avoid knocking. As a result, it is possible to prevent knocking from occurring at the zone start timing. From then on,
The counter value C ₂ of the first counter is from [20]

[0]
There is a notification period while the count is down to
Tn, and specifically corresponds to the 10 revolution section of engine 1. During this period Tn, the flow follows normal knocking control processing, but since the knocking has been sufficiently retarded at the zone start timing _t12 , it is extremely rare to actually detect knocking and perform further retard correction. be. And at timing t ₁₃
When C ₂ = 0, it is determined that the knock induction period Tn has ended, and as shown in Figure 4c, the
SAk is stored as SAm, and the lead angle is immediately corrected to update SAk to 0°. FIG. 5 is a diagram showing a third embodiment of the present invention,
This embodiment is an example in which a microcomputer is applied like the second embodiment, but the processing at the time of advance angle correction is different from the second embodiment. In FIG. 5, steps that perform the same processing as in the first embodiment are given the same numbers and their explanations are omitted, and steps that are different are given numbers in the 30s and their processing contents will be explained. If it is determined that C ₂ = 0 at P ₁₅ and the end of the knock induction period Tn is determined, then the current state at this time is passed through P ₁₇ and then at P ₃₁ .
In addition to storing SAk in memory as SAm,
Set the advance flag ADF (ADF=1) and proceed to _P16 . The advance flag ADF is a flag that displays the degree of advance angle correction after the end of the knock induction period Tn, and when ADF=0, a small value ΔSAa is adopted as the advance angle correction value.
This indicates that a large value ΔSAa ₂ is adopted when ADF=1. Next, in _P16 , it is determined whether or not knocking has occurred, and if knocking has not occurred, the advance flag ADF is determined in _P32 . When ADF=1, the retard angle correction amount SAk is updated (hereinafter referred to as rapid advance angle correction) in accordance with the following equation in P ₃₃ and the process proceeds to P ₁₃ . SAk=SAk′+ΔSAa... In the formula, the advance angle correction value ΔSAa ₂ is set to a value within the range of ΔSAa<ΔSAa ₂ ≦ΔSAr. In addition, in advance angle processing in P ₃₃ , a predetermined upper limit value (a predetermined value less than 0°) is used.
is the limit, and if this upper limit is reached, ADF=
Set to 0. Therefore, in this case, the advance angle is gradually corrected thereafter. Also, when ADF=0 at P ₃₂ ,
In P ₃₄ , SAk is updated (hereinafter referred to as slow advance angle correction) according to the above formula similar to the conventional example, and the process proceeds to P ₁₃ . On the other hand, if knocking occurs at P ₁₆ , retard angle correction is performed in accordance with the above formula at P ₃₅ to suppress knocking, and at the same time, ADF = 0 is set to take into account the possibility of knocking occurring in the next routine and a slow advance angle correction is performed. and proceed to page ₁₃ . In this way, in this embodiment, the knock inducing period Tn
Since the advance angle is appropriately corrected after the end of the first embodiment while paying consideration to knocking, there is an effect that sudden changes in torque can be suppressed and drivability can be further improved compared to the first embodiment. 6a to 6c are timing charts showing ignition timing control based on the above program. The processing at the time of acceleration transition is similar to the first embodiment and is depicted in the same state, and the time of return will be explained. When the knock induction period Tn ends at timing t ₁₃ ,
As shown by the solid line in Figure 6c, SAk at this time is
It is stored as SAm, and a rapid advance angle correction is performed at a faster advance angle speed than usual at each ignition timing.
SAk is sequentially updated to the initial value SAk=0° side. Therefore, the ignition timing is rapidly advanced sequentially at the same time as the knock induction period Tn ends, so that the engine 1
This makes it possible to avoid a sudden change in the torque while suppressing its decrease, thereby appropriately reducing the shock at the time of return.
Incidentally, in the past, as shown in FIG. 10(d), the advance angle was corrected slowly by the value ΔSAa, so a reduction in torque at the time of return was allowed compared to the present embodiment. Further, in this return process, if knocking occurs at timing _t14 , for example, the ignition timing is corrected to suppress knocking, as shown by the broken line in FIG. In this way, even if rapid advance angle correction is performed, if knocking is detected, processing is performed to suppress it immediately, so deterioration in the drivability of the engine 1 is avoided as much as possible and the ignition timing is adjusted as much as possible. Output performance can be secured by advancing the angle. (Effect) According to the present invention, the change amount ΔTp decreases within a predetermined period from the time when the change amount ΔTp in the fuel supply amount Tp determined based on the intake air amount Qa and the engine speed N exceeds a predetermined value. As soon as the transition to the knock inducing period is determined to have started, the retard correction based on the transient retard correction amount is executed. The point at which the amount of change ΔTp starts to decrease is
This is the point at which the fuel actually increases with the acceleration operation, and as a result, the engine speed N begins to rise. Therefore, after this point, the engine is operated under high load and high-energy knocking is likely to occur. Therefore, by retarding the ignition timing, the occurrence of knocking can be prevented. In addition, since the transitional retardation correction is performed only when the amount of change ΔTp starts to decrease within a predetermined period of time, for example, driving conditions in which the accelerator is quickly pressed down and then pressed back down (in general, knocking does not occur) (operating state), the amount of change ΔTp does not become negative within the predetermined period, so unnecessary retard control can be reliably prevented. Moreover, since the ignition timing is not retarded until the engine speed starts to rise, the engine speed can be quickly increased while maintaining a high torque state, and acceleration responsiveness can be ensured.

[Brief explanation of drawings]

Fig. 1 is a basic conceptual diagram of the present invention, Fig. 2 is a block diagram showing a first embodiment of the invention, Figs. 3 and 4 are diagrams showing a second embodiment of the invention, and Fig. 3 is a diagram showing a second embodiment of the invention. 4 is a flowchart showing the ignition timing control program, FIGS. 4a to 4c are timing charts for explaining its operation, and FIGS.
FIG. 5 is a flowchart showing an ignition timing control program, and FIG. 6a is a diagram showing an embodiment.
7 to 10 are diagrams showing the conventional ignition timing control device, FIG. 7 is its overall configuration diagram, FIG. 8 is its block diagram, and FIG. 9 is a timing chart for explaining its operation. The figure shows the relationship between the rotation speed, basic injection amount, and advance angle value, Figure 10a
~d is a timing chart for explaining the effect. DESCRIPTION OF SYMBOLS 1...Engine, 8...Ignition means, 31...Control unit, (knock induction period detection means,
Advance angle value setting means, correction amount calculation means, storage means, ignition signal generation means), 32... transient detector (knock induction period detection means), 34... memory (storage means), 41... operating state detection means , 42... Knock detection means, 43... Correction amount calculation means, 44...
Lead angle value setting means.

Claims (1)

[Claims] 1 Calculate the fuel supply amount (Tp) to the engine based on the engine intake air amount (Qa) and engine rotation speed (N), and calculate the basic advance value of the ignition timing (SAo) according to the engine operating condition. ),
In addition, in a combustion control device for a vehicle engine that calculates a correction amount (SAk) for correcting the basic advance angle value (SAo) depending on whether or not knocking occurs, the amount of change (ΔTp) in the fuel supply amount (Tp) is calculated. ), and if the amount of change (ΔTp) turns to decrease within a predetermined period from the time when the amount of change (ΔTp) exceeds a predetermined value, it is determined that the transition to the knock induction period has started, Combustion control for a vehicle engine, characterized in that a transient retardation correction amount (SAm) is immediately calculated, and the retardation correction is performed using the transient retardation correction amount (SAm) as the correction amount (SAk). Device.