JPS62251451A - Knocking control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To maintain always the ignition timing at a best fuel consumption point and to make it possible to prevent occurrence of knocking, by controlling the amount of intake-air to restrain occurrence of knocking, and by performing MBT control for the ignition timing after the above-mentioned restraint. CONSTITUTION:An intake-air amount control means (c) computes a control value for controlling the amount of intake-air, and controls an operating means (throttle valve) (e) to change the amount of intake-air to restrain occurrence of knocking so that knocking detected by a knocking detecting means (d) is restrained at a predetermined level. Further, after the above-mentioned restraint, an ignition timing control means (d) detects a peak valve of combustion at which the burning pressure of an engine cylinder becomes locally maximum in accordance with an output signal from a pressure detecting means (a), and therefore, performs the MBT (minimum spark advance) control of an ignition means (f) so that the position of the above-mentioned burning peak becomes a desired peak position at which the generated torque of the engine comes to be maximum. Thus, it is possible to greatly enhance the economy of fuel consumption and to prevent the engine from being damage due to knocking.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device for suppressing knocking by controlling the intake air amount or ignition timing of an internal combustion engine such as an automobile.

(Prior Art) The ignition timing of an internal combustion engine needs to be determined according to the state of the engine so that the engine can be operated for an optimal period.

Generally, when considering engine efficiency and fuel efficiency, the minimum advance angle at maximum torque, so-called MBT (formerly nimum ad-
It is known that it is best to ignite near the varrce for Be5t Torque), and depending on the engine condition, when to ignite the MBT! The so-called MBT that changes IJI
Control takes place.

However, in certain engine conditions, advancing the ignition timing causes knocking, making it impossible to operate the engine stably. For example, at low speeds and low loads, MBT
The knocking limit was reached earlier. Furthermore, the knocking limit is easily affected by atmospheric conditions such as temperature and humidity.

Therefore, the so-called knocking control, which controls the ignition timing depending on the presence or absence of knocking, is carried out in the above Ms T 1bl.
A method has been developed that can be used in combination with l control.
For example, Japanese Patent Application Laid-Open No. 58-82074
There is a device described in the publication.

In this device, the pressure inside the combustion chamber (hereinafter referred to as cylinder pressure)
M B
T fldl iTH. At the same time, knocking is detected by passing the cylinder pressure detection signal through a signal processing circuit, and when the knocking level exceeds a predetermined value, the MB
The ignition timing is controlled to the retarded side in order to avoid knocking with priority over T control. This is intended to improve driving performance by increasing the torque generated by the engine as much as possible while suppressing knocking.

Thus, controlling the ignition timing to suppress knocking is considered to be widely adopted because it is easy to control the ignition timing.

(Problem to be Solved by the Invention) However, in the above device, the ignition timing, which is normally set at the timing when the engine has the best combustion condition to maximize the generated torque, is changed to suppress knocking. Since the ignition timing is retarded, the combustion condition deteriorates due to the ignition timing retardation, and the best combustion condition cannot be obtained under each operating condition. Therefore, such a deterioration in the combustion state significantly deteriorates fuel efficiency.

Further, the exhaust gas temperature increases due to the deterioration of the combustion state, which may damage exhaust system members such as the exhaust purification catalyst and the exhaust pipe.

(Objective of the Invention) Therefore, the first invention is to control the amount of intake air to suppress knock, and to perform MBT control on the ignition timing after suppressing knock, thereby adjusting the ignition timing to maximize fuel efficiency. The purpose is to suppress knocking by lowering the intake charging efficiency of the engine when torque is generated while maintaining the engine at the point (M B T), thereby improving fuel efficiency and preventing damage to the engine.

Further, the second invention provides a method for controlling the amount of intake air during steady operation to suppress knock, performs MBT control of the ignition timing after suppressing knock, and controls the ignition timing for suppressing knock during acceleration. , maintains the ignition timing at the best fuel efficiency point (MBT) so that the output torque is always maximized by minimizing the decline in torque and acceleration feeling while appropriately avoiding the occurrence of knocking, improving fuel efficiency and The purpose is to prevent damage to the engine.

(Means for Solving the Problems) In order to achieve the above object, the knocking control device for an internal combustion engine according to the first aspect of the present invention adjusts the combustion pressure of the engine as shown in FIG. a pressure detection means a for detecting the knocking level of the engine; a knock detection means for detecting the knocking level of the engine; When knocking is suppressed by controlling the amount, a combustion peak position at which the combustion pressure becomes maximum is detected based on the output of the pressure detection means a, and this combustion peak position is determined as a target peak position at which the generated torque of the engine is maximized. ignition timing control means d for controlling the ignition timing so that It is equipped with an ignition means for igniting the fire.

In addition, in order to achieve the above-mentioned object, the knocking control device for an internal combustion engine according to the second aspect of the present invention is shown in FIG. 1 (B
), the pressure detection means a detects the combustion pressure of the engine, the knock detection means detects the knocking level of the engine, the operating state detection means C detects the operating state of the engine, and the knocking detection means detects the knocking level at a predetermined level. a first control means n d that calculates a control value to control the intake air amount so as to suppress knocking to a predetermined level; a second control means e that calculates a control value to control the ignition timing so as to suppress knocking to a predetermined level; When knocking occurs, the knocking is suppressed by controlling the selection means f which preferentially selects either the first mm means d or the second control means e according to the operating state of the engine at that time, and by manipulating the intake air amount. Then, the combustion peak position at which the combustion pressure becomes maximum is detected based on the output of the pressure detection means a, and the ignition timing is controlled so that this combustion peak position becomes the target peak position at which the generated torque of the engine is maximized. When the first control means d is selected by the selection means f, the first control means d
When the second control means e is selected by the selection means, the intake air amount operation means changes the intake air amount based on the output of
The air-fuel mixture is ignited based on the output of the second control means e, and the second
When the control means e is not selected, the ignition timing correction means g
ignition means i for igniting the air-fuel mixture based on the output of the ignition means i.

(Operation) In the first invention, the occurrence of knocking is suppressed by controlling the amount of intake air, and after the suppression, the ignition timing is subjected to MBT control. Therefore, the ignition timing is always maintained at the best fuel efficiency point (MBT) so that the output torque is maximized.

Further, in the second aspect of the invention, the occurrence of knocking is suppressed by controlling the amount of intake air during steady operation, and after this suppression, the ignition timing is subjected to MBT control.

On the other hand, during acceleration, knocking is suppressed by controlling the ignition timing. Therefore, the ignition timing is the best fuel efficiency point (M B T
), and the deterioration of torque and acceleration feeling is further minimized.

As a result, fuel efficiency and driving performance are improved, and damage to the engine is prevented.

(Example) Hereinafter, the first invention and the second invention will be described based on the drawings.

2 to 9 are diagrams showing a first embodiment of a knocking control device for an internal combustion engine according to the first invention.

First, the configuration will be explained. In FIG. 2, reference numeral 1 denotes an engine, an amount of 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.

An ignition plug 5 is attached to each cylinder, and the ignition plug 5 is supplied with a high pressure pulse Pi from a high pressure generation unit 6. The spark plug 5 and the high-pressure generation unit 6 constitute an ignition means 7 that ignites the air-fuel mixture, and the ignition means 7 generates a high-pressure pulse Pi based on the ignition signal Sp to cause discharge. Then, the air-fuel mixture in the cylinder is ignited and exploded by the discharge of the high-pressure pulse Pi, and is exhausted.

The intake air flow meter Qa is detected by an air flow meter 8 and controlled by a throttle valve 9 in the intake pipe 3. The throttle valve 9 is driven to open and close by a throttle valve drive unit (operating means) 10, and the throttle valve drive unit IO is driven by, for example, a step motor,
It is composed of an angle sensor and the like, and opens and closes the throttle valve 9 based on the drive signal Sc.

Further, the opening degree θa of the accelerator is detected by an accelerator sensor 11, and the crank angle of the engine 1 is detected by a crank angle sensor 12. The crank angle sensor 12 generates a (H) level pulse at a predetermined position before compression top dead center (TDC) of each cylinder at every explosion interval (120° for a 6-cylinder engine, 180° for a 4-cylinder engine), for example at 70° BTDC. It outputs a reference signal Ca that becomes a pulse of the (H) level for each unit angle (for example, 1 degree) of the crank angle. Note that the engine rotation speed Ne can be determined by counting the pulses of the signal Ca. Air flow meter 8 and crank angle sensor 12
constitutes the operating state detection means 13.

Furthermore, the load of the engine 1 is detected by a load sensor 14, and the cylinder discrimination is detected by a cylinder discrimination sensor 15. The load sensor 14 is constituted by, for example, a throttle valve opening sensor or an intake pipe negative pressure sensor, and outputs a load signal SL depending on the load state. The cylinder discrimination sensor 15 outputs a cylinder discrimination signal S at a predetermined crank angle displacement W (for example, 80° BTDC of the first cylinder) before the compression top dead center of a specific cylinder (for example, the first cylinder). Therefore, this cylinder discrimination signal SK is output once every two revolutions of the crankshaft.

Further, the combustion pressure Pa of the engine 1 is detected by a pressure sensor 16, and the pressure sensor 16 is specifically shown in FIG. 3(A).
, as shown in (B), is formed as a washer for the spark plug 5 screwed onto the cylinder head 17,
The ignition plug 5 is pressed and fixed into the outer recess 7 by the portion 5a.

Then, a pressure signal pa corresponding to the combustion chamber pressure (in-cylinder pressure) of the engine is outputted via a charge amplifier (not shown).

The output of the pressure sensor 16 is input to a knocking detection circuit 18, and the knocking detection circuit 18 detects when knocking occurs based on the pressure signal Pa from the pressure sensor 16 (see FIG. 5 (a)), as shown in FIG. 4, for example. For example, the high frequency component Pa' of 6 to 15 kHz, which is particularly abundant, is contained (Fig. 5 (
A bandpass filter (BP
F) 18a and its high frequency component Pa' are half-wave rectified and an envelope signal is formed from the half-wave rectified signal (envelope detection) to detect knocking according to the knocking level as shown in Fig. 5(c). The waveform shaping circuit 18b outputs the signal SN.

In this knocking detection circuit 18, the pressure signal Pa is smoothed to form a band ground level corresponding to the normal noise level of the engine, and the difference between the formed level and the maximum level of the envelope signal described above is used as the knocking signal. It may also be output as SN.

The pressure sensor 16 and the knocking detection circuit 18 constitute a knocking detection means 19.
The signals from each sensor 8.11.12.14.15 are input to the control unit 20.

The control unit 20 has functions as a knock detection means, an intake control means, and an ignition timing control means.
CPU21, ROM22, RAM as shown in detail in the figure
23, NVM (non-volatile memory) 24 and input/output interface, register, counter, A/D converter,
Input/output control circuit 25 with built-in high frequency cut filter etc.
Consisted of. The CPU 21 takes in necessary external data from the input/output control circuit 25 according to the program written in the ROM 22, and also reads the necessary external data from the RAM 23,
Processing values necessary for knock suppression, throttle valve opening control, and ignition timing control are processed while exchanging data with the NVM 24, and the processed data is output to the input/output control circuit 25 as necessary. do. The input/output control circuit 25 receives signals from the sensor group 8.11.12.14.15, the operating state detection means 13, and the knocking detection circuit 18, and also receives the drive signals Sc and 18 from the input/output control circuit 25. An ignition signal Sp is output. ROM22 is C
Stores the arithmetic program in P U21, and stores it in RAM2.
3. The NVM 24 stores data used in calculations in the form of a map or the like.

The ignition signal sp is manually inputted to the ignition means 7, and the high voltage generation unit 6 of the ignition means 7 is composed of an ignition coil 26, a battery 27, and a transistor Q1, as shown in detail in FIG. Based on transistor Ql
0N10FF$11111 to generate a high voltage Pi on the secondary side of the ignition coil 26, and this high voltage Pi
through the distributor 28 to the spark plugs 29a~
29f and ignites the air-fuel mixture.

Next, the effect will be explained.

FIG. 7 is a flowchart showing the knock suppression control and MBTII 1411 programs written in the ROM 22, and this program is processed by interruption every time the reference signal Ca is input.

First, the accelerator opening θa is read from the A/D conversion value of the accelerator sensor at P, and the engine rotation speed N and the accelerator opening θ, which are parameters representing the engine operating state, are read at PR.
From a, the basic value θt of the target throttle valve opening is set as θt=fun
It is calculated based on the functional form c (θa, N). This θt is stored in advance in the table map as a value that provides a smooth feeling of acceleration over a wide range of rotations, from low speed to high speed, and in P2, by look-amplifying the optimum value. demand.

Next, in P3, the knocking level KN is detected from the knocking signal 8.4, and in P4, this is set as the knocking judgment level K.
Compare with No. When K N > K N o, it is determined that knocking has occurred, and P reduces the feedback correction amount Δθt (Δθt is a negative value) of θt by α, and sets Δθt−α as the new feedback correction amount. Δθ
Store it as t. The correction amount α is the minimum throttle valve opening change necessary to prevent knocking, α=func (
Q, N) (where Q=negative load intake air amount or the value of θt itself)). Then P6
Then, θ(+Δθt is set as a new good value of the throttle valve opening for this time, and a drive signal Sc corresponding to this is outputted.

On the other hand, when K N S K N o, it is determined that knocking has not occurred, and the feedback correction amount Δθt of θt is increased by β (however, β minus α) (small in absolute value) at P. It is determined by Ps whether the value of Δθt is positive or not. When θt≧O, set Δθt=0 at P, regulate the upper limit of Δθt to zero, and proceed to P.
Further, when θ1<0, the process directly proceeds to P. this is,
This is because when Δθt>Q, the opening degree of the throttle valve becomes larger than the basic value of θt.

Then Pl. The MBT control value of the ignition timing is calculated (details will be described later in a subroutine), P, and the ignition signal Sp is output at the ignition timing corresponding to the lever control value.

Through the above step processing of P I''' P *, when knocking occurs, the throttle valve opening is slightly moved in the closing direction even if the accelerator depression amount is constant, and if knocking does not occur, control is performed to return it to the basic value. In other words, the knock suppression process is performed only by manipulating the intake air amount, and the ignition timing is not used for the knock suppression process, but is changed by MBT control.Therefore, it is possible to suppress knock while maintaining the ignition timing at MBT, which is different from conventional methods. Unlike this, it is possible to maintain optimal combustion conditions.

As a result, it is possible to improve fuel efficiency, suppress an excessive rise in exhaust gas temperature, and prevent damage to exhaust members such as the exhaust catalyst and the exhaust pipe. Note that the fuel efficiency, especially at high speeds, is significantly improved compared to the knocking avoidance method by retarding the ignition timing.

Next, MB of the ignition timing corresponding to the above steps P, P,
The T control will be explained in detail.

MBT'#lI'a is calculated when the crank angle θpa+ax (see Fig. 5 (a)) of the maximum cylinder pressure Pmax is at a predetermined value after compression top dead center (for example, 15° to 20° ATDC> Former nimum Advance for B
It gives the ignition timing of e5t Torque (MBT), and performs feedback control so that θpmax becomes the above-mentioned predetermined value. That is, in the subroutine shown in FIG. 8, first P! Cylinder pressure signal P at l
The maximum value Pmax is determined by A/D converting a at every predetermined crank angle, for example, 2 degrees, and then the crank angle at the time of Pmax calculation is determined as θpmax using P, and this is stored.

FIG. 9 is a subroutine for MBT control.

First, in Pill, eight basic ignition timings (omitting correction amounts for engine cooling water temperature, etc.) are obtained from the engine load Q and engine speed N, according to the functional form Be = f unc (Q, N), and in Po, the seventh The current position of θpsax determined by the subroutine shown in the figure is determined.

P when θps+ax is within a predetermined range given to MBT. The final ignition timing A is calculated according to the following formula (2).

A=Bo +FB ・・・・・・■ However, FB: Ignition timing feedback correction amount On the other hand, when θpmax is on the delayed side with respect to the predetermined range that gives MBT, the previous feedback batter correction 11FB is proceeded with psn. The angle correction i1a is added, p'13+a is set as a new correction IFB, and the process proceeds to Pll. Also, when θpmax is on the advance side, the feed bank correction amount FB is
Subtract retard correction 1b from , and set FI3-b to new correction 11
”Proceed to Pll as B.

In this way, in this embodiment, the ignition timing is always maintained at MBT regardless of the state of intake air amount restriction due to knock suppression control. Therefore, there is an advantage in that fuel efficiency is greatly improved.

The first embodiment described above is applicable to the MB regardless of whether or not knocking occurs.
Although T control is executed, MBT control may be executed only when there is no knocking, and this aspect will be shown in the following second embodiment.

FIG. 1θ is a diagram showing a second embodiment of the first invention, and in this embodiment, the processing of steps P10 and Pll is P and P
h, and the rest is the same as in the first embodiment. Therefore, in this second embodiment, since MBT control is performed only when there is no knock, there is an advantage that control stability is good.

Although each of the above embodiments is an example in which MBTilJfal is performed, it goes without saying that the present invention has a corresponding effect even without executing MBT control. MBT may be set and subsequent correction may not be performed in the form of control.

However, if MB'r*jm exists, there is an effect of controlling fuel efficiency to the minimum fuel consumption point by inducing changes in fuel properties, engine changes over time, changes in the environment (temperature, humidity, atmospheric pressure, etc.), etc. Needless to say.

11 to 13 are diagrams showing a third embodiment of the first invention, and in explaining this embodiment, the same components as those in the first embodiment are given the same reference numerals, and the explanation thereof will be omitted.

In this embodiment, as an intake air amount control method, the supercharging pressure is controlled by the opening degree of the swing valve. That is, in addition to the original control of the VN turbo, supercharging pressure control for knocking control is also taken into consideration. Furthermore, in this embodiment, since the cylinder pressure signal is not detected, MBTl control as in the twelfth embodiment is not performed.

In FIG. 11, 41 is an intake pipe, a compressor 42a of an exhaust turbo supercharger 42 is arranged in the intake pipe 41, and the compressor 42a is connected to a turbine 42b arranged in an exhaust pipe 43. . Exhaust turbo supercharger 42
The exhaust gas drives the turbine 42b, and the compressor 42a that works with the turbine 42b supercharges the intake air. The flow rate of exhaust gas passing through the turbine 42b is controlled by a variable nozzle 44 consisting of a waste gate valve and a swing valve (supercharging pressure operating means) 45, and the variable nozzle 44 and the swing valve 45 each receive a control signal S□ having a duty value.
, the pressure applied to the turbine 42b is adjusted based on the S housing 2, and the supercharging pressure PK is set to 5tiIlrn. Further, the variable nozzle 44 is a PCM (Pressure Control).
The swing valve 45 is driven by a PCM valve 47.

In the above configuration, FIG. 12 is a flowchart showing a program for knock suppression control and boost pressure control in this embodiment.

First, the variable nozzle 44 is controlled by Pd2, and the duty of the PCM valve 46 at this time is set to Dl.

Here, the variable nozzle control means that a flap is provided in the turbine nozzle portion of the exhaust turbo supercharger 42 to control the nozzle area depending on the operating condition, which improves the torque and response particularly in the low speed range.

Next, in P4□, the original swing valve 45 determined by the intake air amount is controlled, and the PCM valve 4 at this time is
Let the duty of 7 be D2. P43 detects the knocking level KN, and P44 detects the knocking level KN.
is compared with a predetermined knock determination reference level KN. KN
>KN, it is determined that knocking is occurring, and the duty D is set in the opening direction of the swing valve 45 at P4%.
In order to correct this, the correction amount ΔD, which corrects this error, is d
Reduce by l. ΔD2 is a negative value, with an absolute value of 1Δ
D11 becomes 0, then D in pah:
+ΔD! is the control duty D2 of the new PCM valve M47, and P4'l is the control duty D2 of the new PCM valve M47.
A control signal S having At the same time, the duty D in step P41 is outputted at p4n.

It outputs a control signal S□ having .

On the other hand, when KN≦KN in step P44, it is determined that knocking has not occurred, and in order to correct the duty D2 in the closing direction of the swing valve 45 in step Pd2, the correction amount D2 is set to d (however, d, <dl).

Next, P. It is determined whether the value of the correction amount ΔD2 is positive or not, and when ΔD2≧O, ΔD! is determined in psi. = 0, and proceed to PX3, and when ΔD2 is 0, proceed directly to pzz. As a result, the rimming process of ΔD2 is performed.

Through the above steps P41 to ps+, a knocking control area as shown in the shaded area in FIG. 13 is added to the control area of the PCM valve 47. The upper limit of this region is the maximum torque characteristic determined by the original control of the PCM valves 46, 47, but the lower limit changes depending on how knocking occurs (eg, environmental conditions of the engine, dependence on fuel used, etc.).

Therefore, in this embodiment, it is possible to suppress the occurrence of knocking by controlling the amount of intake air by controlling the opening degree of the swing valve, and it is possible to significantly improve fuel efficiency compared to the knocking avoidance method using ignition timing control.

FIG. 14 is a diagram showing a first embodiment of a knocking control device for an internal combustion engine according to the second invention, and this embodiment corresponds to the first embodiment of the first invention.

In explaining this embodiment, steps that perform the same processing as in the first embodiment of the first invention are given the same numbers and their explanations are omitted, and steps that are different are given step numbers surrounded by circles. The contents will be explained below.

In addition, in this embodiment, the control unit 20 has the same functions as the knock detection means in the first embodiment of the first invention, and also has a first ft1lJ control means, a second control means, a selection means, and an ignition timing correction means. It has the function of

In the program shown in FIG. 14, after passing through P, it is determined at P,1 whether or not the vehicle is accelerating from the detection output of the driving state detection means 13. When it is determined that the vehicle is not accelerating, the process advances to P4 and the subsequent steps are performed in the same manner as in the first embodiment of the first invention. On the other hand, when it is determined that the vehicle is accelerating, the knocking level KN is compared with the knocking determination level KNo in the pit. KN≦KN
When it is 0, it is determined that knocking is not occurring and the output is changed to P. and executes the M B T wI control described above. When KN>KNO, it is determined that knocking has occurred, and the ignition timing feedback correction fiFB is decreased by the retardation correction 'Wkc at Pb3. however,
C takes a value larger than the advance angle correction la of the MBT control described above (c>a). Next, the final ignition timing A is calculated using Pb0 according to the following equation, and the process proceeds to pH.

A=B, +FB...■ However, B: Basic ignition timing and other steps are the same as in the first embodiment of the first invention. Therefore, in this example as well, the first aspect of the first invention
In addition to obtaining the same effects as in the embodiment, the knock suppression mode can be changed to throttle valve opening control (intake air amount control) or ignition timing control by determining the operating condition (acceleration condition, etc.). By selecting the most advantageous one among them, it is possible to minimize the deterioration of the Karen feeling during acceleration.

In other words, during high load steady state, the throttle valve opening control (No. 11i1
By adopting ignition timing control (second control means) when accelerating from a low load, when knocking occurs, the ignition timing is retarded to suppress knocking, and if knocking does not occur, Improve fuel efficiency by maintaining ignition timing at MBT.

In this way, in this embodiment, the knock suppression mode is selected depending on the driving condition, so it is possible to improve fuel efficiency by suppressing knock by controlling the throttle valve opening, and by controlling the retard of the ignition timing, it is possible to improve the knock suppression even during sudden acceleration. Acceleration feeling is greatly improved without reducing filling efficiency.

FIG. 15 is a diagram showing a second embodiment of the second invention, and this embodiment corresponds to the second embodiment of the first invention. It should be noted that in this embodiment, as in the above embodiment, steps that perform the same processing are given the same numbers and their explanations are omitted, and steps that are different are given step numbers surrounded by Q marks and their contents will be explained.

In this embodiment, step P. , the pH treatment is P, and P
, and the rest is exactly the same as the first embodiment of the second invention. Therefore, in this second embodiment, since MBT control is performed only when there is no knock, there is an advantage that the stability of the control is improved as in the case of the second embodiment of the first invention.

Although each of the above embodiments is an example in which MBT control is performed, it goes without saying that the present invention has a corresponding effect even without performing MBT control, and this effect is not limited to the first invention. Same as in case.

FIG. 16 is a diagram showing a third embodiment of the second invention, and this embodiment corresponds to the second embodiment of the first invention. It should be noted that in this embodiment as well, as in the above embodiment, steps that perform the same processing are given the same numbers and their explanations are omitted, and steps that are different are given step numbers surrounded by O marks and their contents will be explained.

In the program of FIG. 16, P4. After passing through, P7,
Then look up the basic ignition timing B0 from the table map and find it, p? At t, an ignition signal Sp is output at an ignition timing corresponding to the lookup value.

Also, it is determined whether the vehicle satisfies the acceleration conditions using Pqx, and if the acceleration conditions are present, the process proceeds to PVA, and if the acceleration conditions are not, the process proceeds directly to ps4.Here, step P
41-P4. (That is, it corresponds to the third embodiment of the first invention) shows the intake air amount control (corresponding to the first control means) for knock suppression as a whole.

PVA detects the boost pressure, and if it is above a predetermined value, it is judged that the supercharging is sufficient and proceeds to Paa, and when the boost pressure is less than the predetermined value, it prioritizes increasing suction charging efficiency, so PTS
Proceed to. That is, the ignition timing side '4B (corresponding to the second control means) is adopted for knock suppression.

In Pqs, the knocking level KN is the knock judgment level K.
Compare with N. When KN>KN, it is determined that knocking has occurred, and the ignition timing feedback correction @FB is decreased by the retardation correction amount C in P16.
At P'F'l, the feedback correction amount FB becomes the predetermined correction 1.
Determine whether it is smaller than trBI, and if FB≦FB, proceed to Pal with FB=FB yo, and FB≦
If not FB, proceed directly to P'l'9. Pal
At 9, it's time for the final ignition! 1liA is calculated according to the following formula (■), and P
Proceed to 7□.

A=B, +FB ・・・・・・■ However, B: Basic ignition timing Also, when KN≦K No in the above pts, it is determined that knocking has not occurred, and P. Increase the feedback correction amount FB by the advance angle correction amount a (however, a×C) at 0. Then, at Pill, determine whether the feedback correction IFB is larger than a predetermined correction amount i;'Bt (however, FBSFBt> Then, when FB≧FB, P. sets FB=FB and proceeds to Pal, and when FB≧FB!, proceed directly to Pal.These Pal, P□, P
, and feedback correction IFH at the peg step
FB range.

Limit processing (here, FB is a value of a plus or minus code material) is performed to satisfy ≦F B S F B.

In this way, in this embodiment, the knock control mode is selected depending on the driving condition (acceleration condition or not, etc.), so that the same effect as in the third embodiment of the first invention (i.e., due to intake air amount control) is achieved. In addition to improving fuel efficiency by suppressing knock, under acceleration conditions, the ignition timing is retarded to suppress knock, which greatly improves acceleration feeling without reducing charging efficiency, especially during sudden acceleration.

In addition, in the first and second inventions, if the suppression of knocking is performed for each cylinder, it is not necessary to control the intake air amount or retard the ignition timing for cylinders in which knocking does not occur. It is also advantageous in terms of fuel efficiency and output.

(Effect) According to the first invention, since the amount of intake air is controlled when suppressing knock, the ignition timing is always adjusted to the best fuel economy point (MBT).
), it is possible to prevent the occurrence of knocking while maintaining the engine speed, thereby significantly improving fuel efficiency and preventing damage to the engine.

Further, according to the second invention, when suppressing knock, the amount of intake air is controlled during steady operation, and the ignition timing is controlled during acceleration, so that in addition to the same effects as the first invention, torque and Deterioration in acceleration feeling can be minimized and the best combustion conditions can be maintained at all times. As a result, it is possible to significantly improve fuel efficiency and driving performance and prevent tM damage to the engine.

[Brief explanation of drawings]

Figure 1 (A) is a basic conceptual diagram of the first invention, Figure 1 (B)
2 is a basic conceptual diagram of the second invention, FIGS. 2 to 9 are diagrams showing a first embodiment of a knocking control device for an internal combustion engine according to the first invention, FIG. 2 is an overall configuration diagram thereof, and FIG. Figure (A) is a sectional view showing the mounting state of the pressure sensor, Figure 3 (B) is a plan view of the pressure sensor, Figure 4 is its block configuration diagram, and Figure 5 is a circuit diagram of the knock detection circuit. , Fig. 6 is a characteristic diagram for explaining the operation of the knock detection circuit, Fig. 7 is a flowchart showing the knock control, throttle valve opening control, and ignition timing control programs, and Fig. 8 is the in-cylinder pressure. A flowchart showing a program for determining the maximum crank angle, FIG. 9 is a flowchart showing a program for MBTm control, and FIG. 1θ shows the knock control and throttle valve according to the second embodiment of the first invention. A flowchart showing a program for opening degree control and ignition timing control, FIGS. 11 to 13 are diagrams showing a third embodiment of the first invention, FIG. 11 is an overall configuration diagram thereof, and FIG. 12 is a knock control thereof. , a flowchart showing programs for boost pressure control il and ignition timing control, FIG. 13 is a diagram showing the swing valve control fa Sr1 region by knock control in terms of the relationship between shaft torque and engine speed, and FIG. FIG. 15 is a flowchart showing programs for knock control, throttle valve opening control, and ignition timing control of the first embodiment of the knock control device for an internal combustion engine according to the invention; FIG. Flowchart showing programs for knock control, throttle valve opening control, and ignition timing control, No. 16
The figure is a flowchart showing programs for knock control, boost pressure control, and ignition timing control in a third embodiment of the second invention. 1... Engine, 7... Ignition means, 10... Throttle valve drive unit (operating means), 19
... Knock detection means, 20 ... Control unit (knock determination means, first control means, second control means, selection means, correction means), 47 ... PCM pulp (Operation means).

Claims (2)

[Claims] (1) a) pressure detection means for detecting the combustion pressure of the engine; b) knock detection means for detecting the knocking level of the engine; and c) a control value for controlling the amount of intake air to suppress knocking to a predetermined level. d) When knocking is suppressed by manipulating the intake air amount, a combustion peak position at which the combustion pressure becomes maximum is detected based on the output of the pressure detection means, and this combustion peak position is detected. ignition timing control means for controlling the ignition timing to a target peak position that maximizes the torque generated by the engine; e) intake air amount operating means for changing the amount of intake air based on the output of the intake air amount control means; f) A knocking control device for an internal combustion engine, comprising: ignition means for igniting an air-fuel mixture based on the output of the ignition timing control means. (2) a) pressure detection means for detecting the combustion pressure of the engine; b) knock detection means for detecting the knocking level of the engine; c) operating state detection means for detecting the operating state of the engine; and d) knocking. e) a first control means for calculating a control value for controlling the intake air amount to suppress knocking to a predetermined level; and e) a second control means for calculating a control value for controlling ignition timing to suppress knocking to a predetermined level. f) selection means for preferentially selecting either the first control means or the second control means according to the operating state of the engine at that time when knocking occurs; and g) by manipulating the amount of intake air. When knocking is suppressed, the combustion peak position where the combustion pressure is maximum is detected based on the output of the pressure detection means, and the ignition timing is adjusted so that this combustion peak position becomes the target peak position where the engine generates the maximum torque. h) when the first control means is selected by the selection means, an intake air amount operation means for changing the amount of intake air based on the output of the first control means; i) the selection means controls the first control means; Ignition means that ignites the air-fuel mixture based on the output of the second control means when the second control means is selected, and ignites the air-fuel mixture based on the output of the ignition timing correction means when the second control means is not selected. A knocking control device for an internal combustion engine, comprising the following.