JPH0633721B2 - Knotting control device for internal combustion engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a device for controlling knocking by controlling an intake air amount or an ignition timing of an internal combustion engine such as an automobile.

(Prior Art) The ignition timing of an internal combustion engine must be determined according to the state of the engine so that the engine operates optimally. It is generally known that it is best to ignite in the vicinity of Iwayu MBT (Minimum advance for Best Torque) in consideration of the efficiency and fuel efficiency of the engine, depending on the engine condition. The so-called MBT control of changing is performed.

However, in a certain engine state, knocking occurs as the ignition timing is advanced, and stable engine operation cannot be performed. For example, MBT at low speed and low load
The knocking limit has come earlier. Further, the knocking limit is easily affected by atmospheric conditions such as temperature and humidity.

Therefore, a system has been developed in which so-called knocking control, which controls ignition timing depending on the presence or absence of knocking, is used in combination with the above MBT control. For example, such a system is disclosed in JP-A-58-82074. There is a described device.

In this device, the pressure in the combustion chamber (hereinafter referred to as cylinder pressure)
Is detected, and the ignition timing is MBT-controlled so that the crank angle θpmax at which the pressure becomes maximum (hereinafter referred to as the combustion peak position) reaches a predetermined position with the maximum torque generated by the engine. At the same time, knocking detection is performed by passing a signal for detecting in-cylinder pressure through a signal processing circuit, and when the knocking level exceeds a predetermined value, the ignition timing is retarded to avoid knocking with priority over MBT control. To do. This intends to improve the driving performance by suppressing the knocking and increasing the generated torque of the engine as much as possible. Thus, it is considered that controlling the ignition timing to suppress knocking is widely adopted because it is easy to control the ignition timing.

(Problems to be Solved by the Invention) However, in the above device, in order to suppress knocking, the ignition timing that is originally set to the timing at which the combustion state is most favorable that maximizes the torque generated by the engine is suppressed. Since the ignition timing is retarded, the combustion state deteriorates due to the ignition timing retard, and the optimum combustion state cannot be obtained under each operating condition. Therefore, fuel consumption is significantly deteriorated by such deterioration of the combustion state.

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

(Object of the Invention) Therefore, the present invention controls the intake air amount during steady operation and controls the ignition timing during acceleration in order to suppress knocking, thereby appropriately avoiding the occurrence of knocking and controlling torque.
The purpose is to minimize deterioration of acceleration feeling and maintain the best combustion condition at all times to improve fuel efficiency and prevent engine damage.

(Means for Solving the Problems) In order to achieve the above object, a knocking control device for an internal combustion engine according to the present invention has a basic concept diagram as shown in FIG. a, operating state detection means b for detecting the operating state of the engine, first control means c for calculating a control value for controlling the intake air amount so as to suppress knocking to a predetermined level, and knocking to a predetermined level. When the knocking occurs, the second control means d for calculating a control value for controlling the ignition timing and the first control means c when the operating state of the engine at that time is steady operation, and the above-mentioned first control means c when the engine is in acceleration operation Selection means e for preferentially selecting the second control means d,
When the selection means e selects the first control means c, the intake amount operation means f for changing the intake air amount based on the output of the first control means c and the selection means e select the second control means d. At this time, ignition means g for igniting the air-fuel mixture based on the output of the second control means d is provided.

(Operation) In the present invention, when knocking occurs during steady operation, the knocking is suppressed by controlling the intake air amount. On the other hand, when knocking occurs during acceleration, the knocking is suppressed by controlling the ignition timing. Therefore, the ignition timing is kept at the best fuel economy point (MBT) and the deterioration of the torque / acceleration feeling is minimized. As a result, fuel economy and driving performance are improved,
And damage to the engine is prevented.

(Example) Hereinafter, the present invention will be described with reference to the drawings.

2 to 9 are views showing the first embodiment of the present invention.

First, the configuration will be described. In FIG. 2, reference numeral 1 denotes an engine, the intake air amount 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 attached to each cylinder, and a high voltage pulse Pi from a high voltage generation unit 6 is supplied to the spark plug. The ignition plug 5 and the high-pressure generation unit 6 constitute an ignition means 7 for igniting the air-fuel mixture, and the ignition means 7 generates a high-voltage pulse Pi based on the ignition signal Sp and discharges it. Then, the air-fuel mixture in the cylinder is ignited, exploded, and exhausted by the discharge of the high-pressure pulse Pi.

The flow rate Qa of the intake air is detected by the air flow meter 8 and controlled by the throttle valve 9 in the intake pipe 3. The throttle valve 9 is opened / closed by a throttle valve drive unit (operating means) 10, and the throttle valve drive unit 10 is constituted by, for example, a step motor, an angle sensor, etc., and opens / closes the throttle valve 9 based on a drive signal Sc.

Further, the accelerator opening θa is detected by the accelerator sensor 11, and the crank angle of the engine 1 is determined by the crank angle sensor 12.
Detected by. The crank angle sensor 12 has an explosion interval (6
(120 ° for cylinder engines, 180 ° for 4-cylinder engines)
A reference signal Ca which becomes a pulse of [H] level at a predetermined position before the compression top dead center (TDC) of each cylinder, for example, BTDC 70 ° is output for each cylinder, and [ [H] level pulse unit signal C ₁
Is output. The engine speed Ne can be known by counting the pulses of the signal Ca. The air flow meter 8 and the crank angle sensor 12 form an operating state detecting means 13.

Further, the load of the engine 1 is detected by the load sensor 14, and the cylinder discrimination is detected by the cylinder discrimination sensor 15.
The load sensor 14 is composed of, for example, a throttle valve opening sensor or an intake pipe negative pressure sensor, and outputs a load signal S _L according to the load state. The cylinder discrimination sensor 15 detects a cylinder discrimination signal S at a predetermined crank angle position (for example, BTDC80 ° of the first cylinder) before compression top dead center of a specific cylinder (for example, the first cylinder).
Output _K. Therefore, the cylinder discrimination signal S _K is output once every two rotations of the crankshaft.

Further, the combustion pressure Pa of the engine 1 is detected by the pressure sensor 16, which is specifically shown in FIG.
As shown in (B), it is formed as a washer of the ignition plug 5 screwed to the cylinder head 17, and is pressed and fixed to the outer recess of the cylinder head 17 by the tightening portion 5a of the ignition plug 5. Then, a pressure signal Pa corresponding to the pressure in the combustion chamber of the engine (cylinder pressure) is output via a charger amplifier (not shown).

The output of the pressure sensor 16 is input to the knocking detection circuit 18, and the knocking detection circuit 18 detects the occurrence of knocking from the pressure signal Pa (see FIG. 5A) from the pressure sensor 16 as shown in FIG. 4, for example. Especially included a lot 6
A band-pass filter (BPF) 18a that passes only the high frequency component Pa '(see FIG. 5B) of -15 kHz, and half-wave rectifies the high frequency component Pa' and forms an envelope signal from the half-wave rectified signal. (Envelope detection)
The waveform shaping circuit 18b outputs a knocking signal _SN corresponding to the knocking level as shown in FIG. 5C.

In this knocking detection circuit 18, the pressure signal P
Alternatively, a may be smoothed to form a background level corresponding to the normal nozzle level of the engine, and the difference between the formed level and the maximum level of the envelope signal may be output as the knocking signal S _N.

The pressure sensor 16 and the knocking detection circuit 18 constitute knock detection means 19, and signals from the knock detection means 19 and the sensors 8, 11, 12, 14, 15 are input to the control unit 20.

The control unit 20 has functions as knock determination means and control means, and as shown in detail in FIG.
U21, ROM22, RAM23, NVM (non-volatile memory)
24 and an input / output control circuit 25 including an input / output interface, a register, a counter, an A / D converter, a high frequency cut filter and the like. CPU21 is ROM
According to the program written in 22, the external data required by the input / output control circuit 25 is taken in, and R
While exchanging data with the AM23 and NVM24, the processing values required for knock suppression, throttle valve opening control and ignition timing control are arithmetically processed, and the input / output control circuit 25 processes the processed data as necessary. Output to. The input / output control circuit 25 receives signals from the sensor groups 8, 11, 12, 14, 15, the operating state detection means 13 and the knocking detection circuit 18, and the input / output control circuit 25 outputs the drive signal Sc and The ignition signal Sp is output. The ROM 22 stores a calculation program in the CPU 21, and the RAM 23 and the NVM 24 store data used for calculation in the form of a map or the like.

The ignition signal Sp is 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. Turn on Q1
/ OFF control is performed to generate a high voltage Pi on the secondary side of the ignition coil 26, and the high voltage Pi is supplied to the spark plugs 29a to 29f via the distributor 28 to ignite the air-fuel mixture.

Next, the operation will be described.

FIG. 7 is a flow chart showing a program for knock suppression control and MBT control written in the ROM 22, and this program is processed by interruption every time the reference signal Ca is input.

First, at P ₁ , the accelerator opening θa is read from the A / D converted value of the accelerator sensor, and at P ₂ , the engine speed N and the accelerator opening θ, which are parameters representing the operating state of the engine.
The basic value θt of the target throttle valve opening from a is θt = fun
The calculation is performed based on the functional form of c (θa, N). This θt is stored in advance in the table map as a value that gives a smooth acceleration feeling over a wide range of rotation from low speed to high speed rotation, and the optimum value should be looked up in P _2. Ask by.

Then, to detect the knocking level KN from knocking signal S _N in P _3, it is determined whether the vehicle from the detection output of the operating condition detecting means 13 at P ₄ is accelerating. When it is determined that the vehicle is not accelerating, the knocking level KN is compared with the knock determination level KN ₀ in P ₅ . KN> KN
When it is ₀ , it is determined that knocking has occurred, and at P ₆ , θt and the feedback correction amount Δθt (Δθt is a negative value).
Is reduced by α and Δθt−α is stored as a new feedback correction amount Δθt. The correction amount α is the minimum change in throttle valve opening required to prevent knocking, and α = f
unc (Q, N) (where Q = load (amount of intake air or value of θt itself)). Then, the operation values of a new throttle valve opening degree in the current and θt + Δθt at P _7, and outputs a drive signal Sc corresponding thereto.

On the other hand, when KN ≦ KN ₀ , it is determined that knocking has not occurred, and the feedback correction amount Δθt of θt at P _S.
Is increased by β (however, β <α) (small as an absolute value), and it is determined whether or not the value of Δθt is positive in P ₉ . When θt ≧ 0, Δθt = 0 is set at P ₁₀ and the upper limit of Δθt is restricted to zero, and the process proceeds to P ₇ . Also, θ
When t <0, the process directly proceeds to P ₇ . This is Δθt>
This is because when the state becomes 0, the opening of the throttle valve becomes larger than the basic value of θt.

Next, at P ₁₁ , the MBT control value of the ignition timing is calculated (details will be described later in a subroutine), and at P ₁₂ , the ignition signal Sp is output at the ignition timing corresponding to this control value.

On the other hand, when it is determined that the vehicle in the step P ₄ is accelerating compares the knock determination level KN ₀ knocking level KN at P _13. When KN ≦ KN ₀ , it is determined that knocking has not occurred, and the process directly proceeds to P ₁₁ to execute the above-mentioned MBT control.

On the other hand, when KN> KN ₀ , it is determined that knocking has occurred, and at P ₁₄ , the ignition timing feedback correction amount FB
Is reduced by the retard correction amount c. However, c is M described later.
It takes a value larger than the advance correction amount a of the BT control (c>
a). Next, at P ₁₅ , the final ignition timing A is calculated according to the time equation, and the routine proceeds to P ₁₂ .

A = B ₀ + FB ... However, B ₀ : basic ignition timing (described later) By the above step processing of P _{1 to} P ₁₅ , the most advantageous knock control mode is selected according to the operating state while giving priority to the MBT control.

That is, the throttle valve opening control (first control means) is adopted when the engine operating state at the time of knocking is high-load steady operation, and at the time of knocking, even if the accelerator depression amount is constant, the throttle opening degree is constant. Is moved a little in the closing direction, and if knocking does not occur, it is returned to the basic value. That is, the knock suppression process is performed only by the operation of the intake air amount, and the ignition timing is changed by the MBT control without being used in the knock suppression process. Therefore, knocking can be suppressed while maintaining the ignition timing at MBT, and the combustion state can be optimally maintained unlike the conventional case. As a result, it is possible to improve fuel efficiency, suppress an excessive rise in exhaust temperature, and prevent damage to exhaust members such as an exhaust catalyst and an exhaust pipe.

Regarding the fuel consumption, the fuel consumption at high speed is greatly improved as compared with the knocking circuit method by retarding the ignition timing.

On the other hand, when the engine operating state when knocking occurs is acceleration operation from low load, ignition timing control (second
When the knocking occurs, the ignition timing is retarded to suppress the knocking, and if the knocking does not occur, the ignition timing is maintained at MBT to improve fuel efficiency.

As described above, in this embodiment, since the knock suppression mode is selected depending on the operating state, the fuel consumption can be improved by suppressing the knock by controlling the throttle opening, and the retard control of the ignition timing can be used to charge the fuel particularly during rapid acceleration. There is no reduction in efficiency and the acceleration feeling is greatly improved.

Next, the ignition timing MB corresponding to steps P ₁₁ and P ₁₂ above
The T control will be described in detail.

MBT control is based on the crank angle θ of the maximum cylinder pressure Pmax.
Minimum Ad when pmax (see FIG. 5 (a)) is at a predetermined value after compression top dead center (for example, 15 ° to 20 ° ATDC)
The ignition timing of vance for Best Torque (MBT) is given, and feedback control is performed so that θpmax becomes the above predetermined value. That is, in the subroutine shown in FIG. 8, first, at P ₂₁ , the in-cylinder pressure signal Pa is A / D converted at predetermined crank angles, for example, every 2 °, and the maximum value Pma is obtained.
x is calculated, and then the crank angle at the time of calculating Pmax is calculated as Ppmax in P ₂₂ , and this is stored.

FIG. 9 shows an MBT control subroutine.

First, the basic ignition timing from the engine load Q and the engine speed N in P ₃₁ (omitted correction amount of the engine coolant temperature)
B ₀ is obtained according to the functional form of B ₀ = func (Q, N), and θpm of this time obtained by the subroutine of FIG. 8 at P ₂₂
Determine the position of ax.

When θpmax is within the predetermined range given to MBT, the final ignition timing A is calculated according to the equation at P ₃₃ .

A = B ₀ + FB ... However, FB: Feedback correction amount of ignition timing On the other hand, when θpmax is on the delay side with respect to the predetermined range giving MBT, the advance angle correction amount FB is advanced to the previous feedback correction amount FB in P _34. The amount a is added, FB + a is set as a new correction amount FB, and the process proceeds to P ₃₃ . When θpmax is on the leading side, P ₃₅
In Pull the retard correction amount b from the feed-back correction amount FB, the process proceeds to P ₃₃ of the FB-b as a new correction amount FB.

As described above, in this embodiment, the ignition timing is always maintained at MBT regardless of the state of the intake air amount operation by the knock suppression control. Therefore, there is an advantage that the fuel economy is particularly improved.

In the first embodiment described above, the MB is irrespective of whether or not knocking has occurred.
Although the T control is executed, the MBT control may be executed only when there is no knock. This mode is shown in the second embodiment below.

FIG. 10 is a diagram showing a second embodiment of the present invention. In this embodiment, the processes of steps P ₁₁ and P ₁₂ are carried out between P ₁₀ and P ₇ , and the others are the same as in the first embodiment. Is. Therefore, in this second embodiment, the MBT is used only when there is no knock.
Since the control is performed, there is an advantage that the stability of the control is good.

Although each of the above embodiments is an example in which the MBT control is performed, it goes without saying that the present invention has a corresponding effect even if the MBT control is not performed. For example, the basic ignition timing B ₀
May be set to MBT in advance so that the subsequent correction is not performed in the form of control.

However, it goes without saying that the MBT control has the effect of absorbing changes in combustion properties, changes in the engine over time, changes in the environment (temperature, humidity, atmospheric pressure, etc.), and controlling to the minimum fuel consumption point.

11 to 13 are views showing a third embodiment of the present invention, and in explaining the present embodiment, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, the supercharging pressure is controlled by the opening degree of the swing valve as a method for controlling the intake air amount. That is, the supercharging pressure control for knocking control is added to the original control of the VN turbo. Further, since the cylinder pressure signal is not detected in this embodiment, the MBT control as in the first and second embodiments is not performed.

In FIG. 11, 41 is an intake pipe, and the intake pipe 41 is provided with a compressor 42a of an exhaust turbocharger 42,
The compressor 42a is a turbine 42b arranged in the exhaust pipe 43.
Connected to. The exhaust turbo supercharger 42 drives the turbine 42b by the exhaust gas, and supercharges the intake air by the compressor 42a which is interlocked with the turbine 42b. The flow rate of the exhaust gas passing through the turbine 42b is controlled by a variable nozzle 44 composed of a waste gated valve and a swing valve (supercharging pressure operating means) 45, and the variable nozzle 44 and the swing valve 45 each have a control signal S _K1 having a duty value. The supercharging pressure P _K is controlled by adjusting the pressure of the turbine 42b based on S _K2 . The variable nozzle 44 is a PCM (Pressure Control Modulator) valve.
Driven by 46, swing valve 45 is PCM valve 47
Driven by.

In the above-mentioned 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 at P ₄₁ , and P at this time is controlled.
The duty of the CM valve 46 is D ₁ . Here, the variable nozzle control is to control the nozzle area according to the operating condition by providing a flap on the turbine nozzle portion of the exhaust turbocharger 42, and the torque and response are improved especially at low speeds.

Next, the original swing valve 45 determined by the intake air amount is controlled at P ₄₂ , and the duty of the PCM valve 47 at this time is set to D ₂ . Knocking level KN on P ₄₃
Detects, determines whether the vehicle in P ₄₄ meets the accelerated conditions. Here, the acceleration condition is a state in which the accelerator or the intake air amount is suddenly changing to the acceleration side or within a predetermined time after the sudden change.For example, in the case of supercharging by a turbocharger, several tens of milliseconds after sudden acceleration It takes several 100 msec to shift to such an acceleration condition. If accelerated conditions proceeds to P _45, the process directly proceeds to P ₄₆ if not accelerated conditions. In P ₄₅ , the supercharging pressure is detected, and if it is equal to or higher than the predetermined value, it is judged that the supercharging is sufficient and the process proceeds to P ₄₆ . The steps following P ₄₆ indicate intake air amount control (corresponding to the first control means).

That is, at P ₄₆ , the knocking level KN is compared with a predetermined knock determination level KN ₀ . When KN> KN ₀ , it is determined that knocking has occurred, and at P ₄₇ , the duty D ₂ is corrected in the opening direction of the swing valve 45, so the correction amount ΔD ₂ for correcting this D ₂ is reduced by d ₁ . . Δ
D ₂ is a negative value, and the absolute value | ΔD ₂ | tends to increase. Next, at P ₄₈ , D ₂ + ΔD ₂ is set as the control duty D ₂ of the new PCM valve 47 at this time, and P ₄₉
The control signal S _K2 having the duty D ₂ is output at and the control signal S _K1 having the duty D ₁ at the step P ₄₁ is output at P ₅₀ . Next, at P ₅₁ , the basic ignition timing B ₀ is obtained by looking up from the table map, and at P ₅₂ , the ignition signal Sp is output at the ignition timing corresponding to the lookup value.

On the other hand, it is determined that knocking when the KN ≦ KN ₀ in step P ₄₆ has not occurred, the swing valve at P ₅₃
Since the duty D ₂ is corrected in the closing direction of 45, the correction amount D
₂ is increased by d ₂ (however, d ₂ <d ₁ ). Next, at P ₅₄ , it is determined whether or not the value of the correction amount ΔD ₂ is positive. If ΔD ₂ ≧ 0, then P _{55 is set} at ΔD ₂ = 0, and the process proceeds to P _{48. If} ΔD ₂ <0, then P the process proceeds to P _48. As a result, the milling process of ΔD ₂ is performed.

By the steps of P _{41 to} P ₅₅ described above, the region by the knocking control as shown by the hatched portion in FIG. 13 is added to the control region of the PCM valve 47. If the upper limit of this region is the maximum torque characteristic determined by the original control of the PCM valves 46, 47, the lower limit changes depending on the manner of occurrence of knocking (for example, engine environmental conditions, dependence on fuel used, etc.).

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

On the other hand, the supercharging pressure at step P ₄₅ is less than the predetermined value the process proceeds to P ₅₆ to priority to increase the intake charging efficiency. That is, the ignition timing control (corresponding to the second control means) is adopted for knock suppression. Knocking level KN at P ₅₆
Is compared with the knock determination level KN ₀ . When KN> KN ₀ , it is determined that knocking has occurred, and the feedback correction amount FB of the ignition timing is reduced by the retardation correction amount c at P ₅₇ . Next, at P ₅₈ , it is determined whether or not the feedback correction amount FB is smaller than the predetermined correction amount FB ₁ , and FB ≦
When it is FB ₁ , FB = FB ₁ is set at P ₅₉ and the program proceeds to P ₆₀ .
If FB ≦ FB ₁ is not satisfied, the process directly proceeds to P ₆₀ . The P ₆₀ In the final ignition timing A calculated according to the following formula proceeds to P _52.

A = B ₀ + FB, where B ₀ : basic ignition timing When KN ≦ KN _{0 in} P ₅₆ , it is determined that knocking has not occurred, and in P ₆₁ , the feedback correction amount F
B is increased by the advance correction amount a (however, a <c). Next, at P ₆₂ , it is determined whether or not the feedback correction amount FB is larger than a predetermined correction amount FB ₂ (however, FB ≦ FB ₂ ), and when FB ≧ FB ₂ , at P ₆₃ , FB = FB ₂ and P
Proceed to ₆₀ , and if FB ≧ FB ₂ is not established, proceed directly to P ₆₀ . Limit processing for setting the range of the step feedback correction amount FB of P ₅₈ , P ₅₉ , P _62, and P ₆₃ to FB ₁ ≦ FB ≦ FB ₂ (where FB is a value with plus and minus signs). ) Is done.

In this way, in this embodiment, the operating state (whether acceleration condition or not)
Since the knock control mode is selected by, the fuel consumption can be improved by suppressing the knock by controlling the intake air amount, and by suppressing the knock by retarding the ignition timing under acceleration conditions, the charging efficiency can be improved even during sudden acceleration. There is no decrease and the acceleration feeling is greatly improved.

Note that, in the present invention, when the mode in which knocking is suppressed is performed for each cylinder, it is not necessary to control the intake air amount or perform the ignition timing tread for cylinders in which knocking does not occur, and the aspects of fuel efficiency and output are reduced. Is also advantageous.

(Effect) According to the present invention, when suppressing knock, the intake air amount is controlled during steady operation, and the ignition timing is controlled during acceleration operation. Therefore, the occurrence of knocking and torque / acceleration feeling can be prevented. The decrease can be minimized, and the best combustion state can always be maintained. As a result, it is possible to significantly improve fuel economy and driving performance and prevent engine damage.

[Brief description of drawings]

FIG. 1 is a basic conceptual diagram of the present invention, FIGS. 2 to 9 are diagrams showing a first embodiment of the present invention, FIG. 2 is its overall configuration diagram, and FIG. 3 (A) is its pressure sensor. Cross-sectional view showing the mounted state,
FIG. 3 (B) is a plan view of the pressure sensor, FIG. 4 is its block configuration diagram, FIG. 5 is its knock detection circuit diagram, and FIG. 6 is a characteristic for explaining the action of the knock detection circuit. FIG. 7 is a flow chart showing a program for knock control, throttle valve opening control and ignition timing control, FIG. 8 is a flow chart showing a program for obtaining a crank angle when the cylinder pressure is maximum, and FIG. 9 is FIG. 10 is a flow chart showing a program for the MBT control, FIG. 10 is a flow chart showing a program for the knock control, throttle valve opening control and ignition timing control showing the second embodiment of the present invention.
FIG. 13 is a diagram showing a third embodiment of the present invention, FIG. 11 is an overall configuration diagram thereof, and FIG. 12 is a flowchart showing programs for knock control, supercharging pressure control and ignition timing control,
FIG. 13 is a view showing the swing valve control region by the knock control in the relationship between the shaft torque and the engine speed. 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), 47 ... PCM valve (operation means).

Claims (1)

[Claims] 1. A knock detecting means for detecting knocking occurring in an engine, b) an operating state detecting means for detecting an operating state of the engine, and c) an intake air amount for suppressing knocking to a predetermined level. First control means for calculating a control value to be controlled; d) second control means for calculating a control value for controlling the ignition timing so as to suppress knocking to a predetermined level; and e) when knocking occurs, Selecting means for preferentially selecting the first control means when the operating state of the engine is steady operation, and selecting the second control means for accelerating operation; and f) when the first control means is selected by the selecting means, Intake amount control means for changing the intake air amount based on the output of the first control means; and g) Mixing based on the output of the second control means when the second control means is selected by the selecting means. Knock control apparatus for an internal combustion engine, characterized by comprising, an ignition means for igniting.