JPH11229951A - Knocking control device for multiple cylinder internal combustion engine provided with variable valve timing control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately perform knock determination using a knock sensor in a knocking controller arranged in a multiple cylinder internal combustion engine provided with a variable valve timing(VVT) controller without the influence of VVT control. SOLUTION: In this knocking controller provided with a VVT controller, a knock signal is taken in from a knock sensor, and a knock determination area, in which knock determination is carried out, is set on the basis of a valve timing of an intake/exhaust valve controlled according to VVT control so as not to overlap to its valve closing timing at least. Consequently, a knock signal including seating noise of the intake/exhaust valve is taken into the knock determination area, and error detection of knocking is prevented, so that knocking control can be carried out with high precision.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-cylinder internal combustion engine having a variable valve timing control device for controlling the opening / closing timing of an intake valve or an exhaust valve of an internal combustion engine in accordance with the operating state of the internal combustion engine. TECHNICAL FIELD The present invention relates to a knocking control device for a multi-cylinder internal combustion engine with a variable valve timing control device, which is suitable for suppressing the occurrence of pressure.

[0002]

2. Description of the Related Art Conventionally, in order to improve the operation performance of an internal combustion engine, the opening / closing timing of an intake valve and / or an exhaust valve is controlled by adjusting the opening / closing speed of an accelerator pedal or a throttle valve operated by a driver. There is known a device provided with a variable valve timing (VVT) control device that performs control in accordance with the above conditions (in other words, the operating state of the internal combustion engine).

[0003] In an internal combustion engine equipped with such a VVT control device, when the opening / closing timing (hereinafter also referred to as valve timing) of an intake valve or an exhaust valve is changed by the VVT control device, the compression ratio of the fuel mixture in the cylinder is reduced. Increase, the amount of intake air taken into the cylinder increases, or the valve overlap period in which the intake valve and the exhaust valve open at the same time increases.
Knocking is likely to occur in the internal combustion engine.

Therefore, conventionally, in an internal combustion engine equipped with a VVT control device, the ignition timing and the amount of fuel supplied to the internal combustion engine are corrected in accordance with the degree of change in the valve timing controlled by the VVT control device. It has been proposed to suppress the occurrence of knocking (see, for example, JP-A-7-279712).

In the internal combustion engine with a supercharger, in order to improve the combustion efficiency in the entire operation range, the valve timing of the intake valve is delayed from a normal state by a VVT control device at a full load when the supercharger operates, and the supercharging is performed. When the valve timing of the intake valve is advanced to a normal value by the VVT control device at the time of the partial load in which the engine does not operate, the response of the variable valve timing switching mechanism constituting the VVT control device to the response of the supercharger becomes slow. However, knocking may occur during the transition of the valve timing due to the shift of the internal combustion engine to a high load. Therefore, in the internal combustion engine with a supercharger that performs such control, the switching of the valve timing by the VVT control device is performed (detailedly, During the transition to the high-load operation side), it is also possible to prevent the occurrence of knocking by retarding the ignition timing. Is (e.g., JP-6
1-1190147).

[0006]

However, the techniques disclosed in the above publications all involve knocking that occurs in an internal combustion engine provided with a VVT control device when VVT control is executed (that is, when halve timing is switched). In order to suppress knocking, a control amount of the internal combustion engine such as an ignition timing is corrected by a preset correction amount.

Accordingly, in the devices disclosed in the above publications, knocking control for determining whether or not knocking has actually occurred in the internal combustion engine using a knock sensor and controlling the ignition timing in accordance with the determination result is a conventional knocking control. The operation will be performed in the same manner as a general knocking control device that is more known.

However, in the conventional knocking control device,
As disclosed in JP-A-7-279712, a knock sensor for detecting mechanical vibration of the internal combustion engine is used to detect knocking occurring in the internal combustion engine. The detection signal is captured during a predetermined knock determination section during the explosion stroke of the internal combustion engine, and the number of times the captured detection signal exceeds the predetermined knock determination level or exceeds the knock determination level is equal to or more than a predetermined number of times. When it is determined that knocking to be suppressed has occurred in the internal combustion engine, the ignition timing is controlled in such a procedure that the ignition timing is delayed, and if knocking has not occurred, the ignition timing is advanced.

For this reason, in a multi-cylinder internal combustion engine in which the valve timing controlled by the VVT control device and the explosion stroke of the internal combustion engine overlap, the intake valve and the exhaust valve are opened and closed during the knock determination period. Vibration (mechanical noise) generated at the time of opening / closing a valve is taken in as a detection signal from a knock sensor to a knock control device, and knocking generated in the internal combustion engine may be erroneously determined.

The reason will be described below with reference to FIG.
FIG. 5A shows cylinders # 1 to # 4 that change every 180 ° C. in synchronization with the rotation of the internal combustion engine in a four-cylinder four-cycle internal combustion engine (the numerical value assigned to # represents the cylinder number). 5 (intake / compression / explosion / exhaust) and the knock determination section, and FIG. 5 (b) shows the opening / closing timing of the intake valves and exhaust valves provided in each of the cylinders # 1 to # 4.

First, the knocking control device is for maximizing the power and torque of the internal combustion engine by controlling the ignition timing as described above. In this knocking control, if erroneous determination is made that "knock is present" during the knock determination section even though knocking has not occurred, the ignition timing is unnecessarily delayed, and the engine power is reduced rather than extracted. Conversely, even if knocking has occurred, if erroneous determination of "no knock" is made during the knock determination section, the ignition timing is advanced more than necessary and an unpleasant knock sound is generated. In addition, it may cause mechanical damage to the internal combustion engine.

Therefore, for example, in a four-cylinder four-cycle internal combustion engine, as shown in FIG. 5 (a), the knocking determination section determines the knocking that occurred during the explosion stroke of each of the cylinders # 1 to # 4, In order to enable accurate detection without being affected by mechanical noise caused by opening and closing of an exhaust valve, etc., the 180
After the top dead center (TDC) of the cylinder in the explosion stroke at every ° C
The predetermined interval is set between the time when the internal combustion engine rotates by a predetermined rotation angle and the time when the explosion stroke ends. In the case of a six-cylinder internal combustion engine, the knock determination section is one of the internal combustion engines.
It is set every 20 ° C. (= 720 ° C. A / number of cylinders).

When the knock determination section is set as described above, if the opening / closing timing of the intake valve and the exhaust valve provided in each cylinder (see FIG. 5B) is always constant,
Based on the detection signal taken from the knock sensor during the knock determination section, the knock determination can be accurately performed,
When the VVT control device is provided in the internal combustion engine,
Since the opening / closing timing of the intake valve and the exhaust valve is changed by the VVT control, the intake valve and the exhaust valve may be opened / closed during the knock determination period, and the mechanical noise generated by the opening / closing is detected by the knock sensor. Then, it is taken into the knocking control device as a detection signal for knock determination, and the knocking control device may erroneously determine that "knock exists" even though knocking does not actually occur. is there.

The problem of the erroneous determination may be caused by mechanical noise generated when a valve opening / closing cam hits each valve when the intake valve or the exhaust valve is opened. When the valve is closed, each valve sits on an intake or exhaust port formed in the cylinder head of the corresponding cylinder, and a large mechanical noise (seating noise) is generated as compared with the mechanical noise generated when each valve is opened. As a result, when the closing timing of the intake valve or the exhaust valve is changed and the seating noise of each valve shown in FIG. 5B is generated during the knock determination section, it is easy to make a false determination of knocking.

On the other hand, in order to solve such a problem, V
It is conceivable to set the knock determination section so as to avoid the range of the valve timing that can be controlled by the VT control device. However, when the knock determination section is set in this manner, the range in which knock determination can be performed during the explosion stroke of each cylinder is narrowed, and the knocking control device has a low probability of detecting the occurrence of knocking. Is likely to be erroneously determined to be "no knock" even though knocking has occurred.

The present invention has been made in view of such a problem, and in a knocking control device that performs knocking control in a multi-cylinder internal combustion engine provided with a VVT control device, the knock determination using a knock sensor is influenced by the VVT control. The purpose is to be able to perform accurately without receiving.

[0017]

According to a first aspect of the present invention, there is provided a knocking control device for detecting a mechanical vibration of an internal combustion engine, similar to the above-described conventional knocking control device. The detection signal from the knock sensor is captured during a predetermined knock determination section during the explosion stroke of each cylinder of the internal combustion engine, and it is determined whether or not knocking has occurred in the internal combustion engine based on the captured detection signal. The knocking is suppressed by controlling the ignition timing of the internal combustion engine based on the knocking.

The knocking control device of the present invention
As described above, when the knock determination section is fixed, the intake valve or the exhaust valve is opened / closed by the VVT control device provided in the multi-cylinder internal combustion engine provided with the variable valve timing control device (VVT control device). When the timing is changed, the intake valve or exhaust valve is opened / closed during the knock determination section, and the mechanical noise generated by the opening / closing is captured from the knock sensor as a detection signal for knock determination, and the occurrence of knocking is detected. Since the erroneous determination may occur, the knock determination interval is determined based on the opening / closing timing of the intake valve or the exhaust valve controlled by the VVT control device so that at least the closing timing of the intake valve or the exhaust valve and the knock determination interval do not overlap. Is set. Knock determination section setting means is provided.

Therefore, according to the present invention, during the knock determination section, the intake valve or the exhaust valve for controlling the opening / closing timing of the VVT control device is closed, and the above-mentioned sitting noise is detected as a knock detection signal for knock determination. It is not captured from the sensor. Therefore, according to the present invention, it is possible to prevent erroneous determination of the occurrence of knocking due to sitting noise, and it is possible to accurately execute knocking control.

When the VVT control device controls both the opening and closing timings of the intake valve and the exhaust valve, the knock determination section setting means ensures that at least the closing timing of each of these valves does not overlap the knock determination section. In this case, the knock determination section may be set.

The knock determination section setting means sets the knock determination section so that the knock determination sections do not overlap not only with the closing timing of the intake valve and the exhaust valve but also with the valve opening timing. It may be configured as follows.
In this manner, the erroneous determination of knocking can be reliably performed even with respect to mechanical noise generated when a cam in the variable valve timing mechanism that opens the intake valve or the exhaust valve in the VVT control device hits each valve. As a result, the control accuracy of the knocking control device can be further improved.

On the other hand, the opening / closing timing of the intake valve or the exhaust valve used by the knock determination section setting means for setting the knock determination section is a target valve timing when the VVT controller controls the opening / closing timing of the intake valve or the exhaust valve. May be used, but the VVT control device
In the transition of the control, the target valve timing and the actual valve timing deviate from each other. Therefore, in order to more reliably prevent erroneous determination of knocking, the knock determination section setting means is configured as described in claim 2. Is preferred.

In other words, in the invention according to claim 2, the knock determination section setting means detects the actual timing of the opening / closing timing of the intake valve or the exhaust valve controlled by the variable valve timing control device, and based on this actual timing, Since the knock determination section is set, it is possible to more reliably prevent the intake valve or the exhaust valve from being opened and closed during the knock determination section.

Next, when the knock determination section setting means sets the knock determination section, the knock determination section is set based on the rotational speed of the internal combustion engine, for example, as in the conventional device, and the set knock determination section is set. Only the start timing (or end timing) of the section may be shifted in accordance with the opening / closing timing of the intake valve or the exhaust valve. But,
When the knock determination section setting means is configured in this manner, for example, in FIG. 5A, the knock determination section becomes narrower as the valve closing timing of each valve that generates the seating noise of the intake valve or the exhaust valve becomes later. In this region, the knocking determination accuracy is reduced.

For this reason, the knock determination section setting means sets the width of the knock determination section to:
It is desirable that the setting be made based on the rotation speed of the internal combustion engine and the start timing of the knock determination section be set based on the opening / closing timing of the intake valve or the exhaust valve, thereby shifting the entire knock determination section. That is, in this way, it is possible to prevent the intake valve or the exhaust valve from being opened and closed in the knock determination section, and to make the width itself of the knock determination section a constant width corresponding to the engine speed. ,
It is possible to prevent the width of the knock determination section from being narrowed and the knock determination accuracy from being reduced.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an internal combustion engine (engine) 2 and its peripheral devices according to an embodiment to which the present invention is applied.

The engine 2 of this embodiment is a four-cylinder four-stroke engine, and each cylinder (only one cylinder is shown in the figure) of the engine 2 is provided with an intake valve 4, an exhaust valve 5, and a spark plug 8. Have been. The intake valve 4 and the exhaust valve 5 of each cylinder are provided with variable valve timing mechanisms 6 and 7, respectively.
It is opened and closed via. The variable valve timing mechanisms 6 and 7 control the opening and closing timings of the intake valve 4 and the exhaust valve 5, respectively.
The above-described variable valve timing control (VVT control) is realized by controlling each according to a control signal from an electronic control unit (hereinafter referred to as an ECU) 20. Since it has been put to practical use and is well known, the detailed configuration will not be described.

The high voltage generated by the ignition coil 14 is sequentially applied to the ignition plugs 8 of the respective cylinders every two revolutions of the engine 2 via a distributor or the like (not shown). Then, the spark plug 8 receiving the high voltage generates a spark discharge in the corresponding cylinder, and ignites the fuel mixture which is sucked in the intake stroke of each cylinder and compressed in the compression stroke. The timing of generating a high voltage by the ignition coil 14 (in other words, the ignition timing of each cylinder) is determined by the ECU 2
Controlled by 0.

Next, the engine 2 has a knock sensor 12, which detects a mechanical vibration of the engine 2 and generates a detection signal (hereinafter referred to as a knock signal) as a sensor for detecting an operation state of the engine 2. An air flow meter 15 for detecting the amount, a rotation angle sensor 1 for generating a rotation angle signal for each predetermined rotation angle (for example, 30 ° C. A) of the engine 2
6. For example, a cylinder discriminating sensor 17 for generating a cylinder discriminating signal once every two revolutions of the engine 2 to identify a specific cylinder in an intake stroke, an opening degree of a throttle valve opened and closed by a driver's accelerator operation And the like, and a detection signal from each of these sensors is input to the ECU 20.

The ECU 20 mainly includes a microcomputer (hereinafter simply referred to as a CPU) 22 including a CPU, a ROM, a RAM, and the like. The ECU 20 generates a high voltage from the ignition coil 14 based on detection signals from these sensors. Ignition timing control to control the ignition timing, knocking control to determine the knocking generated in the engine 2 based on the knock signal from the knock sensor 12 and to retard or advance the ignition timing controlled by the ignition timing control, or ,
The intake valve 4 and the exhaust valve 5 adjusted by the variable valve timing mechanisms 6 and 7 based on the operation state of the engine 2 (such as the throttle opening detected by the throttle sensor 18).
VVT control or the like for controlling the opening / closing timing of the motor is executed.

That is, the ECU 20 functions as the above-described variable valve timing control device (VVT control device) together with the variable valve timing mechanisms 6 and 7, and also functions as the above-described knocking control device together with the knock sensor 12. In order to execute the VVT control in the ECU 20, a sensor for detecting the actual opening / closing timing (actual valve timing) which is a control result by the variable valve timing mechanism 6.7 is incorporated in the intake valve 4 and the exhaust valve 5. The ECU 20 controls the variable valve timing mechanisms 6 and 7 based on the detection from the sensor such that the actual valve timing becomes the target valve timing set based on the throttle opening and the like. .

When executing the knocking control, the ECU 20 sets a knock determination section for each explosion stroke of each cylinder, fetches a knock signal in that section, and sets a signal level of the fetched knock signal in advance. Whether or not knocking has occurred in the engine 2 is determined based on whether or not the knock determination level has been exceeded. The ECU 20 is provided with a gate (not shown) in order to capture a knock signal from the knock sensor 12 within the knock determination section. The knock signal is taken in by opening this gate only during the knock determination section.

Hereinafter, the ECU 20 (specifically, C
The control processing executed for VVT control and knock determination, which is the main processing according to the present invention, among the control processing executed in the PU 22) will be described with reference to the flowchart shown in FIG. First, FIG.
2 shows a base process repeatedly executed together with the calculation of the ignition timing and the like.

As shown in the figure, in this base process, first, at S110 (S represents a step), the rotation angle sensor 1
The engine speed obtained based on the rotation angle signal from the engine 6 and the latest actual valve timing “D” obtained based on the detection signals from the sensors incorporated in the intake valve 4 and the exhaust valve 5 are read. On the basis of the rotation speed and the actual valve timing “D”, a delay time from the top dead center TDC of the cylinder entering the next explosion stroke to the start of the knock signal capture by opening the gate (hereinafter, gate output delay time) "A" is calculated (see FIG. 3).

The process of S110 is performed so that the intake valve 4 and the exhaust valve 5 are not opened and closed by the variable valve timing mechanisms 6 and 7 during the knock determination section where the capture of the knock signal is started. This is a process for setting the start timing to a predetermined rotational angle position of the engine 2. By setting the gate output delay time “A” using the engine speed as described above, the start timing of the knock determination section is It is possible to accurately set the time by measuring the elapsed time after the top dead center TDC of the cylinder in the explosion stroke.

Next, in S120, based on the engine speed read in S110 and the actual valve timing "D", a time width for opening the gate and taking in a knock signal (hereinafter referred to as a gate section time width). “B” is calculated (see FIG. 3). The process of S120 is performed in a gate interval time width (from opening the gate to start capturing the knock signal at the timing determined by the gate output delay time “A” to closing the gate and finishing capturing the knock signal). In other words, the process of setting the width (B) of the knock determination section to “B” to a predetermined time corresponding to the engine speed while confirming that the intake valve 4 and the exhaust valve 5 are not opened and closed in the section. Normally, similarly to the conventional knocking control device, a predetermined time width is set corresponding to the engine speed.

The reason why the gate section time width "B" is set based on the engine speed in this way is to avoid the area where mechanical noise is generated due to the opening and closing of the intake valve 4 or the exhaust valve 5 and to set the knock determination section. This is to set the range as wide as possible, whereby the knocking generated in the engine 2 can be accurately determined from the knock signal taken in the knock determination section.

Next, in S130, the intake valve 4 and the exhaust valve 5, which are opened and closed by VVT control, based on the operating state of the engine 2 detected by the throttle sensor 18 and the like.
Opening / closing timing target value (target valve timing)
"C" is calculated. When the calculation process of the target valve timing “C” is completed, the base process is temporarily terminated in order to execute another control process such as the calculation of the ignition timing. Perform base processing.

Next, FIG. 2B shows a TDC interrupt process executed for each top dead center TDC immediately before each cylinder enters the explosion stroke. This TDC interrupt processing is performed by the rotation angle sensor 16.
Top dead center TDC of each cylinder based on the rotation angle signal inputted from the cylinder and the cylinder discriminating signal inputted from the cylinder discriminating sensor 17.
Triggered by detecting In the present embodiment, since the engine 2 is a four-cylinder engine,
It will be executed every 0 ° C.

In the TDC interrupt processing, first, in S210,
The actual valve timing “D” as a result of the VVT control is taken. Then, in S220, based on the actual valve timing "D" and the target valve timing "C" calculated in 130, the actual valve timing "D"
Becomes the target valve timing “C” so that the control signal (VV
T output), and controls the opening / closing timing of the intake valve 4 and the exhaust valve 5.

Further, as described above, VV is controlled for VVT control.
After correcting the T output, this time, in S230, the current TD
The time t1 when the C interrupt processing is started (TDC input time; FIG. 3
) Is added to the gate output delay time “A” calculated in S110 to obtain a knock determination start time t.
2 (see FIG. 3), and this time t2 is
Timer (not shown) built in
Compare), and the process ends.

When the knock determination start time t2 is set, the timer is thereafter turned on by the ECU 20 as shown in FIG.
When the knock determination start time t2 is reached, a high-level signal is output to the gate, the gate is opened, and a knock signal is input to the CPU 22 from the gate. Then, CPU
22 determines whether or not knocking has occurred based on the signal level of the knock signal input through the gate thereafter, and when it is determined that knocking has occurred, corrects the ignition timing to the retard side, and performs knocking. When it is determined that the ignition has not occurred, the known knocking control for correcting the ignition timing to the advanced side is executed.

Next, FIG. 2C shows that the timer in which the knock determination start time t2 is set in the TDC interrupt processing is:
This represents a gate opening timing interruption process started at the timing when the gate is opened by detecting the knock determination start time t2. In this process, in S310, the gate section width time “B” calculated in S120 is added to the current time (that is, knock determination start time) t2, so that knock determination end time t3 (FIG. 3) ), The time t3 is set in the timer, and the process ends.

Then, as shown in FIG.
Knock determination end time t based on U20 internal clock
3 and the knock determination end time t3 is reached.
The high-level signal that has been output to the gate is lowered to the low level, and the gate is closed. As a result, the knock signal is no longer input to CPU 22, and the knock determination by CPU 22 ends.

As described above, in the present embodiment, when the ECU 20 performs the knocking control, the knock determination section in which the knock signal is fetched and the knock determination is performed is changed by the VVT control into the intake valve 4 and the exhaust valve 5. By changing according to the opening and closing timing of
The knock determination section does not overlap with the opening / closing timing of the intake valve 4 and the exhaust valve 5. Therefore, according to the present embodiment, the intake valve 4 and the exhaust valve 5 are opened and closed during the knock determination section, and mechanical noise generated due to the opening and closing can be prevented from being input from the knock sensor 12 to the CPU 22.

That is, for example, in the four-cylinder engine 2 according to the present embodiment, immediately after each cylinder enters the explosion stroke, the intake valve 4 or the exhaust valve 5 of the other cylinder is closed, resulting in large seating noise. Occurs. When the knock determination section is uniquely set based on the engine speed as in the conventional device, the opening and closing timings of the intake valve 4 and the exhaust valve 5 are fixed as shown in FIG. In this case, the knock determination section can be set within a range that does not include the region where the seating noise occurs, but the VVT control is performed in addition to the knocking control as in the engine 2 of the present embodiment. In an internal combustion engine, as shown in FIG.
Since the generation timing of the sitting noise changes by the VVT control, when the generation timing changes as indicated by the arrow X, the knocking noise is detected by the knock sensor in the knock determination section (indicated by a dotted line in the figure). In some cases, the control signal is taken into the control device as a detection signal for knock determination, and knocking is erroneously determined. However, in this embodiment,
When the occurrence timing of the sitting noise changes due to the VVT control as indicated by an arrow X in FIG. 4B, the entire knock determination section avoids the sitting noise as indicated by an arrow Y in FIG. 4B. Thus, the seating noise detected by the knock sensor is not taken in as a knock signal in the knock determination section.

Therefore, according to the present embodiment, the knock determination by the CPU 22 can always be performed accurately.
Knocking control can be performed with high accuracy.
Particularly, in the present embodiment, in setting the knock determination section, the start timing and the end timing of the knock determination section set from the engine speed are not simply corrected, but as shown in FIG. Since the entire determination section is shifted, the knock determination section of each cylinder is narrowed and the knock determination accuracy is not reduced, and knocking can always be determined with high accuracy in the optimal knock determination section.

In this embodiment, S1 shown in FIG.
The processing of 10, S120, S230, and S310 functions as a knock determination section setting means of the present invention. As mentioned above, although one Example of this invention was described, this invention is not limited to said Example, You can take various aspects.

For example, in the above embodiment, the case where the present invention is applied to a four-cylinder four-cycle engine has been described. However, the present invention relates to a multi-cylinder four-cycle engine having a control device for performing VVT control. The same effects can be obtained by applying the same method as in the embodiment.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an engine of an embodiment and peripheral devices thereof.

FIG. 2 is a flowchart showing control processing executed for VVT control and knock determination in an ECU.

FIG. 3 is an explanatory diagram illustrating a procedure for setting a knock determination section by a control process shown in FIG. 2;

FIG. 4 is a time chart illustrating a knock determination operation and an effect of the embodiment.

FIG. 5 is an explanatory diagram showing a correspondence relationship between a knock determination section and a stroke of each cylinder in a four-cylinder four-cycle internal combustion engine, and an opening / closing timing of an intake valve and an exhaust valve.

[Explanation of symbols]

2 engine, 4 intake valve, 5 exhaust valve, 6, 7 variable valve timing mechanism, 8 ignition plug, 12 knock sensor, 14 ignition coil, 15 air flow meter, 1
6: rotation angle sensor, 17: cylinder discrimination sensor, 18: throttle sensor, 20: ECU, 22: CPU.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kenichi Maki 1-1-1, Showa-cho, Kariya-shi, Aichi Pref.

Claims (3)

[Claims] 1. A multi-cylinder internal combustion engine having a variable valve timing control device that controls the opening / closing timing of at least one of an intake valve and an exhaust valve provided in each cylinder of the internal combustion engine in accordance with an operation state of the internal combustion engine. A detection signal from a knock sensor that detects mechanical vibration of the internal combustion engine is taken into a predetermined knock determination section during an explosion stroke of each cylinder of the internal combustion engine, and the internal combustion engine is knocked from the taken detection signal. A knocking control device that determines whether or not the engine has occurred, and controls knocking by controlling the ignition timing of the internal combustion engine based on the determination result, wherein the variable valve timing control device controls the intake valve or the exhaust gas. Based on the opening and closing timing of the valve, at least the closing timing of the intake valve or the exhaust valve and the knock determination section do not overlap so as not to overlap. Knock control device for a variable valve timing control system with a multi-cylinder internal combustion engine characterized by comprising a knock determination period setting means for setting a knock determination period. 2. The knock determination section setting means detects an actual opening / closing timing of the intake valve or the exhaust valve controlled by the variable valve timing control device, and sets the knock determination section based on the actual timing. The knocking control device for a multi-cylinder internal combustion engine with a variable valve timing control device according to claim 1, wherein 3. The knock determination section setting means sets a width of the knock determination section based on a rotation speed of the internal combustion engine, and sets a start timing of the knock determination section to an opening / closing timing of the intake valve or the exhaust valve. The knocking control device for a multi-cylinder internal combustion engine with a variable valve timing control device according to claim 1 or 2, wherein the knocking control device is set based on: