KR102172165B1 - Engine including knocking control system and knock controlling method of engine - Google Patents

Abstract

The present invention relates to an engine equipped with a knocking control system and a knocking control method of the engine, wherein the engine includes at least one cylinder installed; An intake manifold for supplying intake air to an intake port installed above each of the cylinders; A fuel supply system including a fuel injection device installed at each of the intake ports; And a knocking control system for preventing knocking by additionally supplying air to a corresponding cylinder in which knocking has occurred or has a possibility of knocking, among at least one or more cylinders.
An engine equipped with a knocking control system according to the present invention and a knocking control method of the engine include, in the knock detection unit, the possibility of causing knocking of each cylinder to be detected early, and whether the engine control unit knocks on the basis of the detected knocking signal value. By performing judgment and control and additionally supplying air to the cylinder, knocking can be prevented early by temporarily increasing the air-fuel ratio to the cylinder, so that the combustion situation of the cylinder can be maintained normally, and the balance between the cylinders can be maintained accordingly. In addition, it is possible to prevent a decrease in engine output and to perform a stable operation.

Description

An engine equipped with a knocking control system and its knocking control method {ENGINE INCLUDING KNOCKING CONTROL SYSTEM AND KNOCK CONTROLLING METHOD OF ENGINE}

The present invention relates to an engine equipped with a knocking control system and a knocking control method of the engine.

In gas carriers such as liquefied natural gas (LNG), gas fuel stored in the storage tank is easily used as fuel, while gaseous fuel is used as fuel for ship propulsion engines without re-liquefying the gas vaporized in the tank. In some cases, a gas engine using a gas engine is mounted, or a dual fuel engine that selectively or simultaneously uses oil fuel and gas fuel is installed. In addition, in the case of large diesel engines used in offshore floats, offshore structures, or power generation facilities using gases such as LNG or LPG, dual fuel engines that can be used with gas fuel are being introduced.

For large engines (diesel engines) using dual fuels, gas fuel operation mode using gas fuel, oil fuel operation mode using oil fuel (e.g. Marine Diesel Oil, Heavy Fuel Oil, etc.), and gas fuel and oil. It has a mixed operation mode that uses fuel at the same time. It goes without saying that the gas engine (gasoline engine) has a gas fuel operation mode.

Oil fuel is injected into the combustion chamber by an oil fuel injector provided in each cylinder head, and gas fuel is distributed from the main feed pipe to the distribution pipe for each cylinder, and then the amount of gas in the gas admission valve (GAV) assembly It is adjusted and injected into the intake port of the cylinder head through a gas injector.

Unlike gasoline engines that spark fuel with spark plugs, dual-fuel engines are based on diesel engines that compress the intake air at high temperature and pressure to self-ignition, so gas fuel is not ignited. It is further equipped with a micro pilot injector as a guided small oil fuel injector.

Gas fuel such as natural gas has a low flash point but a high self-ignition (self-ignition) temperature of around 550°C, so just before the main fuel is injected (main injection process) in the gas fuel operation mode. A small amount of pilot oil (e.g., Marine Diesel Oil, Marine Gas Oil, etc.) is injected through the pilot injector to induce ignition (pilot injection process), and stable ignition of gas fuel can be achieved.

In addition, even in the oil fuel operation mode, a small amount of pilot oil is injected through a pilot injector immediately before injection of the main fuel, diesel fuel, thereby improving the combustion environment of the combustion chamber, thereby improving NOx and improving combustion performance.

As described above, in a dual-fuel engine, a separate supply system must be installed for supplying two main fuels and pilot oil, while operating in more than two operation modes, the device is complex and can be controlled. The control system for this is also very complex.

In particular, since a dual fuel engine is based on a diesel engine, precise operation control in the gas fuel mode is a very important factor in determining whether or not the gas fuel mode can be operated. For example, in the oil fuel operation mode, combustion occurs through compression ignition of the fuel like a general diesel engine, but in the gas fuel operation mode, pilot injection must be performed in advance to induce ignition of the gas fuel. Therefore, in the gas fuel operation mode, even if the ignition timing by the gas fuel is set to be the same, the progress of combustion (explosion), combustion pressure, peak pressure generation time, etc. differ for each cylinder.

Therefore, in the dual fuel engine as described above, it is very important to control knocking that occurs in real time in each cylinder and eliminate the cause of knocking early in order to stably maintain the driving characteristics of the engine. It is also very important to maintain balance between cylinders.

In order to ensure operational stability through knocking control or cylinder balancing control, the combustion situation of each cylinder is monitored in real time, and whether there is a combustion situation that may cause knocking is detected early, and knocking is induced by prompt and appropriate measures. The possibility must be blocked in advance to maintain balance between cylinders.

However, conventionally, in order to suppress the occurrence of knocking, a reduction in the total amount of heat generated in the corresponding cylinder due to a reduction in the amount of fuel supplied to the knocking cylinder, delay in the ignition timing, etc., or a decrease in the combustion pressure inside the cylinder according to the perception of combustion is used. In the knocking control method, the output of the corresponding cylinder and the maximum combustion chamber pressure are lowered during the knocking suppression control process, which deteriorates the cylinder balance of the entire engine.When knocking occurs, the control method is based on the decrease in the output of the corresponding cylinder. There is a problem that efficiency and performance are deteriorated.

Korean Patent Publication Publication No. 10-2010-0074084 (published on July 1, 2010) Korean Patent Publication Publication No. 10-2008-0078504 (published on August 27, 2008) Korean Patent Application Publication No. 10-2004-0095274 (published on November 12, 2004)

The present invention was created to solve the problems of the prior art as described above, and an object of the present invention is to recognize the possibility of causing knocking of each cylinder early and effectively cope with it, thereby suppressing the occurrence of knocking and thereby preventing the combustion of the cylinder. To provide an engine and a knocking control method of the engine provided with a knocking control system that enables normal maintenance and thus helps maintain balance between cylinders.

An engine equipped with a knocking control system according to an aspect of the present invention includes at least one cylinder installed; An intake manifold for supplying intake air to an intake port installed above each of the cylinders; A fuel supply system including a fuel injection device installed at each of the intake ports; And a knocking control system for preventing knocking by additionally supplying air to a corresponding cylinder in which knocking has occurred or has a possibility of knocking, among at least one or more cylinders.

Specifically, the knocking control system, the compressed air supply unit; An air injection device installed at each of the intake ports; An air supply pipe connected to each of the air injection devices from the compressed air supply unit; A knock detection unit installed in each of the cylinders; And an engine control unit that compares the knocking signal value detected by each of the knocking detection units with a preset knocking limit value, and controls to additionally supply air to the intake port installed on the upper part of the cylinder through the air injector. can do.

Specifically, the air supply pipe, the main pipe connected to the air supply; And

It may include a branch pipe branched from the main pipe to connect each of the air injector.

Specifically, the main pipe may be further provided with a pressure regulator configured to maintain a constant air pressure supplied to each of the air injection devices through each of the branch pipes.

Specifically, an air valve is provided in each of the branch pipes, and each of the air valves may be controlled to be opened or closed by the engine control unit.

An engine knocking control method according to an aspect of the present invention includes: receiving, by an engine control unit, a knocking signal value from a knocking detection unit installed in each cylinder; The engine control unit comparing the received knocking signal value with a preset knocking limit value to recognize a corresponding cylinder in which knocking has occurred or has a possibility of knocking; And performing, by the engine control unit, a knocking control system so that air is additionally supplied to at least one recognized cylinder.

Specifically, the step of performing the knock removal process by the engine control unit controlling the knock control system, wherein the engine control unit controls a pressure regulator to adjust the pressure of air supplied from the compressed air supply unit to the corresponding cylinder. step; Opening, by the engine control unit, an air valve so that air may be additionally supplied to the corresponding cylinder through an air injection device after a point in time when fuel injection from the corresponding cylinder is finished; And the engine control unit additionally supplying air to the corresponding cylinder until the intake valve of the corresponding cylinder is closed, and closing the air valve.

Specifically, the amount of additional air supplied to the corresponding cylinder is controlled by the engine control unit so that the pressure of the air is higher than the internal pressure of the intake port of the corresponding cylinder, while the air valve is opened. It can be adjusted by controlling the period change.

Specifically, the additional air supply amount may be determined based on a reference value set according to an engine rotation speed, a load, and a knock signal value.

An engine equipped with a knocking control system according to the present invention and a knocking control method of the engine include, in the knock detection unit, the possibility of causing knocking of each cylinder to be detected early, and whether the engine control unit knocks on the basis of the detected knocking signal value. By performing judgment and control and additionally supplying air to the cylinder, knocking can be prevented early by temporarily increasing the air-fuel ratio to the cylinder, so that the combustion situation of the cylinder can be maintained normally, and the balance between the cylinders can be maintained accordingly. In addition, it is possible to prevent a decrease in engine output and to perform a stable operation.

In addition, the engine equipped with the knocking control system and the engine knocking control method according to the present invention can improve stability and reliability in a gas fuel operation mode of a gas engine or a dual fuel engine based on a diesel engine.

1 is a block diagram of an engine equipped with a knocking control system according to an embodiment of the present invention.
2 is a block diagram of a cylinder equipped with a knocking control system according to the present invention.
3 is a graph for explaining the timing of supplying additional air to the cylinder by the knocking control system according to the present invention.
4 is a flowchart illustrating a knocking control method of an engine equipped with a knocking control system according to an embodiment of the present invention.
5 is a partial flowchart illustrating a knocking control method of an engine equipped with a knocking control system according to an embodiment of the present invention.

Objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments associated with the accompanying drawings. In adding reference numerals to elements of each drawing in the present specification, it should be noted that, even though they are indicated on different drawings, only the same elements are to have the same number as possible. In addition, in describing the present invention, when it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a configuration diagram of an engine equipped with a knocking control system according to an embodiment of the present invention, FIG. 2 is a configuration diagram of a cylinder equipped with a knocking control system according to the present invention, and FIG. 3 is a knocking control according to the present invention. This is a graph for explaining the timing of supplying additional air to the cylinder by the system.

1 and 2, an engine 1 equipped with a knocking control system according to an embodiment of the present invention includes an intake manifold 100, an exhaust manifold 200, a cylinder 300, A fuel supply system 400 and a knocking control system 500 are included.

The engine 1 is a marine engine in which an internal combustion engine such as a diesel engine is used, for example, a MEGI engine that is a high-pressure engine mounted on a ship, a dual fuel engine (DFDE) that is a low-pressure engine, an engine for power generation, and other power. It may be an engine for generating, a gas engine, or the like.

The intake manifold 100 may supply intake air to a cylinder 300 to be described later, and may be connected to a cylinder 300 to be described later by an intake port 310.

The exhaust manifold 200 may discharge gas burned in the cylinder 300 to be described later, and may be connected to the cylinder 300 to be described later by an exhaust port 320.

The number of cylinders 300, that is, at least one or more, may be installed along the engine block according to the characteristics or size of the engine 1.

An intake port 310 provided with an intake valve 330 through which a fuel-air mixture is introduced, and an exhaust valve 340 for discharging the burned gas at the upper part of the combustion chamber of the cylinder 300 Exhaust ports 320 may be installed respectively. Here, the mixer means that intake air supplied from the intake manifold 100 and gas fuel or oil fuel supplied from the fuel supply system 400 to be described later are mixed at a predetermined ratio. Hereinafter, the mixer is expressed as'fuel' for convenience, and'fuel' may not necessarily mean that it is a mixer.

In addition, in the case of a gasoline engine, an ignition device 350 may be installed as shown in FIG. 2 to ignite the fuel in the combustion chamber during the explosion stroke. In the case of a dual fuel engine, the intake air is heated at a high temperature. Since it is based on a diesel engine that self-ignitions by compression at high pressure, a micro pilot injector may be further provided as a small oil fuel injector that induces ignition of gas fuel.

The ignition device 350 may be installed above the combustion chamber of the cylinder 300, and when the piston 360 rises in the combustion chamber and reaches top dead center, the fuel is ignited to induce an explosion.

At this time, the fuel is injected downward while the intake valve 330 is opened from the upper part of the combustion chamber, and then ignition is performed at the upper part of the combustion chamber by the ignition device 350. area; 370) exists.

Accordingly, in each cylinder 300, fuel is ignited from the upper part of the combustion chamber by the ignition device 350 to generate a flame, and at the same time, the flame propagates downward from the upper end of the combustion chamber, thereby performing an explosion stroke.

In this case, an additional pressure is generated inside the combustion chamber during the flame propagation process, and due to this pressure, the fuel in the end gas region 370 is instantly compressed to high temperature and high pressure, resulting in abnormal ignition.

This abnormal ignition instantaneously generates another flame, so that the flame propagating from the upper part of the combustion chamber and the flame due to the abnormal ignition in the end gas region 370 collide with each other, causing knocking and increasing soot. In addition, the output efficiency of the engine 1 also decreases.

Accordingly, the present invention provides a knocking control system 500 to be described later in the engine 1 to additionally supply air to the corresponding cylinder 300 that may cause knocking, thereby increasing the air ratio of fuel. , To prevent abnormal ignition in the end gas region 370 of the cylinder 300.

The fuel supply system 400 includes a fuel supply unit 410, a fuel supply pipe 420, and a fuel injection device 430 so that gas fuel or oil fuel can be supplied to the intake port 310 of the cylinder 300. Can be configured. The amount of gas fuel or oil fuel supplied from the fuel supply system 400 to the cylinder 300 may be determined according to a preset value so as to obtain an optimum air-fuel ratio.

The fuel supply unit 410 may include a fuel tank for storing gas fuel or oil fuel, and may supply gas fuel or oil fuel to a fuel injection device 430 to be described later through a fuel supply pipe 420 to be described later. .

The fuel supply pipe 420 is provided to connect the fuel supply unit 410 and a fuel injection device 430 to be described later, and may provide a passage for supplying gas fuel or oil fuel to the fuel injection device 430, It may be composed of a fuel main pipe 421 and a fuel branch pipe 422.

The fuel main pipe 421 is connected to the fuel supply unit 410 and may be disposed at one side of the cylinder 300 along the engine block, and the fuel main pipe 421 has fuel so as to correspond to the position of each cylinder 300. Branch pipes 422 may be installed spaced apart at regular intervals. In this case, a fuel valve 423 capable of opening and closing the internal flow path may be installed in each fuel branch pipe 422, and a fuel injection device 430 to be described later may be connected to an end thereof.

The fuel injector 430 is connected to an end of each fuel branch pipe 422 to transfer gas fuel or oil fuel supplied through the fuel main pipe 421 and the fuel branch pipe 422 into the intake port 310. It can be configured to be able to spray.

In order to prevent knocking by additionally supplying compressed air to the knocking control system 500 and the cylinder 300 where knocking or knocking is likely to occur, the compressed air supply unit 510, the air supply pipe 520, the air injection device ( 530, a knock detection unit 540, and may be configured to include an engine control unit 550.

The knocking control system 500 described above can be used alone in the engine 1, as well as the knocking reduction control method using the conventional knocking control method, for example, delaying the ignition timing and reducing the gas fuel injection period. Of course, it can be applied additionally.

The compressed air supply unit 510 may include a pressurized air tank that stores air, and may supply compressed air to an air injector 530 to be described later through an air supply pipe 520 to be described later.

The compressed air supply unit 510 may use a starting air system used for starting pressurized air of a medium-sized engine or a large engine.

The air supply pipe 520 is provided to connect the compressed air supply unit 510 and the air injection device 530 to be described later, and may provide a passage for supplying compressed air to the air injection device 530, and the main air It may be composed of a pipe 521 and an air branch pipe 522.

The main air pipe 521 is connected to the compressed air supply unit 510 and may be disposed at one side of the cylinder 300 along the engine block, and the main air pipe 521 corresponds to the position of each cylinder 300. The air branch pipes 522 may be spaced apart from each other at regular intervals, and a pressure regulator 524 to be described later may be provided to control the air pressure. At this time, each of the air branch pipes 522 may be provided with an air valve 523 capable of opening and closing the internal flow path, and an air injection device 530 to be described later may be connected to an end thereof.

The pressure regulator 524 may be provided upstream of the air main pipe 521 so that the air pressure supplied to each of the air injectors 530 to be described later through each of the air branch pipes 522 can be kept constant. .

Each of the pressure regulator 524 and the air valve 523 may be controlled by an engine control unit 550 to be described later.

The air injector 530 is connected to the end of each air branch pipe 522 to inject compressed air supplied through the air main pipe 521 and the air branch pipe 522 into the intake port 310. It can be configured to be.

The air injector 530 may be installed in the intake port 310 and may be disposed at a front end or a rear end of the fuel injector 430 installed in the intake port 310.

In addition, the air injector 530 may be an electronically controlled solenoid valve, and in this case, it is controlled by the engine control unit 550 to be described later to inject air at a desired time. When the air injector 530 is an electronically controlled solenoid valve, since the air injector 530 is directly controlled by the engine control unit 550, which will be described later, the air valve 523 is separately attached to each air branch pipe 522. No need to install.

The knock detection unit 540 may be installed in the cylinder 300, detects the possibility of causing knocking of each cylinder 300 early, and transmits the detected knock signal value to the engine control unit 550 to be described later. can do.

The knock detection unit 540 may be a sensor capable of detecting a knocking phenomenon that may occur in the cylinder 300 or a pressure analysis device inside the cylinder.

The engine control unit 550 determines whether to knock by comparing a knocking signal value received from the knocking detection unit 540 with a preset knocking limit value, and controls the pressure regulator 524 and the air valve 523 to control the corresponding cylinder. Allows additional air supply to (300). This engine control unit 550 will be described in detail through the operation of the knocking control system 500 to be described below.

The operation of the knocking control system 500 having the above configuration will be described as follows.

With the engine 1 being driven, the knocking detection unit 540 detects the possibility of causing knocking of each cylinder 300, and transmits the detected knocking signal value to the engine control unit 550 in real time.

The engine control unit 550 determines whether or not knocking has occurred by comparing a preset knocking limit value based on the knocking signal value received from the knocking detection unit 540, and knocking has occurred or knocking has occurred in at least one cylinder 300. If it is determined that there is, the corresponding air valve 523 may be controlled to open in order to additionally supply air to at least one of the corresponding cylinders 300.

At this time, the additional air supply is performed after fuel injection from at least one of the corresponding cylinders 300 is started and before the intake valve 330 of the corresponding cylinder 300 is closed, preferably, as shown in FIG. 3, fuel injection. It may be performed from the end of the operation until the intake valve 330 of the cylinder 300 is closed (IVC). In this way, the additional air is supplied from the point when the fuel injection is completed so that the pressure change in the intake port 310 due to the additional compressed air does not affect the fuel supply.

In addition, the engine control unit 550, in order to additionally supply a desired amount of air to the corresponding cylinder 300 for a limited period, the pressure regulator 524 so that the pressure of the air is sufficiently higher than the internal pressure of the intake port 310 By controlling the pressure of and controlling the change in the opening period of the corresponding air valve 523, the amount of additional air supplied may be adjusted.

The amount of additional air supplied may be determined based on a reference value set according to the engine rotation speed, load, and knocking signal value. After injection to the corresponding cylinder 300 once, the engine control unit 550 sends a knocking signal of the corresponding cylinder 300 It is possible to decide whether to re-inject by receiving feedback from the change in value.

Hereinafter, a knocking control method of an engine equipped with a knocking control system according to an embodiment of the present invention will be described with reference to FIGS. 4 and 5.

4 is a flowchart illustrating a knocking control method of an engine equipped with a knocking control system according to an embodiment of the present invention, and FIG. 5 is a knocking control of an engine equipped with a knocking control system according to an embodiment of the present invention. This is a partial flow chart to explain the method.

As shown in Figure 4, the knocking control method of the engine 1 equipped with the knocking control system 500 according to an embodiment of the present invention, the engine control unit 550 is installed in each of the cylinders 300 Step of receiving a knocking signal value from the knocking detection unit 540 (S610), the engine control unit 550 compares the received knocking signal value with a preset knocking limit value, and knocking has occurred or knocking has occurred in the cylinder 300 Recognizing the possible corresponding cylinder 300 (S620), and the engine control unit 550 controls the knocking control system 500 so that air is additionally supplied to the recognized at least one corresponding cylinder 300 And performing knock removal processing (S630).

In step S610, the engine control unit 550 receives a knocking signal value from the knocking detection unit 540 installed in each of the cylinders 300.

In the above, the knocking detection unit 540 may transmit the knocking signal value of each cylinder 300 to the engine control unit 550 in real time, and the knocking signal value may be different for each cylinder 300. That is, in some cylinder 300, the knocking signal value may correspond to a preset knocking limit value, and in another cylinder 300, the knocking signal value may be different from the preset knocking limit value.

In step S620, the engine control unit 550 compares the received knocking signal value with a preset knocking limit value to recognize the corresponding cylinder 300 in which knocking has occurred or has a possibility of knocking.

In the above, the recognized cylinder 300 may be one or more.

Also, the knocking limit value may be set differently according to the type of engine 1.

In step S630, the engine control unit 550 controls the knocking control system 500 so that air is additionally supplied to the recognized at least one corresponding cylinder 300 to perform knock removal processing.

In the above, in the cylinder 300, the knock removal process may be performed by control by the knocking control system 500, and the process will be described in detail with reference to FIG. 5.

As shown in FIG. 5, in step S630, the engine control unit 550 controls the pressure regulator 524 to adjust the pressure of the air supplied from the compressed air supply unit 510 to the cylinder 300 (S631), the engine control unit 550, the air valve 523 so that air can be additionally supplied to the cylinder 300 through the air injector 530 after the fuel injection in the cylinder 300 is finished. ) Opening (S632), and the engine control unit 550, additionally supply air to the corresponding cylinder 300 until the intake valve 330 of the corresponding cylinder 300 is closed, and open the air valve 523 It may include a step of closing (S633).

In the above, the additional air supply amount is an amount supplied to the corresponding cylinder 300 for a limited period, and it is preferable that a desired amount of air is additionally supplied so as to eliminate knock. For this purpose, the pressure of the air is While controlling the pressure of the pressure regulator 524 to be sufficiently higher than the internal pressure of the intake port 310 of 300, it may be adjusted by controlling the change in the opening period of the corresponding air valve 523.

This additional air supply amount may be determined based on a reference value set according to an engine rotation speed, a load, a knock signal value, and the like.

As described above, in this embodiment, the knock detection unit 540 detects the possibility of causing knocking of each cylinder 300 early, and the engine control unit 550 determines and controls whether to knock based on the detected knocking signal value. By performing additional air supply to the corresponding cylinder 300, knocking can be prevented early by temporarily increasing the air-fuel ratio to the cylinder 300, so that the combustion situation of the cylinder 300 can be maintained normally, and accordingly, Balancing between the cylinders 300 may be maintained, and an output reduction of the engine 1 may be prevented and stable operation may be possible.

In addition, the present embodiment can improve stability and reliability in a gas fuel operation mode of a gas engine or a dual fuel engine based on a diesel engine.

In the above, the present invention has been described centering on the embodiments of the present invention, but this is only an example and does not limit the present invention, and those of ordinary skill in the field to which the present invention belongs will not depart from the essential technical content of the present embodiment. It will be appreciated that various combinations or modifications and applications not illustrated in the embodiments are possible in the range. Accordingly, technical contents related to modifications and applications that can be easily derived from the embodiments of the present invention should be interpreted as being included in the present invention.

1: engine 100: intake manifold
200: exhaust manifold 300: cylinder
310: intake port 320: exhaust port
330: intake valve 340: exhaust valve
350: ignition device 360: piston
370: end gas zone 400: fuel supply system
410: fuel supply unit 420: fuel supply pipe
421: fuel main pipe 422: fuel branch pipe
423: fuel valve 430: fuel injector
500: knocking control system 510: compressed air supply
520: air supply pipe 521: air main pipe
522: air branch pipe 523: air valve
524: pressure regulator 530: air injector
540: knock detection unit 550: engine control unit

Claims (9)

At least one cylinder installed;
An intake manifold for supplying intake air to an intake port installed above each of the cylinders;
A fuel supply system including a fuel injection device installed at each of the intake ports; And
A knocking control system for preventing knocking by an engine control unit controlling to additionally supply air to a corresponding cylinder in which knocking has occurred or is likely to be knocked, among at least one or more cylinders,
The engine control unit controls the knocking control system to perform knock removal processing, but controls the pressure regulator to adjust the pressure of air supplied to the cylinder from the compressed air supply unit, and the fuel injection is completed in the cylinder. Opening the air valve so that air can be additionally supplied to the corresponding cylinder through the air injection device after the point in time, additionally supplying air to the corresponding cylinder until the intake valve of the corresponding cylinder is closed, and closing the air valve Engine, characterized in that. The method of claim 1, wherein the knocking control system,
Compressed air supply;
The air injector installed at each of the intake ports;
An air supply pipe connected to each of the air injection devices from the compressed air supply unit;
A knock detection unit installed in each of the cylinders; And
Comprising the engine control unit for comparing the knocking signal value detected by each of the knocking detection units with a preset knocking limit value, and controlling to additionally supply air to the intake port installed on the upper part of the cylinder through the air injector. Engine, characterized in that. The method of claim 2, wherein the air supply pipe,
A main pipe connected to the compressed air supply unit; And
And a branch pipe branched from the main pipe to connect each of the air injectors. The method of claim 3, wherein the pressure regulator,
An engine provided in the main pipe and configured to maintain a constant air pressure supplied to each of the air injection devices through each of the branch pipes. The method of claim 3, wherein the air valve,
It is provided in each of the branch pipes,
Each of the air valves is controlled to be opened and closed by the engine control unit. Receiving, by the engine control unit, a knocking signal value from a knocking detection unit installed in each cylinder;
The engine control unit comparing the received knocking signal value with a preset knocking limit value to recognize a corresponding cylinder in which knocking has occurred or has a possibility of knocking; And
And performing, by the engine control unit, a knocking control system so that air is additionally supplied to the recognized at least one corresponding cylinder,
The engine control unit controlling the knocking control system to perform knock removal processing,
Controlling, by the engine control unit, a pressure regulator to adjust the pressure of air supplied from the compressed air supply unit to the corresponding cylinder;
Opening, by the engine control unit, an air valve so that air may be additionally supplied to the corresponding cylinder through an air injection device after a point in time when fuel injection from the corresponding cylinder is finished; And
And the engine control unit additionally supplying air to the corresponding cylinder until the intake valve of the corresponding cylinder is closed, and closing the air valve. delete The method of claim 6, wherein the amount of additional air supplied to the corresponding cylinder is
Wherein the engine control unit controls the pressure of the pressure regulator so that the pressure of the air is higher than the pressure inside the intake port of the corresponding cylinder, while controlling the change in the opening period of the air valve. Knock control method. The method of claim 8, wherein the additional air supply amount is
An engine knock control method, characterized in that it is determined based on a reference value set according to an engine rotation speed, a load, and a knock signal value.

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