Engine control device

Abstract

The engine control device of the present application includes: a main chamber injection unit (1, 3) that supplies fuel to a main chamber (8); and a sub chamber injection unit (2) that supplies fuel to a sub chamber (5) after the fuel is supplied by the main chamber injection unit (1, 3). In addition, there are included: a presumption unit (21) that presumes a knock degree (N) that is an index of the strength and the frequency of occurrence of knock; and a fuel control unit (22) that, in the case where the knock degree (N) is a first prescribed value (N1) or more, implements fuel control that reduces a sub chamber fuel amount that is the amount of fuel supplied from the sub chamber injection unit (2). In this way, by reducing the sub chamber fuel amount, it is possible to suppress the occurrence of knock, and it is possible to improve the combustion state of the sub chamber engine.

Description

Technical Field

[0001] This invention relates to an engine control device having a main chamber and an auxiliary chamber within a combustion chamber. Background Technology

[0002] Conventionally, it is well known that a secondary chamber engine has a main chamber (main combustion chamber) and a secondary chamber (secondary combustion chamber) connected within the combustion chamber, with the spark plug electrode disposed inside the secondary chamber. In this engine, the flame generated inside the secondary chamber is formed and ejected in a torch shape toward the main chamber. Thus, even when the air-fuel ratio in the main chamber is leaner than the stoichiometric air-fuel ratio, the fuel mixture can be burned efficiently (see Patent Document 1).

[0003] Existing technology

[0004] Patent documents

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-105171 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] In auxiliary chamber engines, a suitable amount of fuel needs to be supplied to the auxiliary chamber. Compared to other engines, the injection period for fuel injection into the auxiliary chamber is more easily limited. Furthermore, because the correlation between the fuel injection period and ignition timing is also important, the range of suitable ignition timing is narrower than in other engines. Therefore, for faults such as knocking or poor combustion, it is difficult to significantly change the ignition timing, resulting in difficulties in stabilizing the combustion state.

[0008] One of the objectives of this invention is to improve the combustion state of a secondary chamber engine, which addresses the aforementioned issues. It should be noted that the objectives of this invention are not limited to this; achieving the effects obtained through the various structures shown in the "Detailed Embodiments" described below, i.e., effects that cannot be obtained through conventional techniques, is also another objective of this invention.

[0009] The engine control device of the present invention includes: a main chamber injection unit that supplies fuel to the main chamber; an auxiliary chamber injection unit that supplies fuel to the auxiliary chamber after supplying fuel through the main chamber injection unit; a prediction unit that predicts the degree of knock as an indicator of the intensity and frequency of knock occurrence; a fuel control unit that, when the degree of knock is above a first predetermined value, implements fuel control to reduce the amount of auxiliary chamber fuel supplied from the auxiliary chamber injection unit; and an ignition control unit that implements ignition control to delay ignition timing, and after implementing the fuel control through the fuel control unit, implements the ignition control when the degree of knock is above the first predetermined value.

[0010] Invention Effects

[0011] The engine control device according to the present invention can improve the combustion state of a secondary chamber engine. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the engine structure, which is used as an example of a control device.

[0013] Figure 2 This is a schematic diagram showing the structure of other engines for use as an example of a control device.

[0014] Figure 3 It is a mapping used to set the first index value related to the degree of detonation.

[0015] Figure 4 (A) is a chart used to set the second index value related to the degree of knocking, and (B) is a chart used to set the third index value.

[0016] Figure 5 This is a schematic diagram illustrating the relationship between the degree of detonation and the type of control.

[0017] Figure 6 It is a flowchart used to explain the control content.

[0018] Figure 7 It is a flowchart used to explain the control content.

[0019] Figure 8 It is a flowchart used to explain the control content.

[0020] [Symbol Explanation]

[0021] 1. Injection valve (main chamber injection unit)

[0022] 2. Sub-chamber injection valve (sub-chamber injection unit)

[0023] 3. In-cylinder injection valve (main chamber injection unit)

[0024] 4. Multifunctional injection valve (main chamber injection unit, auxiliary chamber injection unit)

[0025] 5th Auxiliary Office

[0026] 6. Spacer

[0027] 7 holes

[0028] 8. Main Room

[0029] 9. Spark plugs

[0030] 10 Engines

[0031] 11 Air Inlet

[0032] 12 Exhaust ports

[0033] 13. Intake valve

[0034] 14. Exhaust valve

[0035] 15. Knock Sensors

[0036] 16-cylinder in-cylinder pressure sensor

[0037] 17 Engine speed sensor

[0038] 18 Accelerator pedal position sensor

[0039] 19 Vehicle speed sensor

[0040] 20 ECU (Control Unit)

[0041] 21. Speculation Unit

[0042] 22 Fuel Control Unit

[0043] 23 Ignition Control Unit

[0044] M1 First Indicator Value

[0045] M2 Second Indicator Value

[0046] M3 Third Indicator Value

[0047] N Detonation level

[0048] N1 First specified value

[0049] N2 second specified value

[0050] N3 Third specified value

[0051] X after time

[0052] Y has elapsed time

[0053] X1 Specified Time

[0054] Y1 Specified Time

[0055] Y2 Specified Time Detailed Implementation

[0056] [1. Composition]

[0057] Figures 1 to 8 This is a diagram illustrating the control device mounted on the engine 10 (internal combustion engine) of a vehicle. Figure 1 and Figure 2The diagrams schematically represent the structure of a passive auxiliary chamber engine 10, in which a main chamber 8 (main combustion chamber) and an auxiliary chamber 5 (auxiliary combustion chamber) are formed in the cylinder. Figure 1 The structure of engine 10 is illustrated, wherein injection valves (sub-chamber injection valve 2) for supplying fuel to the auxiliary chamber 5 and injection valves (port injection valve 1 and in-cylinder injection valve 3) for supplying fuel to the main chamber 8 are respectively provided. On the other hand, Figure 2 An example is given of the structure of an engine 10 that uses a single injection valve (multi-function injection valve 4) to blow fuel into the main chamber 8 and the auxiliary chamber 5 respectively.

[0058] The control device of the engine 10 of the present invention includes: a main chamber injection unit (port injection valve 1, cylinder injection valve 3, multi-function injection valve 4) that supplies fuel to the main chamber 8; and an auxiliary chamber injection unit (auxiliary chamber injection valve 2, multi-function injection valve 4) that supplies fuel to the auxiliary chamber 5. In a combustion cycle (a cycle consisting of four strokes: intake stroke, compression stroke, combustion stroke, and exhaust stroke), fuel supply through the auxiliary chamber injection unit is implemented after the fuel supply through the main chamber injection unit. For example, the fuel supply through the main chamber injection unit is implemented from the latter half of the exhaust stroke to the intake stroke. In contrast, the fuel supply through the auxiliary chamber injection unit is implemented during the intake stroke or compression stroke after the main chamber injection. Therefore, even when the main chamber injection and auxiliary chamber injection are implemented by only a single injection valve, these can be clearly distinguished based on the injection timing.

[0059] It should be noted that all fuel injected from the main chamber injection unit is not limited to combustion in the main chamber 8; a portion of the fuel can also flow into the auxiliary chamber 5. Similarly, all fuel injected from the auxiliary chamber injection unit is not limited to combustion in the auxiliary chamber 5; a portion of the fuel can also flow into the main chamber 8. However, the fuel injected from the main chamber injection unit is intended to burn in the main chamber 8, and is injected at a time when combustion is readily possible in the main chamber 8, with the majority of it burning in the main chamber 8. Likewise, the fuel injected from the auxiliary chamber injection unit is intended to burn in the auxiliary chamber 5, and is injected at a time when combustion is readily possible in the auxiliary chamber 5, with the majority of it burning in the auxiliary chamber 5. Therefore, the main chamber injection unit can be defined as "a unit that supplies fuel at a time suitable for combustion in the main chamber 8," and the auxiliary chamber injection unit can be defined as "a unit that supplies fuel at a time suitable for combustion in the auxiliary chamber 5."

[0060] like Figure 1 , Figure 2 As shown, the auxiliary chamber 5 is, for example, formed as a hollow hemisphere that bulges out from the center of the top surface of the combustion chamber toward the piston side. Figure 1 , Figure 2This illustrates an example where a secondary chamber 5 is positioned between the intake port 11 and the exhaust port 12 in a ridge-type cylinder head. The location of the secondary chamber 5 is preferably determined by considering the overall shape of the combustion chamber, or by considering the operating range of the intake valve 13 or the exhaust valve 14. Alternatively, the secondary chamber 5 may be positioned closer to the outer edge of the cylinder than the intake port 11 or the exhaust port 12.

[0061] Tiny holes 7 are formed in the partition wall 6 separating the auxiliary chamber 5 and the main chamber 8. Additionally, the electrodes of the spark plug 9 are disposed inside the auxiliary chamber 5. When the fuel-air mixture is ignited inside the auxiliary chamber 5, its flame is ejected radially from the auxiliary chamber 5 to the main chamber 8 through the multiple holes 7, appearing as a torch-like flame. It should be noted that the engine 10 of the present invention is a passive type engine 10 in which fuel for forming a flame is supplied from the outside of the auxiliary chamber 5, and fuel for forming the mixture inside the auxiliary chamber 5 is supplied by fuel injection from the auxiliary chamber injection unit. However, it is not limited to the passive type, and includes various methods of supplying fuel for forming a flame from the outside of the auxiliary chamber 5, such as supplying fuel for forming a flame near the auxiliary chamber 5, or introducing fuel supplied near the auxiliary chamber 5 into the auxiliary chamber 5 by increasing the cylinder pressure during the compression stroke. On the other hand, although not specifically described in the present invention, there are also engines 10 that directly inject fuel into the interior of the auxiliary chamber 5. Such an engine 10 is called an active type engine 10.

[0062] Figure 1 The port injection valve 1 shown is one of the main chamber injection units and is a passive injector that injects fuel into the intake port 11. The fuel injection direction through the port injection valve 1 is set, for example, toward the gap between the open intake valve 13 and the intake port 11. Additionally, the port injection valve 3 is also one of the main chamber injection units and is an injector that injects fuel into the main chamber 8. The fuel injection direction through the in-cylinder injection valve 3 is set, for example, according to the direction or velocity of the airflow (tumble or vortex) formed in the combustion chamber during the compression stroke. Either the port injection valve 1 or the in-cylinder injection valve 3 can be omitted.

[0063] Figure 1 The auxiliary chamber injection valve 2 shown is one of the auxiliary chamber injection units, and is a passive injector that injects fuel into the auxiliary chamber 5. The injection direction of the auxiliary chamber injection valve 2 is set, for example, towards the auxiliary chamber 5. However, the injection direction of the auxiliary chamber injection valve 2 is not limited to the direction towards the auxiliary chamber 5. For example, considering the direction or velocity of the airflow (tumble or vortex) formed in the cylinder, the fuel can be injected to a position slightly off-center from the auxiliary chamber 5.

[0064] Figure 2 The multi-functional injection valve 4 shown is an injector that functions as both a main chamber injection unit and a secondary chamber injection unit. At least two injection holes are formed at the front end of the multi-functional injection valve 4. One injection hole is used to achieve [the desired effect]. Figure 1 The same fuel injection orifice as the in-cylinder injection valve 3 is used to inject fuel supplied to the main chamber 8. Another injection orifice is used to achieve the same... Figure 1 The same fuel injection orifice as the auxiliary chamber injection valve 2 is used to inject fuel supplied to the auxiliary chamber 5. The on / off state of each injection orifice is controlled independently.

[0065] Engine 10 is equipped with a knock sensor 15, a cylinder pressure sensor 16, an engine speed sensor 17, an accelerator pedal position sensor 18, and a vehicle speed sensor 19. The knock sensor 15 is used to detect the presence or absence of knocking, a type of abnormal combustion, by detecting forces, pressures, and accelerations generated by cylinder vibrations. The cylinder pressure sensor 16 is used to detect the combustion state within the combustion chamber, measuring the pressure in the main chamber 8. The engine speed sensor 17 is used to detect the operating state of engine 10, for example, by detecting the engine speed per unit time (crankshaft angular velocity). The accelerator pedal position sensor 18 is used to detect the magnitude of the torque required by engine 10 (driver-required torque), detecting the amount of accelerator pedal operation (accelerator pedal position), not shown. The vehicle speed sensor 19 is used to detect the vehicle speed (driving speed) of the vehicle equipped with engine 10. The various information detected by these sensors 15-19 is transmitted to ECU 20.

[0066] ECU20 is an electronic control unit (Engine Control Unit) used to control the operating state of engine 10. It is an electronic device equipped with a processor and memory. The processor is a microprocessor such as CPU (Central Processing Unit) or MPU (Micro Processing Unit), and the memory is such as ROM (Read Only Memory), RAM (Random Access Memory), or non-volatile memory. The control content implemented by ECU20 is recorded as firmware or application program and stored in memory. When the program is executed, the program content is expanded in the memory space and executed by the processor.

[0067] ECU 20 is connected to the controlled devices and sensors 15-19 via an in-vehicle network (not shown). For example... Figure 1 , Figure 2As shown, the controlled devices include the port injection valve 1, the auxiliary chamber injection valve 2, the cylinder injection valve 3, the multi-function injection valve 4, and the spark plug 9. The fuel injection quantity or ignition timing of the engine 10 is managed as a whole by the ECU 20. It should be noted that it can also be combined with... Figure 1 , Figure 2 Information detected by sensors not shown in the diagram can be used to correct fuel injection quantity or ignition timing. For example, fuel injection quantity or ignition timing can be corrected based on temperature information detected by external air temperature sensors and engine coolant temperature sensors.

[0068] The ECU 20 includes a prediction unit 21, a fuel control unit 22, and an ignition control unit 23. These elements represent the functions implemented by the ECU 20, and can be programmed as software recorded and stored in the ROM or auxiliary storage device within the ECU 20. Alternatively, they can be implemented as electronic circuitry (hardware) corresponding to the software, or as a system where software and hardware coexist.

[0069] The estimation unit 21 estimates the knock intensity N as an indicator of the intensity and frequency of knocking. The knock intensity N is calculated based on at least the engine load. Preferably, it is calculated based on the engine load and engine speed, and more preferably, it is calculated considering the cylinder pressure or the rotational fluctuations of the engine 10. The higher the knock intensity N (i.e., the larger the value of knock intensity N), the stronger the knocking intensity or the higher the frequency of knocking. In this invention, the value of knock intensity N is assigned by the product of a first indicator value M1, a second indicator value M2, and a third indicator value M3. The estimation unit 21 calculates each of the first indicator value M1, the second indicator value M2, and the third indicator value M3, for example, for each combustion cycle, and calculates the value of knock intensity N as their product. The knock intensity N calculated here is transmitted to the fuel control unit 22 and the ignition control unit 23.

[0070] The first index value M1 is an index value calculated based at least on engine load. In this invention, the first index value M1 is calculated based on engine load and engine speed. Figure 3 It is a three-dimensional mapping that defines the relationship between the first index value M1 and engine load and engine speed. Engine load is calculated, for example, based on accelerator pedal position and vehicle speed. The value of the first index value M1 is set to be a value that increases with engine load relative to the same engine speed.

[0071] The increment gradient of the first index value M1 is set to increase with increasing engine load. That is, in Figure 3In the 3D mapping diagram shown, the contour lines connecting points with the same value of the first index M1 become narrower towards the area of ​​high engine load, i.e., the upper side. Furthermore, the value of the first index M1 is set to not change significantly with variations in engine speed. That is, in... Figure 3 In the 3D mapping diagram shown, the contour lines for the first index value M1 extend in the left-right direction. Therefore, even if the first index value M1 is calculated based solely on engine load without considering engine speed, the accuracy of this value will not be significantly compromised.

[0072] The second indicator value, M2, is an indicator value calculated based at least on the cylinder pressure. Figure 4 (A) is a two-dimensional mapping graph showing the relationship between the second index value M2 and the cylinder pressure. The value of the second index value M2 is set to be larger as the cylinder pressure increases. The relationship between the second index value M2 and the cylinder pressure is set according to the magnitude of the influence of the cylinder pressure on the knocking degree N. For example, it can be set as a relationship represented by a linear graph or a curve graph.

[0073] The third indicator value, M3, is an indicator value calculated based on the rotational fluctuation of engine 10. Figure 4 (B) is a two-dimensional mapping of the relationship between the third index value M3 and the cylinder pressure. Rotational fluctuations are assigned, for example, by the absolute value of the gradient of engine speed change (angular acceleration). The value of the third index value M3 is set to increase with the magnitude of the rotational fluctuation. The relationship between the third index value M3 and the rotational fluctuation is set according to the magnitude of the rotational fluctuation's influence on the knocking degree N; for example, it can be set as either a linear graph or a curve graph.

[0074] The fuel control unit 22 controls the amount of fuel supplied to the main chamber as fuel to the main chamber injection unit and the amount of fuel supplied to the auxiliary chamber injection unit. These fuel amounts are set primarily based on engine load and engine speed. On the other hand, compared to the normal operating condition of the engine 10, when the knock level N is high, fuel control is implemented to reduce the amount of fuel in the auxiliary chamber. In this case, as the value of the knock level N increases, the amount of fuel reduction in the auxiliary chamber increases. Conversely, compared to the normal operating condition of the engine 10, when the knock level N is low, fuel control is implemented to increase the amount of fuel in the auxiliary chamber. In this case, as the value of the knock level N decreases, the amount of fuel increase in the auxiliary chamber increases.

[0075] The amount of fuel supplied to the auxiliary chamber can also be increased or decreased by controlling the pressure of the fuel supplied to the auxiliary chamber injection unit and the injection pressure. In this case, without changing the start of injection (SOI) and end of injection (EOI), the amount of fuel supplied to the auxiliary chamber in one combustion cycle can be increased or decreased by weakening or strengthening the injection momentum. Alternatively, the amount of fuel supplied to the auxiliary chamber can also be increased or decreased by controlling the start or end of fuel injection. In this case, while keeping the pressure of the fuel supplied to the auxiliary chamber injection unit and the injection pressure constant, the amount of fuel supplied to the auxiliary chamber in one combustion cycle can be increased or decreased by shortening or lengthening the fuel injection period.

[0076] The main chamber fuel quantity can be set according to engine load and engine speed, regardless of the knocking degree N. Alternatively, to keep the total fuel injection quantity constant, the main chamber fuel quantity can be increased (or decreased) by the same amount as the auxiliary chamber fuel quantity. Here, the standard main chamber fuel quantity is denoted as F. MAIN The standard auxiliary chamber fuel quantity is marked as F. SUB If the reduction in the amount of fuel in the auxiliary chamber is labeled as F... DEC The actual amount of fuel injected from the auxiliary chamber injection unit is F. SUB -F DEC At this point, the amount of fuel injected from the main chamber injection unit can be maintained at F. MAIN It can also be F MAIN +F DEC Alternatively, you can also use F. MAIN Above and F MAIN +F DEC The following range defines the amount of fuel injected from the main chamber injection unit. Similarly, if the increase in the auxiliary chamber fuel quantity is denoted as F... INC The actual amount of fuel injected from the auxiliary chamber injection unit is F. SUB +F INC At this point, the amount of fuel injected from the main chamber injection unit can be maintained at F. MAIN It can also be F MAIN -F INC Alternatively, you can also use F. MAIN -F INC Above and F MAIN The following range is used to set the amount of fuel injected from the main chamber injection unit.

[0077] The ignition control unit 23 controls the ignition timing (the moment when the fuel-air mixture is ignited) of the spark plug 9. The ignition timing is set primarily based on engine load and engine speed. However, compared to the normal operating condition of the engine 10, ignition control that delays the ignition timing is implemented when the knock level N is high. But in a sub-chamber engine, it is desirable to have a narrower range of appropriate ignition timing than in other engines, suppressing changes in ignition timing as much as possible. Therefore, ignition delay control only begins when the knock level N is excessively high or when the fuel control effect of reducing the amount of fuel in the sub-chamber is weak.

[0078] Figure 5 This is a table illustrating the relationship between the various controls and the value of the knock intensity N. When the value of the knock intensity N is greater than or equal to a first predetermined value N1, a reduction control of the auxiliary compartment fuel quantity and an ignition delay control are implemented. Here, if the value of the knock intensity N is greater than or equal to the first predetermined value N1 but less than a second predetermined value N2, which is greater than the first predetermined value N1, then a reduction control of the auxiliary compartment fuel quantity is implemented first, followed by ignition delay control. If the value of the knock intensity N decreases to less than the first predetermined value N1 before the ignition delay control begins, ignition delay control is ultimately not implemented, meaning that the combustion state can be improved without adjusting the ignition timing.

[0079] On the other hand, if the knock intensity N is above the second predetermined value N2, it is determined that the knock intensity N is too high. Ignition delay control is implemented first, followed by auxiliary compartment fuel quantity reduction control. Compared to auxiliary compartment fuel quantity reduction control, ignition delay control can improve the combustion state of engine 10 with a high response. That is, in the case of excessively high knock intensity N, by prioritizing ignition delay control, the combustion state can be improved quickly and reliably. It should be noted that if the knock intensity N decreases to less than the second predetermined value N2 before the auxiliary compartment fuel quantity reduction control begins, ignition delay control temporarily ends, and auxiliary compartment fuel quantity reduction control is implemented instead.

[0080] When the knock intensity N is less than a first predetermined value N1, ignition control is implemented at normal ignition timing (ignition timing set based on engine load and engine speed). Furthermore, regarding fuel injection quantity, when the knock intensity N is less than a third predetermined value N3, which is smaller than the first predetermined value N1, fuel control is implemented to increase the amount of fuel injected into the auxiliary chamber. Alternatively, if the knock intensity N is greater than or equal to the third predetermined value N3 but less than the first predetermined value N1, the engine 10 is controlled by normal fuel quantity (the amount of fuel injected into the main chamber and the amount of fuel injected into the auxiliary chamber set based on engine load and engine speed).

[0081] [2. Flowchart]

[0082] Figures 6-8These are flowcharts illustrating the control operations implemented by ECU20. The controls shown in these flowcharts are executed repeatedly in cycles corresponding to one combustion cycle.

[0083] exist Figure 6 In step A1, the standard fuel quantity for the combustion cycle is calculated based on the engine speed and engine load, and the standard ignition timing for the combustion cycle is also calculated. Within the fuel quantity calculation, the main chamber fuel quantity and the auxiliary chamber fuel quantity are calculated separately. In this invention, the auxiliary chamber fuel quantity is calculated as a smaller value than the main chamber fuel quantity. For example, relative to the total fuel quantity, the auxiliary chamber fuel quantity is approximately a few percent to a dozen percent.

[0084] In step A2, the estimation unit 21 estimates the knock intensity N as an indicator of the intensity and frequency of knocking. Here, for example, a first indicator value M1 is calculated based on engine speed and engine load. Additionally, a second indicator value M2 is calculated based on in-cylinder pressure, and a third indicator value M3 is calculated based on rotational fluctuations. Then, the knock intensity N, which is the product of these values, is calculated.

[0085] In step A3, it is determined whether the value of the detonation intensity N is greater than or equal to a first predetermined value N1. If this condition is met, fuel control measures are implemented to at least reduce the amount of fuel in the auxiliary chamber. In this invention, the process proceeds to step A4 for further condition determination. It should be noted that if the value of the detonation intensity N is less than the first predetermined value N1 in step A3, the process described later is initiated. Figure 8 The process (from symbol B to step A22).

[0086] In step A4, it is determined whether the value of the knock intensity N is greater than or equal to a second predetermined value N2, which is greater than the first predetermined value N1. If this condition is met, it is determined that knocking needs to be suppressed immediately, and ignition delay control is performed first, proceeding to step A5. It should be noted that if the value of the knock intensity N is less than the second predetermined value N2 in step A4, the process described later will proceed. Figure 7 The process (from symbol A to step A12).

[0087] In step A5, the elapsed time Y is reset. The elapsed time Y is... Figure 7 The parameters referenced in the process indicate the duration of the state N1≤N<N2. Additionally, step A6 begins measuring elapsed time X, proceeding to step A7. Elapsed time X signifies the duration of the state N≥N2. It should be noted that the units for elapsed time X and Y can be seconds or the number of combustion cycles.

[0088] In step A7, it is determined whether the elapsed time X is less than or equal to a predetermined time X1. The predetermined time X1 can be a pre-set time or number of combustion cycles, or a time or number of combustion cycles set based on engine speed. If this condition is met, proceed to step A8, where fuel injection is performed with standard main chamber and auxiliary chamber fuel quantities. Additionally, in step A9, ignition delay control is performed with a predetermined delay amount. This delay amount is controlled based on standard ignition timing. Control in this combustion cycle ends here, and control is repeated from step A1 in the next combustion cycle. If the knock level N is greater than or equal to the second predetermined value N2, control in steps A8 and A9 continues until the elapsed time X reaches the predetermined time X1. If the elapsed time X exceeds the predetermined time X1, proceed to step A10.

[0089] In step A10, fuel control is implemented to reduce the amount of fuel in the auxiliary chamber based on the knock intensity N. Here, the larger the value of the knock intensity N, the more the amount of fuel in the auxiliary chamber is reduced. Additionally, in step A11, ignition delay control is implemented, gradually reducing the delay amount as time X progresses. That is, ignition delay control is implemented only at a predetermined delay amount during a specified time X1, and then the ignition timing is gradually controlled to approach the standard ignition timing. Furthermore, ignition delay control with a predetermined delay amount is implemented before the reduction control of the auxiliary chamber fuel amount. The control in this combustion cycle ends here, and the control is repeated from step A1 in the next combustion cycle. After time X exceeds the predetermined time X1, as long as the value of the knock intensity N is above the second predetermined value N2, the control in steps A10 and A11 continues.

[0090] exist Figure 6 In step A4, when the value of the knock intensity N is less than the second predetermined value N2, the control enters... Figure 7 The process. In Figure 7 In step A12, the elapsed time X is reset. Then, in step A13, the measurement of elapsed time Y begins, proceeding to step A14. In step A14, it is determined whether the elapsed time Y is less than or equal to a predetermined time Y1. The predetermined time Y1 can be a pre-set time or number of combustion cycles, or it can be a time or number of combustion cycles set based on engine speed. If this condition is met, proceeding to step A15, fuel control is implemented to reduce the amount of fuel in the auxiliary compartment based on the knock intensity N. Here, the higher the value of the knock intensity N, the more the amount of fuel in the auxiliary compartment is reduced.

[0091] In addition, in step A16, ignition control is performed with standard ignition timing. Control in this combustion cycle ends here, and control is repeated starting from step A1 in the next combustion cycle. If the knock intensity N is above a first predetermined value N1 and below a second predetermined value N2, control in steps A15 and A16 continues until the elapsed time Y reaches a predetermined time Y1. If the knock intensity N decreases to below the first predetermined value N1 before the elapsed time Y reaches the predetermined time Y1, only fuel control to reduce the amount of fuel in the auxiliary chamber is implemented without initiating ignition delay. On the other hand, if the elapsed time Y exceeds the predetermined time Y1, step A17 is performed.

[0092] In step A17, it is determined whether the elapsed time Y is less than or equal to a predetermined time Y2, which is greater than or equal to a predetermined time Y1. The predetermined time Y2 can be a pre-set time or number of combustion cycles, or a time or number of combustion cycles set based on engine speed. If this condition is met, the process proceeds to step A18, where fuel control continues by reducing the amount of fuel in the auxiliary chamber based on the knock intensity N. Additionally, in step A19, ignition delay control is implemented with a predetermined delay amount. This delay amount is controlled based on the standard ignition timing. Control in this combustion cycle ends here, and control is repeated from step A1 in the next combustion cycle. If the knock intensity N is greater than or equal to the first predetermined value N1 but less than the second predetermined value N2, control in steps A18 and A19 continues until the elapsed time Y reaches the predetermined time Y2. If the elapsed time Y exceeds the predetermined time Y2, the process proceeds to step A20.

[0093] In step A20, fuel control continues to reduce the amount of fuel in the auxiliary chamber based on the knock intensity N. Additionally, in step A21, ignition delay control is implemented, gradually reducing the delay amount as time Y elapses. That is, ignition delay control is implemented only during the predetermined time Y2-Y1 with a predetermined delay amount, and then the ignition timing is gradually controlled to approach the standard ignition timing. Control in this combustion cycle ends here, and control is repeated from step A1 in the next combustion cycle. After time Y exceeds the predetermined time Y2, as long as the knock intensity N is greater than or equal to the first predetermined value N1 and less than the second predetermined value N2, control in steps A20 and A21 continues.

[0094] exist Figure 6 In step A3, when the value of the knocking intensity N is less than the first predetermined value N1, the control enters... Figure 8 The process. In Figure 8In step A22, the elapsed times X and Y are reset. Additionally, in step A23, it is determined whether the value of the knock intensity N is less than a third predetermined value N3, which is smaller than the first predetermined value N1. If this condition is met, the process proceeds to step A24, where fuel control is implemented to increase the amount of fuel in the auxiliary chamber based on the knock intensity N. Here, the smaller the value of the knock intensity N, the greater the increase in the amount of fuel in the auxiliary chamber. Furthermore, in step A25, ignition control is implemented at standard ignition timing. Control in this combustion cycle ends here, and control is repeated from step A1 in the next combustion cycle. As long as the value of the knock intensity N is less than the third predetermined value N3, control in steps A24 and A25 continues.

[0095] In step A23, if the knock intensity N is greater than or equal to the third predetermined value N3, the process proceeds to step A26, where fuel injection is performed with standard main chamber and auxiliary chamber fuel quantities. Additionally, in step A27, ignition control is performed with standard ignition timing. Thus, when the knock intensity N is N3 ≤ N < N1, normal fuel control and ignition control are implemented. Control in this combustion cycle ends here, and control is repeated starting from step A1 in the next combustion cycle.

[0096] [3. Functions and Effects]

[0097] (1) In the control device (i.e., ECU 20) of the engine 10 described above, when the knock intensity N predicted by the prediction unit 21 is a first predetermined value N1 or higher, the fuel control unit 22 implements fuel control to reduce the amount of fuel in the auxiliary chamber. With this structure, for example, the knock intensity N can be reduced without changing the ignition timing, and the occurrence of knock can be suppressed. Therefore, the combustion state of the engine 10 can be stabilized. In addition, since the reduced amount of fuel is the amount of fuel in the auxiliary chamber, the possibility of adversely affecting the combustion state in the main chamber 8 is very small. Therefore, the combustion state of the engine 10 can be improved. It should be noted that when the amount of fuel in the main chamber is maintained while the amount of fuel in the auxiliary chamber is reduced, the combustion state of the engine 10 can be easily improved without changing the control on the main chamber injection unit side. In addition, when the amount of fuel in the main chamber is increased according to the amount of fuel reduction in the auxiliary chamber, the change in the total amount of fuel can be reduced, and the combustion state of the engine 10 can be further stabilized.

[0098] (2) In the control device of the engine 10 described above, after fuel control is implemented by the fuel control unit 22, if the knock intensity N is greater than or equal to a first predetermined value N1, the ignition control unit 23 implements ignition control that delays the ignition timing. With this structure, for example, if knock cannot be eliminated in a short time by fuel control alone, the knock intensity N can be reliably reduced by using ignition delay control. Therefore, the combustion state of the engine 10 can be improved.

[0099] (3) In the control device of the engine 10 described above, when the knock intensity N is greater than or equal to a second predetermined value N2, which is greater than a first predetermined value N1, the ignition control unit 23 first implements ignition delay control, and then the fuel control unit 22 implements fuel control to reduce the amount of fuel in the auxiliary chamber. Thus, when the knock intensity N is too high, compared to fuel control, by first implementing ignition delay control with superior responsiveness, the knock intensity N can be rapidly reduced. Therefore, the combustion state of the engine 10 can be improved.

[0100] (4) In the control device of the engine 10 described above, the ignition control unit 23 implements control by gradually reducing the amount of ignition timing delay. With this structure, the combustion state of the engine 10 can be stabilized compared to the case where the ignition timing suddenly returns to the standard ignition timing. In addition, the state of ignition timing delay compared to the standard ignition timing lasts for a certain period of time, thus reliably reducing the knocking degree N.

[0101] (5) In the control device of the engine 10, when the knock intensity N is less than a third predetermined value N3, which is less than a first predetermined value N1, the fuel control unit 22 implements fuel control to increase the amount of fuel in the auxiliary chamber. Thus, in a poor combustion state where the knock intensity N is too low, increasing the amount of fuel in the auxiliary chamber can stabilize the combustion state of the engine 10. Furthermore, since the increased fuel amount is from the auxiliary chamber, the possibility of adversely affecting the combustion state in the main chamber 8 is very small. Therefore, the combustion state of the engine 10 can be improved. It should be noted that by increasing only the amount of fuel in the auxiliary chamber while maintaining the amount of fuel in the main chamber, the combustion state of the engine 10 can be easily improved without changing the control on the main chamber injection unit side. Furthermore, by reducing the amount of fuel in the main chamber according to the increase in the amount of fuel in the auxiliary chamber, the change in the total fuel amount can be reduced, further stabilizing the combustion state of the engine 10.

[0102] [4. Variations]

[0103] The above embodiments are merely illustrative and do not exclude the intent of various modifications and technical applications not explicitly shown in these embodiments. Various modifications and implementations of the various structures in these embodiments are possible without departing from these principles. Furthermore, the various structures in these embodiments can be selected or omitted as needed, or appropriately combined. For example, in the above embodiments, a control device for an engine 10 mounted on a vehicle has been described in detail, but the application of the control device of the present invention is not limited to vehicle engines; for example, it can also be applied to engines installed in ships or power generation facilities. At least, the control device of the present invention can be applied to any internal combustion engine equipped with a main chamber injection unit and an auxiliary chamber injection unit.

[0104] Furthermore, in the above embodiments, when the knock intensity N is greater than or equal to a second predetermined value N2, which is greater than the first predetermined value N1, the ignition control unit 23 first implements ignition delay control, and then the fuel control unit 22 implements fuel control to reduce the amount of fuel in the auxiliary chamber. However, when the knock intensity N is greater than or equal to a fourth predetermined value N4, which is greater than the second predetermined value N2, the ignition control unit 23 and the fuel control unit 22 can also start ignition delay control and fuel control simultaneously. In this way, by starting delay control and fuel control simultaneously, the knock intensity N can be reduced more quickly and reliably.

Claims

1. An engine control device, characterized in that, include: The main chamber injection unit supplies fuel to the main chamber; The auxiliary chamber injection unit supplies fuel to the auxiliary chamber after being supplied with fuel by the main chamber injection unit. The prediction unit, which predicts the degree of detonation as an indicator of the intensity and frequency of detonation. The fuel control unit implements fuel control that reduces the amount of fuel supplied from the sub-chamber injection unit when the knocking level is above a first predetermined value. as well as The spark plug ignites the fuel mixture formed in the auxiliary chamber. An ignition control unit that performs ignition control to delay the ignition timing of the spark plugs. The auxiliary chamber injection unit is an auxiliary chamber injection valve capable of controlling the increase or decrease of the amount of fuel supplied to the auxiliary chamber. The electrodes of the spark plug are disposed inside the auxiliary chamber. After fuel control is implemented through the fuel control unit, ignition control is implemented when the knocking level is above the first predetermined value. When the knocking intensity is greater than or equal to a second predetermined value that is greater than the first predetermined value, the ignition control unit first implements the ignition control, and then the fuel control unit implements the fuel control.

2. The engine control device according to claim 1, characterized in that, The ignition control unit gradually reduces the delay amount after delaying the ignition timing.

3. The engine control device according to claim 1 or 2, characterized in that, When the degree of knocking is less than a third predetermined value that is less than the first predetermined value, the fuel control unit implements fuel control to increase the amount of fuel in the auxiliary chamber.

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