Engine control unit

Abstract

To suppress an occurrence of a preignition.SOLUTION: When carrying out a fuel injection in both of a pre-valve-closing period which is a period before closing an intake valve 14 and a post-valve-closing period which is a period after closing the intake valve, an electronic control unit 20 carries out an injection pressure adjusting process which makes an injection pressure of a fuel in the pre-valve-closing period higher than that in the post-valve-closing period.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an engine control device. [Background technology]

[0002] In vehicle engines, when the temperature inside the cylinder rises during high-load operation, the spark plugs may become hot spots, causing pre-ignition. The engine control device described in Patent Document 1 suppresses pre-ignition by increasing the amount of fuel injection and advancing the ignition timing to speed up the combustion speed when pre-ignition is detected. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-130473 Summary of the Invention [Problem to be solved by the invention]

[0004] The normal control target values ​​for the engine's fuel injection amount and ignition timing are set to optimal values ​​in terms of fuel economy and exhaust performance, so increasing the fuel injection amount or advancing the ignition timing will result in a deterioration in the engine's fuel economy and exhaust performance. [Means for solving the problem]

[0005] The engine control device that solves the above problem comprises: It is installed at the top of the cylinder, Inside the cylinder Towards the bottom Fuel injector A spark plug is installed at the top of the cylinder and ignites the fuel injected by the injector. The engine control device controls an engine in which the intake valve closes after the start of the compression stroke. When fuel is injected in both a pre-valve-closing period (before the intake valve closes) and a post-valve-closing period (after the intake valve closes), the engine control device performs an injection pressure adjustment process to make the fuel injection pressure in the pre-valve-closing period higher than the fuel injection pressure in the post-valve-closing period.

[0006] The upper part of an engine cylinder contains areas prone to hot spots during engine operation, such as the exhaust valve and spark plug. Meanwhile, during the compression stroke, the piston rises within the cylinder, pushing up the intake air inside the cylinder. If the intake valve is open at this time, the intake air inside the cylinder escapes through the intake port, creating an upward airflow within the cylinder. If fuel is injected during this airflow, the fuel spray rides the airflow and moves upward toward the cylinder. If the exhaust valve, spark plug, or other components are hot, the fuel spray may come into contact with them and ignite, potentially causing pre-ignition. In other words, in an engine in which the intake valve closes after the start of the compression stroke, pre-ignition is more likely to occur if fuel is injected into the cylinder between the start of the compression stroke and the closing of the intake valve.

[0007] In the injection pressure adjustment process, the fuel injection pressure is increased before the intake valve closes compared to after the valve closes. When the injection pressure increases, the momentum of the injected fuel spray increases, making it less likely for the spray to be swept away by the airflow in the cylinder. Therefore, even if fuel is injected between the start of the compression stroke, when the airflow that causes pre-ignition is generated, and the intake valve closes, pre-ignition is less likely to occur. Therefore, the engine control device has the effect of suppressing the occurrence of pre-ignition.

[0008] The engine control device may be configured to perform a determination process to determine whether or not pre-ignition is likely to occur, and to perform injection pressure adjustment process only if it is determined in the determination process that pre-ignition is likely to occur. In this case, the determination process may be configured to determine whether or not pre-ignition is likely to occur based on engine torque and engine water temperature.

[0009] The engine control device may be configured to perform the injection pressure adjustment process only when the maximum value of the pressure of fuel that can be supplied to the injector is equal to or greater than a predetermined value. The engine control device may be configured not to perform the injection pressure adjustment process when fuel injection is started earlier than a predetermined time before the start of the compression stroke. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram schematically illustrating a configuration of an embodiment of an engine control device. [Figure 2] 3 is a flowchart of a fuel injection control routine executed by the engine control device. [Figure 3] (A) is a time chart showing the intake valve open / close state, (B) is the implementation status of fuel injection when the required injection period is longer than the first injection period, (C) is the change in fuel pressure in that case, (D) is the change in the momentum of the spray in that case, (E) is the implementation status of fuel injection when the required injection period is longer than the third injection period, and (F) is the change in the momentum of the spray in that case. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of an engine control device will be described in detail below with reference to FIGS. <Configuration of engine control unit> First, the configuration of the engine control device of this embodiment will be described with reference to Figure 1. An engine 10, which is the object of control by the engine control device of this embodiment, is mounted on a vehicle. The engine 10 is configured as a hydrogen gas engine that uses hydrogen gas as fuel.

[0012] Engine 10 has cylinder 11. Inside cylinder 11, piston 12 is arranged so as to be able to reciprocate freely in the vertical direction in the drawing. Inside cylinder 11, combustion chamber 13 where combustion takes place is defined by piston 12. An intake port 15 is connected to the top of cylinder 11 via intake valve 14. An exhaust port 17 is also connected to the top of cylinder 11 via exhaust valve 16. Furthermore, an injector 18 that injects hydrogen gas into cylinder 11 and an ignition plug 19 that ignites the hydrogen gas injected by injector 18 are installed at the top of cylinder 11. The valve timing of intake valve 14 in engine 10 is set so that the valve closes after the start of the compression stroke.

[0013] The injector 18 is connected to a fuel tank 28 that stores hydrogen gas via a fuel pressure regulator 29. The fuel pressure regulator 29 regulates the fuel pressure PF, which is the pressure of the hydrogen gas supplied to the injector 18. The fuel pressure regulator 29 has two operating states: one in which the hydrogen gas in the fuel tank 28 is supplied to the injector 18 without being reduced in pressure, and the other in which the hydrogen gas in the fuel tank 28 is reduced to a predetermined set pressure PL and then supplied to the injector 18. In the following description, the pressure of the hydrogen gas in the fuel tank 28 will be referred to as the tank internal pressure PT. In this engine 10, the tank internal pressure PT is the maximum value of the fuel pressure PF that can be supplied to the injector 18. Note that as the amount of hydrogen gas stored in the fuel tank 28 decreases, the tank internal pressure PT decreases, and therefore the maximum value of the fuel pressure PF that can be supplied to the injector 18 decreases. Furthermore, the injector 18 of this engine 10 is configured to inject hydrogen gas at a pressure that is approximately equal to the fuel pressure PF supplied from the fuel pressure regulator 29. Therefore, in the engine control device of this embodiment, the fuel pressure PF is treated as the injection pressure of the hydrogen gas from the injector 18.

[0014] The electronic control unit 20 that controls the engine 10 includes an arithmetic processing unit 21 and a storage device 22. The storage device 22 stores programs and data used for control. The arithmetic processing unit 21 executes the programs read from the storage device 22 to perform various processes related to the control of the engine 10. In this embodiment, the electronic control unit 20 corresponds to an engine control device.

[0015] The electronic control unit 20 is connected to a crank angle sensor 23, an air flow meter 24, a water temperature sensor 25, an accelerator pedal sensor 26, and a tank pressure sensor 27. The crank angle sensor 23 detects the rotational phase of the crankshaft of the engine 10. The air flow meter 24 detects the amount of intake air into the engine 10. The water temperature sensor 25 detects the engine water temperature THW, which is the temperature of the coolant for the engine 10. The accelerator pedal sensor 26 detects the amount of accelerator pedal depression ACC by the driver. The tank pressure sensor 27 detects the tank internal pressure PT, which is the pressure of hydrogen gas in a fuel tank 28. The electronic control unit 20 determines the engine speed NE, which is the rotational speed of the engine 10, from the detection result of the crank angle sensor 23. The electronic control unit 20 also determines the engine load factor KL based on the intake air amount detected by the air flow meter 24 and the engine speed NE. The engine load factor KL represents the intake air filling rate of the combustion chamber 13. In addition to the above, the electronic control unit 20 is also connected to various sensors installed in various parts of the vehicle.

[0016] <Fuel injection control> As part of engine control, the electronic control unit 20 controls the fuel injection of the injector 18. Details of the fuel injection control will be explained below. The electronic control unit 20 controls the injector 18 and the fuel pressure regulator 29 to perform the fuel injection control.

[0017] FIG. 2 shows a flowchart of a fuel injection control routine executed by the electronic control unit 20 for fuel injection control. While the engine 10 is running, the electronic control unit 20 repeatedly executes this routine at predetermined control intervals. After performing step S160 in FIG. 2, the electronic control unit 20 ends the routine for the current control interval. The values ​​of each timing shown in FIG. 2 represent the amount of advance of the crank angle from the compression top dead center. Therefore, a timing with a larger value is earlier than a timing with a smaller value. The values ​​of each period shown in FIGS. 2 and 3 represent the amount of rotation of the crankshaft during the corresponding period.

[0018] When this routine starts, the electronic control unit 20 first calculates the required injection amount QS in step S100 based on the engine speed NE, accelerator pedal depression amount ACC, etc. The required injection amount QS is the required value for the amount of hydrogen gas injected by the injector 18.

[0019] Next, in step S110, the electronic control unit 20 calculates the required injection period TS based on the required injection amount QS and the engine speed NE. The required injection period TS indicates the time required to inject hydrogen gas equivalent to the required injection amount QS, expressed as a value in terms of the rotational angle of the crankshaft for that time at the current engine speed NE. The crank angle represents the rotational angle of the crankshaft, which is the output shaft of the engine 10. Note that the required injection period TS is calculated on the assumption that the fuel pressure PF is equal to the set pressure PL.

[0020] Next, in step S120, the electronic control unit 20 determines whether the engine 10 is operating in the plague operation range. The plague operation range represents an operating range of the engine 10 in which pre-ignition is likely to occur. Pre-ignition is more likely to occur when the spark plug 19 or the exhaust valve 16 is at a high temperature. When the engine torque TE is high, more fuel is burned in the cylinder 11 than when the engine torque TE is low. Therefore, when the engine torque TE is high, pre-ignition is more likely to occur than when the engine torque TE is low. Furthermore, when the temperatures of the spark plug 19 or the exhaust valve 16 increase, the engine water temperature THW also increases. Therefore, when the engine water temperature THW is high, pre-ignition is more likely to occur than when the engine water temperature THW is low. Therefore, in this embodiment, it is determined whether the engine 10 is operating in the plague operation range based on the engine torque TE and the engine water temperature THW. In this embodiment, the process of step S120 corresponds to the determination process of determining whether or not the vehicle is in a state where pre-ignition is likely to occur.

[0021] If the engine 10 is not operating in the pledging operation range (S130: NO), the electronic control unit 20 proceeds to step S140. In step S140, the electronic control unit 20 sets the injection start time IS to a time earlier than the injection end time IE by the required injection period TS. In this embodiment, the injection end time IE is set to a predetermined time immediately before the end of the compression stroke. Next, in step S150, the electronic control unit 20 commands the fuel pressure regulator 29 to maintain the fuel pressure PF at the set pressure PL. In step S160, the electronic control unit 20 commands the injector 18 to inject hydrogen gas during the period from the injection start time IS to the injection end time IE.

[0022] On the other hand, if the engine 10 is operating in the pledging operation range (S130: YES), the electronic control unit 20 proceeds to step S170. In step S170, it is determined whether the tank internal pressure PT is equal to or greater than a predetermined value P0. The predetermined value P0 is set to a value higher than the set pressure PL. If the tank internal pressure PT is less than the predetermined value P0 (S170: NO), the electronic control unit 20 performs the processes of steps S140 to S160 described above.

[0023] On the other hand, if the tank internal pressure PT is equal to or greater than the predetermined value P0 (S170: YES), the electronic control unit 20 proceeds to step S180. In step S180, the electronic control unit 20 determines whether the required injection period TS is longer than the first injection period TT and shorter than the third injection period TL. The first injection period TT indicates the period from the closing timing IVC of the intake valve 14 to the injection end timing IE. The third injection period TL is set to a value longer than the period from the start of the compression stroke to the injection end timing IE. If the required injection period TS is shorter than the first injection period TT or if the required injection period TS is longer than the third injection period TL (S180: NO), the electronic control unit 20 performs the processes of steps S140 to S160 described above.

[0024] On the other hand, if the required injection period TS is longer than the first injection period TT and shorter than the third injection period TL (S180: YES), the electronic control unit 20 proceeds to step S190. In step S190, the electronic control unit 20 calculates the post-IVC injectable amount QL based on the engine speed NE. The post-IVC injectable amount QL indicates the amount of hydrogen gas that the injector 18 can inject during the period from the intake valve closing timing IVC to the injection end timing IE when the fuel pressure PF is equal to the set pressure PL.

[0025] Next, in step S200, the electronic control unit 20 calculates the pre-IVC injection amount QH by subtracting the post-IVC injectable amount QL from the required injection amount QS. Then, in step S210, the electronic control unit 20 calculates the pre-IVC injection period TH based on the pre-IVC injection amount QH, the engine speed NE, and the tank internal pressure PT. The pre-IVC injection period TH indicates the period required to inject hydrogen gas equivalent to the pre-IVC injection amount QH when the fuel pressure PF is set to the tank internal pressure PT. Then, in step S220, the electronic control unit 20 sets the injection start timing IS to a timing earlier than the closing timing IVC of the intake valve 14 by the pre-IVC injection period TH. Next, in step S230, the electronic control unit 20 commands the fuel pressure regulator 29 to increase the fuel pressure PF during the period before the closing timing IVC of the intake valve 14. More specifically, the electronic control unit 20 commands the fuel pressure regulator 29 to increase the fuel pressure PF from the set pressure PL before the start of injection to the tank internal pressure PT, and to decrease the fuel pressure PF from the tank internal pressure PT at the closing timing IVC of the intake valve 14 to the set pressure PL. In this embodiment, the process of step S230 corresponds to the injection pressure adjustment process for setting the fuel injection pressure in the pre-valve closing period higher than the fuel injection pressure in the post-valve closing period when fuel is injected in both the pre-valve closing period and the post-valve closing period. Then, in the above-mentioned step S160, the electronic control unit 20 commands the injector 18 to inject hydrogen gas from the injection start timing IS to the injection end timing IE.

[0026] <Effects of the embodiment> The operation and effects of this embodiment will be described. FIG. 3A shows the transition of the open / closed state of the intake valve 14 in the engine 10. The horizontal axis in FIG. 3 represents the advance amount of the crank angle [° BTDC] relative to the end time T1 of the compression stroke. Here, the compression stroke is defined as the period from when the piston 12 is at bottom dead center (BDC) of the intake stroke to when it is at top dead center (TDC) of the compression stroke. As shown in FIG. 3A, the closing timing IVC of the intake valve 14 in the engine 10 is set later than the start time of the compression stroke. That is, in the engine 10, there is a period during which the intake valve 14 is open after the start of the compression stroke. If the intake valve 14 is open during the compression stroke in which the piston 12 moves upward in the cylinder 11, the intake air in the cylinder 11, which is pressed by the piston 12, escapes to the intake port 15, generating an upward airflow within the cylinder 11.

[0027] On the other hand, when the engine 10 is operating under high load, the spark plug 19, exhaust valve 16, etc., become hot, forming a hot spot that can spark a fire in the upper part of the cylinder 11. If the injector 18 injects hydrogen gas while the intake valve 14 is open during the compression stroke, the spray is carried by the airflow toward the upper part of the cylinder 11. If the spray comes into contact with the hot spot formed in the upper part of the cylinder 11, pre-ignition may occur. In this way, if hydrogen gas is injected while the intake valve 14 is open during the compression stroke, pre-ignition is more likely to occur. In the following explanation, the period from the start of the compression stroke to the closing timing IVC of the intake valve 14 will be referred to as the pre-ignition injection period.

[0028] In step S180 of the fuel injection control routine in Figure 2, the electronic control unit 20 determines whether the required injection period TS is longer than the first injection period TT and shorter than the third injection period TL. As described above, the first injection period TT represents the period from the closing timing IVC of the intake valve 14 to the injection end timing IE.

[0029] 3B shows an embodiment of fuel injection when the required injection period TS is longer than the first injection period TT and shorter than the third injection period TL. In this case, hydrogen gas is also injected during the plague injection period. In this case, the electronic control unit 20 performs the injection pressure adjustment process in step S230 of FIG. 2.

[0030] In Figure 3(C), the solid line shows the change in fuel pressure PF when the injection pressure adjustment process is performed. When the injection pressure adjustment process is performed, the fuel pressure PF is increased from the set pressure PL to the tank pressure PT before the start of fuel injection during the intake stroke. Thereafter, the fuel pressure PF is maintained at the tank pressure PT until the intake valve 14 closes at the IVC timing. Then, at the intake valve 14 closes at the IVC timing, the fuel pressure PF is reduced from the tank pressure PT to the set pressure PL. Note that in Figure 3(C), the dashed line shows the change in fuel pressure PF when the injection pressure adjustment process is not performed. In this case, the fuel pressure PF is maintained at the set pressure PL.

[0031] FIG. 3(D) shows, with a solid line, the transition of the momentum of the spray immediately after injection from the injector 18 when the injection pressure adjustment process is performed. Also, FIG. 3(D) shows, with a dashed line, the transition of the same momentum when the injection pressure adjustment process is not performed. The momentum of the spray is "0" at the start of injection and increases over time. The rate of increase of the momentum of the spray after the start of injection increases as the fuel pressure PF increases. Therefore, when the injection pressure adjustment process is performed, the momentum of the spray after the start of injection increases more quickly than when the injection pressure adjustment process is not performed. Therefore, when the injection pressure adjustment process is performed, the momentum of the spray during the pre-ignition period is greater than when the injection pressure adjustment process is not performed. The smaller the momentum, the more likely the spray is to be swept away by the airflow in the cylinder 11 that occurs during the pre-ignition period. Therefore, when the injection pressure adjustment process is not performed, the spray is swept away by the airflow in the cylinder 11 that occurs during the pre-ignition period, making pre-ignition more likely to occur. In contrast, when the injection pressure adjustment process is performed, the momentum of the spray is large enough during the pre-ignition injection period to prevent it from being carried away by the airflow in the cylinder 11, making it difficult for pre-ignition to occur.

[0032] FIG. 3(E) shows an example of the implementation status of fuel injection when the required injection period TS is longer than the third injection period TL. The electronic control unit 20 does not perform the injection pressure adjustment process when the required injection period TS is longer than the third injection period TL. In this case, there is sufficient time from the start of fuel injection until the pre-ignition injection period begins. Therefore, as shown in FIG. 3(F), the momentum of the spray has sufficiently increased at the start of the pre-ignition injection period. Therefore, in this case, the occurrence of pre-ignition can be suppressed without performing the injection pressure adjustment process.

[0033] According to the engine control device of the present embodiment described above, the following effects can be achieved. (1) When hydrogen gas is injected from before the intake valve 14 closes to after it closes, the electronic control unit 20 performs an injection pressure adjustment process to set the injection pressure of the hydrogen gas before the intake valve 14 closes higher than the injection pressure of the hydrogen gas after it closes. During the pre-ignition injection period from the start of the compression stroke to the closing of the intake valve 14, an upward airflow occurs in the cylinder 11. If the spray of hydrogen gas injected by the injector 18 is carried by this airflow toward the upper part of the cylinder 11, the spray may come into contact with a hot spot such as the spark plug 19 or the exhaust valve 16, causing pre-ignition. Performing the injection pressure adjustment process increases the momentum of the spray of hydrogen gas injected before the intake valve 14 closes, making it less likely for the spray to be carried by the airflow in the cylinder 11. Therefore, the engine control device of this embodiment has the effect of suppressing the occurrence of pre-ignition.

[0034] (2) When the injector 18 stops injecting, the nozzle sits on the nozzle seat. If the injection pressure is increased, the impact at the time of seating becomes greater, which makes the nozzle seat more susceptible to wear. In this embodiment, even when the injection pressure adjustment process is performed, the injection pressure of the injector 18 is reduced after the intake valve 14 is closed. This prevents wear on the nozzle seat.

[0035] (3) In the injection pressure adjustment process, the injection pressure of hydrogen gas is increased before the intake valve 14 closes, but increasing the injection pressure has the trade-off of deteriorating the fuel economy of the engine 10 and the accuracy of the injection amount of hydrogen gas. In response to this, the electronic control unit 20 performs a determination process to determine whether or not a state in which pre-ignition is likely to occur is present, and performs the injection pressure adjustment process only if the determination process determines that a state in which pre-ignition is likely to occur is present. Therefore, the trade-off that accompanies the execution of the injection pressure adjustment process can be suppressed.

[0036] (4) The electronic control unit 20 determines whether or not a state in which pre-ignition is likely to occur is based on the engine torque TE and the engine water temperature THW. Hot spots in the cylinder 11 that cause pre-ignition are likely to form when the engine torque TE or the engine water temperature THW is high. Therefore, based on the engine torque TE and the engine water temperature THW, it is possible to accurately determine whether or not a state in which pre-ignition is likely to occur is present.

[0037] (5) In the engine 10, the maximum value of the fuel pressure PF that can be supplied to the injector 18 is determined by the tank internal pressure PT. Therefore, when the tank internal pressure PT is low, the injection pressure adjustment process cannot sufficiently increase the injection pressure of hydrogen gas before the intake valve 14 closes. In response to this, the electronic control unit 20 performs the injection pressure adjustment process only when the tank internal pressure PT is equal to or greater than a predetermined value PO. Therefore, unnecessary execution of the injection pressure adjustment process in situations where it is difficult to achieve the effect of suppressing pre-ignition is suppressed.

[0038] (6) If the start of hydrogen gas injection is sufficiently earlier than the start of the compression stroke, the momentum of the spray during the plague injection period will be sufficiently large even without performing the injection pressure adjustment process. The electronic control unit 20 does not perform the injection pressure adjustment process if hydrogen gas injection is started earlier than the predetermined time before the start of the compression stroke.

[0039] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility. The injection pressure before and after the intake valve 14 is closed during the injection pressure adjustment process may be changed in a manner different from that described above. For example, if the injector 18 is configured to be able to adjust the nozzle lift amount, the injection pressure during the injection pressure adjustment process can be changed by adjusting the nozzle lift amount.

[0040] The determination in step S120 in FIG. 2 may be made based on parameters other than the engine torque TE and the engine water temperature THW. The fuel injection control routine may be executed without determining whether or not the engine is in a state where pre-ignition is likely to occur. In this case, the injection pressure adjustment process is executed regardless of whether or not the engine is in a state where pre-ignition is likely to occur. In other words, hydrogen gas injection during the pre-ignition injection period is not executed regardless of whether or not the engine is in a state where pre-ignition is likely to occur.

[0041] The injection pressure adjustment process may be performed regardless of the tank internal pressure PT. For example, the fuel injection control routine of Fig. 2 may be performed without step S170.

[0042] The injection pressure adjustment process may be performed even when fuel injection is started earlier than the predetermined timing before the start of the compression stroke. For example, in step S180 of FIG. 2, it may be determined only whether the required injection period TS is longer than the first injection period TT.

[0043] The fuel injection control in the above embodiment may also be applied to engines that use fuels other than hydrogen gas. [Explanation of symbols]

[0044] 10...Engine 11...cylinder 12...Piston 13...Combustion chamber 14...Intake valve 15...Intake port 16...Exhaust valve 17...Exhaust port 18...Injector 19...Spark plug 20...Electronic control unit 21...Processing device 22...Storage device 23...Crank angle sensor 24...Air flow meter 25...Water temperature sensor 26...Accelerator pedal sensor 27...Tank pressure sensor 28...Hydrogen gas tank 29…Fuel pressure adjustment device

Claims

1. A device for controlling an engine that includes an injector installed at the top of a cylinder and that injects fuel toward the bottom of the cylinder, and an ignition plug installed at the top of the cylinder and that ignites the fuel injected by the injector, and that closes an intake valve after the start of a compression stroke, When fuel injection is performed in both a pre-valve-closing period, which is a period before the intake valve is closed, and a post-valve-closing period, which is a period after the intake valve is closed, an injection pressure adjustment process is performed to make the fuel injection pressure in the pre-valve-closing period higher than the fuel injection pressure in the post-valve-closing period. Engine control device.

2. Perform a determination process to determine whether or not pre-ignition is likely to occur, 2. The engine control device according to claim 1, wherein the injection pressure adjustment process is performed only when it is determined in the determination process that the engine is in a state where pre-ignition is likely to occur.

3. 3. The engine control device according to claim 2, wherein the determination process determines whether or not the state is such that pre-ignition is likely to occur based on engine torque and engine water temperature.

4. 2. The engine control device according to claim 1, wherein the injection pressure adjustment process is performed only when the maximum pressure of the fuel that can be supplied to the injector is equal to or greater than a predetermined value.

5. 2. The engine control device according to claim 1, wherein the injection pressure adjustment process is not performed when fuel injection is started earlier than a predetermined time before the start of the compression stroke.

Images