WO2025258068A1 - Dispositif de commande de soupape d'injection - Google Patents

Dispositif de commande de soupape d'injection

Info

Publication number
WO2025258068A1
WO2025258068A1 PCT/JP2024/021713 JP2024021713W WO2025258068A1 WO 2025258068 A1 WO2025258068 A1 WO 2025258068A1 JP 2024021713 W JP2024021713 W JP 2024021713W WO 2025258068 A1 WO2025258068 A1 WO 2025258068A1
Authority
WO
WIPO (PCT)
Prior art keywords
period
injection
upper limit
fuel
engine
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/JP2024/021713
Other languages
English (en)
Japanese (ja)
Inventor
武司 田岡
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Motors Corp
Original Assignee
Mitsubishi Motors Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Motors Corp filed Critical Mitsubishi Motors Corp
Priority to PCT/JP2024/021713 priority Critical patent/WO2025258068A1/fr
Publication of WO2025258068A1 publication Critical patent/WO2025258068A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/30—Controlling fuel injection
    • F02D41/38—Controlling fuel injection of the high pressure type
    • F02D41/40—Controlling fuel injection of the high pressure type with means for controlling injection timing or duration
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M51/00—Fuel-injection apparatus characterised by being operated electrically

Definitions

  • This case relates to an injection valve control device that controls the injection valves that inject fuel supplied from a common rail into the cylinders of an engine.
  • One known fuel injection technique is to supply fuel from a common rail, which stores fuel pumped by a fuel pump, to an injection valve (also called an injector), which then injects the fuel into a cylinder.
  • the fuel injected from the injection valve into the cylinder is pressurized by the fuel stored in the common rail.
  • a plurality of injection valves are provided corresponding to the respective cylinders, and fuel is supplied to the plurality of injection valves from a common rail.
  • Patent Document 1 proposes technology for setting the injector valve open time based on the fuel pressure detected by a pressure sensor that detects the pressure of fuel stored in the common rail.
  • the opening period of the injection valve in which the opening period of the injection valve is set based on the value detected by the sensor, the opening period cannot be appropriately set when the sensor itself breaks down or when an abnormality occurs in the signal system. For example, if the value detected by the sensor is lower than the actual fuel pressure, the opening period may be set longer than appropriate. Setting such an opening period longer than necessary may result in an excessive increase in the fuel injection amount, which may in turn increase the load on the engine. Therefore, there is room for improvement in suppressing an excessive increase in the fuel injection amount.
  • the injection valve control device of this case was devised in light of these issues, and one of its objectives is to suppress excessive increases in fuel injection volume. However, this objective is not the only objective. Another objective of this case is to achieve effects derived from the various configurations shown in the "Mode for Carrying Out the Invention" below, which are not obtainable with conventional technology.
  • the disclosed injection valve control device can be realized as the embodiments (application examples) disclosed below, which solve at least part of the above-mentioned problems.
  • Each of the embodiments from embodiment 2 onwards is an embodiment that can be selected additionally as appropriate, and each of them is an embodiment that can be omitted. None of the embodiments from embodiment 2 onwards discloses an embodiment or configuration that is essential to the present case.
  • the disclosed injection valve control device includes a target pressure acquisition unit, a reference setting unit, an upper limit setting unit, and a control unit.
  • the target pressure acquisition unit acquires a target pressure, which is a target value for the pressure of fuel inside a common rail of an engine mounted on the vehicle, based on information related to the operating state of the vehicle.
  • the reference setting unit sets a reference valve opening period of the injection valve as a reference period based on a detection value of a fuel pressure sensor that detects the pressure of fuel in the common rail and a target injection amount of an injection valve that injects fuel supplied from the common rail.
  • the upper limit setting unit sets an upper limit period, which is an upper limit of the valve opening period, based on the target pressure.
  • the control unit sets the reference period as the valve opening period if the reference period is equal to or shorter than the upper limit period, and sets the upper limit period as the valve opening period if the reference period is longer than the upper limit period.
  • the upper limit setting unit sets the upper limit period to be longer when there is a request to accelerate the vehicle than when there is no request to accelerate the vehicle.
  • Aspect 3 it is preferable that the upper limit setting unit sets the upper limit period from the start of engine startup until the predetermined period has elapsed longer than the period after the predetermined period has elapsed from the start of engine startup.
  • Aspect 4 In any one of Aspects 1 to 3 above, it is preferable that the engine performs multi-stage fuel injection, and the upper limit setting unit sets the upper limit period during the compression stroke before top dead center of the engine.
  • the multi-stage injection in the compression stroke of the engine includes a pilot injection and a pre-injection performed after the pilot injection, and the upper limit setting unit sets the upper limit period to be shorter for the pilot injection than for the pre-injection.
  • the injection valve control device preferably includes a lower limit setting unit that sets a lower limit of the valve opening period that is shorter than the upper limit period based on the target pressure.
  • the control unit sets the reference period as the valve opening period when the reference period is equal to or greater than the lower limit period and equal to or less than the upper limit period, and sets the lower limit period as the valve opening period when the reference period is shorter than the lower limit period.
  • the lower limit setting unit sets the lower limit period to be longer when there is a deceleration request for the vehicle than when there is no deceleration request for the vehicle.
  • Aspect 8 In the above-described aspect 6 or 7, it is preferable that the engine performs multi-stage injection of fuel, the multi-stage injection including a pilot injection in a compression stroke of the engine, a pre-injection performed after the pilot injection, and a main injection in a combustion stroke of the engine, and the lower limit setting unit sets the lower limit period for the pilot injection, the pre-injection, and the main injection.
  • the disclosed injection valve control device can prevent excessive increases in fuel injection amount.
  • 1 is a schematic diagram showing a vehicle including an injection valve control device according to an embodiment
  • 4 is an example of a flowchart illustrating control performed by an injection valve control device according to an embodiment
  • 3 is an example of a flowchart illustrating setting of an upper limit period performed in part of the control shown in FIG. 2
  • 3 is an example of a flowchart illustrating setting of a lower limit period performed in a part of the control shown in FIG. 2 .
  • the injection valve control device of this embodiment is a control device for an injection valve that injects fuel in an engine mounted on a vehicle.
  • This injection valve control device is applied to a vehicle equipped with an engine in which fuel injection is performed using a common rail or injection valves, and controls the injection valves that inject fuel supplied from the common rail.
  • vehicles to which the injection valve control device is applied are not limited to automobiles equipped with only an engine as a drive source, but also include hybrid automobiles (HEVs) equipped with an engine and a motor as drive sources, and hybrid automobiles equipped with an engine for generating electricity and a motor as a drive source.
  • HEVs hybrid automobiles
  • Hybrid vehicles also include plug-in hybrid vehicles (plug-in hybrid electric vehicles, PHEVs).
  • a plug-in hybrid vehicle is a hybrid vehicle that allows the battery to be charged externally or powered externally from the battery.
  • Plug-in hybrid vehicles are equipped with a charging port (inlet) for inserting a charging cable that supplies power from external charging equipment, and an outlet for external power supply.
  • the injection valve control device generates a control signal based on information input from an input system configuration and outputs the control signal to an output system configuration.
  • the operation of the output system configuration is controlled by the control signal output from the injection valve control device.
  • the configuration of the output system and the configuration of the input system will be described below with reference to Fig. 1, and then the configuration of the injection valve control device 10 will be described.
  • Fig. 1 is a schematic diagram showing a vehicle including an injection valve control device according to one embodiment.
  • the output system includes an injection valve 3 that injects fuel into a cylinder 2 of the engine 1 .
  • the engine 1 is a reciprocating engine that outputs rotational power by burning fuel in a cylinder 2.
  • the engine 1 is a diesel engine that uses light oil as fuel.
  • the engine 1 illustrated here is a multi-cylinder engine having a plurality of cylinders (also referred to as cylinders). Fig. 1 illustrates only one of the cylinders provided in the engine 1. However, the engine 1 may also be a single-cylinder engine having only one cylinder.
  • Injection valves 3 are provided at the top of cylinder 2 with their tips protruding toward the combustion chamber. Injection valves 3 are direct injection injectors that inject fuel directly into cylinder 2. Injection valves 3 are connected to common rail 4, a shared pressure accumulator. A fuel pump 5 is connected to common rail 4 and stores high-pressure fuel. Fuel is injected from injection valves 3 based on the fuel pressure in common rail 4 (also called rail pressure, hereafter abbreviated as "fuel pressure”), and the fuel pressure in common rail 4 changes according to the output of fuel pump 5. Note that injection valves 3 may also be provided with their tips protruding into the intake passage, and supply fuel to cylinder 2 by injecting fuel into the intake passage.
  • fuel pressure also called rail pressure, hereafter abbreviated as "fuel pressure”
  • the amount and timing of fuel injected from the injection valve 3 into the cylinder 2 are controlled by the injection valve control device 10, details of which will be described later.
  • a control pulse signal control signal
  • the nozzle hole of the injection valve 3 is opened for a period corresponding to the magnitude of the control pulse signal (the injection valve 3 opens).
  • the period during which the nozzle hole of the injection valve 3 is open will be referred to as the "valve open period.”
  • the amount of fuel injected at this time depends on the fuel pressure in the common rail 4 and the magnitude of the control pulse signal (drive pulse width), and the fuel injection timing depends on the time the control pulse signal is transmitted.
  • the injector 3 exemplified in the embodiment performs multi-stage injection in which fuel is injected multiple times per cycle of the engine 1.
  • multi-stage injection for example, pilot injection, pre-injection, main injection, after-injection, and post-injection are performed in this order. Pilot injection and pre-injection are performed during the compression stroke before top dead center of the engine 1, and are injections that spark the main injection. During pilot injection, the injected fuel has not yet ignited, and during pre-injection, the injected fuel can ignite.
  • the main injection, after injection, and post injection are performed in the combustion stroke after the top dead center of the engine 1.
  • the main injection is an injection to obtain the output of the engine 1.
  • the after injection and post injection are injections for aftertreatment to improve exhaust performance.
  • the engine 1 that performs multi-stage injection as described above is not limited to one that performs all of pilot injection, pre-injection, main injection, after-injection, and post-injection, but may also perform two or more types of injection including at least main injection.
  • the input system is configured to detect information necessary for control by the injection valve control device 10.
  • sensors such as an engine rotation speed sensor 21, an accelerator opening sensor 22, a brake pedal switch 23, an ignition switch 24, and a fuel pressure sensor 25 are exemplified as components of the input system.
  • the engine speed sensor 21 is a sensor that detects the speed of the engine 1, and is provided, for example, near the crankshaft of the engine 1.
  • the accelerator opening sensor 22 is a sensor that detects the amount of depression of the accelerator pedal (accelerator opening), and is provided, for example, near the accelerator pedal.
  • the accelerator pedal depression and its time rate of change are parameters corresponding to the magnitude of the output the vehicle driver requests from the engine 1 (i.e., the vehicle's required output), and are used to determine whether or not there is a request for acceleration of the vehicle. For example, if the time rate of change of the accelerator pedal depression is positive, it is determined that there is a request for acceleration of the vehicle.
  • the brake pedal switch 23 is a sensor that detects whether the brake pedal is being depressed, and is located, for example, near the brake pedal. Whether the brake pedal is being depressed is used to determine whether there is a request to decelerate the vehicle. For example, if the brake pedal is being depressed, it is determined that there is a request to decelerate the vehicle, and if the brake pedal is not being depressed, it is determined that there is no request to decelerate the vehicle.
  • the ignition switch 24 is a switch that is operated when starting the engine 1.
  • the engine 1 starts to start from the moment the ignition switch 24 is operated.
  • the fuel pressure sensor 25 is a sensor that detects the fuel pressure in the common rail 4.
  • the fuel pressure detected by the fuel pressure sensor 25 will be referred to as the "detected value.”
  • the configuration of the input system is not limited to the above-mentioned sensors, and other configurations may be used.
  • the information detected by the input system configuration is transmitted to the injection valve control device 10, which will be described next.
  • An ECU Electronic Control Unit
  • the ECU is a computer that incorporates a processor (central processing unit), memory (main memory), storage, interface device, timer function, etc., which are connected to each other via an internal bus.
  • the injection valve control device 10 can be an engine ECU for vehicles that are driven solely by the engine 1, and a PHEV-ECU (integrated ECU) or engine ECU for plug-in hybrid vehicles.
  • This injection valve control device 10 is not limited to being implemented in an integrated control device (integrated ECU), but may also be implemented in an ECU that is lower in level than the integrated control device.
  • the injection valve control device 10 has a target injection amount acquisition unit 11 that acquires a target injection amount based on the vehicle's required output, and a reference setting unit 12 that sets a reference period based on the target injection amount and the detection value of the fuel pressure sensor 25 in order to control the opening period of the injection valve 3.
  • a target injection amount acquisition unit 11 that acquires a target injection amount based on the vehicle's required output
  • a reference setting unit 12 that sets a reference period based on the target injection amount and the detection value of the fuel pressure sensor 25 in order to control the opening period of the injection valve 3.
  • actual fuel pressure hereinafter referred to as "actual fuel pressure"
  • the injection valve control device 10 has not only a reference setting unit 12 that sets the reference period, but also a target pressure acquisition unit 13 and a restriction setting unit 14 that set a guard period that restricts the reference period. Furthermore, the injection valve control device 10 has a control unit 15 that compares the length of the reference period and the guard period to finally determine the opening period of the injection valve 3.
  • the target injection amount acquisition unit 11, the reference setting unit 12, the target pressure acquisition unit 13, the regulation setting unit 14, and the control unit 15 are elements that are conveniently classified according to their roles (functions) in the injection valve control device 10, and each may be written as an independent program, or may be written as a composite program that combines the functions of both.
  • the target injection amount obtaining unit 11 obtains the target injection amount of the injector 3 based on the required output of the vehicle.
  • the target injection amount obtaining unit 11 obtains the target injection amount based on the accelerator opening corresponding to the "required output of the vehicle".
  • the target injection amount is the fuel injection amount (i.e., the instructed injection amount) instructed to the injector 3 according to the accelerator opening.
  • the target injection amount is set to a larger amount as the accelerator opening detected by the accelerator opening sensor 22 increases. Note that a known method may be used for the method by which the target injection amount obtaining unit 11 obtains the target injection amount.
  • the reference setting unit 12 sets a reference period based on the detection value of the fuel pressure sensor 25 and the target injection amount of the injection valve 3 .
  • the reference period is set as a reference valve opening period, and is set to a shorter period as the detection value of the fuel pressure sensor 25 increases, and is set to a longer period as the target injection amount increases.
  • One example of a method for setting the reference period by the reference setting unit 12 is to calculate the reference period using the detection value of the fuel pressure sensor 25 and the target injection amount as arguments from a map in which reference periods corresponding to the detection value of the fuel pressure sensor 25 and the target injection amount are stored in advance.
  • the reference period may also be calculated using a formula that derives the reference period from the detection value of the fuel pressure sensor 25 and the target injection amount.
  • the guard period is set by the target pressure obtaining unit 13 and the restriction setting unit 14, which will be described next.
  • the target pressure acquisition unit 13 acquires the target pressure based on information related to the driving state of the vehicle.
  • the "information related to the driving state of the vehicle” includes the rotation speed and target injection amount of the engine 1.
  • the rotation speed and target injection amount of the engine 1 can also be considered parameters corresponding to the magnitude of the output required by the driver of the vehicle from the engine 1 (i.e., the required output of the vehicle). Therefore, the target pressure acquisition unit 13 can also be said to be an element that acquires the target pressure based on the required output of the vehicle.
  • the target pressure is a target value of the fuel pressure.
  • a known method can be used for the method of acquiring the target pressure by the target pressure acquisition unit 13. Once the target pressure is acquired by the target pressure acquisition unit 13, the output of the fuel pump 5 is controlled so that the fuel pressure in the common rail 4 approaches the target pressure.
  • the target pressure has been conventionally used for controlling the output of the fuel pump 5.
  • the restriction setting unit 14 sets the guard period based on the target pressure acquired by the target pressure acquisition unit 13 .
  • This restriction setting unit 14 has an upper limit setting unit 41 that sets a guard period (hereinafter referred to as the "upper limit period”) that restricts the upper limit of the reference period, and a lower limit setting unit 42 that sets a guard period (hereinafter referred to as the "lower limit period”) that restricts the lower limit of the reference period.
  • One method for setting the upper limit period and the lower limit period is to read the upper limit period and the lower limit period from a table in which upper limit periods and lower limit periods corresponding to the target pressure are stored in advance, using the target pressure as an argument.
  • the upper limit period and the lower limit period are not fixed periods regardless of the level of the target pressure, but are variable periods depending on the level of the target pressure.
  • the upper limit setting unit 41 sets the upper limit period based on the target pressure.
  • the upper limit period is a period that restricts the upper limit of the reference period, and therefore can be said to be the upper limit of the opening period of the injection valve 3.
  • this upper limit period is a period during which an excessive increase in the fuel injection amount or an excessive increase in the load on the engine 1 is suppressed when fuel is injected from the injection valve 3 at the target pressure.
  • the actual fuel pressure tends to be lower than the target pressure due to a delay in the actual fuel pressure following the target pressure. Also, immediately after the vehicle begins to start, the actual fuel pressure has not risen sufficiently, and the actual fuel pressure tends to be lower than the target pressure. In situations like these where the actual fuel pressure is likely to deviate lower from the target pressure (hereinafter referred to as a "low-pressure deviation situation"), the opening period of the injector 3 must be relatively long to inject a sufficient amount of fuel, so the reference period is likely to be set relatively long.
  • an upper limit period based on the target pressure (hereinafter referred to as the "standard upper limit period”) is simply set uniformly, the reference period is likely to be longer than the standard upper limit period. Therefore, there is a risk that the opening period of the injector 3 will be restricted by the standard upper limit period to be shorter than necessary.
  • the upper limit setting unit 41 sets an upper limit period (hereinafter referred to as a "low-pressure upper limit period”) that is longer than the standard upper limit period that is set in a situation in which the actual fuel pressure and the target pressure are unlikely to deviate from each other (hereinafter referred to as a "non-deviation situation").
  • the upper limit setting unit 341 sets a longer low pressure upper limit period when there is a request for acceleration of the vehicle than when there is no request for acceleration of the vehicle.
  • the upper limit setting unit 41 sets a longer low pressure upper limit period from the start of engine 1 startup until the predetermined period has elapsed than after the predetermined period has elapsed from the start of engine 1 startup.
  • predetermined period is a period that is set in advance as a period required for the actual fuel pressure to increase to the target pressure from the start of starting the engine 1.
  • This predetermined period may be set in advance as an engine start period required from the start of starting the engine 1 to the completion of starting, or may be set as a period that includes a margin added to this engine start period.
  • the low pressure upper limit period that is set when there is a vehicle acceleration request after a predetermined period has elapsed since the start of engine 1 startup is referred to as the "acceleration upper limit period.”
  • the low pressure upper limit period that is set when there is no vehicle acceleration request from the start of engine 1 until a predetermined period has elapsed is referred to as the "startup upper limit period.”
  • the following inequalities I and II hold.
  • Inequality I Standard upper limit period ⁇ Acceleration upper limit period
  • Inequality II Standard upper limit period ⁇ Starting upper limit period
  • the upper limit setting unit 41 sets a low pressure upper limit period (in other words, a "start-up and acceleration upper limit period") that is longer than the acceleration upper limit period and the start-up upper limit period.
  • Methods for setting the low pressure upper limit period include a method of calculating the standard upper limit period by multiplying it by a coefficient (a coefficient of 1 or more) that lengthens it, and a method of calculating the standard upper limit period by adding a correction.
  • the low pressure upper limit period set by these methods is a variable period. For example, the greater the accelerator opening detected by the accelerator opening sensor 22, the greater the acceleration request may be determined to be, and the longer the acceleration upper limit period may be set. However, the low pressure upper limit period may also be set to a fixed period that is uniformly set in advance.
  • the upper limit setting unit 41 can be said to implement a setting that switches the standard upper limit period to a low-pressure upper limit period when the situation changes from a non-deviation situation to a low-pressure deviation situation. It can also be said that the upper limit setting unit 41 implements a setting that switches from the low-pressure upper limit period to the standard upper limit period when the situation changes from a low-pressure deviation situation to a non-deviation situation.
  • One example of a method for switching from one of the standard upper limit period and the low-pressure upper limit period to the other is to use a program switch built into the injection valve control device 10 to perform the switching.
  • the upper limit setting unit 41 exemplified in this embodiment sets an upper limit period during the compression stroke before top dead center of the engine 1. Specifically, an upper limit period is set for the valve-open period during which fuel is injected during pilot injection and pre-injection. Note that in this embodiment, an upper limit period is set only for the valve-open period during which fuel is injected during pilot injection and pre-injection, but an upper limit period may also be set for the engine 1 after the compression stroke. In other words, it is sufficient to set an upper limit period for at least pilot injection and pre-injection.
  • after-injection and post-injection are injections for after-treatment purposes that aim to improve exhaust performance, even if the fuel injection amount is large, they are unlikely to cause an excessive increase in in-cylinder pressure, so it is preferable to simplify control without setting an upper limit period.
  • the upper limit setting unit 41 illustrated here sets a shorter upper limit period for pilot injection, which has a longer period until ignition (fuel is injected earlier), than for pre-injection, thereby suppressing the rapid rise in in-cylinder pressure when the fuel ignites, which is caused by a large amount of fuel mixing with the intake air.
  • the lower limit setting unit 42 sets a lower limit period that is shorter than the upper limit period based on the target pressure.
  • the lower limit period is a period that restricts the lower limit of the reference period, and therefore can be said to be the lower limit of the opening period of the injection valve 3.
  • the lower the target pressure, the longer the lower limit period is set by the lower limit setting unit 42.
  • This lower limit period is set as a period for ensuring the output of the engine 1 and preventing the engine from stalling when fuel is injected from the injection valve 3 at the target pressure.
  • the actual fuel pressure tends to be higher than the target pressure due to a delay in the actual fuel pressure following the target pressure. Furthermore, when there is a request for vehicle deceleration, the target injection quantity for the injector 3 is set to a small value. For these reasons, it is conceivable that the reference period will be extremely short when there is a request for vehicle deceleration.
  • the lower limit setting unit 42 sets a lower limit period (hereinafter referred to as a "high pressure lower limit period”) that is longer in a high pressure deviation state than the standard lower limit period that is set in a non-deviation state. Specifically, the lower limit setting unit 42 sets a longer high pressure lower limit period when there is a deceleration request of the vehicle than when there is no deceleration request.
  • the high-pressure lower limit period can be set by replacing the standard upper limit period described in the above-mentioned method for setting the low-pressure upper limit period with the standard lower limit period.
  • the high-pressure lower limit period set by this method is a variable period, but it may also be set to a fixed period that is uniformly set in advance.
  • This lower limit setting unit 42 can be said to implement a setting that switches the standard lower limit period to the high-pressure lower limit period when the situation changes from a non-deviation situation to a high-pressure deviation situation. It can also be said that the lower limit setting unit 42 implements a setting that switches from the high-pressure lower limit period to the standard lower limit period when the situation changes from a high-pressure deviation situation to a non-deviation situation.
  • One example of a method for switching from either the standard lower limit period or the high-pressure lower limit period to the other is a method of switching using a program switch built into the injection valve control device 10, similar to the method for switching the upper limit period.
  • the lower limit setting unit 42 illustrated in this embodiment sets lower limit periods for pilot injection, pre-injection, and main injection.
  • a lower limit period is set for all injections of the multi-stage injection, excluding the injection for post-treatment.
  • a shorter lower limit period is set for pilot injection than for pre-injection.
  • lower limit periods are set only for the valve-open periods during which fuel is injected in each of pilot injection, pre-injection, and main injection.
  • lower limit periods may also be set for at least one of the after-injection and post-injection of the engine 1. In other words, it is sufficient to set lower limit periods for at least pilot injection, pre-injection, and main injection.
  • after-injection and post-injection are injections for post-treatment that aim to improve exhaust performance, even a small amount of fuel injection is unlikely to cause a decrease in output or engine stall of the engine 1. Therefore, it is preferable to simplify control without setting a lower limit period.
  • the control unit 15 sets the upper limit period as the open period of the injector 3, and when the reference period is shorter than the lower limit period, the control unit 15 sets the lower limit period as the open period of the injector 3.
  • the open period of the injector 3 is restricted by the upper limit period or the lower limit period.
  • Flowchart 2 to 4 the control procedure (flow) performed by the injection valve control device 10 will be described below.
  • the control described here is repeatedly performed at a predetermined cycle when the vehicle engine 1 is started.
  • Fig. 2 is an example of a flowchart illustrating control performed by the injection valve control device 10 of one embodiment.
  • Fig. 3 and Fig. 4 show an example of a period setting subroutine performed as part of the control shown in Fig. 2.
  • Fig. 3 shows an example of setting an upper limit period
  • Fig. 4 shows an example of setting a lower limit period.
  • step S10 various periods including a reference period, an upper limit period, and a lower limit period are set (step S10).
  • setting of a reference period step S20
  • setting of an upper limit period step S30
  • setting of a lower limit period step S40
  • Setting of the reference period step S20) is performed after obtaining the target injection amount (step S11).
  • Setting of the upper limit period (step S30) and setting of the lower limit period step S40) are performed after obtaining the target pressure (step S12).
  • the target injection amount is acquired by the target injection amount acquisition unit 11 based on the accelerator opening corresponding to the output demand of the vehicle.
  • the reference period is set by the reference setting unit 12 based on the detection value of the fuel pressure sensor 25 and the target injection amount of the injection valve 3 .
  • the target pressure is acquired by the target pressure acquisition unit 13 based on information relating to the operating state of the vehicle, including the rotation speed of the engine 1 and the target injection amount.
  • the upper limit period and the lower limit period are set by the restriction setting unit 14 .
  • the upper limit period is set by the upper limit setting unit 41 based on the target pressure. As shown in FIG. 3, the length of the upper limit period is set depending on whether or not the pressure deviation state is low. If the low pressure deviation state exists (positive determination in step S32), the upper limit period is set to the low pressure upper limit period (step S34).
  • the acceleration upper limit period is set as the upper limit period.
  • the startup upper limit period is set as the upper limit period. If the low pressure deviation state is not present, that is, if the non-deviation state is present (negative determination in step S32), the upper limit period is set to the standard upper limit period (step S36).
  • the lower limit period is set by the lower limit setting unit 42 based on the target pressure. As shown in FIG. 4, the length of the lower limit period is set depending on whether or not there is a high pressure deviation state. If the high pressure deviation state is present (YES in step S42), the lower limit period is set to the high pressure lower limit period (step S44). Specifically, when there is a vehicle deceleration request (an example of a high pressure deviation state), the high pressure lower limit period is set as the lower limit period. If the high pressure deviation state is not present, that is, if the non-deviation state is present (negative determination in step S42), the lower limit period is set to the standard lower limit period (step S46).
  • the upper limit period and lower limit period are compared with the reference period (step S50), as shown in Fig. 2. This period comparison is performed by the control unit 15. Then, depending on the comparison result between the upper limit period, the lower limit period and the reference period, one of the upper limit period, the lower limit period and the reference period is set as the valve opening period of the injector 3 (steps S60, S70, S80). Such determination of the valve opening period is performed by the control unit 15.
  • the upper limit period is set as the opening period of the injection valve 3 (step S60). If the reference period is equal to or greater than the lower limit period and equal to or less than the upper limit period, the reference period is set as the valve opening period of the injection valve 3 (step S70). If the reference period is shorter than the lower limit period, the lower limit period is set as the valve opening period of the injection valve 3 (step S80). Then, this control cycle ends (return).
  • the injection valve control device 10 of this embodiment is configured as described above, and therefore has the following functions and effects. (1) When a malfunction occurs in which the detected value of the fuel pressure sensor 25 is detected as lower than the actual fuel pressure, fuel is injected from the injector 3 at a pressure corresponding to the actual fuel pressure that is higher than the detected value of the fuel pressure sensor 25. Therefore, if fuel is injected over a reference period based on the detected value, there is a risk that more fuel than the target injection amount will be injected.
  • the injection valve control device 10 sets not only a reference period based on the actual fuel pressure but also an upper limit period based on the target pressure, and if the reference period is longer than the upper limit period, the upper limit period is used as the opening period of the injection valve 3. This restricts (or “guards") the upper limit of the opening period of the injection valve 3 to the upper limit period. This makes it possible to prevent an excessive increase in the fuel injection amount. This in turn makes it possible to prevent an increase in the load on the engine 1 due to an increase in the fuel injection amount.
  • the upper limit setting unit 41 sets a longer upper limit period from the start of starting the engine 1 until the predetermined period has elapsed than after the predetermined period has elapsed. That is, a longer upper limit period is used within the predetermined period compared to after the predetermined period has elapsed. Therefore, even if the actual fuel pressure has not risen sufficiently immediately after the start of the vehicle, the opening period of the injection valve 3 can be prevented from being restricted by an upper limit period that is shorter than necessary, which contributes to preventing the engine 1 from stalling within a predetermined period from the start of the start of the engine 1.
  • the upper limit setting unit 41 sets an upper limit on the valve-open period during which fuel is injected during the compression stroke of the engine 1. This makes it possible to suppress an excessive increase in in-cylinder pressure during the compression stroke, which would be caused by excessive fuel injection during the compression stroke. This makes it possible to suppress the load on the engine 1 while ensuring the output of the engine 1 through the main injection. (5) Furthermore, the upper limit setting unit 41 sets a shorter upper limit period for the pilot injection than for the pre-injection. In this way, the fuel injection amount for the pilot injection is more likely to be suppressed than the fuel injection amount for the pre-injection, thereby suppressing a sudden increase in in-cylinder pressure when fuel is ignited. This also reduces the load on the engine 1.
  • the injection valve control device 10 sets not only a reference period based on the actual fuel pressure but also a lower limit period based on the target pressure, and when the reference period is shorter than the lower limit period, the lower limit period is set as the opening period of the injection valve 3. This restricts (i.e., "guards") the lower limit of the opening period of the injection valve 3 to the lower limit period. This makes it possible to prevent engine stall and ensure the output of the engine 1.
  • the lower limit setting unit 42 sets a longer lower limit period when there is a deceleration request than when there is no deceleration request. That is, a longer lower limit period is used when there is a deceleration request compared to when there is no deceleration request. Therefore, even if the actual fuel pressure becomes higher than the target pressure due to a delay in the follow-up of the actual fuel pressure to the target pressure when there is a deceleration request, it is possible to prevent the opening period of the injection valve 3 from being restricted by an unnecessarily short lower limit period, which ultimately contributes to preventing engine stalls.
  • This lower limit setting unit 42 sets lower limit periods for pilot injection, pre-injection, and main injection. Restricting the valve-open period during which fuel is injected by pilot injection or pre-injection to the lower limit period contributes to good combustion of fuel by main injection. Furthermore, restricting the valve-open period during which fuel is injected by main injection to the lower limit period contributes to ensuring the output of engine 1. This makes it possible to prevent engine stall and suppress a decrease in engine output.
  • the lower limit setting unit is not limited to setting the high-pressure lower limit period when there is a deceleration request as described above, and may instead or additionally set the high-pressure lower limit period when the vehicle is decelerating.
  • the upper limit setting unit is not limited to setting the low-pressure upper limit period when there is an acceleration request, and may instead or additionally set the low-pressure upper limit period when the vehicle is accelerating.
  • a vehicle speed sensor that detects vehicle speed is provided as part of the input system. If the time rate of change of vehicle speed detected by the vehicle speed sensor is negative, the high-pressure lower limit period is set assuming that the vehicle is decelerating. Furthermore, if the time rate of change of vehicle speed detected by the vehicle speed sensor is positive, the low-pressure upper limit period is set assuming that the vehicle is accelerating.
  • the upper limit setting unit is not limited to a configuration in which it sets the low-pressure upper limit period in addition to the standard upper limit period, and may set only the standard upper limit period without setting the low-pressure upper limit period. In this configuration, it is possible to simplify the logic for setting the upper limit period, while suppressing an excessive increase in the fuel injection amount and suppressing an increase in the engine load due to an increase in the fuel injection amount.
  • the lower limit setting unit is not limited to the configuration in which it sets the high-pressure lower limit period in addition to the standard lower limit period, and may set only the standard lower limit period without setting the high-pressure lower limit period. In this configuration, it is possible to prevent engine stall and ensure engine output while simplifying the logic for setting the lower limit period.
  • the upper limit period of the pilot injection may be set to be longer than the upper limit period of the pre-injection set by the upper limit setting unit, and the length of these upper limit periods can be set as desired. Furthermore, an upper limit period and a lower limit period may be set for at least one of the pilot injection, pre-injection, main injection, after-injection, and post-injection that are performed in the multi-stage injection.
  • control of an engine that performs multi-stage injection has been described, but this control can also be applied to an engine in which fuel is injected once per engine cycle.
  • the engine to which the injection valve control device is applied is not limited to a diesel engine, but may also be a gasoline engine.
  • the target pressure acquisition unit may acquire the target pressure based on at least information related to the vehicle's operating state, and the information related to the vehicle's operating state may include an accelerator pedal position. If the accelerator pedal position is included in the information related to the vehicle's operating state, the target injection amount acquisition unit may also be considered an element that acquires the target injection amount based on information related to the vehicle's operating state. In other words, the target pressure acquisition unit may be considered an element that acquires the target pressure based on information related to the accelerator pedal position instead of or in addition to the target injection amount.
  • the target injection amount obtaining unit may be omitted from the injection valve control device, in which case the target injection amount of the injection valve is obtained in the injection valve control device by a known method.
  • This invention can be used in the vehicle manufacturing industry, which uses injection valves to inject fuel into engine cylinders.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)

Abstract

L'invention concerne un dispositif de commande de soupape d'injection (10) pourvu d'une unité d'acquisition de pression cible (13), d'une unité de réglage de référence (12), d'une unité de réglage de limite supérieure (41) et d'une unité de commande (15). L'unité d'acquisition de pression cible (13) acquiert une pression cible, qui est une valeur cible pour une pression de carburant dans un rail commun (4), sur la base d'informations concernant un état de conduite d'un véhicule. L'unité de réglage de référence (12) règle une période d'ouverture de soupape d'une soupape d'injection (3) en tant que période de référence sur la base de la valeur détectée d'un capteur de pression de carburant (25) qui détecte la pression du carburant dans le rail commun (4) et la quantité d'injection cible de la soupape d'injection (3) qui injecte le carburant fourni par le rail commun (4). L'unité de réglage de limite supérieure (41) règle une période limite supérieure, qui est la limite supérieure de la période d'ouverture de soupape, sur la base de la pression cible. L'unité de commande (15) règle la période de référence en tant que période d'ouverture de soupape lorsque la période de référence est inférieure ou égale à la période limite supérieure, et règle la période limite supérieure en tant que période d'ouverture de soupape lorsque la période de référence est plus longue que la période limite supérieure.
PCT/JP2024/021713 2024-06-14 2024-06-14 Dispositif de commande de soupape d'injection Pending WO2025258068A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/JP2024/021713 WO2025258068A1 (fr) 2024-06-14 2024-06-14 Dispositif de commande de soupape d'injection

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2024/021713 WO2025258068A1 (fr) 2024-06-14 2024-06-14 Dispositif de commande de soupape d'injection

Publications (1)

Publication Number Publication Date
WO2025258068A1 true WO2025258068A1 (fr) 2025-12-18

Family

ID=98051022

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2024/021713 Pending WO2025258068A1 (fr) 2024-06-14 2024-06-14 Dispositif de commande de soupape d'injection

Country Status (1)

Country Link
WO (1) WO2025258068A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002147266A (ja) * 2000-11-16 2002-05-22 Denso Corp 蓄圧式燃料噴射装置
JP2003027995A (ja) * 2001-07-13 2003-01-29 Mazda Motor Corp ディーゼルエンジンの制御装置及び制御方法
US20160298569A1 (en) * 2015-04-13 2016-10-13 Cummins, Inc. Fuel pressure control for engine fuel systems

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002147266A (ja) * 2000-11-16 2002-05-22 Denso Corp 蓄圧式燃料噴射装置
JP2003027995A (ja) * 2001-07-13 2003-01-29 Mazda Motor Corp ディーゼルエンジンの制御装置及び制御方法
US20160298569A1 (en) * 2015-04-13 2016-10-13 Cummins, Inc. Fuel pressure control for engine fuel systems

Similar Documents

Publication Publication Date Title
CN100523464C (zh) 设计用于使内燃机的燃烧噪声最小化的燃料喷射控制设备
US7380537B2 (en) Control apparatus for vehicle
JP4289280B2 (ja) 噴射量学習制御装置
WO2005124129A1 (fr) Système de commande de l’allumage d’un moteur à combustion interne
JP3572937B2 (ja) 蓄圧式燃料噴射機構の燃料圧制御装置
US11236693B2 (en) Fuel injection control apparatus
US11162446B2 (en) Fuel injection control apparatus
US11401878B2 (en) Fuel injection control apparatus
WO2025258068A1 (fr) Dispositif de commande de soupape d'injection
JP7559744B2 (ja) 内燃機関システム
US11242818B2 (en) Control device of internal combustion engine
JP5332871B2 (ja) 火花点火式内燃機関の燃料噴射制御装置
JP2005147019A (ja) 筒内噴射型内燃機関の燃圧制御装置
US11306677B2 (en) Fuel injection control apparatus
JP2000130234A (ja) 筒内燃料噴射式内燃機関の燃料噴射制御装置
JP4450324B2 (ja) 内燃機関の始動制御装置
US11352970B2 (en) Control device of internal combustion engine
JP7491328B2 (ja) 車両の制御装置
JP5834699B2 (ja) 圧縮自己着火式エンジンの始動制御装置
JP2025171725A (ja) 内燃機関の制御装置
JP2023113329A (ja) 内燃機関の燃料噴射制御装置
JPH11117796A (ja) ディーゼル機関の燃料噴射制御装置および燃料噴射制御方法、記録媒体
JP2007278167A (ja) 内燃機関の燃料供給装置
JP2019210844A (ja) 燃料噴射制御装置およびその方法
JP2008169745A (ja) 内燃機関の制御装置、制御方法、その方法を実現させるプログラムおよびそのプログラムを記録した記録媒体

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 24943480

Country of ref document: EP

Kind code of ref document: A1