WO2015194342A1 - Ignition timing control device for internal combustion engine and ignition timing control method for internal combustion engine - Google Patents

Ignition timing control device for internal combustion engine and ignition timing control method for internal combustion engine Download PDF

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Publication number
WO2015194342A1
WO2015194342A1 PCT/JP2015/065377 JP2015065377W WO2015194342A1 WO 2015194342 A1 WO2015194342 A1 WO 2015194342A1 JP 2015065377 W JP2015065377 W JP 2015065377W WO 2015194342 A1 WO2015194342 A1 WO 2015194342A1
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WIPO (PCT)
Prior art keywords
misfire limit
fuel cut
ignition timing
internal combustion
combustion engine
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PCT/JP2015/065377
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French (fr)
Japanese (ja)
Inventor
小倉　健太郎
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ボッシュ株式会社
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Publication of WO2015194342A1 publication Critical patent/WO2015194342A1/en

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    • 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
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/04—Introducing corrections for particular operating conditions
    • F02D41/12—Introducing corrections for particular operating conditions for deceleration
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
    • F02P5/00—Advancing or retarding ignition; Control therefor
    • F02P5/04—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions
    • F02P5/145—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions using electrical means
    • F02P5/15—Digital data processing
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/40—Engine management systems

Definitions

  • the present invention relates to an ignition timing control device for an internal combustion engine that controls the ignition timing of an internal combustion engine such as a gasoline engine so as not to exceed a misfire limit, and an ignition timing control method thereof.
  • ⁇ Such a shock problem can be improved by reducing the torque step.
  • the torque level difference can be reduced by reducing the amount of air in the combustion chamber or reducing the fuel when returning to fuel cut.
  • the air amount and fuel cannot be increased due to a response delay, and the engine stop cannot be sufficiently suppressed. That is, even if an attempt is made to cope with the amount of air or fuel in order to prevent the engine from being stopped due to a sudden decrease in the number of revolutions, depending on the timing, intake and compression are required, so the response for one rotation is delayed. Such a delay in response may not prevent the engine from stopping.
  • Patent Document 1 describes that the ignition timing is temporarily retarded when the fuel cut is restored. Due to such a temporary retardation of the ignition timing, it is possible to prevent the engine from being stopped by immediately advancing the ignition timing even if a sudden drop in rotation occurs.
  • the present invention has been made in view of the above-described problems, and an ignition timing control device for an internal combustion engine capable of reducing a torque step generated when fuel cut is restored while reliably avoiding a stop of the internal combustion engine, and An object is to provide a method for controlling the ignition timing.
  • the present invention has the following means.
  • An ignition timing control device for an internal combustion engine is an ignition timing control device for an internal combustion engine that controls the ignition timing of the internal combustion engine so as not to exceed a misfire limit, and the internal combustion engine continues to cut fuel.
  • a time-counting unit that counts the continuous duration
  • a misfire limit-retarding unit that retards the misfire limit by a predetermined amount when the measured duration has passed a predetermined time, and a fuel cut is completed after retarding the misfire limit
  • a misfire limit advancement part for advancing the misfire limit stepwise so as to return before delaying by a predetermined amount.
  • the misfire limit can be retarded compared to the operation state in which the fuel cut is not performed mainly for two reasons. That is, as a first reason, if the fuel cut for a predetermined time or longer continues, the residual gas in the combustion chamber (cylinder) of the internal combustion engine is replaced with fresh air, so that the fuel is compared with the state where there is no replacement with fresh air. This is because the air-fuel mixture after mixing is easy to burn.
  • the second reason is that the residual air is replaced with fresh air as described above, so that the actual air amount after continuing the fuel cut for a predetermined time or more is recognized using various sensors in the operating state in which the fuel cut is not performed. This is because it becomes larger than the possible air volume.
  • the misfire limit is retarded by a predetermined amount as compared with the operation state in which the fuel cut is not performed, and then returns to the state before the predetermined amount is retarded when the fuel cut ends.
  • advance the misfire limit step by step it is possible to reduce the torque level difference that occurs at the time of return from fuel cut while reliably avoiding engine stoppage.
  • a replacement time memory that stores a replacement time until the residual gas in the combustion chamber of the internal combustion engine before the fuel cut starts is replaced with fresh air after the fuel cut starts.
  • the misfire limit retarding portion preferably retards the misfire limit when the timed duration has passed the replacement time.
  • the residual gas before the start of the fuel cut is started in the combustion chamber of the internal combustion engine based on information from a sensor attached to the internal combustion engine. It is preferable that an exhaust time estimation unit for estimating a replacement time for replacement with fresh air is further provided, and the misfire limit retarding unit retards the misfire limit when the measured duration has passed the replacement time.
  • a retard information storage unit that stores retard information indicating a retard amount that is retarded to the limit, and the misfire limit retard unit is indicated by the retard information when the measured duration has exceeded a predetermined time. It is preferable to retard the misfire limit with a retarded amount.
  • the present invention as described above can also be understood as an ignition timing control method for an internal combustion engine.
  • the present embodiment relates to an ignition timing control device for an internal combustion engine that controls the ignition timing of an internal combustion engine such as a gasoline engine so as not to exceed a misfire limit.
  • the ignition timing control device is incorporated in an engine control unit 500 (hereinafter referred to as ECU 500) for controlling the engine 100 as shown in FIG.
  • ECU 500 engine control unit 500
  • a port injection type engine will be described as an example.
  • the engine control system 10 including the engine 100 and the ECU 500 will be described prior to the description of the ignition timing control device.
  • Engine control system 10 For example, as shown in FIG. 1, the engine control system 10 includes an engine 100, an air cleaner 102, an intake pipe 104, an intake manifold 106, an injector 108, a spark plug 110, an exhaust manifold 112, and a catalyst 114.
  • Engine 100 is an aspect of an internal combustion engine according to the present invention, and is, for example, a four-cylinder gasoline engine including a total of four cylinders 101 as shown in FIG.
  • the number of cylinders of engine 100 may be other than four.
  • the air cleaner 102 supplies clean air from which dust and the like have been separated to the intake pipe 104 side by filtering air taken from outside the vehicle.
  • the air cleaner 102 is provided with an air flow meter 526 on the side connected to the intake pipe 104. Air flow meter 526 detects the amount of air taken from air cleaner 102 toward intake pipe 104 and transmits a signal indicating the detection result to ECU 500.
  • the intake pipe 104 is a pipe that guides the air supplied from the air cleaner 102 to the intake manifold 106.
  • the intake pipe 104 is provided with a throttle valve 116 in the pipe.
  • the throttle valve 116 is an electronically controlled valve whose opening degree can be controlled by the ECU 500, for example, and controls the amount of air introduced into the cylinder 101 via the intake manifold 106.
  • the intake manifold 106 is a manifold for introducing the air guided from the intake pipe 104 into the four cylinders 101.
  • the injector 108 is installed in the intake manifold 106 so as to face each cylinder 101, and injects gasoline fuel into each cylinder 101.
  • the timing and amount of fuel injection are controlled by the ECU 500.
  • the ignition plug 110 is provided inside each cylinder 101 and ignites a mixture of air introduced from the intake manifold 106 and fuel injected by the injector 108.
  • the ignited air-fuel mixture expands by combustion to generate driving force.
  • the air-fuel mixture after combustion, that is, exhaust gas, is guided to the exhaust manifold 112.
  • the engine 100 is provided with a water temperature sensor 534 and a rotation speed sensor 536.
  • Water temperature sensor 534 detects the temperature of the cooling water that cools engine 100 and transmits the detection result to ECU 500.
  • rotation speed sensor 536 detects the rotation speed of engine 500 and transmits the detection result to ECU 500.
  • the exhaust manifold 112 is a manifold that combines the exhaust passages of the exhaust gas discharged from the four cylinders 101 into one, and guides the exhaust gas gathered in one exhaust passage to the catalyst 114. Further, the exhaust manifold 112 is provided with an air-fuel ratio sensor 532 for detecting the oxygen concentration in the exhaust gas, that is, the air-fuel ratio. Air-fuel ratio sensor 532 transmits a signal representing the detection result to ECU 500.
  • the ECU 500 installs a control program for controlling the engine control system 10 in a general-purpose computer such as a processor, a ROM, and a RAM, thereby controlling the entire engine control system 10 based on signals transmitted from various sensors. Realize the function. Specifically, for example, ECU 500 determines the torque of engine 100 by determining the opening of throttle valve 116 and the ignition timing by spark plug 110 based on the accelerator opening transmitted from accelerator opening sensor 528. Control.
  • the accelerator opening sensor 528 is provided, for example, in an accelerator pedal, detects the accelerator opening, and transmits the detection result to the ECU 500.
  • Ignition timing control device according to first embodiment 2-1. Device Configuration An ignition timing control device 1a according to the first embodiment, which can be realized as a function inside the ECU 500, will be described with reference to FIG.
  • the ignition timing control device 1a includes a misfire limit setting unit 11, an ignition timing setting unit 12, a fuel cut determination unit 13, a fuel cut duration measuring unit 14, a storage unit 15, and a misfire.
  • a limit retardation portion 16 and a misfire limit advancement portion 17 are provided.
  • the misfire limit setting unit 11 sets a normal misfire limit that is a retard limit of the ignition timing in an operating state where fuel cut is not performed (hereinafter also referred to as normal time). For example, the misfire limit setting unit 11 further sets a target air-fuel ratio value (for example, the theoretical air-fuel ratio) based on the air amount detected by the air flow meter 526 and the rotational speed of the engine 100 detected by the rotational speed sensor 536 during normal times. If the target is the value, set the normal misfire limit. In addition, this setting may be set in consideration of the water temperature detected by the water temperature sensor 534. Alternatively, instead of the target air-fuel ratio value, it may be set in consideration of the target fuel injection amount value in an operating state where fuel cut is not performed. A signal representing the set normal fire misfire limit is transmitted to the ignition timing setting unit 12.
  • a target air-fuel ratio value for example, the theoretical air-fuel ratio
  • the ignition timing setting unit 12 sets the ignition timing of each cylinder 101 so as not to exceed the normal misfire limit set by the misfire limit setting unit 11, and the ignition plug of each cylinder 101 is set to the set ignition timing. 110 is controlled to ignite. Further, the ignition timing setting unit 12 sets the ignition timing so as not to exceed the misfire limit retarded and advanced by the misfire limit retarding portion 16 and the misfire limit advancement portion 17, respectively.
  • the ignition timing setting unit 12 can control the torque in accordance with the ignition timing while suppressing the stop of the engine 100 due to a sudden drop in the rotation of the engine 100.
  • FIG. 3 shows the ignition timing on the horizontal axis and the torque of the engine 100 on the vertical axis.
  • the torque of the engine 100 can be increased by advancing the ignition timing, while the torque of the engine 100 is decreased by retarding the ignition timing to the “misfire limit” in FIG. Can do.
  • the ignition timing setting unit 12 is apparent from the four stroke cycles shown in FIG. 4, that is, from the “compression”, “expansion”, “exhaust”, and “intake” cycles of the four cylinders 101 “Cylinder 1” to “Cylinder 4”.
  • ignition timings T42, T43, and T44 in FIG. 4 indicate ignition timings of “Cylinder 2”, “Cylinder 3”, and “Cylinder 4”, respectively.
  • the fuel cut determination unit 13 determines whether or not the engine 100 has transitioned to the fuel cut state from the normal time, and transmits a signal representing the determination result to the fuel cut duration measuring unit 14. Specifically, the fuel cut determination unit 13 determines whether or not the fuel cut state has been made from the normal time by the processing unit that controls the injector 108 inside the ECU 500.
  • the fuel cut determination unit 13 may function as a processing unit for controlling the injector 108 in this case. In this case, the fuel cut determination unit 13 switches from the normal time to the fuel cut based on the accelerator opening, the rotational speed of the engine 100, and the like. It is determined whether or not transition is possible.
  • the fuel cut duration timer 14 measures the duration of the fuel cut based on the determination result from the fuel cut determiner 13 and transmits a signal representing the duration to the misfire limit retarder 16.
  • the storage unit 15 is a storage unit that stores information related to the state of the engine 100 that changes due to the continuation of the fuel cut.
  • the storage unit 15 includes a replacement time storage unit 151 and a retard amount storage unit 152.
  • the replacement time storage unit 151 stores a replacement time until the residual gas in the combustion chamber of the internal combustion engine, that is, the cylinder 101 before the start of the fuel cut is replaced with fresh air after the start of the fuel cut.
  • the retard amount storage unit 152 delays from a misfire limit corresponding to the internal state of the cylinder 101 in an operation state where fuel cut is not performed to a misfire limit corresponding to the internal state of the cylinder 101 in which the residual gas is replaced with fresh air. Retardation information indicating the amount of retarding angle is stored.
  • the “operating state in which fuel cut is not performed” refers to the operation of the engine detected using various sensors regardless of whether the fuel cut is on because the fuel cut on condition is satisfied.
  • the driving states of the vehicle including the state on / off of the fuel cut means an operating state that is turned off.
  • the “operating state in which fuel cut is not performed” includes an operating state in which fuel cut is not performed (see paragraph [0032], also referred to as normal time).
  • the operation state assuming that the fuel cut is not performed (off) is “perform fuel cut. No operating state ".
  • the fuel cut-on condition is the accelerator off and the engine speed is a predetermined value or more
  • the accelerator opening as the vehicle operating state is the accelerator off
  • the engine rotation is the engine operating state.
  • the engine operating state is detected using various sensors, that is, for example, using an air flow meter 526
  • the detected air amount and the engine speed detected using the engine speed sensor 536 are detected using various sensors, that is, for example, using an air flow meter 526
  • the engine speed sensor 536 On the basis of the detected air amount and the engine speed detected using the engine speed sensor 536 (in addition, for example, according to the air amount at that time so as to satisfy the target air-fuel ratio.
  • FIG. 5 is a graph showing the amount of air on the horizontal axis and the misfire limit on which the retard and advance are possible on the vertical axis.
  • the misfire limit is retarded by the retard amount of the arrow A in FIG.
  • the second reason is that the residual air is replaced with fresh air as described above, so that the actual air amount RA after the fuel cut continues for a predetermined time or longer as shown in FIG. 5 does not perform the fuel cut.
  • the retard limit is retarded by the retard amount of the arrow B in FIG.
  • the misfire limit retarding portion 16 determines that the inside of the cylinder 101 has been replaced with fresh air as shown in FIG. Is delayed by a predetermined amount, and a signal indicating the retarded misfire limit is transmitted to the ignition timing setting unit 12. Thus, by retarding the misfire limit by a predetermined amount, the ignition timing can be further retarded to keep the torque of the engine 100 low.
  • the retard limit advance portion 17 advances the misfire limit stepwise so that it returns to a predetermined amount when the fuel cut ends after the misfire limit retard portion 16 retards the misfire limit. To do. Specifically, when the fuel cut is completed based on the determination result from the fuel cut determination unit 13, the retard limit advance portion 17 is fixed by a certain amount every time a total of four cylinders 101 burn once. The misfire limit is advanced so as to return to the normal misfire limit at a rate of. For example, when the retard amount by the misfire limit retard portion 16 is 1, the retard limit advance portion 17 advances the misfire limit so as to return to the normal misfire limit at a rate of 0.3.
  • FIG. 6 and FIG. 7 are used for processing in which the ignition timing control device 1a controls the misfire limit depending on whether or not there is a fuel cut. I will explain.
  • the fuel cut bit is data representing the determination result of the fuel cut determination unit 13 and indicates “false” in a normal time and “true” in a fuel cut state.
  • the fuel cut counter is data used by the fuel cut duration measuring unit 14 to keep time, and its initial value is zero.
  • the post-return counter is data used to set the timing at which the misfire limit advance portion 17 advances the misfire limit, and the initial value is zero.
  • the retardation coefficient is the retardation ratio of the misfire limit with respect to the normal time, and the initial value is zero.
  • step S601 the fuel cut duration measuring unit 14 reads the fuel cut bit and proceeds to step S602.
  • step S602 the fuel cut duration measuring unit 14 determines whether or not the fuel cut bit is true. If the fuel cut bit is true, i.e., if it is in a fuel cut state (S602: Yes), the process proceeds to step S603. When it is normal time (S602: No), it progresses to step S604.
  • step S603 the fuel cut duration measuring unit 14 increments the fuel cut counter, that is, increments the counter value by 1, and proceeds to step S605.
  • step S604 the ignition timing control device 1a sets all of the fuel cut counter, the post-return counter, and the retardation coefficient to 0, and ends the process shown in FIG.
  • step S605 the misfire limit retardation unit 16 determines whether or not the fuel cut counter is equal to or greater than a set value. If the fuel cut counter is less than the set value (S605: No), it is determined that the fuel cut duration has not passed the replacement time stored in the replacement time storage unit 151, and the process proceeds to step S606. On the other hand, if the fuel cut counter is greater than or equal to the set value (S605: Yes), the process proceeds to step S607 assuming that the fuel cut duration has passed the replacement time stored in the replacement time storage unit 151.
  • step S606 the misfire limit retardation unit 16 sets the retardation coefficient to 0, that is, the retardation amount to 0, and returns to step S602.
  • step S607 the misfire limit retardation unit 16 sets the retardation coefficient to 1.
  • the fuel cut duration measuring unit 14 returns the fuel cut counter to 0, which is an initial value. Thereafter, the process proceeds to step S608.
  • step S608 the misfire limit retard portion 16 and the misfire limit advance portion 17 retard and advance the misfire limit according to the following equation (1), and the misfire limit advance portion 17 sets the counter after returning to 0.
  • the process proceeds to step S609.
  • Misfire limit normal misfire limit + set retard amount x retard angle coefficient (1)
  • the normal misfire limit is a misfire limit set by the misfire limit setting unit 11.
  • the set retard amount is the retard amount stored in the retard amount storage unit 152.
  • step S609 the fuel cut duration measuring unit 14 determines whether or not the fuel cut counter is equal to or smaller than the set value. If the fuel cut counter is equal to or smaller than the set value (S609: Yes), the process proceeds to step S610. If exceeded (S609: No), the process returns to step S607. In this step, when the fuel cut is continued beyond the replacement time, the process simply returns to step S607 by increasing the fuel cut counter.
  • step S609 when the fuel cut is resumed after returning from the fuel cut to the normal time in steps S610 to S615 to be described later and the flow returns to step S609, the resumption time of the resumed fuel cut has not passed the replacement time ( (S609: Yes) The process proceeds to step S610, and when the resumption time of the restarted fuel cut exceeds the replacement time (S609: No), the misfire limit is retarded again by returning to step S607.
  • step S610 the fuel cut duration measuring unit 14 determines whether or not the fuel cut bit is false, and if false, that is, if the fuel cut returns to normal time (S610: Yes), the process proceeds to step S611, and true. That is, when the fuel cut is continued (S610: No), the process proceeds to step S612.
  • step S611 the misfire limit advancement unit 17 determines whether or not the retardation coefficient exceeds 0. If the retardation coefficient exceeds 0 (S611: Yes), the process proceeds to step S613. If the angle coefficient does not exceed 0 (S611: No), the process proceeds to step S604. On the other hand, in step S612, the fuel cut duration measuring unit 14 increments the fuel cut counter, that is, increments the value of the counter by 1, and returns to step S609. By incrementing the fuel cut counter in step S612, it is possible to measure the duration of the fuel cut resumed after returning to the normal time.
  • step S613 the misfire limit advancement unit 17 increments the counter after returning, that is, increments the counter value by 1, and proceeds to step S614.
  • step S614 the misfire limit advancement unit 17 determines whether or not a condition that the counter after return is equal to the number of cylinders 101, that is, 4 is satisfied. If the condition is satisfied (S614: Yes), step S615 is performed. If the condition is not satisfied (S614: No), the process returns to step S613.
  • step S615 the misfire limit advancement unit 17 sets a retardation coefficient by the following equation (2), and returns to step S608.
  • Delay angle coefficient max (0, delay angle coefficient-return ratio) (2) Assuming that max (x, y), the function is a function that outputs a larger value of x and y.
  • the misfire limit advancement portion 17 changes the delay angle coefficient from 1 to 0.7 ⁇ 0.4 ⁇ as long as the fuel cut bit is false.
  • the misfire limit can be advanced stepwise and returned to the normal misfire limit.
  • FIG. 7 shows an example of a timing chart when the processing shown in FIG. 6 is executed.
  • the fuel cut counter increases.
  • the misfire limit is retarded.
  • the value of the counter after return changes, and the misfire limit advances at timings T74, T75, and T76 and returns to the normal misfire limit.
  • the ignition timing control device 1a retards the misfire limit by a predetermined amount compared to the normal time when the duration of the fuel cut has passed a predetermined time, After that, when the fuel cut is completed, the misfire limit is advanced step by step so as to return before the predetermined amount is retarded.
  • the misfire limit is advanced step by step so as to return before the predetermined amount is retarded.
  • the ignition timing control device 1a delays the misfire limit based on the replacement time stored in the replacement time storage unit 151, thereby accurately grasping the point in time when the inside of the cylinder 101 is replaced with fresh air.
  • the limit can be retarded and the torque can be reduced.
  • the ignition timing control device 1a can retard the misfire limit reliably while suppressing the occurrence of misfire by retarding the misfire limit using the retard amount stored in the retard amount storage unit 152. Can do.
  • the ignition timing control device 1b includes a misfire limit setting unit 11, an ignition timing setting unit 12, a fuel cut determination unit 13, a fuel cut duration measuring unit 14, a storage unit 15, and a misfire.
  • a limit retarding portion 16, a misfire limit advancement portion 17, and a replacement time estimating portion 18 are provided.
  • the configurations of the misfire limit retarding portion 16 and the replacement time estimating portion 18 are different from those of the first embodiment, and other configurations are the same as those of the first embodiment. For this reason, below, it explains paying attention and explains the composition of misfire limit retarding part 16 and exchange time estimating part 18, and omits explanation about other composition.
  • the replacement time estimation unit 18 estimates a replacement time in which residual gas before the start of fuel cut is replaced with fresh air after the start of fuel cut in the cylinder 101. . Specifically, the replacement time estimation unit 18 estimates the replacement time with high accuracy by increasing or decreasing the replacement time stored in the replacement time storage unit 151 based on information from various sensors.
  • the replacement time estimation unit 18 estimates the replacement time as follows. That is, when the rotational speed at the start of the fuel cut is equal to or greater than the predetermined number, it is assumed that the replacement from the residual gas to the fresh air is faster than when the rotational speed is less than the predetermined number, and the replacement time storage unit 151 A predetermined time is subtracted from the stored replacement time, and a signal represented as replacement estimated time is transmitted to the misfire limit retarding portion 16.
  • the replacement time estimation unit 18 estimates the replacement time as follows. In other words, when the amount of air at the start of the fuel cut or during the fuel cut is less than the predetermined amount, it is assumed that the replacement from the residual gas to the fresh air is slower than when the air amount is the predetermined amount or more, and the replacement time A fixed time is added from the replacement time stored in the storage unit 151, and a signal expressed as the replacement estimated time is transmitted to the misfire limit retarding unit 16.
  • the estimated replacement time may be calculated based on detection information from various sensors such as the temperature sensor 530 and the water temperature sensor 534, for example, not limited to the rotational speed and air-fuel ratio of the engine 100 as described above.
  • the misfire limit retarding portion 16 retards the set delay amount from the normal misfire limit when the fuel cut duration has passed the estimated replacement time estimated by the replacement time estimating portion 18.
  • the ignition timing control device 1b takes the time during which the residual gas in the cylinder 101 is replaced with fresh air in consideration of the state of the entire engine control system 10 at the start of fuel cut. Can be estimated with high accuracy.
  • the ignition timing control device 1b can accurately grasp the point in time when the inside of the cylinder 101 is replaced with fresh air based on the estimated replacement time, and can retard the misfire limit and reduce the torque.
  • a port injection type engine has been described as an example, but the present invention is not limited to this.
  • an injector is directly inserted into a cylinder. It may be a direct injection type engine installed.
  • the present invention is not limited to a type using an electric throttle.
  • a mechanical throttle valve may be used, or a mechanical throttle valve, an idling control bypass pipe and a bypass pipe provided therein may be provided. It may have an electric or mechanical valve.
  • the present invention is not limited to a type using an air flow meter, and may be a type that calculates the amount of air to be inhaled based on the pressure in the intake pipe detected by an intake pipe pressure sensor, for example. is there.

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

Abstract

Provided are an ignition timing control device for an engine and an ignition timing control method for an engine with which stopping of the engine can be reliably avoided, and the torque difference occurring when recovering from a fuel cut can be minimized. The ignition timing control device (1a) for an engine (100) controls the ignition timing of the engine (100) so as not to exceed a misfire limit. The ignition timing control device is equipped with: a duration measurement unit (14) that measures the duration of a fuel cut in the engine (100); a misfire limit retarded angle unit (16) that moves the misfire limit by a prescribed amount to the retarded-angle side when the duration measured by the duration measurement unit (14) exceeds a prescribed amount of time; and a misfire limit advanced angle unit (17) that, after the misfire limit has been moved to the retarded-angle side and the fuel cut has ended, gradually moves the misfire limit to the advanced-angle side so as to return to the value prior to the movement by the prescribed amount to the retarded-angle side.

Description

内燃機関の点火時期制御装置、及び内燃機関の点火時期制御方法Ignition timing control device for internal combustion engine and ignition timing control method for internal combustion engine
　本発明は、ガソリンエンジンなどの内燃機関の点火時期を、失火限界を超えないように制御する内燃機関の点火時期制御装置及びその点火時期制御方法に関する。 The present invention relates to an ignition timing control device for an internal combustion engine that controls the ignition timing of an internal combustion engine such as a gasoline engine so as not to exceed a misfire limit, and an ignition timing control method thereof.
　ガソリンエンジンなどの内燃機関において、燃料カットからの復帰時には、その他の場合より多くの燃料を噴射することが必要な場合がある。このような必要性の主な理由の一つは、まず、燃料カットからの復帰時には、内燃機関の燃焼室壁面に付着した燃料が、また、ポート噴射式エンジンではこれに加えて吸気バルブ表面に付着した燃料が、燃料カットによって無くなることを考慮して、それを補うべきであることである。また、もう一つの理由は、燃料カットからの復帰時には、シリンダー内の残留ガスが新気になることにより、燃料量を変えないと失火する虞があることである。 In an internal combustion engine such as a gasoline engine, when returning from a fuel cut, it may be necessary to inject more fuel than in other cases. One of the main reasons for this necessity is that, at the time of return from fuel cut, the fuel adhering to the combustion chamber wall surface of the internal combustion engine is added to the surface of the intake valve in addition to this on the port injection engine. In consideration of the fact that the adhering fuel is lost by the fuel cut, it should be compensated. Another reason is that when returning from the fuel cut, the residual gas in the cylinder becomes fresh, and there is a risk of misfire unless the fuel amount is changed.
　しかしながら、一方、燃料カットからの復帰時に燃料の再噴射が始まると、エンジン出力が急に立ち上がる現象が起こる。この現象は、ショックの発生につながり、運転者や同乗者の快適性を損なうという問題が生じる。 However, on the other hand, when fuel re-injection starts when returning from a fuel cut, a phenomenon occurs in which the engine output suddenly rises. This phenomenon leads to the occurrence of a shock and causes a problem that the comfort of the driver and passengers is impaired.
　このようなショックの発生の問題に対しては、トルク段差を少なくすることで、ショックを改善することができる。例えば、燃料カット復帰時に燃焼室内の空気量を少なくしたり、燃料を薄くしたりすることで、トルク段差を少なくすることができる。しかし、燃料カット復帰時に運転手がブレーキを踏む等で急激にエンジンの回転が落ちると、応答遅れによって空気量と燃料を増やすことができず、エンジンの停止を十分に抑制することができない。つまり、急激に回転数の低下によるエンジンの停止を防止するために空気量や燃料量で対応しようとしても、タイミングによっては吸気と圧縮とを要するため、１回転分の応答が遅れてしまう。このような応答の遅れによって、エンジンの停止を防止できない場合がある。 ¡Such a shock problem can be improved by reducing the torque step. For example, the torque level difference can be reduced by reducing the amount of air in the combustion chamber or reducing the fuel when returning to fuel cut. However, if the engine suddenly falls due to the driver stepping on the brake when returning to fuel cut, the air amount and fuel cannot be increased due to a response delay, and the engine stop cannot be sufficiently suppressed. That is, even if an attempt is made to cope with the amount of air or fuel in order to prevent the engine from being stopped due to a sudden decrease in the number of revolutions, depending on the timing, intake and compression are required, so the response for one rotation is delayed. Such a delay in response may not prevent the engine from stopping.
　また、トルク段差を少なくするため、例えば特許文献１には、燃料カット復帰時に一時的に点火時期を遅角することが記載されている。このような点火時期の一時的な遅角により、急な回転落ちが発生しても即座に点火時期を早めることでエンジンの停止を防止することもできる。 In order to reduce the torque step, for example, Patent Document 1 describes that the ignition timing is temporarily retarded when the fuel cut is restored. Due to such a temporary retardation of the ignition timing, it is possible to prevent the engine from being stopped by immediately advancing the ignition timing even if a sudden drop in rotation occurs.
特開２０１３－２１７２７１号公報JP 2013-217271 A
　上記の通り、燃料カット復帰時に点火時期を遅角することで、燃料カットからの復帰に伴う燃料噴射量の増量の必要がある場合にはそれに応えつつ、トルク段差を少なくすることと、急激な回転数の低下に起因したエンジンの停止を防止することとを両立することができる。しかしながら、エンジンの点火時期については、失火を防止可能な遅角限界が予め決められている。つまり、点火時期を遅角可能な失火限界が予め決められているため、燃料カット復帰時において、快適性を失わない程度に十分にトルク段差を少なくすることができなかった。 As described above, by retarding the ignition timing at the time of fuel cut return, if there is a need to increase the fuel injection amount accompanying the return from the fuel cut, while responding to it, reducing the torque step, It is possible to achieve both preventing the engine from being stopped due to the decrease in the rotational speed. However, as for the ignition timing of the engine, a retard limit that can prevent misfire is determined in advance. That is, since a misfire limit that can retard the ignition timing is determined in advance, the torque step cannot be reduced sufficiently to the extent that comfort is not lost when the fuel cut is restored.
　本発明は、上述した課題に鑑みてなされたものであり、内燃機関の停止を確実に回避しつつ、燃料カット復帰時に生じるトルク段差を少なくすることが可能な内燃機関の点火時期制御装置、及びその点火時期制御方法を提供することを目的とする。 The present invention has been made in view of the above-described problems, and an ignition timing control device for an internal combustion engine capable of reducing a torque step generated when fuel cut is restored while reliably avoiding a stop of the internal combustion engine, and An object is to provide a method for controlling the ignition timing.
　上述した従来の課題を解決するため、本発明は、以下の手段を有する。 In order to solve the conventional problems described above, the present invention has the following means.
　（１）本発明に係る内燃機関の点火時期制御装置は、内燃機関の点火時期を、失火限界を超えないように制御する内燃機関の点火時期制御装置であって、内燃機関が燃料カットを継続する継続時間を計時する計時部と、計時した継続時間が所定時間を経過した場合に、失火限界を所定量遅角する失火限界遅角部と、失火限界を遅角した後に燃料カットが終了した場合に、所定量遅角する前に戻るように、失火限界を段階的に進角する失火限界進角部と、を備えることを特徴とする。 (1) An ignition timing control device for an internal combustion engine according to the present invention is an ignition timing control device for an internal combustion engine that controls the ignition timing of the internal combustion engine so as not to exceed a misfire limit, and the internal combustion engine continues to cut fuel. A time-counting unit that counts the continuous duration, a misfire limit-retarding unit that retards the misfire limit by a predetermined amount when the measured duration has passed a predetermined time, and a fuel cut is completed after retarding the misfire limit And a misfire limit advancement part for advancing the misfire limit stepwise so as to return before delaying by a predetermined amount.
　本発明において、内燃機関が燃料カットを継続する継続時間が所定時間を経過した場合には、主に２つの理由から、燃料カットを行わない動作状態に比べて失火限界を遅角することができる。つまり、第１の理由としては、所定時間以上の燃料カットが継続すると、内燃機関の燃焼室（シリンダー）内の残留ガスが新気に入れ替わるため、新気への入れ替わりが無い状態に比べて燃料混合後の混合気が燃焼しやすいためである。また、第２の理由としては、上述の通り残留ガスが新気に入れ替わることで、所定時間以上の燃料カット継続後の実空気量が、燃料カットを行わない動作状態に各種センサを用いて認識可能な空気量に比べて多くなるためである。 In the present invention, when the continuation time during which the internal combustion engine continues the fuel cut has passed a predetermined time, the misfire limit can be retarded compared to the operation state in which the fuel cut is not performed mainly for two reasons. . That is, as a first reason, if the fuel cut for a predetermined time or longer continues, the residual gas in the combustion chamber (cylinder) of the internal combustion engine is replaced with fresh air, so that the fuel is compared with the state where there is no replacement with fresh air. This is because the air-fuel mixture after mixing is easy to burn. The second reason is that the residual air is replaced with fresh air as described above, so that the actual air amount after continuing the fuel cut for a predetermined time or more is recognized using various sensors in the operating state in which the fuel cut is not performed. This is because it becomes larger than the possible air volume.
　本発明によれば、上記第１及び第２の理由に基づき、燃料カットを行わない動作状態に比べて失火限界を所定量遅角し、その後燃料カットが終了すると所定量遅角する前に戻るように、失火限界を段階的に進角する。このように失火限界を遅角及び進角することにより、エンジンの停止を確実に回避しつつ、燃料カット復帰時に生じるトルク段差を少なくすることができる。 According to the present invention, based on the first and second reasons, the misfire limit is retarded by a predetermined amount as compared with the operation state in which the fuel cut is not performed, and then returns to the state before the predetermined amount is retarded when the fuel cut ends. Like, advance the misfire limit step by step. Thus, by retarding and advancing the misfire limit, it is possible to reduce the torque level difference that occurs at the time of return from fuel cut while reliably avoiding engine stoppage.
　（２）また、本発明に係る内燃機関の点火時期制御装置において、内燃機関の燃焼室内における燃料カット開始前の残留ガスが燃料カット開始後に新気に入れ替わるまでの入替時間を記憶した入替時間記憶部を、更に備え、失火限界遅角部は、計時した継続時間が入替時間を経過した場合に、失火限界を遅角することが好ましい。 (2) Further, in the ignition timing control device for an internal combustion engine according to the present invention, a replacement time memory that stores a replacement time until the residual gas in the combustion chamber of the internal combustion engine before the fuel cut starts is replaced with fresh air after the fuel cut starts. The misfire limit retarding portion preferably retards the misfire limit when the timed duration has passed the replacement time.
　（３）また、本発明に係る内燃機関の点火時期制御装置において、内燃機関に取り付けられたセンサからの情報に基づいて、内燃機関の燃焼室内において、燃料カット開始前の残留ガスが燃料カット開始後に新気に入れ替わる入替時間を推測する排気時間推測部を、更に備え、失火限界遅角部は、計時した継続時間が入替時間を経過した場合に、失火限界を遅角することが好ましい。 (3) In the ignition timing control device for an internal combustion engine according to the present invention, the residual gas before the start of the fuel cut is started in the combustion chamber of the internal combustion engine based on information from a sensor attached to the internal combustion engine. It is preferable that an exhaust time estimation unit for estimating a replacement time for replacement with fresh air is further provided, and the misfire limit retarding unit retards the misfire limit when the measured duration has passed the replacement time.
　（４）また、本発明に係る内燃機関の点火時期制御装置において、燃料カットを行わない動作状態に対応した失火限界から、燃料カット開始前の残留ガスが新気に置き換わった状態に対応した失火限界まで遅角する遅角量を示す遅角情報を記憶した遅角情報記憶部を更に備え、失火限界遅角部は、計時した継続時間が所定時間を経過した場合に、遅角情報で示される遅角量で、失火限界を遅角することが好ましい。 (4) Further, in the ignition timing control device for an internal combustion engine according to the present invention, a misfire corresponding to a state in which the residual gas before the start of the fuel cut is replaced with fresh air from a misfire limit corresponding to an operating state in which the fuel cut is not performed. Further provided is a retard information storage unit that stores retard information indicating a retard amount that is retarded to the limit, and the misfire limit retard unit is indicated by the retard information when the measured duration has exceeded a predetermined time. It is preferable to retard the misfire limit with a retarded amount.
　以上のような本発明は、内燃機関の点火時期制御方法として捉えることも可能である。 The present invention as described above can also be understood as an ignition timing control method for an internal combustion engine.
　本発明によれば、エンジンの停止を確実に回避しつつ、燃料カット復帰時に生じるトルク段差を少なくすることができる。 According to the present invention, it is possible to reduce the torque level difference that occurs when the fuel cut is restored while reliably avoiding the engine stop.
本発明を適用した点火時期制御装置が組み込まれたエンジン制御系の具体例について説明するための図である。It is a figure for demonstrating the specific example of the engine control system in which the ignition timing control apparatus to which this invention is applied was incorporated. 第１の実施形態に係る点火時期制御装置について説明するための図である。It is a figure for demonstrating the ignition timing control apparatus which concerns on 1st Embodiment. 点火時期とエンジンのトルクとの関係を説明するための図である。It is a figure for demonstrating the relationship between an ignition timing and the torque of an engine. ４ストロークサイクルの点火時期について説明するための図である。It is a figure for demonstrating the ignition timing of a 4-stroke cycle. 空気量と失火限界との関係を説明するための図である。It is a figure for demonstrating the relationship between the air quantity and a misfire limit. 燃料カットの有無に応じて失火限界を制御する処理について説明するための図である。It is a figure for demonstrating the process which controls a misfire limit according to the presence or absence of a fuel cut. 燃料カットの有無に応じて失火限界を制御したときのタイミングチャートの一例を示す図である。It is a figure which shows an example of a timing chart when the misfire limit is controlled according to the presence or absence of a fuel cut. 第２の実施形態に係る点火時期制御装置について説明するための図である。It is a figure for demonstrating the ignition timing control apparatus which concerns on 2nd Embodiment.
　本発明を実施するための形態（以下、本実施形態という。）について具体例を示して説明する。本実施形態は、ガソリンエンジンなどの内燃機関の点火時期を、失火限界を超えないように制御する内燃機関の点火時期制御装置に関する。具体的に、当該点火時期制御装置は、例えば図１に示すようなエンジン１００を制御するエンジンコントロールユニット５００（以下、ＥＣＵ５００という。）に組み込まれるものである。なお、本実施形態においては、一例として、ポート噴射タイプのエンジンを例に挙げて説明する。以下では、点火時期制御装置の説明に先立ち、エンジン１００とＥＣＵ５００とから構成されるエンジン制御系１０について説明する。 A mode for carrying out the present invention (hereinafter referred to as the present embodiment) will be described with a specific example. The present embodiment relates to an ignition timing control device for an internal combustion engine that controls the ignition timing of an internal combustion engine such as a gasoline engine so as not to exceed a misfire limit. Specifically, the ignition timing control device is incorporated in an engine control unit 500 (hereinafter referred to as ECU 500) for controlling the engine 100 as shown in FIG. In the present embodiment, a port injection type engine will be described as an example. Hereinafter, the engine control system 10 including the engine 100 and the ECU 500 will be described prior to the description of the ignition timing control device.
　１．エンジン制御系１０
　エンジン制御系１０は、例えば図１に示すように、エンジン１００、エアクリーナ１０２と、吸気管１０４、インテークマニホールド１０６、インジェクタ１０８、点火プラグ１１０、エギゾーストマニホールド１１２、及び触媒１１４から構成される。 1. Engine control system 10
For example, as shown in FIG. 1, the engine control system 10 includes an engine 100, an air cleaner 102, an intake pipe 104, an intake manifold 106, an injector 108, a spark plug 110, an exhaust manifold 112, and a catalyst 114.
　エンジン１００は、本発明に係る内燃機関の一態様であって、例えば図１に示すように合計４つのシリンダー１０１から構成された４気筒ガソリンエンジンである。なお、エンジン１００の気筒数は４以外であってもよい。 Engine 100 is an aspect of an internal combustion engine according to the present invention, and is, for example, a four-cylinder gasoline engine including a total of four cylinders 101 as shown in FIG. The number of cylinders of engine 100 may be other than four.
　エアクリーナ１０２は、車外から吸気した空気をろ過することにより、粉塵などを分離した清浄な空気を吸気管１０４側に供給する。また、エアクリーナ１０２には、吸気管１０４との接続部側に、エアフローメータ５２６が設けられている。エアフローメータ５２６は、エアクリーナ１０２から吸気管１０４側に吸気される空気量を検出し、検出結果を示す信号をＥＣＵ５００に送信する。 The air cleaner 102 supplies clean air from which dust and the like have been separated to the intake pipe 104 side by filtering air taken from outside the vehicle. The air cleaner 102 is provided with an air flow meter 526 on the side connected to the intake pipe 104. Air flow meter 526 detects the amount of air taken from air cleaner 102 toward intake pipe 104 and transmits a signal indicating the detection result to ECU 500.
　吸気管１０４は、エアクリーナ１０２から供給される空気をインテークマニホールド１０６に導く管路である。吸気管１０４には、その管内にスロットルバルブ１１６が設けられている。スロットルバルブ１１６は、例えば、バルブの開度がＥＣＵ５００により制御可能な電子制御式バルブであって、インテークマニホールド１０６を介してシリンダー１０１に導入する空気量を制御する。 The intake pipe 104 is a pipe that guides the air supplied from the air cleaner 102 to the intake manifold 106. The intake pipe 104 is provided with a throttle valve 116 in the pipe. The throttle valve 116 is an electronically controlled valve whose opening degree can be controlled by the ECU 500, for example, and controls the amount of air introduced into the cylinder 101 via the intake manifold 106.
　インテークマニホールド１０６は、吸気管１０４から導かれた空気を４つのシリンダー１０１に導入するための多岐管である。 The intake manifold 106 is a manifold for introducing the air guided from the intake pipe 104 into the four cylinders 101.
　インジェクタ１０８は、各シリンダー１０１に臨まれるようにインテークマニホールド１０６に設置されており、各シリンダー１０１にガソリン燃料を噴射する。燃料を噴射するタイミング及び噴射量は、ＥＣＵ５００により制御される。 The injector 108 is installed in the intake manifold 106 so as to face each cylinder 101, and injects gasoline fuel into each cylinder 101. The timing and amount of fuel injection are controlled by the ECU 500.
　点火プラグ１１０は、各シリンダー１０１内部に設けられ、インテークマニホールド１０６から導入された空気と、インジェクタ１０８により噴射された燃料との混合気を点火する。点火した混合気が燃焼によって膨張することで駆動力が発生する。燃焼後の混合気、すなわち排気ガスは、エギゾーストマニホールド１１２に導かれる。 The ignition plug 110 is provided inside each cylinder 101 and ignites a mixture of air introduced from the intake manifold 106 and fuel injected by the injector 108. The ignited air-fuel mixture expands by combustion to generate driving force. The air-fuel mixture after combustion, that is, exhaust gas, is guided to the exhaust manifold 112.
　また、混合気の燃焼によるエンジン１００の動作状態をＥＣＵ５００が認識するため、エンジン１００には、水温センサ５３４と回転数センサ５３６とが設けられている。水温センサ５３４は、エンジン１００を冷却する冷却水の温度を検出し、検出結果をＥＣＵ５００に送信する。また、回転数センサ５３６は、エンジン５００の回転数を検出し、検出結果をＥＣＵ５００に送信する。 Further, in order for the ECU 500 to recognize the operation state of the engine 100 due to the combustion of the air-fuel mixture, the engine 100 is provided with a water temperature sensor 534 and a rotation speed sensor 536. Water temperature sensor 534 detects the temperature of the cooling water that cools engine 100 and transmits the detection result to ECU 500. Further, rotation speed sensor 536 detects the rotation speed of engine 500 and transmits the detection result to ECU 500.
　エギゾーストマニホールド１１２は、４つのシリンダー１０１から排出される排気ガスの排気流路を１つにまとめる多岐管であって、１つの排気流路にまとめられた排気ガスを触媒１１４に導く。また、エギゾーストマニホールド１１２には、排出ガス中の酸素濃度、つまり空燃比率を検出する空燃比センサ５３２が設けられている。空燃比センサ５３２は、検出結果を表す信号をＥＣＵ５００に送信する。 The exhaust manifold 112 is a manifold that combines the exhaust passages of the exhaust gas discharged from the four cylinders 101 into one, and guides the exhaust gas gathered in one exhaust passage to the catalyst 114. Further, the exhaust manifold 112 is provided with an air-fuel ratio sensor 532 for detecting the oxygen concentration in the exhaust gas, that is, the air-fuel ratio. Air-fuel ratio sensor 532 transmits a signal representing the detection result to ECU 500.
　ＥＣＵ５００は、プロセッサ、ＲＯＭ、及びＲＡＭなどの汎用的なコンピュータに、エンジン制御系１０を制御する制御プログラムをインストールすることで、各種センサから送信される信号に基づいてエンジン制御系１０全体を制御する機能を実現する。具体的には、例えば、ＥＣＵ５００は、アクセル開度センサ５２８から送信されるアクセル開度に基づいて、スロットルバルブ１１６の開度、点火プラグ１１０による点火時期を決定することにより、エンジン１００のトルクを制御する。なお、アクセル開度センサ５２８は、例えばアクセルペダルに設けられ、アクセル開度を検出し、検出結果をＥＣＵ５００に送信する。 The ECU 500 installs a control program for controlling the engine control system 10 in a general-purpose computer such as a processor, a ROM, and a RAM, thereby controlling the entire engine control system 10 based on signals transmitted from various sensors. Realize the function. Specifically, for example, ECU 500 determines the torque of engine 100 by determining the opening of throttle valve 116 and the ignition timing by spark plug 110 based on the accelerator opening transmitted from accelerator opening sensor 528. Control. The accelerator opening sensor 528 is provided, for example, in an accelerator pedal, detects the accelerator opening, and transmits the detection result to the ECU 500.
　２．第１の実施形態に係る点火時期制御装置
　２－１．装置構成
　上記のＥＣＵ５００内部の機能として実現可能な、第１の実施形態に係る点火時期制御装置１ａについて図２を参照して説明する。 2. 2. Ignition timing control device according to first embodiment 2-1. Device Configuration An ignition timing control device 1a according to the first embodiment, which can be realized as a function inside the ECU 500, will be described with reference to FIG.
　点火時期制御装置１ａは、図２に示すように、失火限界設定部１１と、点火時期設定部１２と、燃料カット判断部１３と、燃料カット継続時間計時部１４と、記憶部１５と、失火限界遅角部１６と、失火限界進角部１７と、を備える。 As shown in FIG. 2, the ignition timing control device 1a includes a misfire limit setting unit 11, an ignition timing setting unit 12, a fuel cut determination unit 13, a fuel cut duration measuring unit 14, a storage unit 15, and a misfire. A limit retardation portion 16 and a misfire limit advancement portion 17 are provided.
　失火限界設定部１１は、燃料カットを行っていない動作状態（以下では、通常時ともいう。）において、点火時期の遅角限界である通常時の失火限界を設定する。失火限界設定部１１は、例えば、通常時においてエアフローメータ５２６で検出した空気量と、回転数センサ５３６で検出したエンジン１００の回転数とに基づき、さらに目標の空燃比の値（例えば理論空燃比を目標としているのならその値）を考慮して通常時の失火限界を設定する。この設定には、その他に、水温センサ５３４で検出した水温を考慮して設定したものであってもよい。あるいは、目標の空燃比の値のかわりに燃料カットを行っていない動作状態での目標の燃料噴射量の値を考慮して設定したものであってもよい。設定した通常時の失火限界を表す信号は、点火時期設定部１２に送信される。 The misfire limit setting unit 11 sets a normal misfire limit that is a retard limit of the ignition timing in an operating state where fuel cut is not performed (hereinafter also referred to as normal time). For example, the misfire limit setting unit 11 further sets a target air-fuel ratio value (for example, the theoretical air-fuel ratio) based on the air amount detected by the air flow meter 526 and the rotational speed of the engine 100 detected by the rotational speed sensor 536 during normal times. If the target is the value, set the normal misfire limit. In addition, this setting may be set in consideration of the water temperature detected by the water temperature sensor 534. Alternatively, instead of the target air-fuel ratio value, it may be set in consideration of the target fuel injection amount value in an operating state where fuel cut is not performed. A signal representing the set normal fire misfire limit is transmitted to the ignition timing setting unit 12.
　点火時期設定部１２は、失火限界設定部１１で設定された通常時の失火限界を超えないように、各シリンダー１０１の点火時期を設定して、設定した点火時期に、各シリンダー１０１の点火プラグ１１０が点火するように制御する。また、点火時期設定部１２は、失火限界遅角部１６及び失火限界進角部１７によりそれぞれ遅角及び進角された失火限界を超えないように、点火時期を設定する。 The ignition timing setting unit 12 sets the ignition timing of each cylinder 101 so as not to exceed the normal misfire limit set by the misfire limit setting unit 11, and the ignition plug of each cylinder 101 is set to the set ignition timing. 110 is controlled to ignite. Further, the ignition timing setting unit 12 sets the ignition timing so as not to exceed the misfire limit retarded and advanced by the misfire limit retarding portion 16 and the misfire limit advancement portion 17, respectively.
　また、点火時期設定部１２は、次の説明から明らかなように、急激なエンジン１００の回転落ちに起因したエンジン１００の停止を抑制しながら、点火時期に応じてトルクを制御することができる。 Further, as will be apparent from the following description, the ignition timing setting unit 12 can control the torque in accordance with the ignition timing while suppressing the stop of the engine 100 due to a sudden drop in the rotation of the engine 100.
　図３は、横軸に点火時期を示し、縦軸にエンジン１００のトルクを示した図である。図３に示すように、点火時期を進角することでエンジン１００のトルクを高めることができる一方、図３中の「失火限界」まで点火時期を遅角することでエンジン１００のトルクを下げることができる。また、点火時期設定部１２は、図４に示す４ストロークサイクル、つまり４つのシリンダー１０１「Ｃｙｌｉｎｄｅｒ１」～「Ｃｙｌｉｎｄｅｒ４」の「圧縮」、「膨張」、「排気」、「吸気」の各サイクルから明らかなように、Ｔ４０点で運転手のブレーキ操作により急激にエンジン１００の回転数が落ちても、その直後に点火するシリンダー１０１「Ｃｙｌｉｎｄｅｒ１」の点火時期Ｔ４１を進角することで、エンジン１００が停止することを抑制できる。なお、図４中の点火時期Ｔ４２、Ｔ４３、Ｔ４４は、それぞれ「Ｃｙｌｉｎｄｅｒ２」、「Ｃｙｌｉｎｄｅｒ３」、「Ｃｙｌｉｎｄｅｒ４」の点火時期を示している。 FIG. 3 shows the ignition timing on the horizontal axis and the torque of the engine 100 on the vertical axis. As shown in FIG. 3, the torque of the engine 100 can be increased by advancing the ignition timing, while the torque of the engine 100 is decreased by retarding the ignition timing to the “misfire limit” in FIG. Can do. Further, the ignition timing setting unit 12 is apparent from the four stroke cycles shown in FIG. 4, that is, from the “compression”, “expansion”, “exhaust”, and “intake” cycles of the four cylinders 101 “Cylinder 1” to “Cylinder 4”. In this way, even if the speed of the engine 100 suddenly drops due to the driver's brake operation at the point T40, the engine 100 is stopped by advancing the ignition timing T41 of the cylinder 101 “Cylinder 1” that is ignited immediately after that. Can be suppressed. Note that ignition timings T42, T43, and T44 in FIG. 4 indicate ignition timings of “Cylinder 2”, “Cylinder 3”, and “Cylinder 4”, respectively.
　燃料カット判断部１３は、エンジン１００が通常時から燃料カットの状態に遷移したか否かを判断し、判断結果を表す信号を燃料カット継続時間計時部１４に送信する。具体的には、燃料カット判断部１３は、ＥＣＵ５００内部でインジェクタ１０８を制御する処理部によって、通常時から燃料カットの状態をしたか否かを判断する。なお、燃料カット判断部１３は、それ自体がインジェクタ１０８を制御する処理部として機能してもよく、この場合には、アクセル開度、エンジン１００の回転数などに基づいて通常時から燃料カットに遷移可能か否かを判断する。 The fuel cut determination unit 13 determines whether or not the engine 100 has transitioned to the fuel cut state from the normal time, and transmits a signal representing the determination result to the fuel cut duration measuring unit 14. Specifically, the fuel cut determination unit 13 determines whether or not the fuel cut state has been made from the normal time by the processing unit that controls the injector 108 inside the ECU 500. The fuel cut determination unit 13 may function as a processing unit for controlling the injector 108 in this case. In this case, the fuel cut determination unit 13 switches from the normal time to the fuel cut based on the accelerator opening, the rotational speed of the engine 100, and the like. It is determined whether or not transition is possible.
　燃料カット継続時間計時部１４は、燃料カット判断部１３からの判断結果に基づいて、燃料カットを継続する継続時間を計時し、継続時間を表す信号を失火限界遅角部１６に送信する。 The fuel cut duration timer 14 measures the duration of the fuel cut based on the determination result from the fuel cut determiner 13 and transmits a signal representing the duration to the misfire limit retarder 16.
　記憶部１５は、燃料カットの継続により変化するエンジン１００の状態に関する情報を記憶する記憶部であって、具体的には、入替時間記憶部１５１と、遅角量記憶部１５２とから構成される。入替時間記憶部１５１は、内燃機関の燃焼室、つまりシリンダー１０１内における燃料カット開始前の残留ガスが燃料カット開始後に新気に入れ替わるまでの入替時間を記憶している。また、遅角量記憶部１５２は、燃料カットを行わない動作状態におけるシリンダー１０１の内部状態に対応した失火限界から、残留ガスが新気に置き換わったシリンダー１０１の内部状態に対応した失火限界まで遅角する遅角量を示す遅角情報を記憶している。 The storage unit 15 is a storage unit that stores information related to the state of the engine 100 that changes due to the continuation of the fuel cut. Specifically, the storage unit 15 includes a replacement time storage unit 151 and a retard amount storage unit 152. . The replacement time storage unit 151 stores a replacement time until the residual gas in the combustion chamber of the internal combustion engine, that is, the cylinder 101 before the start of the fuel cut is replaced with fresh air after the start of the fuel cut. Further, the retard amount storage unit 152 delays from a misfire limit corresponding to the internal state of the cylinder 101 in an operation state where fuel cut is not performed to a misfire limit corresponding to the internal state of the cylinder 101 in which the residual gas is replaced with fresh air. Retardation information indicating the amount of retarding angle is stored.
　本実施形態において、「燃料カットを行わない動作状態」とは、燃料カットｏｎ条件を満たしたために燃料カットがｏｎされているか否か、にはよらず、各種センサを用いて検出したエンジンの動作状態を含む車両の運転状態のうち、燃料カットのｏｎ／ｏｆｆについてはｏｆｆとされている動作状態を意味する。なお、「燃料カットを行わない動作状態」は、燃料カットを行っていない動作状態（段落［００３２］参照。通常時ともいう。）を含む。また、燃料カットｏｎ条件を満たしたために、エンジンの動作状態が燃料カット中であったとしても、燃料カットがされていない（ｏｆｆとされている）と想定した動作状態は、「燃料カットを行わない動作状態」とする。例えば、燃料カットｏｎ条件がアクセルオフかつエンジン回転数が所定の値以上の場合の例を説明すると、車両の運転状態としてのアクセル開度がアクセルオフであり、かつエンジンの動作状態としてのエンジン回転数が所定の値以上であるため、すなわち燃料カットｏｎ条件を満たしたために、エンジンの動作状態が燃料カット中であったとしても、各種センサを用いて検出した、すなわち、例えばエアフローメータ５２６を用いて検出した空気量とエンジン回転数センサ５３６を用いて検出したエンジン回転数に基づいて、（さらに例えば、目標空燃比を考慮して設定され、目標空燃比を満たすようその時の空気量に応じて）制御された量の燃料が噴射されており燃料カットがされていない（すなわちｏｆｆとされている）と想定した動作状態は、「燃料カットを行わない動作状態」とする。また、その他の方法の制御が行われている場合であっても、燃料カットが行われる期間の前あるいは後に行われるのと同じ制御方法であって、燃料カットすなわち燃料噴射を一時的に止める制御が行われてはいないと想定した動作状態は、「燃料カットを行わない動作状態」とする。 In the present embodiment, the “operating state in which fuel cut is not performed” refers to the operation of the engine detected using various sensors regardless of whether the fuel cut is on because the fuel cut on condition is satisfied. Among the driving states of the vehicle including the state, on / off of the fuel cut means an operating state that is turned off. The “operating state in which fuel cut is not performed” includes an operating state in which fuel cut is not performed (see paragraph [0032], also referred to as normal time). In addition, even if the engine operating state is during fuel cut because the fuel cut-on condition is satisfied, the operation state assuming that the fuel cut is not performed (off) is “perform fuel cut. No operating state ". For example, an example in which the fuel cut-on condition is the accelerator off and the engine speed is a predetermined value or more will be described. The accelerator opening as the vehicle operating state is the accelerator off, and the engine rotation is the engine operating state. Even if the engine operating state is during fuel cut because the number is equal to or greater than a predetermined value, that is, the fuel cut-on condition is satisfied, it is detected using various sensors, that is, for example, using an air flow meter 526 On the basis of the detected air amount and the engine speed detected using the engine speed sensor 536 (in addition, for example, according to the air amount at that time so as to satisfy the target air-fuel ratio. ) Motion assuming that a controlled amount of fuel has been injected and fuel cut has not been performed (ie off) State, and the "operation state that does not perform the fuel cut". Further, even when other methods are controlled, the control method is the same as that performed before or after the period during which the fuel cut is performed, and the fuel cut, that is, the control for temporarily stopping the fuel injection. The operation state that is assumed not to be performed is an “operation state in which fuel cut is not performed”.
　一般的に、燃料噴射量を減らすと、燃料と空気の混合気の燃焼しやすさが低くなり燃焼の伝播が遅くなるので、その場合にも失火させないためには、燃焼の伝播が遅い状況を補うべく早いタイミングで点火する、すなわち進角させる側の制御をすることになり、失火限界もどちらかといえば進角させる制御となる。このような一般的な手法に対して、本発明の発明者は鋭意努力し、記憶部１５に記憶された各種情報を利用することで、内燃機関が燃料カットを継続する継続時間が所定時間を経過した場合には通常時よりも失火限界を遅角できることを見出すに至った。このようにできる理由について、図５を用いて説明する。図５は、横軸に空気量を示し、縦軸に遅角及び進角可能な失火限界を示した図である。 In general, reducing the amount of fuel injected reduces the ease of combustion of the fuel / air mixture and slows the propagation of combustion. In order to compensate, ignition is performed at an early timing, that is, control is performed to advance, and the misfire limit is rather controlled to advance. With respect to such a general technique, the inventor of the present invention has made diligent efforts and uses various information stored in the storage unit 15 so that the duration time during which the internal combustion engine continues to cut the fuel has reached a predetermined time. When it has passed, it has been found that the misfire limit can be delayed more than usual. The reason why this is possible will be described with reference to FIG. FIG. 5 is a graph showing the amount of air on the horizontal axis and the misfire limit on which the retard and advance are possible on the vertical axis.
　まず、第１の理由としては、所定時間以上の燃料カットが継続すると、内燃機関の燃焼室（シリンダー）内の残留ガスが新気に入れ替わるため、この新気への入れ替わりの無い通常時に比べて燃料混合後の混合気が燃焼しやすくなるため、図５の矢印Ａの遅角量で失火限界が遅角する。また、第２の理由としては、上述の通り残留ガスが新気に入れ替わることで、図５に示すような、所定時間以上の燃料カット継続後の実空気量ＲＡが、燃料カットを行わない動作状態に、各種センサを用いて認識可能なＥＣＵ認識空気量ＳＡに比べて多くなるため、図５の矢印Ｂの遅角量で遅角限界が遅角する。 First, as a first reason, if the fuel cut for a predetermined time or more continues, the residual gas in the combustion chamber (cylinder) of the internal combustion engine is replaced with fresh air. Therefore, compared to the normal time when there is no replacement with fresh air. Since the air-fuel mixture after the fuel mixture is easily combusted, the misfire limit is retarded by the retard amount of the arrow A in FIG. The second reason is that the residual air is replaced with fresh air as described above, so that the actual air amount RA after the fuel cut continues for a predetermined time or longer as shown in FIG. 5 does not perform the fuel cut. In the state, since the amount of air is larger than the ECU recognized air amount SA that can be recognized using various sensors, the retard limit is retarded by the retard amount of the arrow B in FIG.
　失火限界遅角部１６は、計時した継続時間が所定時間を経過した場合には、図５で示したように、シリンダー１０１内部が新気に入れ替わったものと判断して、通常時から失火限界を所定量遅角し、遅角した失火限界を表す信号を点火時期設定部１２に送信する。このように失火限界を所定量遅角することによって、点火時期を更に遅角してエンジン１００のトルクを低く抑えることができる。 The misfire limit retarding portion 16 determines that the inside of the cylinder 101 has been replaced with fresh air as shown in FIG. Is delayed by a predetermined amount, and a signal indicating the retarded misfire limit is transmitted to the ignition timing setting unit 12. Thus, by retarding the misfire limit by a predetermined amount, the ignition timing can be further retarded to keep the torque of the engine 100 low.
　遅角限界進角部１７は、失火限界遅角部１６により失火限界を遅角した後に燃料カットが終了した場合に、所定量遅角する前に戻るように、失火限界を段階的に進角する。具体的に、遅角限界進角部１７は、燃料カット判断部１３からの判断結果に基づいて燃料カットが終了した場合には、合計４つのシリンダー１０１が１回ずつ燃焼する毎に、一定量の割合で通常時の失火限界に戻るように失火限界を進角する。例えば、失火限界遅角部１６による遅角量を１とした場合、遅角限界進角部１７は、０．３の割合で、通常時の失火限界に戻るように失火限界を進角する。 The retard limit advance portion 17 advances the misfire limit stepwise so that it returns to a predetermined amount when the fuel cut ends after the misfire limit retard portion 16 retards the misfire limit. To do. Specifically, when the fuel cut is completed based on the determination result from the fuel cut determination unit 13, the retard limit advance portion 17 is fixed by a certain amount every time a total of four cylinders 101 burn once. The misfire limit is advanced so as to return to the normal misfire limit at a rate of. For example, when the retard amount by the misfire limit retard portion 16 is 1, the retard limit advance portion 17 advances the misfire limit so as to return to the normal misfire limit at a rate of 0.3.
　２－２．点火時期制御装置１ａにおける処理
　本実施形態の点火時期制御装置１ａにおける処理の一例として、点火時期制御装置１ａが、燃料カットの有無に応じて失火限界を制御する処理について図６及び図７を用いて説明する。 2-2. Processing in Ignition Timing Control Device 1a As an example of processing in the ignition timing control device 1a of this embodiment, FIG. 6 and FIG. 7 are used for processing in which the ignition timing control device 1a controls the misfire limit depending on whether or not there is a fuel cut. I will explain.
　図６に示す処理の前提として、燃料カットＢｉｔとは、燃料カット判断部１３の判断結果を表すデータであって、通常時では「ｆａｌｓｅ」を示し、燃料カットの状態では「ｔｒｕｅ」を示す。燃料カットカウンタは、燃料カット継続時間計時部１４が計時するのに用いるデータであって、初期値は０である。復帰後カウンタは、失火限界進角部１７が失火限界を進角するタイミングを設定するのに用いるデータであって、初期値は０である。遅角係数は、通常時に対する失火限界の遅角割合であって、初期値は０である。 As a premise of the processing shown in FIG. 6, the fuel cut bit is data representing the determination result of the fuel cut determination unit 13 and indicates “false” in a normal time and “true” in a fuel cut state. The fuel cut counter is data used by the fuel cut duration measuring unit 14 to keep time, and its initial value is zero. The post-return counter is data used to set the timing at which the misfire limit advance portion 17 advances the misfire limit, and the initial value is zero. The retardation coefficient is the retardation ratio of the misfire limit with respect to the normal time, and the initial value is zero.
　ステップＳ６０１において、燃料カット継続時間計時部１４は、燃料カットＢｉｔを読み込んでステップＳ６０２に進む。 In step S601, the fuel cut duration measuring unit 14 reads the fuel cut bit and proceeds to step S602.
　ステップＳ６０２において、燃料カット継続時間計時部１４は、燃料カットＢｉｔがｔｒｕｅであるか否かを判断し、ｔｒｕｅつまり燃料カットの状態である場合（Ｓ６０２：Ｙｅｓ）にはステップＳ６０３に進み、ｆａｌｓｅつまり通常時である場合（Ｓ６０２：Ｎｏ）にはステップＳ６０４に進む。 In step S602, the fuel cut duration measuring unit 14 determines whether or not the fuel cut bit is true. If the fuel cut bit is true, i.e., if it is in a fuel cut state (S602: Yes), the process proceeds to step S603. When it is normal time (S602: No), it progresses to step S604.
　ステップＳ６０３において、燃料カット継続時間計時部１４は、燃料カットカウンタをインクリメントする、つまりカウンタの値を１増加してステップＳ６０５に進む。一方、ステップＳ６０４では、点火時期制御装置１ａは、燃料カットカウンタ、復帰後カウンタ、遅角係数を全て０に設定して図６に示す処理を終了する。 In step S603, the fuel cut duration measuring unit 14 increments the fuel cut counter, that is, increments the counter value by 1, and proceeds to step S605. On the other hand, in step S604, the ignition timing control device 1a sets all of the fuel cut counter, the post-return counter, and the retardation coefficient to 0, and ends the process shown in FIG.
　ステップＳ６０５において、失火限界遅角部１６は、燃料カットカウンタが設定値以上であるか否かを判断する。燃料カットカウンタが設定値未満である場合（Ｓ６０５：Ｎｏ）には、燃料カットの継続時間が、入替時間記憶部１５１が記憶する入替時間を経過していないものとして、ステップＳ６０６に進む。一方、燃料カットカウンタが設定値以上である場合（Ｓ６０５：Ｙｅｓ）には、燃料カットの継続時間が、入替時間記憶部１５１が記憶する入替時間を経過したものとしてステップＳ６０７に進む。 In step S605, the misfire limit retardation unit 16 determines whether or not the fuel cut counter is equal to or greater than a set value. If the fuel cut counter is less than the set value (S605: No), it is determined that the fuel cut duration has not passed the replacement time stored in the replacement time storage unit 151, and the process proceeds to step S606. On the other hand, if the fuel cut counter is greater than or equal to the set value (S605: Yes), the process proceeds to step S607 assuming that the fuel cut duration has passed the replacement time stored in the replacement time storage unit 151.
　ステップＳ６０６において、失火限界遅角部１６は、遅角係数を０、つまり遅角量を０に設定してステップＳ６０２に戻る。 In step S606, the misfire limit retardation unit 16 sets the retardation coefficient to 0, that is, the retardation amount to 0, and returns to step S602.
　ステップＳ６０７において、失火限界遅角部１６は遅角係数を１に設定する。また、本ステップにおいて、燃料カット継続時間計時部１４は、燃料カットカウンタを初期値である０に戻す。その後、ステップＳ６０８に進む。 In step S607, the misfire limit retardation unit 16 sets the retardation coefficient to 1. In this step, the fuel cut duration measuring unit 14 returns the fuel cut counter to 0, which is an initial value. Thereafter, the process proceeds to step S608.
　ステップＳ６０８において、失火限界遅角部１６及び失火限界進角部１７は下記式（１）に従って失火限界を遅角及び進角し、失火限界進角部１７は復帰後カウンタを０に設定して、ステップＳ６０９に進む。 In step S608, the misfire limit retard portion 16 and the misfire limit advance portion 17 retard and advance the misfire limit according to the following equation (1), and the misfire limit advance portion 17 sets the counter after returning to 0. The process proceeds to step S609.
　失火限界＝通常時失火限界＋設定遅角量×遅角係数　・・・　（１）
　ここで、通常時失火限界とは、失火限界設定部１１により設定された失火限界である。また、設定遅角量とは、遅角量記憶部１５２が記憶する遅角量である。 Misfire limit = normal misfire limit + set retard amount x retard angle coefficient (1)
Here, the normal misfire limit is a misfire limit set by the misfire limit setting unit 11. The set retard amount is the retard amount stored in the retard amount storage unit 152.
　ステップＳ６０９において、燃料カット継続時間計時部１４は、燃料カットカウンタが設定値以下であるか否かを判断し、設定値以下である場合（Ｓ６０９：Ｙｅｓ）にはステップＳ６１０に進み、設定値を超えた場合（Ｓ６０９：Ｎｏ）にはステップＳ６０７に戻る。本ステップでは、入替時間を超えて燃料カットを継続しているときは燃料カットカウンタの増加によって単にステップＳ６０７に戻る。一方、後述するステップＳ６１０～Ｓ６１５によって燃料カットから通常時へ復帰した後、燃料カットを再開してステップＳ６０９に戻ったときは、再開した燃料カットの継続時間が入替時間を経過していないと（Ｓ６０９：Ｙｅｓ）ステップＳ６１０に進み、再開した燃料カットの継続時間が入替時間を経過すると（Ｓ６０９：Ｎｏ）ステップＳ６０７に戻ることで失火限界を再度遅角することになる。 In step S609, the fuel cut duration measuring unit 14 determines whether or not the fuel cut counter is equal to or smaller than the set value. If the fuel cut counter is equal to or smaller than the set value (S609: Yes), the process proceeds to step S610. If exceeded (S609: No), the process returns to step S607. In this step, when the fuel cut is continued beyond the replacement time, the process simply returns to step S607 by increasing the fuel cut counter. On the other hand, when the fuel cut is resumed after returning from the fuel cut to the normal time in steps S610 to S615 to be described later and the flow returns to step S609, the resumption time of the resumed fuel cut has not passed the replacement time ( (S609: Yes) The process proceeds to step S610, and when the resumption time of the restarted fuel cut exceeds the replacement time (S609: No), the misfire limit is retarded again by returning to step S607.
　ステップＳ６１０において、燃料カット継続時間計時部１４は、燃料カットＢｉｔがｆａｌｓｅであるか否かを判断し、ｆａｌｓｅつまり燃料カットから通常時に復帰した場合（Ｓ６１０：Ｙｅｓ）にはステップＳ６１１に進み、ｔｒｕｅつまり燃料カットを継続している場合（Ｓ６１０：Ｎｏ）にはステップＳ６１２に進む。 In step S610, the fuel cut duration measuring unit 14 determines whether or not the fuel cut bit is false, and if false, that is, if the fuel cut returns to normal time (S610: Yes), the process proceeds to step S611, and true. That is, when the fuel cut is continued (S610: No), the process proceeds to step S612.
　ステップＳ６１１において、失火限界進角部１７は、遅角係数が０を超えているか否かを判断し、遅角係数が０を超えている場合（Ｓ６１１：Ｙｅｓ）にはステップＳ６１３に進み、遅角係数が０を超えていない場合（Ｓ６１１：Ｎｏ）にはステップＳ６０４に進む。一方、ステップＳ６１２において、燃料カット継続時間計時部１４は、燃料カットカウンタをインクリメントする、つまりカウンタの値を１増加してステップＳ６０９に戻る。ステップＳ６１２により燃料カットカウンタをインクリメントすることで、通常時に復帰した後に再開した燃料カットの継続時間を計時することができる。 In step S611, the misfire limit advancement unit 17 determines whether or not the retardation coefficient exceeds 0. If the retardation coefficient exceeds 0 (S611: Yes), the process proceeds to step S613. If the angle coefficient does not exceed 0 (S611: No), the process proceeds to step S604. On the other hand, in step S612, the fuel cut duration measuring unit 14 increments the fuel cut counter, that is, increments the value of the counter by 1, and returns to step S609. By incrementing the fuel cut counter in step S612, it is possible to measure the duration of the fuel cut resumed after returning to the normal time.
　ステップＳ６１３において、失火限界進角部１７は、復帰後カウンタをインクリメントする、つまり、カウンタの値を１増加してステップＳ６１４に進む。 In step S613, the misfire limit advancement unit 17 increments the counter after returning, that is, increments the counter value by 1, and proceeds to step S614.
　ステップＳ６１４において、失火限界進角部１７は、復帰後カウンタがシリンダー１０１の数、つまり４であるという条件を満たすか否かを判断し、当該条件を満たす場合（Ｓ６１４：Ｙｅｓ）にはステップＳ６１５に進み、当該条件を満たさない場合（Ｓ６１４：Ｎｏ）にはステップＳ６１３に戻る。 In step S614, the misfire limit advancement unit 17 determines whether or not a condition that the counter after return is equal to the number of cylinders 101, that is, 4 is satisfied. If the condition is satisfied (S614: Yes), step S615 is performed. If the condition is not satisfied (S614: No), the process returns to step S613.
　ステップＳ６１５において、失火限界進角部１７は、下記式（２）により遅角係数を設定して、ステップＳ６０８に戻る。 In step S615, the misfire limit advancement unit 17 sets a retardation coefficient by the following equation (2), and returns to step S608.
　遅角係数＝ｍａｘ（０、遅角係数－戻り割合）　・・・　（２）
　ｍａｘ（ｘ、ｙ）とすると、当該関数はｘとｙのうち大きい値を出力する関数である。 Delay angle coefficient = max (0, delay angle coefficient-return ratio) (2)
Assuming that max (x, y), the function is a function that outputs a larger value of x and y.
　上記式（２）において、戻り割合を０．３に設定することで、失火限界進角部１７は、燃料カットＢｉｔがｆａｌｓｅである限り、遅角係数を１から０．７→０．４→０．１→０に順次変更することで失火限界を段階的に進角して、通常時失火限界まで戻すことができる。 In the above formula (2), by setting the return ratio to 0.3, the misfire limit advancement portion 17 changes the delay angle coefficient from 1 to 0.7 → 0.4 → as long as the fuel cut bit is false. By sequentially changing from 0.1 to 0, the misfire limit can be advanced stepwise and returned to the normal misfire limit.
　上記図６に示す処理を実行したときの、タイミングチャートの一例を、図７に示す。例えば、図７のタイミングＴ７１において、燃焼カットＢｉｔがｆａｌｓｅからｔｒｕｅになると、燃料カットカウンタが増加する。そして、増加する燃料カットカウンタがタイミングＴ７２で設定値以上になると、失火限界が遅角する。その後、タイミングＴ７３において、燃焼カットＢｉｔがｔｒｕｅからｆａｌｓｅになると、復帰後カウンタの値が変化し、タイミングＴ７４、Ｔ７５、Ｔ７６毎に失火限界が進角して通常時失火限界まで戻る。 FIG. 7 shows an example of a timing chart when the processing shown in FIG. 6 is executed. For example, when the combustion cut bit changes from false to true at timing T71 in FIG. 7, the fuel cut counter increases. When the increasing fuel cut counter becomes equal to or greater than the set value at timing T72, the misfire limit is retarded. Thereafter, when the combustion cut bit changes from “true” to “false” at timing T73, the value of the counter after return changes, and the misfire limit advances at timings T74, T75, and T76 and returns to the normal misfire limit.
　上記の図６及び図７から明らかなように、点火時期制御装置１ａは、燃料カットの継続時間が所定時間を経過した場合には、通常時などに比べて失火限界を所定量遅角し、その後燃料カットが終了すると所定量遅角する前に戻るように、失火限界を段階的に進角する。このように失火限界を遅角及び進角することにより、エンジンの停止を確実に回避しつつ、燃料カット復帰時に生じるトルク段差を少なくすることができる。 As apparent from FIGS. 6 and 7, the ignition timing control device 1a retards the misfire limit by a predetermined amount compared to the normal time when the duration of the fuel cut has passed a predetermined time, After that, when the fuel cut is completed, the misfire limit is advanced step by step so as to return before the predetermined amount is retarded. Thus, by retarding and advancing the misfire limit, it is possible to reduce the torque level difference that occurs at the time of return from fuel cut while reliably avoiding engine stoppage.
　また、点火時期制御装置１ａでは、入替時間記憶部１５１が記憶している入替時間に基づいて失火限界を遅角することで、シリンダー１０１内部が新気に入れ替わる時点を精度良く把握して、失火限界を遅角しトルクを小さくすることができる。 In addition, the ignition timing control device 1a delays the misfire limit based on the replacement time stored in the replacement time storage unit 151, thereby accurately grasping the point in time when the inside of the cylinder 101 is replaced with fresh air. The limit can be retarded and the torque can be reduced.
　さらに、点火時期制御装置１ａは、遅角量記憶部１５２が記憶している遅角量を用いて失火限界を遅角することで、失火の発生を抑えながら確実に失火限界を遅角することができる。 Furthermore, the ignition timing control device 1a can retard the misfire limit reliably while suppressing the occurrence of misfire by retarding the misfire limit using the retard amount stored in the retard amount storage unit 152. Can do.
　３．第２の実施形態に係る点火時期制御装置
　第２の実施形態に係る点火時期制御装置１ｂについて図８を参照して説明する。点火時期制御装置１ｂは、図２に示すように、失火限界設定部１１と、点火時期設定部１２と、燃料カット判断部１３と、燃料カット継続時間計時部１４と、記憶部１５と、失火限界遅角部１６と、失火限界進角部１７と、入替時間推定部１８と、を備える。 3. Ignition Timing Control Device According to Second Embodiment An ignition timing control device 1b according to a second embodiment will be described with reference to FIG. As shown in FIG. 2, the ignition timing control device 1b includes a misfire limit setting unit 11, an ignition timing setting unit 12, a fuel cut determination unit 13, a fuel cut duration measuring unit 14, a storage unit 15, and a misfire. A limit retarding portion 16, a misfire limit advancement portion 17, and a replacement time estimating portion 18 are provided.
　点火時期制御装置１ｂの構成のうち、失火限界遅角部１６および入替時間推定部１８の構成が第１の実施形態と異なり、他の構成は第１の実施形態と同様である。このため、以下では、失火限界遅角部１６および入替時間推定部１８の構成について注目して説明し、その他の構成に関する説明を省略する。 Among the configurations of the ignition timing control device 1b, the configurations of the misfire limit retarding portion 16 and the replacement time estimating portion 18 are different from those of the first embodiment, and other configurations are the same as those of the first embodiment. For this reason, below, it explains paying attention and explains the composition of misfire limit retarding part 16 and exchange time estimating part 18, and omits explanation about other composition.
　入替時間推定部１８は、エンジン制御系１０に取り付けられた各種センサからの情報に基づいて、シリンダー１０１内において、燃料カット開始前の残留ガスが燃料カット開始後に新気に入れ替わる入替時間を推測する。具体的に、入替時間推定部１８は、各種センサからの情報に基づいて、入替時間記憶部１５１が記憶している入替時間を増減することで、入替時間を高精度に推測する。 Based on information from various sensors attached to the engine control system 10, the replacement time estimation unit 18 estimates a replacement time in which residual gas before the start of fuel cut is replaced with fresh air after the start of fuel cut in the cylinder 101. . Specifically, the replacement time estimation unit 18 estimates the replacement time with high accuracy by increasing or decreasing the replacement time stored in the replacement time storage unit 151 based on information from various sensors.
　第１の例として、回転数センサ５３６が検出したエンジン１００の回転数に基づいて、入替時間推定部１８は、入替時間を次のように推定する。つまり、燃料カット開始時の回転数が所定数以上の場合には、回転数が所定数未満の場合に比べて残留ガスから新気への入れ替えが早いと推測して、入替時間記憶部１５１が記憶している入替時間から一定時間を減算し、入替推定時間として表した信号を失火限界遅角部１６に送信する。 As a first example, based on the rotation speed of the engine 100 detected by the rotation speed sensor 536, the replacement time estimation unit 18 estimates the replacement time as follows. That is, when the rotational speed at the start of the fuel cut is equal to or greater than the predetermined number, it is assumed that the replacement from the residual gas to the fresh air is faster than when the rotational speed is less than the predetermined number, and the replacement time storage unit 151 A predetermined time is subtracted from the stored replacement time, and a signal represented as replacement estimated time is transmitted to the misfire limit retarding portion 16.
　第２の例として、エアフローメータ５２６が検出した空気量に基づいて、入替時間推定部１８は、入替時間を次のように推定する。つまり、燃料カット開始時または燃料カット中の空気量が所定量以下の場合には、空気量が所定量以上の場合に比べて残留ガスから新気への入れ替えが遅いと推測して、入替時間記憶部１５１が記憶している入替時間から一定時間を加算し、入替推定時間として表した信号を失火限界遅角部１６に送信する。 As a second example, based on the amount of air detected by the air flow meter 526, the replacement time estimation unit 18 estimates the replacement time as follows. In other words, when the amount of air at the start of the fuel cut or during the fuel cut is less than the predetermined amount, it is assumed that the replacement from the residual gas to the fresh air is slower than when the air amount is the predetermined amount or more, and the replacement time A fixed time is added from the replacement time stored in the storage unit 151, and a signal expressed as the replacement estimated time is transmitted to the misfire limit retarding unit 16.
　上記のようなエンジン１００の回転数および空燃比に限らず、例えば温度センサ５３０、水温センサ５３４など、各種センサからの検出情報に基づいて入替推定時間を算出してもよい。 The estimated replacement time may be calculated based on detection information from various sensors such as the temperature sensor 530 and the water temperature sensor 534, for example, not limited to the rotational speed and air-fuel ratio of the engine 100 as described above.
　失火限界遅角部１６は、燃料カットの継続時間が、入替時間推定部１８により推定した入替推定時間を経過した場合に、通常時失火限界から設定遅角量分遅角する。 The misfire limit retarding portion 16 retards the set delay amount from the normal misfire limit when the fuel cut duration has passed the estimated replacement time estimated by the replacement time estimating portion 18.
　以上のような構成からなる第２の実施形態に係る点火時期制御装置１ｂは、燃料カット開始時のエンジン制御系１０全体の状態を考慮して、シリンダー１０１内の残留ガスが新気に入れ替わる時間を精度良く推定することができる。そして、点火時期制御装置１ｂは、精度良く推定した入替推定時間に基づいて、シリンダー１０１内部が新気に入れ替わる時点を精度良く把握して、失火限界を遅角しトルクを小さくすることができる。 The ignition timing control device 1b according to the second embodiment having the above-described configuration takes the time during which the residual gas in the cylinder 101 is replaced with fresh air in consideration of the state of the entire engine control system 10 at the start of fuel cut. Can be estimated with high accuracy. The ignition timing control device 1b can accurately grasp the point in time when the inside of the cylinder 101 is replaced with fresh air based on the estimated replacement time, and can retard the misfire limit and reduce the torque.
なお、以上実施の形態の説明においては、一例として、ポート噴射タイプのエンジンを例に挙げて説明したが、本発明はこれに限られるものでなく、例えば、インジェクタがシリンダー内に直接挿入されて設置される直噴タイプのエンジンであってもよいのである。また、本発明は、電動スロットルを用いたタイプに限られるものでなく、例えば、機械式スロットルバルブを用いたものであっても、あるいは、機械式スロットルバルブとアイドリング制御用バイパスパイプとそこに設けられた電動あるいは機械式バルブを持つものであってもよいのである。さらに、本発明は、エアフローメータを用いたタイプに限られるものでなく、例えば、吸気管圧力センサによって検出する吸気管内の圧力に基づいて吸気される空気量を算出されるタイプあってもよいのである。
  In the above description of the embodiment, a port injection type engine has been described as an example, but the present invention is not limited to this. For example, an injector is directly inserted into a cylinder. It may be a direct injection type engine installed. Further, the present invention is not limited to a type using an electric throttle. For example, a mechanical throttle valve may be used, or a mechanical throttle valve, an idling control bypass pipe and a bypass pipe provided therein may be provided. It may have an electric or mechanical valve. Furthermore, the present invention is not limited to a type using an air flow meter, and may be a type that calculates the amount of air to be inhaled based on the pressure in the intake pipe detected by an intake pipe pressure sensor, for example. is there.

Claims (5)

  1. 　内燃機関の点火時期を、失火限界を超えないように制御する内燃機関の点火時期制御装置において、
    　前記内燃機関が燃料カットを継続する継続時間を計時する計時部と、
    　前記計時した継続時間が所定時間を経過した場合に、前記失火限界を所定量遅角する失火限界遅角部と、
    　前記失火限界を遅角した後に燃料カットが終了した場合に、前記所定量遅角する前に戻るように、前記失火限界を段階的に進角する失火限界進角部と、を備えることを特徴とする内燃機関の点火時期制御装置。     In an ignition timing control device for an internal combustion engine that controls the ignition timing of the internal combustion engine so as not to exceed the misfire limit,
    A time measuring unit for measuring a duration of time during which the internal combustion engine continues the fuel cut;
    A misfire limit retarding portion that retards the misfire limit by a predetermined amount when the measured duration has exceeded a predetermined time; and
    A misfire limit advancement section that advances the misfire limit stepwise so that the fuel cut ends when the fuel cut ends after retarding the misfire limit. An ignition timing control device for an internal combustion engine.
  2. 　前記内燃機関の燃焼室内における燃料カット開始前の残留ガスが燃料カット開始後に新気に入れ替わるまでの入替時間を記憶した入替時間記憶部を、更に備え、
    　前記失火限界遅角部は、前記計時した継続時間が前記入替時間を経過した場合に、前記失火限界を遅角することを特徴とする請求項１記載の点火時期制御装置。     A replacement time storage unit that stores a replacement time until the residual gas before the start of fuel cut in the combustion chamber of the internal combustion engine is replaced with fresh air after the start of fuel cut;
    2. The ignition timing control device according to claim 1, wherein the misfire limit retarding section retards the misfire limit when the timed duration has passed the replacement time. 3.
  3. 　前記内燃機関に取り付けられたセンサからの情報に基づいて、前記内燃機関の燃焼室内において、燃料カット開始前の残留ガスが燃料カット開始後に新気に入れ替わる入替時間を推測する入替時間推測部を、更に備え、
    　前記失火限界遅角部は、前記計時した継続時間が前記入替時間を経過した場合に、前記失火限界を遅角することを特徴とする請求項１記載の点火時期制御装置。     Based on information from a sensor attached to the internal combustion engine, a replacement time estimation unit that estimates a replacement time in which the residual gas before the start of fuel cut is replaced with fresh air after the start of fuel cut in the combustion chamber of the internal combustion engine, In addition,
    2. The ignition timing control device according to claim 1, wherein the misfire limit retarding section retards the misfire limit when the timed duration has passed the replacement time. 3.
  4. 　燃料カットを行わない動作状態に対応した失火限界から、燃料カット開始前の残留ガスが新気に置き換わった状態に対応した失火限界まで遅角する遅角量を示す遅角情報を記憶した遅角情報記憶部をさらに備え、
    　前記失火限界遅角部は、前記計時した継続時間が所定時間を経過した場合に、前記遅角情報で示される遅角量で、前記失火限界を遅角することを特徴とする請求項１乃至３のうちいずれか１項記載の点火時期制御装置。     Retardation that stores retard information indicating the amount of retard that retards from the misfire limit corresponding to the operating state where fuel cut is not performed to the misfire limit corresponding to the state where the residual gas before the start of fuel cut is replaced with fresh air An information storage unit;
    2. The misfire limit retarding portion retards the misfire limit by a retard amount indicated by the retard information when the measured duration has exceeded a predetermined time. The ignition timing control device according to claim 1, wherein
  5. 　内燃機関の点火時期を、失火限界を超えないように制御する内燃機関の点火時期制御方法において、
    　前記内燃機関が燃料カットを継続する継続時間を計時するステップと、
    　前記計時した継続時間が所定時間を経過した場合に、前記失火限界を所定量遅角するステップと、
    　前記失火限界を所定量遅角した後に燃料カットを終了した場合に、前記所定量遅角する前に戻るように、前記失火限界を段階的に進角するステップと、を有することを特徴とする内燃機関の点火時期制御方法。     In the internal combustion engine ignition timing control method for controlling the internal combustion engine ignition timing so as not to exceed the misfire limit,
    Measuring the duration for which the internal combustion engine continues to cut fuel; and
    A step of retarding the misfire limit by a predetermined amount when the measured duration has passed a predetermined time;
    A step of advancing the misfire limit stepwise so that the fuel cut is completed after the misfire limit is retarded by a predetermined amount so as to return before the predetermined amount is retarded. An ignition timing control method for an internal combustion engine.
PCT/JP2015/065377 2014-06-18 2015-05-28 Ignition timing control device for internal combustion engine and ignition timing control method for internal combustion engine WO2015194342A1 (en)

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US20220243674A1 (en) * 2021-01-29 2022-08-04 Toyota Jidosha Kabushiki Kaisha Misfire detection device for internal combustion engine

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JP2008231985A (en) * 2007-03-19 2008-10-02 Toyota Motor Corp Control device for torque demand type internal combustion engine
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