WO2018159298A1 - Système de soupape variable pour moteur à combustion interne et dispositif de commande de mécanisme de soupape variable - Google Patents

Système de soupape variable pour moteur à combustion interne et dispositif de commande de mécanisme de soupape variable Download PDF

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Publication number
WO2018159298A1
WO2018159298A1 PCT/JP2018/005157 JP2018005157W WO2018159298A1 WO 2018159298 A1 WO2018159298 A1 WO 2018159298A1 JP 2018005157 W JP2018005157 W JP 2018005157W WO 2018159298 A1 WO2018159298 A1 WO 2018159298A1
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Prior art keywords
valve
exhaust
timing
intake
variable valve
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PCT/JP2018/005157
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English (en)
Japanese (ja)
Inventor
中村　信
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日立オートモティブシステムズ株式会社
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Publication of WO2018159298A1 publication Critical patent/WO2018159298A1/fr

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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
    • F02D13/00—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing
    • F02D13/02—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D21/00—Controlling engines characterised by their being supplied with non-airborne oxygen or other non-fuel gas
    • F02D21/06—Controlling engines characterised by their being supplied with non-airborne oxygen or other non-fuel gas peculiar to engines having other non-fuel gas added to combustion air
    • F02D21/08—Controlling engines characterised by their being supplied with non-airborne oxygen or other non-fuel gas peculiar to engines having other non-fuel gas added to combustion air the other gas being the exhaust gas of engine
    • 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
    • F02D41/06—Introducing corrections for particular operating conditions for engine starting or warming up
    • 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
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/01—Internal exhaust gas recirculation, i.e. wherein the residual exhaust gases are trapped in the cylinder or pushed back from the intake or the exhaust manifold into the combustion chamber without the use of additional passages
    • 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
    • Y02T10/12—Improving ICE efficiencies
    • 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 a variable valve system for an internal combustion engine, and more particularly to a variable valve system for an internal combustion engine having a variable valve mechanism for controlling the opening and closing phases of an intake valve and an exhaust valve, and a control device for the variable valve mechanism. is there.
  • variable valve mechanism for controlling the opening / closing phase of an intake valve or an exhaust valve of an internal combustion engine
  • a variable phase variable valve mechanism for controlling the opening / closing phase of the intake valve
  • PVO positive valve overlap
  • high-temperature residual gas containing unburned HC is caused to flow back to the intake system during the period of “positive valve overlap” (PVO) at the beginning of startup, and unburned in the subsequent intake stroke thereafter.
  • PVO positive valve overlap
  • Non-Patent Document 1 high-temperature residual gas including unburned HC is caused to flow back to the intake system during the period of “positive valve overlap” (PVO) at the initial stage of starting, and the subsequent intake air thereafter.
  • PVO positive valve overlap
  • the unburned HC reintroduces the residual gas containing soot into the cylinder and re-combusts it, thereby reducing the emission of harmful exhaust components in the exhaust gas.
  • the main object of the present invention is to provide a novel variable valve system for an internal combustion engine and a variable valve control apparatus capable of reducing harmful exhaust components in exhaust gas by suppressing deterioration of combustion at the time of cold start. There is.
  • the intake valve opening timing (IVOc) is set to an advanced angle side with respect to the most retarded angle opening timing (IVOrtd) by the intake valve variable valve mechanism.
  • the exhaust angle is set to the retarded angle side by a predetermined angle (ITc) from the exhaust top dead center (TDC), and the exhaust valve variable valve mechanism is used to close the exhaust valve (EVCc).
  • the negative valve overlap (NVOc) is formed so that the intake valve opening timing (IVOc) and the exhaust valve closing timing (EVCc) do not overlap.
  • a “negative valve overlap” is formed from the end of the exhaust stroke to the beginning of the intake stroke, thereby producing a high temperature combustion gas (high temperature EGR).
  • Gas is contained in the cylinder, and the remaining cylinder gas and the engine body are heated by pressurizing with a piston, suppressing deterioration of combustion at the time of cold start, and exhaust harmful components in the exhaust gas. Can be reduced.
  • FIG. 1 shows a configuration of a main part of a variable valve system of an internal combustion engine.
  • An exhaust camshaft 10 is provided with two exhaust cams 11 per cylinder.
  • the exhaust cam 11 opens and closes the exhaust valve 12.
  • a sprocket mechanism 13 and an exhaust valve variable valve mechanism (hereinafter referred to as an exhaust VTC) 14 fixed to the sprocket mechanism 13 are attached to one end of the exhaust camshaft 10, and the exhaust camshaft 10 is connected to the sprocket mechanism.
  • the relative rotational position of the exhaust cam 11 is controlled by making relative rotation (phase conversion) with respect to 13.
  • the sprocket mechanism 13 includes a timing sprocket 15 and is rotated by a crankshaft by a timing belt (not shown).
  • the exhaust VTC 14 includes a housing 16 and a vane that is hydraulically driven in a space formed by the front cover 17 and the rear cover 18 fixed to both ends of the housing 16.
  • the timing sprocket 15 and the rear cover 18 are fixed to each other, and the vane is fixed to the exhaust camshaft 10. Therefore, by adjusting the rotational position of the vane by hydraulic pressure, the exhaust camshaft 10 adjusts the opening / closing phase of the exhaust valve correspondingly.
  • the intake camshaft 20 is provided with two intake cams 21 per cylinder.
  • the intake cam 21 opens and closes the intake valve 22.
  • a sprocket mechanism 23 and an intake valve variable valve mechanism (hereinafter referred to as intake VTC) 24 fixed to the sprocket mechanism 23 are attached to one end of the intake camshaft 20, and the intake camshaft 20 is connected to the sprocket mechanism.
  • the relative rotational position of the intake cam 21 is controlled by relative rotation (phase conversion) with respect to 23.
  • the sprocket mechanism 23 includes a timing sprocket 25, and is rotated by a crankshaft by a timing belt (not shown).
  • the intake VTC 24 has a housing 26 and a vane that is hydraulically driven in a space formed by a front cover 27 and a rear cover 28 fixed to both ends of the housing 26.
  • the timing sprocket 25 and the rear cover 28 are fixed to each other, and the vane is fixed to the intake camshaft 20. Therefore, the intake camshaft 20 adjusts the opening / closing phase of the intake valve correspondingly by adjusting the rotational position of the vane by hydraulic pressure.
  • the control device 30 receives various operating state information of the internal combustion engine, an exhaust VTC actual position signal, an intake VTC actual position signal, and the like, supplies an exhaust phase control signal to the exhaust electromagnetic switching valve 31, and supplies an intake phase control signal.
  • the intake electromagnetic switching valve 32 By supplying the intake electromagnetic switching valve 32, the exhaust phase control hydraulic pressure of the exhaust VTC 14 and the intake phase control hydraulic pressure of the intake VTC 24 are controlled.
  • the housing 35 (16) has a cylindrical housing body 35a whose front end opening is closed by a disc-shaped front cover 17 (see FIG. 1) and whose rear end opening is a disk.
  • the rear cover 18 (see FIG. 1) is closed.
  • shoes 35b that are four partition walls project from the inner side.
  • the rear cover 18 is integrally provided at the center position of the timing sprocket 13, and the outer peripheral portion thereof is fastened to the housing body 35 a and the front cover 17 by four bolts 39.
  • a large-diameter bearing hole that is supported on the outer periphery of the cylindrical portion of the vane rotor 36 is formed in the center of the rear cover 18 in the axial direction.
  • the vane rotor 36 includes a cylindrical rotor 37 having a bolt insertion hole in the center, and four vanes 38 and 38a provided integrally at approximately 90 ° in the circumferential direction of the outer peripheral surface of the rotor 37.
  • the rotor 37 has a small diameter cylindrical portion on the front end side rotatably supported by the central support hole of the front cover 17, while a small diameter cylindrical portion on the rear end side is rotatably supported by the bearing hole of the rear cover 18. .
  • the vane rotor 36 is fixed to the front end portion of the exhaust camshaft 10 from the axial direction by a fixing bolt 40 inserted through the bolt insertion hole of the rotor 37 from the axial direction.
  • Each vane 38, 38a is disposed between each shoe 35b, and a seal member that slidably contacts the inner peripheral surface of the housing main body 35a in an elongated holding groove formed in the axial direction of each outer surface and the seal.
  • a leaf spring that presses the member in the direction of the inner peripheral surface of the housing body is fitted and held.
  • retarding chambers 41 and advance chambers 42 are respectively formed between both sides of the vanes 38 and 38a and both sides of the shoes 35b.
  • the vane 38a has an advance side stopper function and a retard side stopper function.
  • the intake VTC 24 has the same configuration, but the advance chamber and the retard chamber have an opposite relationship, and the four coil springs that constantly urge the vane rotor 36 in the retard direction include the retard chamber. Are attached to each.
  • the intermediate angle time (Emid) is between the most advanced angle time (Emax) and the most retarded angle time (Emin), and is slightly behind the most advanced angle time (Emax).
  • the fastening pin 45 built in the vane 38a and the fastening hole on the rear cover 18 side coincide with each other, and the vanes 38a and 38 are positioned at the default position. It is like that.
  • the intake VTC 24 has a structure similar to that of the exhaust VTC 14 shown in FIG. 2, but the conversion phase angle formed between the most advanced angle timing (Imax) and the most retarded angle magnetism (Imin) is larger than that of the exhaust VTC 14. Is set.
  • the intermediate angle timing (Imid) is set between the most advanced timing (Imax) and the most retarded timing (Imin), and the fastening pin in the vane matches the fastening hole on the rear cover side.
  • the default position is set to the retard side that is larger than the most advanced timing (Imax), and is set to be slightly advanced from the most retarded timing (Imin).
  • the fastening pin in the vane and the fastening hole on the rear cover 28 coincide with each other like the exhaust VTC 14 so that the vane is positioned at the default position. It has become.
  • FIG. 3 “(A) cold start state”, “(B) partial load state after warm-up”, and “(C) post-warm state”.
  • Each valve timing characteristic of “full load state” is shown.
  • “(A) the cold start state” is, for example, a state where the main body temperature of the internal combustion engine is 40 ° C. or less
  • “(B) the partial load state after warming up” is, for example, the accelerator pedal being in the middle
  • “(C) full load state after warm-up” is a state where, for example, the accelerator pedal is depressed to the maximum extent.
  • each valve timing characteristic will be described.
  • valve timings of the exhaust valve and the intake valve are the valve timings shown in “(A) Cold machine start state” in FIG.
  • the exhaust top dead center is when the exhaust valve closing timing (EVC) is more retarded than the exhaust valve most advanced timing (EVCadv) and more advanced than the most retarded timing (EVCrtd).
  • the exhaust valve closing timing (EVCc) on the advance side is set by a predetermined angle (ETc) from (TDC).
  • EDC exhaust valve closing timing
  • the intake valve opening timing (IVO) is an advance side of the most retarded angle opening timing (IVOrtd) of the intake valve, and is between the retarded side of the most advanced angle opening timing (IVOaddv) and the exhaust top dead center (
  • the intake valve opening timing (IVOc) is set at a delay angle side by a predetermined angle (ITc) from TDC).
  • the most advanced angle opening time (IVOadv) is the same as the most advanced angle time (Imax)
  • the most retarded angle opening time (IVOrtd) is the same as the most retarded angle time (Imin).
  • the predetermined angle (ITc) and the predetermined angle (ETc) are set to substantially the same angle.
  • substantially the same angle is a concept including mechanical errors after assembly of the exhaust VTC 14 and the intake VTC 24, design tolerances, and the like, and does not necessarily mean the same angle.
  • high temperature combustion gas high temperature EGR gas
  • NVOc negative valve overlap
  • the intake valve opening timing (IVOc) is retarded in the present embodiment.
  • the period (intake operating angle) can be set narrow, whereby the valve friction resistance of the intake valve can be reduced and the use of the driving force of the internal combustion engine can be suppressed.
  • the exhaust valve closing timing (EVCc) is advanced in this embodiment.
  • the valve opening period (exhaust operating angle) can be set narrow, whereby the valve frictional resistance of the exhaust valve can be reduced, and use of the driving force of the internal combustion engine can be suppressed.
  • the exhaust valve opening timing EVO
  • the exhaust valve is opened before the combustion gas temperature decreases, and the exhaust gas having a high temperature is supplied to the exhaust gas purification catalyst. It is possible to increase the temperature of the exhaust gas purifying catalyst to reduce harmful components of exhaust gas at the time of cold start while suppressing an increase in valve frictional resistance.
  • the EGR gas can also be introduced into the cylinder by the conventional “positive valve overlap” (PVO).
  • the temperature of the EGR gas is in principle the “negative valve overlap” according to the present embodiment. It is lower than (NVO), and the valve opening period (intake / exhaust operating angle) of the intake valve and the exhaust valve is set to be large, so there is a problem that the valve friction resistance of the intake valve and the exhaust valve increases. .
  • the intake valve opening timing (IVO) is further retarded than the intake valve opening timing (IVOc) in the cold start state, and the exhaust The timing is converted into the open timing (IVOp) on the retard side by a predetermined angle (ITp) from the dead point (TDC).
  • the opening timing (IVOp) is the same as the most retarded opening timing (IVOrtd).
  • the intake valve closing timing (IVC) is set to the intake valve closing timing (IVCp) retarded to near the middle position between the intake bottom dead center (BDC) and the compression top dead center (TDC).
  • the vane may be phase-converted by the intake VTC 24 until the aforementioned most retarded opening timing (Imin) of the intake valve.
  • the exhaust valve closing timing (EVC) is further advanced than the exhaust valve closing timing (EVCc) in the cold start state, and the exhaust The dead time (TDC) is converted into the closing timing (EVCp) on the advance side by a predetermined angle (ETp).
  • the closing time (EVCp) is the same as the most advanced angle closing time (EVCadv).
  • the exhaust valve opening timing (EVO) is advanced to a section between the exhaust bottom dead center (BDC) and the compression top dead center (TDC) to open the exhaust valve opening timing (EVOp).
  • BDC exhaust bottom dead center
  • TDC compression top dead center
  • the vanes 38a and 38 may be phase-converted by the exhaust VTC 14 up to the most advanced timing (Emax) of the exhaust valve.
  • the frictional resistance of the internal combustion engine mechanism system may be lower than that in the cold state, and the intake air amount can be reduced compared to that in the cold state.
  • the throttle valve is closed to reduce the intake air amount, so-called pump loss may increase and fuel consumption performance may deteriorate.
  • the throttle valve opening time (IVC) is greatly retarded to near the middle position between the intake bottom dead center and the compression top dead center, so that a so-called “lately closed Atkinson cycle” is established, so that the throttle valve opening is greatly opened. It is conceivable to reduce the amount of intake air while maintaining the same.
  • the gas temperature at the compression top dead center can be increased by a large “negative valve overlap” (NVOp), so that the deterioration of combustion is avoided and the desired fuel consumption is reduced. An effect comes to be acquired.
  • NVOp negative valve overlap
  • a large “negative valve overlap” reduces the amount of fresh air by relatively increasing the amount of high-temperature combustion gas in the cylinder, so that a predetermined partial load torque can be obtained.
  • the required throttle opening can be further increased (throttle large opening ⁇ p range shown in FIG. 5), and thus pump loss can be further reduced and fuel efficiency can be improved.
  • the intake valve opening timing (IVOp) is retarded in the present embodiment.
  • the period (intake operating angle) can be set narrow, thereby reducing the valve frictional resistance of the intake valve and suppressing unnecessary use of the driving force of the internal combustion engine, resulting in improved fuel efficiency. It becomes possible to do.
  • the exhaust valve closing timing (EVCp) is advanced in this embodiment.
  • the valve opening period exhaust operating angle
  • the valve opening period can be set narrow, thereby reducing the valve frictional resistance of the exhaust valve and suppressing the wasteful use of the driving force of the internal combustion engine. Can be improved.
  • the predetermined angle (ITp) and the predetermined angle (ETp) are set to be substantially the same angle. This makes it possible to reduce pump loss that occurs during “negative valve overlap” (NVOp). The reason will be described with reference to the PV diagram shown in FIG.
  • the predetermined angle (ITp) and the predetermined angle (ETp) are set to substantially the same angle.
  • the substantially same angle is a mechanical error or design after assembling the exhaust VTC 14 and the intake VTC 24. It is a concept that includes the above tolerances, etc., and does not necessarily mean the same angle.
  • FIG. 4A shows a PV diagram of the present embodiment (the valve timing characteristics shown in FIG. 3B), and FIG. 4B shows Reference Example 1 (ETp ⁇ 0) as a comparison target.
  • the PV diagram at ⁇ ITp) is shown, and
  • FIG. 4C shows the PV diagram at Reference Example 2 (ETp> ITp ⁇ 0) as a comparison object.
  • in-cylinder negative pressure develops in the section (ITp) from the exhaust top dead center (TDC) to the intake valve opening timing (IVOp) in the process of lowering the piston.
  • This in-cylinder negative pressure acts so as to suppress the downward movement of the piston, so that a pump loss (downward triangular area) at the initial stage of suction occurs as shown in the PV diagram.
  • the piston rises toward the exhaust top dead center (TDC) from the closing timing (EVCp) when the exhaust valve before the exhaust top dead center (TDC) is closed.
  • in-cylinder positive pressure develops in the section (ETp) to the exhaust top dead center (TDC).
  • This in-cylinder positive pressure acts to suppress the upward movement of the piston.
  • the intake valve opens when the exhaust top dead center (TDC) is exceeded, the positive pressure gas in the cylinder flows backward to the intake side and can be recovered as energy for promoting the downward movement of the piston. Can not.
  • pump loss upward triangular region
  • the exhaust valve closing timing (EVCp) is before the exhaust top dead center (TDC), and from the exhaust valve closing timing (EVCp) to the exhaust top dead center (TDC), the high-temperature combustion gas
  • the (high temperature EGR gas) is compressed by a predetermined angle (ETp), and at that time, it acts to suppress the upward movement of the piston.
  • predetermined angle (ETp) predetermined angle (ITp) is most preferable.
  • the pump loss at the end of the exhaust stroke and the initial pump loss of the intake stroke Both can be removed.
  • the valve timing characteristic in the partial load state of the present embodiment shown in FIG. 4A can further improve the fuel efficiency from the viewpoint of suppressing the pump loss before and after the exhaust top dead center (TDC). Is. ⁇ Full load state after warm-up >> Next, the valve timing in the full load state after warm-up will be described. At the full load after warm-up, the valve timing characteristics shown in “(C) Full-load state after warm-up” in FIG. 3 are obtained.
  • the opening timing (IVO) of the intake air valve is advanced to a more advanced side than the opening timing (IVOc) of the intake valve in the cold start state, and is a predetermined angle from the exhaust top dead center (TDC). Only (ITh) is converted to the opening timing (IVOh) on the advance side.
  • the opening time (IVOh) is the same as the most advanced angle opening time (IVOadv).
  • the stopper surface 44 of the exhaust VTC 14 is subjected to the maximum retardation conversion until the most retarded timing (Emin).
  • the closing timing (EVC) of the exhaust valve is retarded to the far side of the closing timing (EVCc) of the exhaust valve in the cold start state, and a predetermined angle (ETh) from the exhaust top dead center (TDC). Is converted into the retard timing (EVCh).
  • the closing timing (EVCh) is the same as the most advanced angle closing timing (EVCrtd).
  • valve timing characteristics it is possible to sufficiently increase the engine torque in the full load state after warm-up. That is, since the opening timing (EVOh) of the exhaust valve is retarded to the vicinity of the expansion bottom dead center (BDC), the timing when the negative pressure wave of the exhaust pulsation arrives near the exhaust valve is “positive valve overlap” (PVOh). ) Will be delayed until near.
  • EVOh opening timing
  • BDC expansion bottom dead center
  • the negative pressure wave of exhaust pulsation is synchronized with “positive valve overlap” (PVOh).
  • the scavenging effect can be increased. That is, the timing at which the negative pressure wave of the exhaust pulsation arrives in the vicinity of the exhaust valve can be brought closer to the center of the section of “positive valve overlap” (PVOh).
  • the air-fuel mixture burned in the cylinder of the internal combustion engine may be a lean air-fuel mixture in the partial load state after cold or warm-up.
  • the air-fuel ratio is leaner than the stoichiometric air-fuel ratio, there are advantages such as less generation of harmful exhaust components from the engine body and further improvement in fuel efficiency, but there is a problem in combustion stability.
  • the stability of combustion can be improved by the effect of the NVO described above, so that the advantage of using the lean air-fuel mixture can be fully exhibited.
  • a moderate “negative valve overlap” can stabilize combustion and improve warm-up performance during cold operation. Improve fuel efficiency and reduce harmful components of exhaust gas through improvements.
  • the opening degree ⁇ c of the throttle valve is increased to increase the engine torque in order to overcome this frictional resistance.
  • the valve timing during cold operation is maintained. That is, for example, the “negative valve overlap” (NVOi) of the idle after warm-up is matched with the “negative valve overlap” (NVOc) during the cold operation.
  • the throttle valve opening is closed to a small opening ⁇ i in order to reduce the combustion torque.
  • the intake negative pressure increased by reducing the opening of the throttle valve causes the internal EGR in the cylinder to pass through the open intake valve.
  • the exhaust gas is sucked into the intake system, and further, the intake negative pressure is re-inhaled into the cylinder from the exhaust port side through the exhaust valve that is open in the section of “positive valve overlap” (PVO). End up.
  • the internal EGR sucked into the intake system is reintroduced into the cylinder in the next intake stroke, and the internal EGR introduced into the cylinder from the exhaust port side as described above is also added, and finally the cylinder EGR is added.
  • the internal EGR introduced into the inside becomes excessive and the combustion stability deteriorates.
  • the valve overlap need not be set to “0”. It is possible to suppress the range of change from “lap” (NVOp) to “negative valve overlap” (NVOi) in the idle state after warm-up. As a result, it is possible to avoid the problem of delay in conversion response between the intake VTC 24 and the exhaust VTC 14 in an operating state in which the engine operating conditions cross both regions.
  • a large “negative valve overlap” (NVOp) or an Atkinson cycle can reduce the charging efficiency (torque) without reducing the opening of the throttle valve.
  • the degree is a large opening ⁇ p.
  • the engine torque in the full load state after warm-up can be sufficiently increased. That is, since the opening timing (EVOh) of the exhaust valve is retarded to the vicinity of the expansion bottom dead center (BDC), the timing when the negative pressure wave of the exhaust pulsation arrives near the exhaust valve is “positive valve overlap” (PVOh). ) Therefore, the high-temperature combustion gas in the cylinder is sucked out by the negative pressure wave through the open exhaust valve, and cool fresh air is introduced into the cylinder through the open intake valve.
  • FIG. 6 shows a control flow for mechanically stabilizing the exhaust VTC 14 and the intake VTC 24 at a default position where “negative valve overlap (NVOc)” occurs when the internal combustion engine is stopped.
  • step S10 engine stop information for stopping the internal combustion engine and operating condition information for the internal combustion engine are read.
  • the engine stop information for stopping the internal combustion engine there is typically a key-off signal, and there are many signals indicating the operating condition information of the internal combustion engine.
  • the engine speed information, the intake air There are quantity information, water temperature information, required load information (accelerator opening), and the like, and further, actual position information of the exhaust VTC 14 and the intake VTC 24, and the like. If various information is read in this step S10, it will transfer to step S11.
  • Step S11 it is determined whether the engine stop transition condition is satisfied. For this determination, for example, the key-off signal may be monitored, and if the key-off signal is not input, the process returns to return and waits for the next activation timing. On the other hand, when the key-off signal is input, the engine stop transition condition is determined and the process proceeds to step S12.
  • Step S12 a conversion control signal is output to the exhaust electromagnetic switching valve 31 of the exhaust VTC 14 and the intake electromagnetic switching valve 32 of the intake VTC 24 so that the exhaust VTC 14 and the intake VTC 24 are shifted to the default positions. That is, in order to respond to the next start, the hydraulic pressure is controlled so that the valve timing characteristics of “(A) cold start state” of FIG. 3 are obtained.
  • Step S13 From the actual position information of the exhaust VTC 14 and the intake VTC 24, the exhaust VTC 14 and the intake VTC 24 are set to the default positions, that is, the exhaust valve closing timing (EVCc) is set. It is determined whether or not the valve opening timing (IVOc) has been set. If it is determined that the exhaust valve closing timing (EVCc) and the intake valve opening timing (IVOc) are not set, the process returns to step S12 again, and the exhaust valve closing timing (EVCc) If it is determined that the opening time (IVOc) is set, the process proceeds to step S14.
  • the exhaust valve closing timing EVCc
  • Step S14 the output control signal to the fuel injection valve and the ignition device is stopped to stop the internal combustion engine.
  • the rotational speed Ne of the internal combustion engine decreases, and the hydraulic pressure of the hydraulic oil of the hydraulic pump decreases accordingly.
  • the exhaust VTC 14 and the intake VTC 24 execute the following operations based on the mechanism. This operation is not a control step in the flowchart, but will be described as a control step for convenience.
  • Step S15 to Step S17 As the rotational speed Ne of the internal combustion engine decreases, the discharge pressure of the hydraulic oil from the hydraulic pump also decreases, so that the fastening pin 45 held in the vanes of the exhaust VTC 14 and the intake VTC 24 (see FIG. 2) is moved toward the rear cover by the return spring. On the other hand, the advance chamber and the retard chamber of the exhaust VTC 14 and the intake VTC 24 are filled with hydraulic oil, and the vane position is maintained as it is even when the rotational speed Ne is decreased.
  • the fastening pin is further moved toward the rear cover by the return spring and fastened to the fastening hole, so that the vane is fixed to the housing, the exhaust valve closing timing (EVCc), and the intake valve opening timing (IVOc). ) Is finally determined to the default position.
  • the tip of the fastening pin is formed in a taper shape, and the fastening pin can be engaged with the fastening hole even if the vane is slightly out of phase.
  • the exhaust VTC 14 and the intake VTC 24 are expressed as “the negative valve overlap (NVOc) is obtained, the exhaust valve closing timing (EVCc) and the intake valve opening timing (IVOc). ) Can be mechanically stabilized at the default position.
  • control flow when the operation of the internal combustion engine is resumed from this state will be described with reference to FIG. This control flow is also executed by the control device 30.
  • Step S20 engine start information for starting the internal combustion engine and operating condition information for the internal combustion engine are read.
  • the engine start information for starting the internal combustion engine is typically a key-on signal or a starter activation signal, and there are many signals indicating the operating condition information of the internal combustion engine.
  • Step S21 it is determined whether the engine start condition is satisfied. For this determination, for example, the starter activation signal may be monitored. If the starter activation signal is not input, the process returns to return and waits for the next activation timing. On the other hand, when the starter activation signal is input, the engine start condition is determined and the process proceeds to step S22.
  • the starter activation signal may be monitored. If the starter activation signal is not input, the process returns to return and waits for the next activation timing. On the other hand, when the starter activation signal is input, the engine start condition is determined and the process proceeds to step S22.
  • Step S22 In step S22, in response to the starter start signal, cranking of the internal combustion engine by the starter motor is started. Then, as soon as cranking is started, the process proceeds to step S23.
  • Step S23 a conversion control signal is output to the exhaust electromagnetic switching valve 31 of the exhaust VTC 14 and the intake electromagnetic switching valve 32 of the intake VTC 24 so that the exhaust VTC 14 and the intake VTC 24 are shifted to the default positions. This is because the vanes of the exhaust VTC 14 and the intake VTC 24 are maintained at the default positions even when the fastening pin is pulled out of the fastening hole for some reason and the fastening state is released when the hydraulic pressure of the hydraulic pump hydraulic oil rises. Control.
  • the conversion control signal is output to the exhaust electromagnetic switching valve 31 of the exhaust VTC 14 and the intake electromagnetic switching valve 32 of the intake VTC 24, the process proceeds to step S24.
  • Step S24 From the actual position information of the exhaust VTC 14 and the intake VTC 24, the exhaust VTC 14 and the intake VTC 24 are set to the default positions, that is, the exhaust valve closing timing (EVCc) is set. It is determined whether or not the valve opening timing (IVOc) has been set. If it is determined that the exhaust valve closing timing (EVCc) and the intake valve opening timing (IVOc) are not set, the process returns to step S23 again, and the exhaust valve closing timing (EVCc) and the intake valve opening timing are set. If it is determined that the opening time (IVOc) is set, the process proceeds to step S25.
  • Step S25 an output control signal is supplied to the fuel injection valve and the ignition device in order to start the internal combustion engine in accordance with the rotation of the starter motor.
  • the rotational speed Ne of the internal combustion engine increases, and the hydraulic pressure of the hydraulic oil of the hydraulic pump increases accordingly.
  • the output control signal is supplied to the fuel injection valve and the ignition device, the process proceeds to step S26.
  • Step S26 the engine temperature (cooling water temperature) of the internal combustion engine is detected to determine whether or not a predetermined temperature T0 has been exceeded. If the temperature does not exceed the predetermined temperature T0, it is determined that the engine is in a cold state, and the process returns to return and waits for the next start timing. This state is a cold start state. Therefore, the "negative valve overlap" (NVOc) is set by the exhaust valve closing timing (EVCc) and the intake valve opening timing (IVOc) in "(A) cold start state” in FIG. Will be.
  • NVOc exhaust valve closing timing
  • IVOc intake valve opening timing
  • step S27 if the temperature exceeds the predetermined temperature T0, it is determined that the warm-up is completed from the cold state, and the exhaust VTC 14 and the intake VTC 24 are controlled based on the control map according to the respective operation conditions. Therefore, if the warm-up is completed exceeding the predetermined temperature T0, the process proceeds to step S27.
  • Step S27 it is determined whether or not the engine is in an idle condition from the opening of the throttle valve or the opening of the accelerator pedal.
  • the process proceeds to step S28, and the exhaust VTC 14 and the intake VTC 24 cause the exhaust valve closing timing (EVCi) during idling and the intake valve opening timing (IVOi) to indicate "negative" "Valve Overlap” (NVOi).
  • EVCi exhaust valve closing timing
  • IVOi intake valve opening timing
  • NVOi intake valve opening timing
  • Step S29 it is determined whether the partial load condition is satisfied from the opening of the throttle valve or the opening of the accelerator pedal. If the partial load condition is determined, the process proceeds to step S30, where the exhaust VTC 14 and the intake VTC 24 cause the partial load depending on the exhaust valve closing timing (EVCp) at the partial load and the intake valve opening timing (IVOp). It controls to “negative valve overlap” (NVOp).
  • the valve timing characteristic at this partial load is the valve timing shown in “(B) Partial load state after warm-up” in FIG.
  • the process proceeds to step S31.
  • Step S31 to Step S32 it is determined whether or not the full load condition is satisfied from the opening of the throttle valve or the opening of the accelerator pedal.
  • the process proceeds to step S32, where the exhaust VTC 14 and the intake VTC 24 cause the exhaust valve closing timing (EVCh) at the full load and the intake valve opening timing (IVOh) to reach the full load.
  • the time is controlled to “positive valve overlap” (PVOh).
  • the valve timing characteristic at this full load is the valve timing shown in “(C) Full load state after warm-up” in FIG.
  • the process returns to return and waits for the next activation timing.
  • valve timing characteristics that can manage the combustion state in a stable state over a wide operation range, suppress the generation of harmful exhaust components, and improve the fuel efficiency. become able to.
  • the second embodiment is different in that a variable valve lift valve mechanism that can continuously adjust the operating angle and the opening / closing timing is used on both the exhaust side and the intake side. .
  • exhaust VEL exhaust valve lift variable valve mechanism
  • intake VEL intake valve lift variable valve mechanism
  • the operating angle is reduced by the intake air VEL, and the valve timing characteristics such as “(A) cold start state” in FIG. 8 are set.
  • the closing timing (IVC) of the intake valve advances to near the bottom dead center as the closing timing (IVCc ′). It is horned.
  • the effective compression ratio is increased as compared with the first embodiment, so that the combustion state is improved and the exhaust harmful components in the exhaust gas can be further reduced.
  • the operating angle is expanded by the intake VEL, and the valve timing characteristics such as “(B) partial load state after warm-up” in FIG. 8 are set.
  • the closing timing (IVC) of the intake valve is dead as the closing timing (IVCp ′). It is retarded to the point side.
  • the effect of the Atkinson cycle is enhanced as compared with the first embodiment, so that the fuel efficiency can be further improved.
  • the exhaust valve closing timing (EVC) is dead as the closing timing (EVCh ′). It has been advanced to the point side. Compared with the first embodiment, this is a form in which a part on the retarded side in the “positive overlap” (PVO) is removed.
  • variable valve lift valve mechanism capable of continuously adjusting the operating angle and the opening / closing timing is used on both the exhaust side and the intake side. It is also possible to use a variable valve mechanism and the other variable phase valve mechanism (the above-mentioned VTC) in which the operating angle is constant and the valve lift is unchanged.
  • variable valve mechanism intake / exhaust VTC
  • intake / exhaust VTC hydraulically driven phase variable mechanism
  • intake / exhaust VL an intake / exhaust VVL that adjusts the operating angle stepwise should be used. Can do.
  • specific form of the variable valve mechanism is not limited as long as the gist of the present invention is satisfied.
  • the intake valve opening timing (IVOc) is advanced from the most retarded angle opening timing (IVOrtd) by the intake valve variable valve mechanism.
  • a predetermined angle (ITc) is set to the retarded angle side from the exhaust top dead center (TDC), and the exhaust valve is closed by the exhaust valve variable valve mechanism.
  • the timing (EVCc) is retarded from the most advanced angle closing timing (EVCadv), and more advanced than the most retarded timing (EVCrtd), and a predetermined angle (ETc) from the exhaust top dead center (TDC).
  • NVOc negative valve overlap
  • a “negative valve overlap” (NVOc) is formed from the end of the exhaust stroke to the initial stage of the intake stroke, whereby high temperature combustion gas (high temperature EGR gas) is generated in the cylinder.
  • high temperature combustion gas high temperature EGR gas
  • the remaining in-cylinder gas and the engine main body are heated by pressurizing with a piston and suppressing deterioration of combustion at the time of cold start, and exhaust harmful components in the exhaust gas can be reduced. It becomes like this.
  • this invention is not limited to above-described embodiment, Various modifications are included.
  • the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described.
  • a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment.
  • EVCc exhaust valve closing at cold start Timing
  • IVOadv most advanced timing of intake valve
  • IVOrtd most retarded timing of intake valve
  • EVCadv exhaust valve The most advanced period of, EVCrtd ... the most retarded timing of the exhaust valve.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Output Control And Ontrol Of Special Type Engine (AREA)
  • Exhaust-Gas Circulating Devices (AREA)
  • Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)

Abstract

Pendant le démarrage à froid d'un moteur à combustion interne, un mécanisme variable de soupape d'admission règle une synchronisation d'ouverture de soupape d'admission (IVOc) sur le côté retardé du point mort haut d'échappement selon un angle prédéterminé (ITc) de sorte que celle-ci soit comprise entre le côté avancé de la synchronisation d'ouverture retardée maximale (IVOrtd) et le côté retardé de la synchronisation d'ouverture avancée maximale (IVOadv), et un mécanisme variable de soupape d'échappement règle une synchronisation de fermeture de soupape d'échappement (EVCc) vers le côté avancé du point mort haut d'échappement selon un angle prédéterminé (ETc) de sorte qu'elle se trouve entre le côté retardé de la synchronisation de fermeture avancée maximale (EVCadv) et le côté avancé de la synchronisation de fermeture retardée maximale (EVCrtd)), ce qui permet de former un "chevauchement de soupape négatif" (NVOc) où la synchronisation d'ouverture de soupape d'admission (IVOc) et la synchronisation de fermeture de soupape d'échappement (EVCc) ne se chevauchent pas l'une l'autre.
PCT/JP2018/005157 2017-02-28 2018-02-15 Système de soupape variable pour moteur à combustion interne et dispositif de commande de mécanisme de soupape variable WO2018159298A1 (fr)

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JP2017035878A JP2018141403A (ja) 2017-02-28 2017-02-28 内燃機関の可変動弁システム及び可変動弁機構のコントロール装置

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Cited By (1)

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Publication number Priority date Publication date Assignee Title
EP4283108A1 (fr) * 2022-05-24 2023-11-29 Mazda Motor Corporation Appareil de commande de moteur, système de moteur et véhicule

Families Citing this family (1)

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JP7559615B2 (ja) 2021-02-26 2024-10-02 株式会社アイシン 内燃機関の制御装置

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JP2001355464A (ja) * 2000-06-09 2001-12-26 Nissan Motor Co Ltd 内燃機関の可変動弁装置
JP2008088875A (ja) * 2006-09-29 2008-04-17 Mazda Motor Corp 火花点火式ガソリンエンジン
JP2008088874A (ja) * 2006-09-29 2008-04-17 Mazda Motor Corp 火花点火式直噴ガソリンエンジン
JP2008267300A (ja) * 2007-04-23 2008-11-06 Hitachi Ltd 内燃機関の可変動弁装置
JP2009156029A (ja) * 2007-12-25 2009-07-16 Hitachi Ltd 内燃機関の可変動弁システム及び該可変動弁システムに用いられるコントローラ
JP2010209859A (ja) * 2009-03-11 2010-09-24 Toyota Motor Corp 内燃機関の制御装置

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Publication number Priority date Publication date Assignee Title
JP2001355464A (ja) * 2000-06-09 2001-12-26 Nissan Motor Co Ltd 内燃機関の可変動弁装置
JP2008088875A (ja) * 2006-09-29 2008-04-17 Mazda Motor Corp 火花点火式ガソリンエンジン
JP2008088874A (ja) * 2006-09-29 2008-04-17 Mazda Motor Corp 火花点火式直噴ガソリンエンジン
JP2008267300A (ja) * 2007-04-23 2008-11-06 Hitachi Ltd 内燃機関の可変動弁装置
JP2009156029A (ja) * 2007-12-25 2009-07-16 Hitachi Ltd 内燃機関の可変動弁システム及び該可変動弁システムに用いられるコントローラ
JP2010209859A (ja) * 2009-03-11 2010-09-24 Toyota Motor Corp 内燃機関の制御装置

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4283108A1 (fr) * 2022-05-24 2023-11-29 Mazda Motor Corporation Appareil de commande de moteur, système de moteur et véhicule

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