JP5092956B2 - Method for controlling internal combustion engine for vehicle and internal combustion engine system - Google Patents

Description

  The present invention relates to a method for controlling an internal combustion engine for a vehicle and an internal combustion engine system for a vehicle.

  In general, in a spark ignition engine (internal combustion engine) for a vehicle, the amount of air supplied to a combustion chamber and thus the output torque of the engine is controlled by opening and closing a throttle valve disposed in an intake passage. . Further, in such an engine, air is sucked into the combustion chamber during the intake stroke when the intake valve is opened. The displacement characteristic of the intake valve, for example, the lift amount or the closing timing of the intake valve is changed. Thus, the amount of air taken into the combustion chamber can be controlled.

Therefore, by controlling the opening of the throttle valve (hereinafter referred to as “throttle opening”) and controlling the displacement characteristics of the intake valve, the amount of air sucked into the combustion chamber, and thus the output torque, can be made more precise. An engine that is controlled has been proposed (see, for example, Patent Document 1). In the engine disclosed in Patent Document 1, the lift amount of the intake valve and the opening degree of the throttle valve are controlled according to the driver's request, while the intake valve is used to reduce the intake air amount when the transmission is shifted. The amount of lift and the opening of the throttle valve are controlled.
JP 2007-154832 A (paragraph [0022], FIG. 1)

  On the other hand, control of engine output torque unrelated to the driver's request or intention (hereinafter referred to as “driver non-participation control”), for example, temporarily reducing engine output torque when a wheel slips during driving. There is also known a vehicle in which traction control is performed such that the driving force of the wheels (drive wheels) is reduced to suppress slip, but in such non-driver-involved control, when the output torque of the engine is reduced Good or quick response is required.

  Therefore, it is theoretically considered that the response is considered to be the best, such that the engine output torque is reduced by controlling the displacement characteristics of the intake valve (for example, the lift amount of the intake valve, the valve closing timing, etc.). Conceivable. However, since the actuator that controls the displacement characteristics of the intake valve is attached to the engine body, it is exposed to severe thermal conditions. For this reason, in the case of driver non-participatory control that requires good responsiveness, control by changing the displacement characteristics of the intake valve is not always effective, unlike when the engine output torque is controlled according to the driver's request or intention. There is a problem that it is not a good idea.

  The present invention has been made to solve the above-described conventional problems, and reliably and appropriately performs non-driver-related control such as traction control in a vehicle engine or an internal combustion engine with good responsiveness. It is an object to be solved to provide a means for enabling this.

  An intake valve that is driven by a crankshaft and that reciprocates in synchronization with the rotation of the crankshaft to open and close a communication portion between the intake passage and the combustion chamber. In a method for controlling an internal combustion engine for a vehicle having a throttle valve disposed in an intake passage (hereinafter referred to as “internal combustion engine control method”), a first mode and a second mode are provided. In the first mode, the lift amount of the intake valve and the opening degree of the throttle valve are controlled so that a target air amount of air determined according to the required torque of the driver of the vehicle is filled in the combustion chamber. In the second mode, the lift amount of the intake valve and the throttle valve are adjusted so that the combustion chamber is filled with air of a target air amount determined in accordance with a required torque from a vehicle other than the vehicle driver (for example, a vehicle control device). Control the opening. In this internal combustion engine control method, the intake valve lift amount in the second mode and the intake valve lift amount in the first mode flow into the combustion chamber in the second mode than in the first mode for the same air amount. The throttle valve opening in the second mode is set smaller than the throttle valve opening in the first mode.

  In the internal combustion engine control method according to the present invention, in the first mode and the second mode, the valve closing timing of the intake valve may be controlled together with or in place of the lift amount control of the intake valve. Good. In this case, for the same amount of air, the closing timing of the intake valve in the second mode and the closing timing of the intake valve in the first mode are the flow rates of air flowing into the combustion chamber in the second mode than in the first mode. It is preferable to set the throttle valve opening in the second mode to be smaller than the throttle valve opening in the first mode.

  In the internal combustion engine control method according to the present invention, the required torque may be decreased when the second mode control is executed, and the required torque may be increased (or restored) after the second mode control is completed. You may make it perform control of 1st mode before and after execution of control of 2nd mode. Further, in the second mode, the throttle valve may be controlled with a corrected opening degree obtained by adding a lead correction to the opening degree of the throttle valve determined by the target air amount as a target value.

  In the internal combustion engine control method according to the present invention, when the actual output torque is larger than the required torque during the execution of the control in the second mode, the amount of fuel supplied to the combustion chamber is reduced and / or the ignition timing. May be retarded. Further, the lift amount of the intake valve may be increased as the target air amount is increased, or the closing timing of the intake valve may be advanced.

  An internal combustion engine system according to the present invention includes a vehicle internal combustion engine and a controller. Here, the vehicle internal combustion engine includes an intake valve that is driven by a crankshaft and reciprocates in synchronization with rotation of the crankshaft to open and close a communication portion between the intake passage and the combustion chamber, and an intake valve lift A variable lift amount mechanism for changing the amount and a throttle valve disposed in the intake passage are provided. In the first mode, the controller fills the combustion chamber with air of a target air amount that is determined according to the required torque of the driver of the vehicle, while in the second mode, it is determined according to the required torque from something other than the driver of the vehicle. The lift amount variable mechanism and the throttle valve are controlled so that the target air amount is filled in the combustion chamber. In this internal combustion engine system, the lift amount of the intake valve in the second mode is set larger than the lift amount of the intake valve in the first mode for the same air amount, and the opening degree of the throttle valve in the second mode is It is set smaller than the opening of the throttle valve in the 1 mode.

  In the internal combustion engine system according to the present invention, a phase variable mechanism for changing the phase of the intake valve is provided in addition to or instead of the lift amount variable mechanism, and the controller is added to or replaced with the lift amount variable mechanism. Thus, the phase variable mechanism may be controlled. In this case, for the same amount of air, the closing timing of the intake valve in the second mode is set earlier than the closing timing of the intake valve in the first mode, and the throttle opening in the second mode is the throttle opening in the first mode. The opening is preferably set smaller than the opening.

  According to the internal combustion engine control method or the internal combustion engine system according to the present invention, when the cylinder air amount is controlled according to the request of the vehicle driver, the intake pipe pressure is set to be relatively high. The In this case, the operation efficiency of the internal combustion engine can be improved by reducing the pump loss. On the other hand, when the cylinder air amount is controlled by a request from a person other than the driver of the vehicle, the cylinder air amount is controlled by lowering the intake pipe pressure with a throttle valve having a relatively small thermal load. Thereby, it is possible to reliably and appropriately control the amount of air in a scene where good responsiveness is required. Thus, driver non-participation control such as traction control in an internal combustion engine for a vehicle can be reliably and appropriately performed with good responsiveness.

(Embodiment 1)
Embodiment 1 of the present invention will be specifically described below with reference to the accompanying drawings.
FIG. 1 is a schematic diagram showing the configuration of an internal combustion engine system according to Embodiment 1 of the present invention. As shown in FIG. 1, the internal combustion engine system S controls an engine 1 (internal combustion engine), various actuators attached to the engine 1, various sensors, and each actuator based on signals from these sensors. An engine control unit 100 (controller).

  The engine 1 is, for example, a spark ignition type four-cycle four-cylinder engine that uses gasoline, ethanol, LPG, hydrogen, or the like as fuel, which is not shown, but includes first to fourth four cylinders 11 (cylinders). Have In the present invention, the engine 1 is not limited to a four-cylinder engine, and may have any number of cylinders. The engine 1 is mounted on a vehicle such as an automobile, and its crankshaft 14 is connected to drive wheels (not shown) via a transmission (not shown) to propel the vehicle. The geometric compression ratio of the engine 1 is preferably 13 or more, particularly preferably 14 or more and 16 or less.

  As the geometric compression ratio of the engine 1 increases, the expansion ratio increases and the engine efficiency increases. Therefore, in the first embodiment, the geometric compression ratio is set to 13 or more, and the high torque and the fuel consumption are significantly reduced while avoiding the occurrence of knocking by the ignition timing retard or the like. In addition, the higher the geometric compression ratio, the higher the possibility of abnormal combustion such as pre-ignition and knocking. Therefore, it is also necessary to reduce the effective compression ratio to reduce the charging efficiency. However, when the effective compression ratio is reduced, the output per unit volume of the cylinder 11 is reduced, and the efficiency when viewed in terms of the weight ratio of the internal combustion engine system S is reduced. Furthermore, when the engine 1 is mounted on a vehicle, a problem arises in layout or mountability in the engine room. Considering such various circumstances, the upper limit of the geometric compression ratio is preferably 16.

  The engine 1 includes a cylinder block 12 and a cylinder head 13 disposed thereon, and four cylinders 11 are formed therein. A crankshaft 14 is rotatably supported in the cylinder block 12. The crankshaft 14 is connected to the piston 15 of each cylinder 11 via a connecting mechanism including a connecting rod 16 and the like.

  In each cylinder 11, the piston 15 is slidably inserted into the cylinder 11 to define a combustion chamber 17. The cylinder head 13 is formed with two intake ports 18 and two exhaust ports 19 for each cylinder 11 (one in FIG. 1 is shown). Both ports 18, 19 communicate with the combustion chamber 17. An intake valve 21 and an exhaust valve 22 that can block or block the ports 18 and 19 and the combustion chamber 17 are provided for the intake port 18 and the exhaust port 19, respectively. The intake valve 21 and the exhaust valve 22 are driven by an intake valve drive mechanism 30 and an exhaust valve drive mechanism 40, respectively, and reciprocate at a predetermined timing to open and close the intake port 18 and the exhaust port 19.

The intake valve drive mechanism 30 has an intake camshaft 31, while the exhaust valve drive mechanism 40 has an exhaust camshaft 41. Both camshafts 31 and 41 are rotationally driven by the crankshaft 14 via a power transmission mechanism such as a known chain / sprocket mechanism. The power transmission mechanism of the engine 1 is configured such that both camshafts 31 and 41 rotate once while the crankshaft 14 rotates twice. The phase angle of the intake camshaft 31 is detected by the cam phase sensor 70, and its detection signal θ _{VVT is} detected. _A is input to the engine control unit 100. Further, the lift amount θ _VVL of the intake valve 21 _{A is} also input to the engine control unit 100.

  The spark plug 51 is attached to the cylinder head 13. The ignition system 52 receives the control signal SA from the engine control unit 100 and energizes the spark plug 51 so that a spark is generated at a desired ignition timing. The fuel injection valve 53 is attached to one side surface (intake side) of the cylinder head 13. The tip of the fuel injection valve 53 is positioned below the two intake ports 18 in the vertical direction, and is positioned in the middle of the two intake ports 18 in the horizontal direction and faces the combustion chamber 17.

  Although not shown, the fuel supply system 54 includes a high-pressure pump that boosts the fuel and supplies the fuel to the fuel injection valve 53, a pipe and a hose that supply the fuel in the fuel tank to the high-pressure pump, and the fuel injection valve 53. And an electric circuit to be driven. This electric circuit receives the control signal FP from the engine control unit 100, operates the solenoid of the fuel injection valve 53, and causes the fuel injection valve 53 to inject a predetermined amount of fuel at a predetermined timing.

  The intake port 18 is connected to a surge tank 55 a that stabilizes the flow of intake air (fuel combustion air) via an intake passage 55 b in the intake manifold 55. Intake air from an air cleaner (not shown) is supplied to the surge tank 55 a through the throttle body 56. A throttle valve 57 is disposed in the throttle body 56. The throttle valve 57 throttles the intake air toward the surge tank 55a and controls or adjusts the flow rate thereof. The throttle actuator 58 receives the control signal TVO from the engine control unit 100 and controls or adjusts the opening degree of the throttle valve 57.

  The exhaust port 19 communicates with the exhaust passage in the exhaust pipe via the exhaust passage in the exhaust manifold 60. An exhaust gas purification system having one or a plurality of catalytic converters 61 is disposed in the exhaust passage downstream of the exhaust manifold 60. The catalytic converter 61 uses an exhaust gas purification catalyst such as a three-way catalyst, a lean NOx catalyst, or an oxidation catalyst. Note that any type of catalyst other than these catalysts may be used as long as it meets the purpose of exhaust gas purification.

The intake manifold 55 and the exhaust manifold 60 communicate with each other via the EGR pipe 62, whereby a part of the exhaust gas is recirculated to the intake system as EGR gas. The EGR pipe 62 is provided with an EGR valve 63 for controlling or adjusting the flow rate of the EGR gas that flows back to the intake system through the EGR pipe 62. The EGR valve 63 is driven by an EGR valve actuator 64. The EGR valve actuator 64 drives the EGR valve 63 so that the opening degree of the EGR valve 63 becomes the EGR opening degree EGR _OPEN calculated by the engine control unit 100. Thereby, the flow rate of EGR gas is appropriately controlled or adjusted.

  The engine control unit 100 is a comprehensive controller of the internal combustion engine system S or engine 1 having a computer or a microcomputer, and includes a central processing unit (CPU) that executes processing such as computation according to a program, RAM, and ROM And a memory for storing programs and data, and an input / output bus (I / O bus) serving as an input / output path for electric signals to the engine control unit 100.

The engine control unit 100 includes, as control information, the valve phase angle θ _VVT of the intake camshaft 31 detected by the cam phase sensor 70. _A , lift amount θ _VVL of intake valve 21 _A , various signals such as an intake air flow rate AF detected by the air flow sensor 71, an intake manifold pressure MAP (intake pressure) detected by the intake pressure sensor 72, and a crank angle pulse signal detected by the crank angle sensor 73 are input. The Then, the engine control unit 100 calculates the engine rotation speed N _ENG based on, for example, a crank angle pulse signal. Further, the engine control unit 100 detects the oxygen concentration EGO (and thus the air-fuel ratio) of the exhaust gas detected by the oxygen concentration sensor 74 (for example, a linear oxygen concentration sensor) and the depression amount of the accelerator pedal 69, that is, the accelerator opening. The accelerator control signal α output from the accelerator opening sensor 75 and the vehicle speed signal VSP output from the vehicle speed sensor 76 for detecting the rotational speed of the output shaft (not shown) of the transmission and the vehicle speed are input.

The engine control unit 100 calculates various control parameters of the engine 1 based on the various control information input thereto. For example, an appropriate throttle opening TVO, fuel injection amount FP, ignition timing SA, valve phase angle θ _VVT , lift amount θ _{VVL, and the} like are calculated. Then, based on these control parameters, throttle control signals TVO, fuel injection pulse signals FP, ignition pulse signals SA, valve phase angle signals θ _VVT , lift amount signals θ _VVL, etc. are used as the corresponding control signals. It outputs to the actuator 58, the fuel supply system 54, the ignition system 52, the phase variable mechanism 32 of the intake camshaft 31, the lift amount variable mechanism 33, and the like.

  Next, the intake valve drive mechanism 30 according to the first embodiment will be described in detail with reference to FIGS. 2 and 3. FIG. 2 is a perspective view showing a specific configuration of intake valve drive mechanism 30 of engine 1 of internal combustion engine system S shown in FIG. FIGS. 3A to 3D are cross-sectional views showing the main parts of the intake valve drive mechanism 30 shown in FIG. 3A shows a state where the lift amount of the intake valve 21 is 0 in the large lift amount control state, and FIG. 3B shows a state where the lift amount of the intake valve 21 is maximum in the large lift amount control state. 3C shows a state where the lift amount of the intake valve 21 is 0 in the small lift amount control state, and FIG. 3D shows a state where the lift amount of the intake valve 21 is maximum in the small lift amount control state. Show.

  As shown in FIGS. 2 and 3A to 3D, the intake valve drive mechanism 30 includes a displacement adjustment mechanism that adjusts the displacement characteristics of the intake valve 21. This displacement adjustment mechanism includes a phase variable mechanism 32 (hereinafter referred to as “VVT mechanism 32”) that can change the rotation phase of the intake camshaft 31 with respect to the crankshaft 14, and a lift amount (valve lift amount) of the intake valve 21. The lift amount variable mechanism 33 (hereinafter referred to as “VVL mechanism 33”) that can be continuously changed. The VVT mechanism 32 is drivingly connected to the crankshaft 14 by a chain drive mechanism. Although not shown, the chain drive mechanism is provided with a drive sprocket of the crankshaft 14 in addition to the driven sprocket 104 and a chain wound around both the sprockets.

  The VVT mechanism 32 has a case fixed to the driven sprocket 104 and rotating integrally with the driven sprocket 104, and a rotor housed in the case and fixed to the inner shaft 105 and rotated integrally with the inner shaft 105. . Although not shown in detail, a plurality of hydraulic chambers are provided between the case and the rotor, and these hydraulic chambers are formed around the central axis X in the circumferential direction. Then, the liquid pressurized by the pump (for example, engine oil) is selectively supplied to each hydraulic pressure chamber, and a pressure difference is formed between the hydraulic pressure chambers facing each other. The VVT mechanism 32 is a hydraulic type, but an electromagnetic or mechanical VVT mechanism may be used.

The engine control unit 100 outputs a valve phase angle signal θ _VVT (control signal) to the electromagnetic valve 32a of the VVT mechanism 32, and the electromagnetic valve 32a receives the valve phase angle signal θ _VVT and performs hydraulic pressure duty control. Control or adjust the flow rate, pressure, etc. of the liquid supplied to the pressure chamber. Thus, the actual phase difference between the driven sprocket 104 and the inner shaft 105 is changed, thereby achieving the desired rotational phase of the inner shaft 105. A VVT control unit for controlling the VVT mechanism 32, which is separate from the engine control unit 100, may be provided.

  The VVL mechanism 33 has a disc-shaped eccentric cam 106 provided on the inner shaft 105 corresponding to each cylinder 11. These eccentric cams 106 are provided eccentric from the axis of the inner shaft 105 and rotate at a phase determined by the VVT mechanism 32. A ring-shaped arm 107 is rotatably fitted to the outer periphery of the eccentric cam 106. Here, when the inner shaft 105 rotates around the central axis X, the ring-shaped arm 107 rotates around the center of the eccentric cam 106 while revolving around the central axis X.

  Further, the inner shaft 105 is provided with a rocker connector 110 for each cylinder 11. The rocker connector 110 has a cylindrical shape, and is externally inserted into the inner shaft 105 and is coaxially supported. In other words, the rocker connector 110 is supported so as to be rotatable about its central axis X, while the outer peripheral surface of the rocker connector 110 is a bearing journal, and the bearing cap (see FIG. (Not shown) is rotatably supported.

  The rocker connector 110 is integrally provided with first and second rocker cams 111 and 112. Since the configuration of both the rocker cams 111 and 112 is the same, only the first rocker cam 111 is shown in FIGS. 3A to 3D, and the second rocker cam 112 is not shown. The first rocker cam 111 has a cam surface 111a and a circumferential base surface 111b (see FIG. 3D), and both the cam surface 111a and the base surface 111b are in sliding contact with the upper surface of the tappet 115. It is like that. The first rocker cam 111 presses the tappet 115 to open the intake valve 21 in the same manner as a cam of a general intake valve drive mechanism except that it does not rotate continuously and swings. It is. The tappet 115 is supported by a valve spring 116. The valve spring 116 is supported between two cages 117 and 118 (see FIG. 3B).

  A control shaft 120 is disposed above the assembly in parallel with the assembly including the inner shaft 105, the rocker connector 110, and both rocker cams 111 and 112. The control shaft 120 is rotatably supported by a bearing (not shown), and a coaxial worm gear 121 protruding from the outer peripheral surface is integrally provided near the center in the longitudinal direction.

The worm gear 121 is engaged with the worm 122. The worm 122 is fixed to the output shaft of a stepping motor 123 that is an actuator of the VVL mechanism 33. Therefore, the operation of the stepping motor 123 that receives the lift amount signal θ _VVL ) (control signal) from the engine control unit 100 can rotate the control shaft 120 to a desired position. A control arm 131 for each cylinder 11 is attached to the control shaft 120 rotated in this way, and these control arms 131 are rotated together with the rotation of the control shaft 120.

  The control arm 131 is connected to the ring-shaped arm 107 via the control link 132. That is, one end of the control link 132 is rotatably connected to the tip of the control arm 131 by the control pivot 133. The other end of the control link 132 is rotatably connected to the ring-shaped arm 107 by a common pivot 134.

  Here, the common pivot 134 connects the other end of the control link 132 to the ring-shaped arm 107 as described above, and penetrates the ring-shaped arm 107 to the one end of the rocker link 135. Are also rotatably connected. The other end of the rocker link 135 is rotatably connected to the first rocker cam 111 by a rocker pivot 136. Thereby, the rotation of the ring-shaped arm 107 is transmitted to the rocker cam 111.

  Specifically, when the inner shaft 105 rotates and the eccentric cam 106 rotates integrally therewith, as shown in FIGS. 3A and 3C, if the eccentric cam 106 is positioned on the lower side, The ring-shaped arm 107 is also located on the lower side. On the other hand, as shown in FIGS. 3B and 3D, when the eccentric cam 106 is positioned on the upper side, the ring-shaped arm 107 is also positioned on the upper side. At this time, the position of the common pivot 134 that connects the ring-shaped arm 107 and the control link 132 is a three-way positional relationship between the position of the control pivot 133 and the common center position of the eccentric cam 106 and the ring-shaped arm 107. Determined by. Therefore, when the position of the control pivot 133 does not change, that is, when the control shaft 120 does not rotate, the common pivot 134 generally corresponds only to the rotation around the common center of the eccentric cam 106 and the ring-shaped arm 107. Reciprocate up and down.

  Such reciprocating motion of the common pivot 134 is transmitted to the first rocker cam 111 by the rocker link 135. As a result, the first rocker cam 111 swings around the central axis X together with the second rocker cam 112 connected by the rocker connector 110. Thus, as shown in FIGS. 3B and 3C, the rocker cam 111 that swings can resist the tappet 115 against the spring force of the valve spring 116 while the cam surface 111 a contacts the upper surface of the tappet 115. And push down. As a result, the tappet 115 pushes down the intake valve 21, and as a result, the intake port 18 is opened.

  On the other hand, as shown in FIGS. 3A and 3C, when the base surface 111b of the rocker cam 111 contacts the upper surface of the tappet 115, the tappet 115 is not pushed down. This is because the radius of the base surface 111 b of the rocker cam 111 around the central axis X is set to be equal to or smaller than the distance between the central axis X and the upper surface of the tappet 115. In the mutual positional relationship between the control pivot 133, the common pivot 134, and the common center of the eccentric cam 106 and the ring-shaped arm 107, if the position of the control pivot 133 is changed, this causes mutual interaction between the three parties. A change occurs in the positional relationship, and the common pivot 134 reciprocates along a different locus.

  Therefore, the rocking range of both rocker cams 111 and 112 can be changed by rotating the control shaft 120 and the control arm 131 by operating the stepping motor 123 and changing the position of the control pivot 133. For example, when the control arm 131 is rotated clockwise in the positional relationship in FIG. 3 and the control pivot 133 is shifted from the position shown in FIG. 3A to the upper left side as shown in FIG. 3C, The rocking range of the rocker cam 111 is relatively strong in that the base surface 111 b tends to contact the upper surface of the tappet 115.

FIG. 4 is a diagram showing a setting example of displacement characteristics or operation characteristics (lift amount and opening / closing timing of the intake valve 21) of the intake valve 21 in the intake valve drive mechanism 30 of the internal combustion engine system S or the engine 1. As shown in FIG. 4, the lift amount θ _VVL of the intake valve 21 is, for example, θ _VVL by the intake valve drive mechanism 30 and each component related thereto. _{From min} to θ _{VVL In} the range up to _max , control is performed so as to increase in accordance with an increase in the target cylinder air amount (target value of the air amount charged in each cylinder 11). On the other hand, the valve closing timing θ _VVT of the intake valve 21 is set to θ _VVT according to the increase in the lift amount θ _{VVL. From min} to θ _{VVT The} angle is retarded in the range of _max . Specifically, in this internal combustion engine system S, for example, when the engine speed N _ENG is 1500 rpm, when the intake valve 21 is opened and closed during the intake stroke, the opening timing of the intake valve 21 is exhausted in most operating regions. The valve opening is started immediately before the top dead center, and the valve closing timing (valve closing timing) is changed according to the required torque.

Further, in the internal combustion engine system S, regard the valve closing timing of the intake valve 21, and the earlier closing operation mode _{M EIVC,} are provided and later closing operation mode _{M LIVC.} Here, the early closing operation mode M _EIVC is a mode selected at low load when the cylinder air amount (the amount of air charged in the cylinder) is small, and the slow closing operation mode M _LIVC is a high load where the cylinder air amount is large. This is the mode that is sometimes selected. In the early closing operation mode M _EIVC , the intake valve 21 is closed in a first valve closing timing range INC _1st that is set to an advance side of the intake valve closing timing at which the charging efficiency becomes maximum at _every engine rotation speed N _ENG . It is done. On the other hand, in the slow closing operation mode _MLIVC , the valve closing timing is set to the retarded angle side with respect to the valve closing timing at which the charging efficiency becomes maximum at the engine rotational speed N _ENG and is separated from the first valve closing timing range INC _1st. The intake valve 21 is closed in the second valve closing timing range INC _2nd .

As is apparent from FIG. 4, the second valve closing timing range INC _2nd in which the slow closing operation mode _MLIVC is set is delayed from the first valve closing timing range INC _1st in which the early closing operation mode is set, and It is separated. Therefore, between the both valve closing timing ranges INC _1st and INC _2nd, there is an intermediate valve closing timing range (abnormal combustion concern range) INC _{IM in} which the intake valve 21 does not close during steady operation. Near the bottom dead center BDC in the intermediate closing timing range INC _IM, charging efficiency is present closing timing of the intake valve 21 becomes maximum.

  The reason for setting such an operation mode is approximately as follows. That is, when the intake valve 21 is quickly closed, the rocking amount of the rocker cam 111 is small and the resistance of the valve spring 116 is small, as is apparent from FIGS. 3 (c) and 3 (d). Operation is preferable on the low load side. However, if the closing timing of the intake valve 21 is retarded to near the intake bottom dead center as the required load increases, the possibility of abnormal combustion such as pre-ignition and knocking increases in the high compression ratio engine 1. Further, when the intake valve 21 is closed early by simply avoiding the operation region in which abnormal combustion is a concern, when the required load is high, the cylinder air amount cannot be secured and the required output cannot be obtained. .

  On the other hand, when the intake valve 21 is delayed, air can be introduced into the cylinder 11 until the piston 15 moves to the bottom dead center. Therefore, it is sufficient to close the intake valve 21 when the effective compression ratio is low. A sufficient amount of cylinder air can be secured. As apparent from FIGS. 3 (a) and 3 (b), the lift amount or lift range of the intake valve 21 is set to a maximum value near the maximum value in the operation region where the target cylinder air amount is small at low speed and low load. Since it is necessary, problems such as increased mechanical loss occur.

Therefore, in this internal combustion engine system S, while increasing the expansion ratio as much as possible in the continuous operation region, while avoiding abnormal combustion, reducing pump loss, mechanical loss in the operation region where the target cylinder air amount is small The first valve closing timing range INC _1st and the second valve closing timing range INC _2nd are set in order to reduce output and secure output in an operation region where the target cylinder air amount is large. When the transition from the early closing operation mode M _EIVC to the slow closing operation mode M _LIVC or the transition from the slow closing operation mode M _LIVC to the early closing operation mode M _EIVC is performed, the closing timing of the intake valve 21 is intermediate. Although passing through the valve closing timing range INC _IM , at this time, the tendency to excessive air is suppressed by lowering the intake pressure.

FIG. 5 is a characteristic diagram showing an example of an operation region for setting the operation mode. As shown in FIG. 5, in the internal combustion engine system S, in the operation region R _LIVC that is on the higher load side than the characteristic L1 on the high load side, the slow closing operation mode _MLIVC is set and the load is lower than the characteristic L2 on the low load side In the operation region R _EIVC which is the side, the early closing operation mode M _EIVIC is set. In FIG. 5, an operation region _RTR between the characteristic L1 and the characteristic L2 is a region used for switching the operation mode by providing hysteresis. For this reason, even if the required load increases from the operation region _REIVC , the operation mode is maintained in the early closing operation mode _MEIVC until the characteristic L1 is exceeded. On the other hand, even if the required load becomes lower from the operation region _RLIVC , the operation mode _RLIVC is maintained until the characteristic L2 is exceeded.

  As described above, the engine control unit 100 is a comprehensive control device for the internal combustion engine system S or the engine 1, and based on various control information detected by the sensors 70 to 76 and the like, the VVT mechanism 32 (electromagnetic By controlling or driving the valve 32a), the VVL mechanism 33, the spark plug 51 (ignition system 52), the fuel injection valve 53 (fuel supply system 54), the throttle valve 53 (throttle actuator 54), the EGR valve 63, etc., fuel In addition to performing normal engine control such as injection control, ignition timing control, EGR control, etc., the control according to the present invention, such as adjusting the displacement characteristics of the intake valve 21 and the opening of the throttle valve 53 in response to the required torque (hereinafter referred to as the control) "Requested torque response control"). However, for ordinary engine control, the control method is well known to those skilled in the art, and since such ordinary engine control is not the gist of the present invention, the description thereof will be omitted. The required torque response control according to the present invention will be described.

  FIG. 6 is a block diagram showing a control algorithm for request torque response control by the engine control unit 100. As shown in FIG. 6, the engine control unit 100 functionally includes a target torque calculation unit B1, a target indicated average effective pressure calculation unit B2 (hereinafter referred to as “target Pi calculation unit B2”), and target air. A filling amount calculation unit B3 (hereinafter referred to as “target CE calculation unit B3”), a target boost calculation unit B4, a target intake valve closing timing range calculation unit B5 (hereinafter referred to as “target INC calculation unit B5”), A target charging efficiency calculation unit B6 (hereinafter referred to as “target ηvp calculation unit B6”), a target throttle opening calculation unit B7 (hereinafter referred to as “target TVO calculation unit B7”), and a target lift amount calculation unit B8 (hereinafter referred to as “target”). Target VVL calculation unit B8 ") and target intake valve closing timing calculation unit B9 (hereinafter referred to as" target VVT calculation unit B9 ").

Thus, the target torque calculator B1 calculates the target torque of the engine 1 based on the accelerator opening (accelerator control signal α) and the engine speed (engine speed signal N _ENG ). The target Pi calculation unit B2 calculates a target indicated mean effective pressure (target Pi) based on the target torque calculated by the target torque calculation unit B1, the mechanical resistance of the engine 1, and the pump loss. Specifically, the target indicated mean effective pressure corresponding to the target combustion torque (target cylinder air amount) that should actually be generated by the engine 1, which is the sum (total) of the target torque and the mechanical resistance and torque loss as torque loss. calculate.

  The target CE calculation unit B3 calculates a target air filling amount (target CE) based on the target indicated mean effective pressure calculated by the target Pi calculation unit B2 and the engine speed. The target boost calculation unit B4 calculates a target boost based on the target indicated mean effective pressure calculated by the target Pi calculation unit B2, the engine speed, and the traction execution flag. The traction execution flag is a flag whose value is “1” when the traction control of the vehicle is being executed, and whose value is returned to “0” when the traction control is finished. The traction control of the vehicle suppresses slip by reducing the driving force of the driving wheel by temporarily reducing the output torque of the engine 1 when the driving wheel of the vehicle driven by the engine 1 slips. Alternatively, the control is to suppress, and is performed by a well-known ordinary control method, and thus detailed description thereof is omitted.

  The target INC calculation unit B5 calculates the target valve closing timing range (target INC) of the intake valve 21 based on the target indicated average effective pressure calculated by the target Pi calculation unit B2, the engine speed, and the traction execution flag. To do. The target ηvp calculation unit B6 calculates the target charging efficiency or the target volume efficiency (target ηvp) based on the target air filling amount calculated by the target CE calculation unit B3 and the target boost calculated by the target boost calculation unit B4. To do.

  The target TVO calculation unit B7 opens the target throttle based on the target air filling amount calculated by the target CE calculation unit B3, the target charging efficiency or target volume efficiency calculated by the target ηvp calculation unit B6, and the engine speed. The degree (target TVO) is calculated. The target VVL calculation unit B8 calculates the target valve closing timing range of the intake valve 21 calculated by the target INC calculation unit B5, the target charging efficiency or target volume efficiency calculated by the target ηvp calculation unit B6, and the engine speed. Based on this, the target lift amount (target CVVL lift amount) is calculated. The target VVT calculation unit B9 is configured to generate a target intake valve closing timing phase angle (target VVT) based on the target valve closing timing range calculated by the target INC calculation unit B5 and the target lift amount calculated by the target VVL calculation unit B8. (Phase angle) is calculated.

  Hereinafter, an outline of the required torque response control executed by the engine control unit 100 including the calculation units B1 to B9 will be described. In the required torque response control, the control in the first mode or the control in the second mode is performed depending on whether the required torque is caused by the request or intention of the driver of the vehicle. That is, during normal operation in which special torque control such as traction control based on the judgment of the engine control unit 100 itself is not performed, control in the first mode is performed, while when such special torque control is performed. Control in the second mode is performed. In the first embodiment, the control method of the required torque response control is described taking the case where traction control is performed as such special control as an example. In the present invention, such special torque control is described. Is not limited to traction control.

  Specifically, in the first mode, the lift of the intake valve 21 is basically set so that the combustion chamber 17 is filled with air of a target air amount determined according to the accelerator opening, that is, the required torque of the driver of the vehicle. The amount, the intake valve closing timing phase angle, and the throttle opening are controlled. On the other hand, in the second mode, the lift amount of the intake valve 21 and the intake valve are set so that the combustion chamber 17 is filled with air of a target air amount determined according to the required torque of the engine control unit 100 itself during traction control. The valve closing timing phase angle and the throttle opening are controlled. When the traction control is started, the required torque becomes low. That is, when the control in the second mode is started during the control in the first mode, the required torque is reduced. When the control in the second mode is completed and the control returns to the control in the first mode, the required torque is reduced. Is raised (returned).

  In this required torque response control, the lift amount of the intake valve 21 in the second mode is such that the flow rate of air flowing into the combustion chamber 17 in the second mode is larger in the second mode than in the first mode for the same air amount. A value larger than the lift amount of the intake valve 21 in the first mode is set, and the throttle opening in the second mode is set to a value smaller than the throttle opening in the first mode.

  In the required torque response control, when the control in the second mode is performed, the throttle valve 57 is controlled with a corrected opening obtained by performing advance correction on the throttle opening determined by the target air amount as a target value. In addition, when the actual output torque is larger than the required torque when the second mode control is executed, the amount of fuel supplied to the combustion chamber 17 can be reduced in order to quickly reduce the output torque, and / or The ignition timing is retarded and the output torque of the engine 1 is reduced. Furthermore, the larger the target air amount, the larger the lift amount of the intake valve 21 is set, and / or the valve closing timing of the intake valve 21 is advanced.

  Hereinafter, an example of the control method of the required torque response control according to the first embodiment executed by the engine control unit 100 will be described in detail with reference to the flowchart shown in FIG. Although not shown in the flowchart shown in FIG. 7, in the internal combustion engine system S or the engine 1, the fuel injection amount control and the ignition timing control are performed simultaneously with the required torque response control.

  As shown in FIG. 7, in this requested torque response control, when control is started (start), first, various signals are read as control information in step S1. For example, signals corresponding to the intake camshaft phase angle, intake air flow rate, intake manifold pressure, crank angle pulse signal, exhaust gas oxygen concentration, accelerator opening, vehicle speed, etc. detected by the sensors 70 to 76, etc. (see FIG. 1) and each signal corresponding to the traction flag value, engine speed, etc. generated or calculated by the engine control unit 100 itself are read.

Subsequently, in step S2, the target torque of the engine 1 is calculated based on the accelerator opening (accelerator control signal α) and the engine speed (engine speed signal N _ENG ). Note that the fuel injection amount of the fuel injection valve 53 and the ignition timing of the spark plug 51 are set based on the target torque and the engine speed. In step S3, the target indicated mean effective pressure corresponding to the target combustion torque to be actually generated by the engine 1, which is the sum of the target torque calculated in step S2 and the loss torque resulting from mechanical resistance and pump loss. (Target Pi) is calculated. Further, in step S4, a target air filling amount (target CE) is calculated based on the target indicated mean effective pressure calculated in step S3 and the engine speed.

  Next, in step S5, it is determined whether or not the value of the traction execution flag is “1”, that is, whether or not traction control is being executed. During execution of traction control, a required torque lower than that in the normal driving state is set according to a torque down request according to the slip state of the vehicle. For example, the required torque decreases as the slipping degree of the drive wheel increases.

  When it is determined in step S5 that the value of the traction execution flag is not “1” (NO), that is, in a normal driving state in which traction control is not executed (normal time), basically in step S6, The target boost for normal time corresponding to the required torque of the driver of the vehicle is calculated. In this case, in the subsequent steps S8 and S10 to S14, the control of the first mode is performed based on the normal target boost.

  On the other hand, when it is determined in step S5 that the value of the traction execution flag is “1” (YES), that is, when traction control is being executed (at the time of traction control), the target boost for traction control at step S7. Is calculated. In this case, in the subsequent steps S9 to S14, control of the second mode is performed based on the target boost for traction control. Here, during traction control execution, a target boost lower than that during normal operation is set, but with the conventional control method, normal boost is set even during traction control execution (see FIG. 8).

  Thus, after the target boost for normal time or traction control is calculated in step S6 or step S7, depending on whether it is normal time or traction control time, step S8 or step S9 Based on the target indicated mean effective pressure calculated in S3 and the engine speed, the target valve closing timing range (target INC) of the intake valve 21 for normal use or traction control is calculated.

  Next, in step S10, based on the target air filling amount calculated in step S4 and the target boost calculated in step S6 or step S7, the target charging corresponding to the mode (first mode or second mode) is performed. Efficiency or target volume efficiency (target ηvp) is calculated. Subsequently, in step S11, based on the target air filling amount calculated in step S4, the target charging efficiency or target volume efficiency calculated in step S10, and the engine speed, the target throttle opening corresponding to the mode. (Target TVO) is calculated.

  Further, in step S12, the target valve closing timing range of the intake valve 21 for normal time or traction control calculated in step S8 or step S9, the target charging efficiency or target volume efficiency calculated in step S10, and Based on the engine speed, the target lift amount (target CVVL lift amount) corresponding to the mode is calculated. Subsequently, in step S13, the normal valve or traction control target valve closing timing range calculated in step S8 or step S9 and the target lift amount calculated in step S12 are set according to the mode. A target intake valve closing timing phase angle (target VVT phase angle) is calculated.

  Thereafter, in step S14, based on the target throttle opening calculated in step S11, the target lift amount calculated in step S12, and the target intake valve closing timing phase angle calculated in step S13, The throttle actuator 58, the VVT mechanism 32 (electromagnetic valve 32a), and the VVL mechanism 33 are driven so that the target value is realized. At the same time, fuel injection by the fuel injection valve 53 and ignition of the air-fuel mixture by the spark plug 51 are performed at a predetermined timing.

Specifically, the signal θ _VVT is output to the VVT mechanism 32, and the VVT mechanism 32 operates so that the phase of the intake camshaft 31 with respect to the crankshaft 14 has a value corresponding to the signal θ _VVT . Then, the signal θ _VVL is output to the VVL mechanism 33, and the VVL mechanism 33 operates so that the lift amount of the intake valve 21 becomes a value corresponding to the signal θ _VVL . Further, the signal actuator TVO is output to the throttle actuator 58, and the throttle actuator 58 operates so that the opening degree TVO of the throttle valve 57 becomes a value corresponding to the signal TVO.

  The fuel injection amount signal FP is output to the fuel system 54, and an amount of fuel corresponding to FP per cylinder cycle is injected from the fuel injection valve 53. Further, an ignition timing signal SA is output to the ignition system 52, and at a time corresponding to the signal SA in the cylinder cycle, the spark plug 51 generates a spark and ignites the air-fuel mixture in the combustion chamber 17. As a result, the required amount of air-fuel mixture is ignited and combusted at an appropriate time, and the target torque is output from the engine 1.

FIG. 8 shows a case where the traction control is started at time t ₁ and the traction control ends at time t ₂ and returns to a normal driving state in the vehicle in which the requested torque response control according to the first embodiment is performed. 5 is a graph showing change characteristics with respect to time of required torque, boost, throttle opening, lift amount (CVVL lift) of intake valve 21 and torque (or air charge amount CE). In FIG. 8, a solid line graph indicates a state when the required torque response control according to the first embodiment is performed, and a broken line graph indicates a state when the conventional traction control is performed. .

As is apparent from FIG. 8, in the required torque response control according to the first embodiment, when the traction control is being executed (time t ₁ to time t ₂ ), that is, when the second mode control is being performed, A lower required torque is set than when the control in the first mode is performed. The target boost is set lower than normal. For this reason, the throttle opening is set smaller than normal, while the target lift amount is set larger than normal.

As a result, the output torque of the engine 1 (solid line), after the traction control is started at time t _1, rapidly decreases as compared to conventional control (broken line), after the traction control has been completed in time t _2, the Compared to the conventional control (broken line), it quickly rises or returns. That is, according to the required torque response control according to the first embodiment, the actual torque responsiveness to the torque down request at the time of executing the traction control becomes better than the conventional control. For this reason, vehicle traction control can be reliably and appropriately performed with good responsiveness.

(Embodiment 2)
The second embodiment of the present invention will be described below with reference to FIGS. However, the configuration, function, control system, and the like of the internal combustion engine system S ′ or the engine 1 ′ according to the second embodiment have many common points with the internal combustion engine system S or the engine 1 according to the first embodiment. In order to avoid duplication, the following mainly describes differences from the first embodiment. In the internal combustion engine system S ′ shown in FIG. 9, the same reference numerals are given to components having the same configuration and function as those of the internal combustion engine system S shown in FIG.

  As shown in FIG. 9, in the internal combustion engine system S ′ according to the second embodiment, the displacement adjustment mechanism of the intake valve 21 of the intake valve drive mechanism 30 changes the rotational phase of the intake camshaft 31 relative to the crankshaft 14. The VVT mechanism 32 (variable phase mechanism) and the electromagnetic valve 32a are provided, but the VVL mechanism (variable lift amount mechanism) for changing the lift amount of the intake valve 21 is not provided. The other points are substantially the same as the configuration of the internal combustion engine system S according to the first embodiment.

  The configuration and function of the VVT mechanism 32 according to the second embodiment are substantially the same as those of the VVT mechanism 32 in the engine 1 according to the first embodiment. That is, the VVT mechanism 32 according to the second embodiment is for changing the valve timing of the intake valve 21, and is arranged coaxially with the intake camshaft 31 and driven shaft that is directly driven by the crankshaft 14. By changing the phase difference between the intake camshaft 31 and the intake camshaft 31, the phase difference between the crankshaft 14 and the intake camshaft 31 is changed. As the VVT mechanism 32, for example, a hydraulic mechanism similar to that in the first embodiment or an electromagnet provided between the driven shaft and the intake camshaft 31 are provided, and electric power is applied to the electromagnet. An electromagnetic mechanism or the like that changes the phase difference can be used.

The VVT mechanism 32 changes the phase difference based on the valve timing of the intake valve 21 calculated by the engine control unit 100. The VVT mechanism 32 changes the phase difference while keeping the valve opening period and the lift amount, that is, the valve profile, of the intake valve 21 constant, thereby adjusting the valve opening timing and the valve closing timing (IVC) of the intake valve 21. change. The phase angle of the intake camshaft 31 is detected by the cam phase sensor 70, and its signal θ _IVC is detected. _A is transmitted to the engine control unit 100.

  As shown in FIG. 10, generally, the air filling amount CE in the cylinder 11 becomes the largest when the valve closing timing IVC of the intake valve 21 is slightly retarded from the bottom dead center (BDC). On the more retarded side, the air in the cylinder 11 is blown back to the intake port side 18 and thus decreases.

  FIG. 11 is a block diagram showing a control algorithm for required torque response control by the engine control unit 100 in the internal combustion engine system S ′ according to the second embodiment. As shown in FIG. 11, in this engine control unit 100, the lift amount of the intake valve 21 is not controlled, and therefore the target VVL calculation unit is not provided. Then, the target VVT calculation unit B9 is configured to close the target intake valve based on the target valve closing timing range calculated by the target INC calculation unit B5 and the target charging efficiency or target volume efficiency calculated by the target ηvp calculation unit B6. Calculate the timing phase angle. Other points are substantially the same as those of the engine control unit 100 according to the first embodiment.

  Hereinafter, the control method of the required torque response control according to the second embodiment executed by the engine control unit 100 will be specifically described with reference to the flowchart shown in FIG. Although not described in the flowchart shown in FIG. 12, in this internal combustion engine system S ′ or engine 1 ′ as well as in the first embodiment, the fuel injection amount control and ignition are performed simultaneously with the required torque response control. Timing control is performed.

  As shown in FIG. 12, in this required torque response control, when control is started (start), first, in step S21, various signals are read as control information as in the case of the first embodiment (step S1). It is. Subsequently, in step S22, the target torque of the engine 1 is calculated as in the case of the first embodiment (step S2). Note that the fuel injection amount of the fuel injection valve 53 and the ignition timing of the spark plug 51 are set based on the target torque and the engine speed.

  Next, in steps S23 and S24, as in the case of the first embodiment (steps S3 and S4), the target indicated mean effective pressure (target Pi) and the target air filling amount (target CE) are calculated. Subsequently, in steps S25 to S27, as in the case of the first embodiment (steps S5 to S7), depending on whether or not the value of the traction execution flag is “1” (for the first mode) ) Or a target boost for traction control (second mode) is calculated. In step S28 or step S29, as in the case of the first embodiment (steps S8 and S9), the target valve closing timing range (target INC) of the intake valve 21 for normal time or for traction control is calculated. The Further, in step S30, as in the case of the first embodiment (step S10), the target filling efficiency or the target volume efficiency (target ηvp) is calculated. Subsequently, in step S31, the target throttle opening (target TVO) is calculated as in the case of the first embodiment (step S11).

  Further, in step S32, the target intake air based on the target valve closing timing range for normal time or for traction control calculated in step S28 or step S29 and the target charging efficiency or target volume efficiency calculated in step S30. A valve closing timing phase angle (target VVT phase angle) is calculated. Thereafter, in step S33, the throttle actuator 58 is realized so that the target value is realized based on the target throttle opening calculated in step S31 and the target intake valve closing timing phase angle calculated in step S32. Then, the VVT mechanism 32 (electromagnetic valve 32a) is driven.

Specifically, the signal θ _VVT is output to the VVT mechanism 32, and the VVT mechanism 32 operates so that the phase of the intake camshaft 31 with respect to the crankshaft 14 has a value corresponding to the signal θ _VVT . Then, the signal TVO is output to the throttle actuator 58, and the throttle actuator 58 operates so that the opening degree TVO of the throttle valve 57 becomes a value corresponding to the signal TVO. As in the case of the first embodiment, fuel is injected from the fuel injection valve 53, the air-fuel mixture in the combustion chamber 17 is ignited, and the air-fuel mixture composed of the required amount of air and fuel is appropriate. It is ignited and burned at the time, and the target torque is output from the engine 1.

  Thus, even with the internal combustion engine system S ′ or the required torque response control according to the second embodiment, the actual torque responsiveness to the torque down request at the time of executing the traction control becomes better than the conventional control. For this reason, vehicle traction control can be reliably and appropriately performed with good responsiveness.

It is a schematic diagram which shows the structure of the internal combustion engine system which concerns on Embodiment 1 of this invention. It is a perspective view which shows the structure of the intake valve drive mechanism of the internal combustion engine system shown in FIG. (A)-(d) is a partial cross section elevation view of the intake valve drive mechanism shown in FIG. 2, respectively. 3 is a graph showing an example of setting a displacement characteristic of an intake valve in the intake valve drive mechanism of the internal combustion engine system shown in FIG. 1. It is a figure which shows the area | region where the early closing mode is set, and the area | region where the late closing mode is set which uses an engine speed and target cylinder air quantity as parameters. It is a block diagram which shows the control algorithm of the engine control unit of the internal combustion engine system shown in FIG. It is a flowchart which shows the control method of the request torque response control which concerns on Embodiment 1 by an engine control unit. 6 is a graph showing change characteristics with respect to time of required torque, boost, throttle opening, lift amount of an intake valve, and torque in a vehicle in which required torque response control according to Embodiment 1 is performed. It is a schematic diagram which shows the structure of the internal combustion engine system which concerns on Embodiment 2 of this invention. 6 is a graph showing the relationship between intake valve closing timing and air charge amount in an engine according to Embodiment 2; It is a block diagram which shows the control algorithm of the engine control unit of the internal combustion engine system shown in FIG. It is a flowchart which shows the control method of the request torque response control which concerns on Embodiment 2 by an engine control unit.

Explanation of symbols

  S internal combustion engine system, S ′ internal combustion engine system, 1 engine, 1 ′ engine, 11 cylinder, 14 crankshaft, 17 combustion chamber, 21 intake valve, 22 exhaust valve, 30 intake valve drive mechanism, 31 camshaft, 32 phase variable Mechanism (VVT mechanism), 33 Lift amount variable mechanism (VVL mechanism), 56 Throttle body, 57 Throttle valve, 100 Engine control unit.

Claims (11)

A vehicle having an intake valve that is driven by a crankshaft and reciprocates in synchronization with rotation of the crankshaft to open and close a communication portion between the intake passage and the combustion chamber, and a throttle valve disposed in the intake passage A method for controlling an internal combustion engine for
A first mode for controlling the lift amount of the intake valve and the opening of the throttle valve so that air of a target air amount determined according to the torque required by the driver of the vehicle is filled in the combustion chamber, and other than the driver of the vehicle A second mode for controlling the lift amount of the intake valve and the opening of the throttle valve so that the combustion chamber is filled with air of a target air amount determined according to the required torque from the engine,
For the same air amount, the lift amount of the intake valve in the second mode and the lift amount of the intake valve in the first mode are such that the flow rate of the air flowing into the combustion chamber is larger in the second mode than in the first mode. And setting the opening of the throttle valve in the second mode to be smaller than the opening of the throttle valve in the first mode. A vehicle having an intake valve that is driven by a crankshaft and reciprocates in synchronization with rotation of the crankshaft to open and close a communication portion between the intake passage and the combustion chamber, and a throttle valve disposed in the intake passage A method for controlling an internal combustion engine for
A first mode for controlling the closing timing of the intake valve and the opening of the throttle valve so that air of a target air amount determined according to a required torque of the driver of the vehicle is filled in the combustion chamber; A second mode for controlling the closing timing of the intake valve and the opening of the throttle valve so that air of a target air amount determined according to a required torque from other than that is filled in the combustion chamber,
For the same amount of air, the closing timing of the intake valve in the second mode and the closing timing of the intake valve in the first mode are the flow rates of air flowing into the combustion chamber in the second mode than in the first mode. And setting the opening of the throttle valve in the second mode to be smaller than the opening of the throttle valve in the first mode.   The method for controlling an internal combustion engine according to claim 1, wherein the required torque is reduced when the second mode control is executed, and the required torque is increased after the end of the second mode control.   The method for controlling an internal combustion engine according to claim 3, wherein the control in the first mode is executed before and after the execution of the control in the second mode.   The second mode is characterized in that the throttle valve is controlled with a corrected opening obtained by adding a lead correction to the opening of the throttle valve determined by a target air amount as a target value. A method for controlling an internal combustion engine according to any one of the preceding claims.   6. The internal combustion engine according to claim 5, wherein the amount of fuel supplied to the combustion chamber is reduced when the actual output torque is larger than the required torque when the second mode control is executed. Method.   6. The method for controlling an internal combustion engine according to claim 4, wherein the ignition timing is retarded when the actual output torque is larger than the required torque when the control in the second mode is executed.   2. The method for controlling an internal combustion engine according to claim 1, wherein the lift amount of the intake valve is increased as the target air amount increases.   3. The method for controlling an internal combustion engine according to claim 2, wherein the closing timing of the intake valve is advanced as the target air amount increases. An intake valve that is driven by the crankshaft and reciprocates in synchronization with the rotation of the crankshaft to open and close the communicating portion between the intake passage and the combustion chamber, and a lift amount variable mechanism that changes the lift amount of the intake valve And an internal combustion engine having a throttle valve disposed in the intake passage,
In the first mode, air of a target air amount determined according to the required torque of the driver of the vehicle is filled in the combustion chamber, while in the second mode, the target air amount determined according to the required torque from other than the driver of the vehicle. An internal combustion engine system including the lift variable mechanism and the controller for controlling the throttle valve so that the air is filled in the combustion chamber,
For the same air amount, the lift amount of the intake valve in the second mode is set to be larger than the lift amount of the intake valve in the first mode, and the opening degree of the throttle valve in the second mode is the same as that in the first mode. An internal combustion engine system characterized in that it is set smaller than the opening of the throttle valve. An intake valve that is driven by the crankshaft to reciprocate in synchronization with the rotation of the crankshaft to open and close the communication portion between the intake passage and the combustion chamber; and a phase variable mechanism that changes the phase of the intake valve; An internal combustion engine having a throttle valve disposed in the intake passage;
In the first mode, air of a target air amount determined according to the required torque of the driver of the vehicle is filled in the combustion chamber, while in the second mode, the target air amount determined according to the required torque from other than the driver of the vehicle. An internal combustion engine system comprising the phase variable mechanism and a controller for controlling the throttle valve so that the air is filled in the combustion chamber,
For the same amount of air, the closing timing of the intake valve in the second mode is set earlier than the closing timing of the intake valve in the first mode, and the opening of the throttle valve in the second mode is the first mode. An internal combustion engine system characterized in that the opening is set smaller than the opening of the throttle valve.

Images