JP2010196499A - Variable valve gear of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable valve gear of an internal combustion engine suitable for the prevention of the interference of intake/exhaust valves with a piston. <P>SOLUTION: There are provided steps S27-S28 as a response speed limiting means for lowering the response speed of a valve limit amount in a preset predetermined range up to a limit value set in step S22 as a valve lift amount limit value setting means, or steps S9-S10 as a response speed limiting means for lowering the response speed of a valve timing in a preset predetermined range up to a limit value set in a step S4 as a valve timing limit value setting means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a variable valve system for an internal combustion engine that independently performs valve timing control and valve lift amount control on at least one of an intake valve and an exhaust valve of the internal combustion engine, and more particularly, an intake valve near the top dead center. The present invention relates to a variable valve operating apparatus for an internal combustion engine suitable for preventing interference between an exhaust valve and a piston.

  Conventionally, in a variable valve system that controls the valve timing or valve lift amount of an intake valve or an exhaust valve to an optimal control amount according to the operating state of the internal combustion engine, an intake / exhaust valve and a piston near top dead center Has been proposed (see Patent Document 1).

  This is because the intake side camshaft is provided with a variable valve timing (open / close timing) mechanism and a valve characteristic switching mechanism, and both the valve timing and valve lift amount of the intake valve can be varied. Thus, the valve timing and the valve lift amount of the intake valve are variably controlled for each operation region determined by the engine speed and load. The target valve timing of the variable valve timing mechanism (VTC) on the intake valve side is obtained from the engine load and the rotational speed, while the VTC is determined according to the actual valve lift amount of the variable valve lift mechanism (VEL) on the intake valve side. When the VTC target valve timing obtained from the load and the engine speed exceeds the target valve timing upper limit value, the target valve timing is limited to the VTC target valve timing upper limit value. Yes.

JP 2002-285871 A

  However, in the above conventional example, the target valve timing is limited within the valve timing upper limit value to prevent interference between the intake / exhaust valve and the piston, but the valve timing and the response speed of the valve lift depend on the conditions. Since the actual valve lift amount is detected and there is a time delay before the valve timing is limited to the valve timing upper limit value, the valve timing advance amount increases. There is a possibility that the intake / exhaust valve and the piston may interfere with each other, and it is necessary to increase a recess (dent) provided in the piston to prevent interference.

  Accordingly, the present invention has been made in view of the above problems, and an object thereof is to provide a variable valve operating apparatus for an internal combustion engine suitable for preventing interference between an intake / exhaust valve and a piston.

  The present invention provides a limit value for limiting the control range of the valve lift amount of the corresponding intake valve or exhaust valve according to the operating state of the valve timing that is variably controlled with respect to at least one of the intake valve or the exhaust valve. A valve lift amount limit value setting unit to be set, a valve lift control limiting unit for limiting a control range of the valve lift control based on the limit value set by the valve lift amount limit value setting unit, and the valve lift amount Response speed limiting means for reducing the response speed of the valve lift amount in a predetermined range within a predetermined range up to a limit value set by the limit value setting means, or at least one of an intake valve and an exhaust valve Depending on the operating state of the valve lift that is variably controlled, the valve of the corresponding intake valve or exhaust valve Valve timing limit value setting means for setting a limit value for limiting the timing control range, and a valve for limiting the control range of the valve timing control based on the limit value set by the valve timing limit value setting means Timing control limiting means, and response speed limiting means for reducing the response speed of the valve timing in a predetermined range within a predetermined range up to a limit value set by the valve timing limit value setting means.

  Therefore, in the present invention, the response speed limiting means for reducing the response speed of the valve lift amount in a predetermined range within a predetermined range up to the limit value set by the valve lift amount limit value setting means, or the valve timing limit value Since there is a response speed limiting means for reducing the response speed of the valve timing in a predetermined range within a predetermined range up to the limit value set by the setting means, the valve timing, or the valve, where the intake / exhaust valve approaches the piston In the lift amount, when each response speed is slowed down, the valve lift amount is limited according to the valve timing operating state, or there is a time delay until the valve timing is limited according to the valve lift amount operating state. Reduce the IVO advance amount or valve lift increase amount, It is possible to achieve a reduction Seth.

The system block diagram of the variable valve operating apparatus of the internal combustion engine which shows one Embodiment of this invention. The block diagram of a variable valve apparatus. The valve lift characteristic view by a variable valve apparatus. The block diagram of a control system. The flowchart of the main control by the side of ECM of the 1st example. The flowchart of the main control by the side of VEL-C / U of 1st Example. The operation characteristic figure of a variable valve apparatus. The flowchart of the main control by the side of ECM of 2nd Example. The flowchart of the main control by the side of VEL-C / U of 2nd Example.

  Hereinafter, a variable valve operating apparatus for an internal combustion engine of the present invention will be described based on an embodiment.

  FIG. 1 is a system diagram of an engine (direct injection spark ignition type internal combustion engine) showing an embodiment of the present invention. In an intake passage 2 of the engine 1, an electric throttle valve 3 whose opening degree is controlled by an engine control unit (hereinafter referred to as ECM) 10 is installed. The air controlled by the electric throttle valve 3 is taken into the combustion chamber 5 of the engine 1 through the intake valve 4.

  The intake valve 4 is a valve operation angle (open period) of the intake valve 4, more specifically, a valve operation angle and lift amount variable device (VEL device; VEL actuator) capable of continuously changing the valve operation angle and the lift amount. 49) and a valve timing variable device (VTC device; VTC actuator 51) capable of continuously changing the valve timing of the intake valve 4 (center phase of the valve operating angle). The

  An ignition plug 6 and a fuel injection valve 7 are installed in the combustion chamber 5 of the engine 1. The fuel injection valve 7 is energized to the solenoid by an injection pulse signal output in the intake stroke or the compression stroke in synchronization with the engine rotation from the ECM 10, and is adjusted to a predetermined pressure in the combustion chamber 5. Inject fuel.

  The fuel injected into the combustion chamber 5 forms an air-fuel mixture with the air introduced into the combustion chamber, and is ignited and burned by the ignition plug 6 at the ignition timing determined by the ECM 10. The exhaust gas after combustion is discharged to the exhaust passage 9 via the exhaust valve 8.

  The ECM 10 includes signals as engine operating conditions such as an accelerator opening APO detected by the accelerator pedal sensor 11, an engine speed Ne detected by the crank angle sensor 12, and an intake air amount Qa detected by the air flow meter 13. Is entered.

  The variable valve operating device of the intake valve 4 is configured as shown in FIG. Above the valve lifter 40 at the end of the intake valve 4 (two are provided per cylinder), a camshaft 41 that is driven to rotate around the shaft in conjunction with a crankshaft (not shown) extends in the cylinder row direction. is doing. A swing cam 42 is swingably mounted on the outer periphery of the cam shaft 41 corresponding to the intake valve 4, and the swing cam 42 abuts against and presses the valve lifter 40. The valve 4 is driven to open and close against the spring force of a valve spring (not shown).

  Between the cam shaft 41 and the swing cam 42, the posture of the link that mechanically links both 41 and 42 is changed so that the valve operating angle (open period) and the lift amount of the intake valve 4 are continuously increased. Are provided with a variable valve operating angle and lift variable device (VEL device).

  The VEL device includes a drive cam 43 that is eccentrically provided on the cam shaft 41 and rotates integrally with the cam shaft 41, a ring-shaped link 44 that is fitted on the outer periphery of the drive cam 43 so as to be relatively rotatable, and a cam shaft. 41, a control shaft 45 extending substantially parallel to the cylinder row direction, a control cam 46 that is eccentrically provided on the control shaft 45 and rotates integrally with the control shaft 45, and a relative rotation around the outer periphery of the control cam 46 The rocker arm 47 has one end connected to the tip of the ring-shaped link 44 and is rotatably connected to the other end of the rocker arm 47 and the tip of the swing cam 42. , 42 are coupled to each other mechanically.

  The cam shaft 41 and the control shaft 45 are rotatably supported on the cylinder head side of the engine 1 via a bearing bracket. One end of the control shaft 45 is connected to the output end of an actuator (VEL actuator) 49 for changing the valve operating angle and lift amount. The control shaft 45 is driven to rotate around the axis within a predetermined control angle range by the VEL actuator 49. And maintained at a predetermined rotational phase.

  With the above configuration, when the camshaft 41 rotates in conjunction with the crankshaft, the ring-shaped link 44 is operated to reciprocate in the direction orthogonal to the camshaft 41 via the drive cam 43, thereby controlling the rocker arm 47. The intake valve 4 is driven to open and close by swinging around the cam 46 and swinging the swing cam 42 via the rod-shaped link 48.

  Further, by changing the rotation position of the control shaft 45 by the VEL actuator 49, the center position of the control cam 46 which is the rocking center of the rocker arm 47 is changed, and the postures of the links 44, 48, etc. are changed. The swing angle range of the swing cam 42 changes. As a result, the valve operating angle and the lift amount continuously change while the central phase of the valve operating angle remains substantially constant. For example, when the control shaft 45 is rotated in one direction, the valve operating angle and the lift amount are increased, and when the control shaft 45 is rotated in the other direction, the valve operating angle and the lift amount are decreased. If the valve operating angle is determined, the valve lift amount is uniquely determined.

  Therefore, by duty-controlling the energization amount of the VEL actuator 49, the rotational position of the control shaft 45 can be changed to change the valve operating angle and the lift amount of the intake valve 4 (see A in FIG. 3). Thus, a valve operating angle and lift amount variable device (VEL device) is configured.

  On the other hand, the camshaft 41 is driven by the rotation of the crankshaft being input to the sprocket 50 by the timing belt, and the rotational phase of the camshaft 41 is controlled between the sprocket 50 and the camshaft 41 to change the valve timing. A possible rotary actuator (VTC actuator) 51 is mounted.

  Therefore, by duty-controlling the energization amount of the VTC actuator 51, the rotational phase between the crankshaft and the camshaft 41 can be changed, and the valve timing (center phase of the valve operating angle) of the intake valve 4 can be changed. (Refer to A in FIG. 3) This forms a variable valve timing device (VTC device).

  The VTC actuator 51 of the VTC device is controlled by the ECM 10 that is the first control unit, as shown in FIG. 4, and the VEL actuator 49 of the VEL device is the same as the ECM 10 that is the first control unit. Control is performed by another second control unit (hereinafter referred to as VEL-C / U) 20.

  For each control described above, the ECM 10 has a function of detecting a VTC actual value (actual valve timing) by inputting a signal of the VTC position sensor 51S that detects the actual position of the VTC actuator 51, and VEL-C / U20 has a function of detecting a VEL actual value (actual valve operating angle) by inputting a signal of a VEL position sensor 49S that detects the actual position of the VEL actuator 49.

  However, the function for calculating the VEL target value (target valve operating angle) according to the engine operating condition and the function for calculating the VTC target value (target valve timing) according to the engine operating condition include various sensors relating to the engine operating condition. Are concentrated on the ECM 10 to which the signals are input.

  The ECM 10 and the VEL-C / U 20 are connected by a communication means (CAN) 30 so that a VEL target value (target valve operating angle) is transmitted from the ECM 10 to the VEL-C / U 20. The CAN (Controller Area Network) enables data transmission / reception between the control units by connecting the control units with a communication line and performing serial communication.

  Further, the VEL actual value (actual valve operating angle) is transmitted from the VEL-C / U 20 to the ECM 10. This is because the actual valve operating angle is used for the calculation of the intake air amount in the ECM 10 and is related to the valve timing control for the following reason. Valve timing control and valve operating angle control (valve lift amount control) of the intake valve 4 are performed independently, and each control range maximizes engine performance (operating performance, exhaust purification performance, etc.) by each control characteristic. It is set so that it can be increased. Therefore, when these controls are used in combination, for example, as shown in FIG. 3B, when the valve timing is controlled to the advance side and the valve operating angle is controlled to the wide angle side (the valve lift amount is the high lift side), The valve lift amount at the top dead center becomes extremely large, and there is a possibility that interference occurs between the intake valve 4 and the piston.

  In order to limit the maximum advance angle value of the VTC device of the intake valve 4 and the maximum operating angle (maximum lift amount) of the VEL device so that the valve lift amount does not become excessively large near the top dead center of the piston, If the restriction is limited, the control range is narrowed.

  Therefore, the advance side limit value for the VTC target value (target valve timing) is set according to the VEL actual value (actual valve operating angle), so that it does not exceed the advance side limit value when calculating the VTC target value. To limit.

  For this reason, the VEL actual value is transmitted from the VEL-C / U 20 having the function of detecting the VEL actual value to the ECM 10 having the function of calculating the VTC target value.

  FIG. 5 is a flowchart of the main control of the first embodiment executed by the ECM 10, which will be described.

  In step S1, the VEL target value (target valve operation) is determined by referring to the map based on the engine speed Ne and the basic fuel injection amount Tp (= K × Qa / Ne; K is a constant) representing the engine load. Corner). The calculated VEL target value is transmitted to the VEL-C / U 20 by the communication means 30.

  In step S2, the VTC target value (target valve timing) is calculated by referring to the map based on the engine speed Ne and the basic fuel injection amount Tp representing the engine load.

  In step S3, the VEL actual value (actual valve operating angle) received by the communication means 30 from the VEL-C / U 20 that is a value detected by the VEL-C / U 20 via the VEL position sensor is read.

  In step S4, the limit value (advance side limit value) of the VTC target value (target valve timing) is calculated by referring to the table based on the VEL actual value (actual valve operating angle).

  As shown in FIG. 7, the limit value of the VTC target value (target valve timing) is such that the VTC actual value (actual valve operating angle) is in the range from small to medium, even if the VTC is controlled to the most advanced value. Since there is no possibility that the intake valve 4 and the piston interfere with each other, the position is the same as the most advanced angle position regulated by the stopper mechanism of the VTC device.

  On the other hand, when the valve operating angle of the intake valve 4 becomes a large region, the intake valve 4 and the piston may interfere with each other at the piston top dead center as the valve timing approaches the most advanced angle position. The limit value is gradually set to the retard side.

  In step S5, the VTC actual value (actual valve timing) is detected based on the detection signal of the VTC position sensor 51S.

  In step S6, the VTC actual value obtained in step S5 is compared with the limit value obtained in step S4. If VTC actual value> limit value (when the VTC actual value is on the advance side of the limit value), step S6 is performed. Proceeding to S7, limiting the VTC target value as VTC target value = limit value, then proceeding to step S8. When VTC actual value ≦ limit value (when the VTC actual value is retarded from the limit value), the process proceeds to step S8 as it is.

  In step S8, a deviation VTCERR between the VTC target value (target valve timing) and the VTC actual value (actual valve timing) is calculated.

  In step S9, it is determined whether or not the difference between the VTC limit value and the VTC actual value is equal to or less than a predetermined value X set in advance. That is, the case where the difference between the VTC limit value and the VTC actual value is equal to or smaller than the predetermined value X is a state where the VTC actual value is close to the VTC limit value. For example, in FIG. 7, it means that the limit value is close to the limit value indicated by the bold line and is within a limit region within a predetermined value X (see the broken line in the figure). The case where the difference between the VTC limit value and the VTC actual value exceeds the predetermined value X is a state in which the VTC actual value is far from the VTC limit value. For example, in FIG. 7, it means that it exists in the safe area | region which does not exceed the predetermined value X shown with the broken line in the figure away from the limit value.

  If the difference between the VTC limit value and the VTC actual value is less than or equal to the predetermined value, the process proceeds to step S10, the deviation VTCERR is multiplied by a coefficient of 1 or less, the deviation VTCERR is subtracted, and the process proceeds to step S11. . Thereby, the correction deviation VTCERR is made smaller than the original deviation VTCERR. The coefficient of 1 or less is an arbitrarily set coefficient such as 0.1 to 0.5, and is set in advance. If the difference between the VTC limit value and the actual VTC value exceeds a predetermined value, the process proceeds to step S11.

  In step S11, a control output for the VTC actuator is calculated and output in accordance with the deviation VTCERR so that the VTC actual value matches the VTC target value, and feedback control is performed to control the valve timing.

Specifically, first, based on the deviation VTCERR and the feedback gains Gp (proportional component), Gi (integral component), Gd (derivative component), the proportional component control amount VTCp and the integral component control amount are expressed by the following equations. VTCi and differential control amount VTCd are as follows:
VTCp = Gp · VTCERR
VTCi = VTCiz + Gi · VTCERR
VTCd = Gd · (VTCERR−VTCERRz)
Ask for each. The subscript z indicates the previous value.

Next, the basic duty value BASDTYvtc and the control amounts VTCp, VTCi, and VTCd are added to calculate the VTC duty value VTCDTY (see the following equation),
VTCDTY = BASDTYvtc + VTCp + VTCi + VTCd
Using this as an output signal, the VTC actuator 51 is driven. Here, when the VTC duty value VTCDTY = basic duty value BASDTYvtc (for example, 50%), the VTC actuator 51 is fixed at the position at that time, and is set to the plus side or the minus side for the deviation. If driven and no deviation occurs, VTC duty value VTCDTY = basic duty value BASDTYvtc, and fixed at that position. The same applies to the VEL actuator 49.

  FIG. 6 is a flowchart of the main control of the first embodiment executed by the VEL-C / U 20, which will be described.

  In step S21, a VEL target value (target valve operating angle) that is a value calculated by the ECM 10 and received from the ECM 10 by the communication unit 30 is read.

  In step S22, the limit value (large operating angle side limit value) of the VEL target value (target valve operating angle) is calculated by referring to the table based on the VTC actual value (actual valve timing).

  As shown in FIG. 7, the limit value of the VEL target value (target valve operating angle) has a high possibility that the intake valve 4 and the piston will interfere when the VTC actual value (actual valve timing) is advanced. Since the valve operating angle limit value becomes smaller and the possibility that the intake valve 4 and the piston interfere with each other on the retard side of the VTC actual value (actual valve timing), the valve operating angle limit value is set to be larger. ing.

  In step S23, the VEL actual value (actual valve operating angle) is detected based on the detection signal of the VEL position sensor 49S. The detected VEL actual value is transmitted to the ECM 10 by the communication means 30.

  In step S24, the VEL actual value obtained in step S23 is compared with the limit value obtained in step S22. When VEL actual value> limit value (when the VEL target value is larger than the limit value on the larger operating angle side), Proceeding to step S25, limiting the VEL target value as VEL target value = limit value, then proceeding to step S26. When VEL actual value ≦ limit value (when the VEL actual value is on the smaller operating angle side than the limit value), the process directly proceeds to step S26.

  In step S26, a deviation VELERR between the VEL target value (target valve operating angle) and the VEL actual value (actual valve operating angle) is calculated.

  In step S27, it is determined whether or not the difference between the VEL limit value and the VEL actual value is equal to or less than a predetermined value Y set in advance. That is, the case where the difference between the VEL limit value and the VEL actual value is equal to or smaller than the predetermined value Y is a state where the VEL actual value is close to the VEL limit value. For example, in FIG. 7, it means that the limit value is close to the limit value indicated by the thick line and is within the limit value Y (see the broken line in the figure).

  The case where the difference between the VEL limit value and the VEL actual value exceeds the predetermined value Y is a state where the VEL actual value is far from the VEL limit value. For example, in FIG. 7, it means that it exists in the safe area | region which does not exceed the predetermined value Y shown with the broken line in the figure away from the limit value.

  If the difference between the VEL limit value and the actual VEL value is less than or equal to the predetermined value, the process proceeds to step S28, the deviation VELERR is multiplied by a coefficient of 1 or less, the deviation VELERR is subtracted, and the process proceeds to step S29. . Thereby, the correction deviation VELERR is made smaller than the original deviation VELERR. The coefficient of 1 or less is an arbitrarily set coefficient such as 0.1 to 0.5, and is set in advance. If the difference between the VEL limit value and the actual VEL value exceeds a predetermined value, the process proceeds directly to step S29.

  In step S29, a control output for the VEL actuator 49 is calculated and output in accordance with the deviation VELERR so that the actual VEL value matches the VEL target value, feedback control is performed, and the valve operating angle is controlled. The details of the feedback control are the same as the feedback control for the VTC actuator 51 in the ECM 10.

  In the variable valve system for an internal combustion engine described above, when the VEL operating angle and the VTC advance position are in the limit regions that are close to the limit values, the response speeds of the VEL device and the VTC device are changed low. Therefore, even when there is a time delay until the valve timing is limited according to the VEL actual value or the valve lift amount is limited according to the VTC actual value, the IVO (the valve opening of the intake valve 4 is opened). Valve) Advancing amount or valve lift increase amount can be reduced, the depth of the recess provided in the piston can be reduced to avoid interference, the thermal efficiency can be improved by reducing the piston recess, fuel efficiency improvement, exhaust The performance can be improved and the output can be improved.

  For example, in FIG. 7, even when the VEL device is stuck near the maximum operating angle (see arrow E in the figure), the valve timing is limited in order to limit the operating speed of the VTC device toward the advance side of the valve timing. Even if there is a delay time before starting, interference between the valve and the piston can be avoided.

  Further, in FIG. 7, even when the VTC device is fixed in the vicinity of the most advanced angle (see arrow F in the figure), the valve lift amount starts to be limited in order to limit the operating speed toward the large operating angle side in the VEL device. Even if there is a delay time before, the interference between the valve and the piston can be similarly avoided.

  Further, in FIG. 7, in order to limit the operating speed of the VTC device to the advance side even when the VTC device is erroneously advanced to the advance side due to the error of the POS signal and PHASE signal (see arrow G in the figure). Even if there is a delay time until the valve timing is started to be limited, the interference between the valve and the piston can be similarly avoided.

  8 and 9 show a second embodiment of a variable valve operating apparatus for an internal combustion engine to which the present invention is applied. FIG. 8 is a part of a flowchart of main control executed by the ECM 10, and FIG. It is a part of flowchart of the main control performed by C / U20 side. In the present embodiment, when the difference between the VTC limit value and the VTC actual value or the difference between the VEL limit value and the VEL actual value is lower than a predetermined value X or a predetermined value Y, the VTC target value is set. Alternatively, when the VEL target value is set in a direction away from each limit value, a configuration that allows the deviation VTCERR or the deviation VELERR according to the value is added to the first embodiment. The same apparatus as that of the first embodiment is denoted by the same reference numeral, and the description thereof is omitted or simplified.

  FIG. 8 showing steps S5 to S11 is a flowchart of main control executed by the ECM 10. Steps S1 to S4 (not shown) and steps S5 to S11 shown are those of the first embodiment. 5 is executed in the same manner as the flowchart shown in FIG. In this embodiment, step S12 is added between step S9 and step S10.

  Moreover, FIG. 9 which shows step S23-step S29 is a flowchart of the main control performed by VEL-C / U20, step S21-step S22 which is not illustrated, and step S23-step S29 which are illustrated are It is executed in the same manner as the flowchart shown in FIG. 6 of the first embodiment. In this embodiment, step S30 is added between step S27 and step S28. Other configurations are the same as those of the first embodiment.

  In this embodiment, when the difference between the VTC limit value and the actual VTC value is equal to or less than a predetermined value in step S9 of the flowchart of the main control executed by the ECM 10, the process proceeds to step S12. In step S12, when the deviation VTCERR is larger than zero, that is, in the “advance direction”, the process proceeds to step S10, the deviation VTCERR is multiplied by a coefficient of 1 or less, and the deviation VTCERR is subtracted and corrected. Proceed to However, when the deviation VTCERR is zero or less than zero, that is, in the “retarding direction”, the process proceeds to step S11 without going through step S10. That is, only when the VTC target value is set in a direction approaching the limit value, the deviation VTCERR is subtracted and corrected, and when the VTC target value is set in a direction away from the limit value, the deviation VTCERR is set according to the value. Allow.

  If the difference between the VEL limit value and the actual VEL value is equal to or smaller than the predetermined value in step S27 in the main control flowchart executed by the VEL-C / U 20, the process proceeds to step S30. In step S30, if the deviation VELERR is larger than zero, that is, in the “large operating angle direction”, the process proceeds to step S28, the deviation VELERR is multiplied by a coefficient of 1 or less, and the deviation VELERR is subtracted and corrected. Proceed to S29. However, when the deviation VELERR is zero or less than zero, that is, in the “small operating angle direction”, the process proceeds to step S29 without going through step S28. That is, only when the VEL target value is set in a direction approaching the limit value, the deviation VELERR is subtracted and corrected. When the VEL target value is set in a direction away from the limit value, the deviation VELERR is set according to the value. Allow.

  In the present embodiment, when the difference between the VTC limit value and the VTC actual value or the difference between the VEL limit value and the VEL actual value is lower than a predetermined value X or a predetermined value Y, the VTC target value is set. Alternatively, when the VEL target value is set in a direction away from each limit value, the response speed is set for a target in a direction away from each limit value in order to allow the deviation VTCERR or the deviation VELERR according to the value. Without limiting, it is possible to suppress the approach to the limit value while ensuring responsiveness.

  In the above embodiment, as a response speed limiting means for reducing the response speed of the valve lift amount in a predetermined range within a predetermined range up to the limit value set in step S22 as the valve lift limit value setting means. Steps S27 to S28 and step S9 as response speed limiting means for reducing the response speed of the valve timing in a predetermined range within a predetermined range up to the limit value set in step S4 as valve timing limit value setting means Although what provided both of -S10 was demonstrated, you may provide only any one.

  Further, in the above embodiment, the description has been given of the case where the VTC device and the VEL device are provided only on the intake valve 4 side. However, in the case where the VTC device and the VEL device are provided on the exhaust valve 8 side, the exhaust valve 8 can also be applied to the case where the exhaust valve 8 may interfere with the piston when the valve timing retard amount is large and the valve lift amount is set to the maximum lift amount side. This can be similarly implemented by replacing the amount of advancement of the valve timing 4 with the amount of retardation of the valve timing of the exhaust valve 8.

  For example, in the above-described embodiment, the electric actuator 49 is used as the driving unit of the VEL device, but a driving device using a hydraulic actuator may be used instead of the electric actuator 49. Further, the VTC device may be an electric VTC device instead of the hydraulic one as in the VEL device. Further, as the valve lift amount variable means, a VEL device that continuously variably controls the valve lift amount and the operating angle is used as the valve lift amount variable means. However, the valve lift amount is variably controlled in several stages. Also good.

  In the present embodiment, the following effects can be achieved.

  (A) For limiting the control range of the valve lift amount of the corresponding intake valve 4 or exhaust valve 8 according to the operating state of the valve timing that is variably controlled with respect to at least one of the intake valve 4 or the exhaust valve 8 Valve lift control limit for limiting the control range of the valve lift control based on step S22 as the valve lift amount limit value setting means for setting the limit value and the limit value set by the valve lift amount limit value setting means Steps S24 to S25 as means and step as response speed limiting means for reducing the response speed of the valve lift amount in a predetermined range within a predetermined range up to the limit value set by the valve lift amount limit value setting means S27 to S28, that is, variable control of the intake valve 4 or the exhaust valve 8 is performed. When the valve lift amount is controlled as required according to the operating state of the engine regardless of the valve timing operation state, if there is interference with the piston, the limit value of the control range of the valve lift amount control The response speed is reduced before the valve, so that even if there is a time delay until the valve lift amount exceeds the limit value and the valve lift amount starts to be restricted, interference with the piston is prevented. be able to. Even if the valve lift amount is controlled as required regardless of the valve timing operation state, if it does not interfere with the piston, the other is controlled as it is as required to maximize the engine performance. be able to. For example, it is possible to improve the output and the exhaust purification performance in the operating state such as during cold start or lean combustion.

  (A) For limiting the control range of the valve timing of the corresponding intake valve 4 or exhaust valve 8 according to the operating state of the valve lift amount variably controlled with respect to at least one of the intake valve 4 or the exhaust valve 8 As valve timing control limiting means for limiting the control range of the valve timing control based on step S4 as valve timing limit value setting means for setting a limit value and the limit value set by the valve timing limit value setting means Steps S6 to S7, and Steps S9 to S10 as response speed limiting means for reducing the response speed of the valve timing in a predetermined range within a predetermined range up to the limit value set by the valve timing limit value setting means. In other words, the intake valve 4 or the exhaust valve 8 is variable. When the valve timing is controlled as required according to the operating state of the engine regardless of the operating state of the valve lift amount to be controlled, when there is interference with the piston, the limit of the control range of the valve timing control By reducing the response speed before the value, it is possible to prevent interference with the piston even when the valve timing exceeds the limit value and there is a time delay before the valve timing restriction starts. Can do. Further, even if the valve timing is controlled as required regardless of the operation state of the valve lift amount, if it does not interfere with the piston, the other is controlled as it is as it is, as in the first invention, The engine performance can be maximized.

  (C) Steps S27 to S28 as response speed limiting means for reducing the response speed of the valve lift amount in a predetermined range within a predetermined range up to the limit value set in step S22 as the valve lift amount limit value setting means. And steps S9 to S10 as response speed limiting means for reducing the response speed of the valve timing in a predetermined range within a predetermined range up to the limit value set in step S4 as the valve timing limit value setting means. When equipped, the valve timing at which the intake / exhaust valve and piston approach each other, or the valve lift amount, slow down the response speed and limit the valve lift amount according to the operating state of the valve timing, or the valve lift amount There is a time lag before limiting the valve timing according to the operating state of In case, it is possible to reduce the IVO advance amount or the valve lift increase, up to the valve-piston interference avoidance control is started, achieving piston recess reduction. For this reason, the thermal efficiency can be improved by reducing the piston recess, and the fuel efficiency, the exhaust performance can be improved, and the output can be improved.

  (D) Steps S12 and S30 as response speed limiting means for reducing the response speed of the valve lift amount and the response speed of the valve timing are limited to the valve lift amount change or the valve timing change in the direction away from each limit value. By not adding, the response speed is not limited for a target in a direction away from each limit value, and approach to the limit value can be suppressed while ensuring the response.

1 Engine 4 Intake valve 8 Exhaust valve 10 ECM (first control unit)
20 VEL-C / U (second control unit)
30 Communication Means 49 VEL Actuator 49S VEL Position Sensor 51 VTC Actuator 51S VTC Position Sensor

Claims (4)

A variable valve operating apparatus for an internal combustion engine that performs valve lift control so as to continuously change a valve lift amount with respect to at least one of an intake valve and an exhaust valve of the internal combustion engine,
A valve for setting a limit value for limiting the control range of the valve lift amount of the corresponding intake valve or exhaust valve according to the operating state of the valve timing that is variably controlled with respect to at least one of the intake valve or the exhaust valve Lift amount limit value setting means,
Valve lift control limiting means for limiting the control range of the valve lift control based on the limit value set by the valve lift amount limit value setting means;
Response speed limiting means for reducing the response speed of the valve lift amount in a predetermined range within a predetermined range up to a limit value set by the valve lift amount limit value setting means. Variable valve gear. A variable valve operating apparatus for an internal combustion engine that performs valve timing control so as to change the valve timing with respect to at least one of an intake valve and an exhaust valve of the internal combustion engine,
A valve for setting a limit value for limiting the control range of the valve timing of the corresponding intake valve or exhaust valve according to the operating state of the valve lift amount variably controlled with respect to at least one of the intake valve or the exhaust valve Timing limit value setting means;
Valve timing control limiting means for limiting the control range of the valve timing control based on the limit value set by the valve timing limit value setting means;
Response speed limiting means for reducing the response speed of the valve timing in an area of a predetermined range set in advance to a limit value set by the valve timing limit value setting means. Valve device. A valve lift amount target value setting means for setting a target value according to the engine operating state in order to continuously change the valve lift amount for at least one of the intake valve and the exhaust valve of the internal combustion engine;
Valve lift control means for controlling the valve lift amount based on the actual valve lift operating state and the target value;
Valve lift amount limit value setting means for setting a limit value for limiting the control range of the valve lift amount of the corresponding intake valve or exhaust valve according to the operating state of the valve timing to be variably controlled;
Valve lift control limiting means for limiting the control range of the valve lift control based on the limit value set by the valve lift amount limit value setting means;
Valve timing target value setting means for setting a target value according to an engine operating state in order to change the valve timing for at least one of the intake valve and the exhaust valve;
Valve timing control means for controlling the valve timing based on the actual valve timing operating state and the target value;
A valve for setting a limit value for limiting the control range of the valve timing of the corresponding intake valve or exhaust valve according to the operating state of the valve lift amount variably controlled with respect to at least one of the intake valve or the exhaust valve Timing limit value setting means;
Valve timing control limiting means for limiting the control range of the valve timing control based on the limit value set by the valve timing limit value setting means,
Response speed limiting means for reducing the response speed of the valve lift amount in a predetermined range within a predetermined range up to a limit value set by the valve lift amount limit value setting means;
Response speed limiting means for reducing the response speed of the valve timing in an area of a predetermined range set in advance to a limit value set by the valve timing limit value setting means. Valve device.   The response speed limiting means for reducing the response speed of the valve lift amount and the response speed of the valve timing does not limit the valve lift amount change or the valve timing change in a direction away from each limit value. The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 3.

Images