JP2006329023A - Air intake controller of engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the engine torque from being fluctuated owing to a control delay of a VCT 18 in accelerating from a low load rotation range such as idling so as to attain smooth acceleration feeling. <P>SOLUTION: The lift amount of air intake valves 1 and 2 is changed to be greater by a lift variable mechanism VVL as approaching the high load or high rotation side. A phase angle is retarded by the VCT 18 to be a peak in the middle point of air-intake stroke of a cylinder in the idle operation range, while the phase angle is relatively controlled in the adjoining partial load range. The predetermined period restricts the action of the VCT 18 in accelerating from the idle operation range (Steps S5 and S6), and the lift amount is corrected to be smaller (S7). Thereafter, when the phase angle of the air intake valves 1 and 2 is advanced by the action of the VCT 18, the lift amount is gradually increased corresponding thereto (S8). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an intake control device for an engine in which the lift amount and phase angle of an intake valve are changed in accordance with the operating state of the engine, and particularly relates to the field of control technology at the time of transition in which the operating state changes.

  2. Description of the Related Art Conventionally, as disclosed in, for example, Japanese Patent Application Laid-Open No. H10-260260, there has been known an engine valve system that is provided with a variable lift mechanism that continuously changes the lift amount and opening / closing timing of an intake valve. In this device, the operation of the eccentric cam of the intake side camshaft is transmitted to the swing cam via a link, and the intake valve is opened and closed by this swing cam. Then, by changing the position of the fulcrum of the link, the swing locus of the swing cam is made variable so that the lift amount of the intake valve is continuously changed.

  A phase variable mechanism is also known in which the phase of the lift of the intake valve is continuously changed within a predetermined angle range by changing the phase of rotation of the intake camshaft with respect to the crankshaft. It has already been proposed to provide such a phase variable mechanism together with the lift variable mechanism as described above (see, for example, Patent Document 2).

  In the engine having the two variable mechanisms as described above, in order to increase the lift amount and the valve opening period of the intake valve on the high load and high rotation side in accordance with the operating state, and to use the inertia of the intake flow It is preferable that the intake valve closing timing is greatly retarded until after the bottom dead center of the cylinder. On the other hand, on the low-load low-rotation side, a so-called intake early closing characteristic is preferable in order to reduce pumping loss. For this reason, it is considered that the lift characteristic of the intake valve is preferably controlled so that the lift amount becomes smaller and the phase angle is advanced toward the low load and low rotation side.

  However, if the phase angle is advanced on the low load and low rotation side, the lift amount of the intake valve is only small in an operating state where both the engine load and the rotational speed are very low, such as during idle operation. However, it closes substantially in the first half of the intake stroke of the cylinder, and the lowering speed of the piston at the lift peak is also low, so the amount of intake charge to the cylinder is significantly reduced and combustion stability is impaired. There is a fear.

On the other hand, the applicant of the present application assumes that the basic lift characteristics of the intake valve are as described above, but in a specific operation range such as idle operation where the lift amount is small, the intake valve lift We developed a variable valve system that ensures combustion stability by significantly retarding the phase angle and controlling it so that it reaches the lift peak state in the middle of the intake stroke with the highest intake efficiency. A patent application has already been filed (see Japanese Patent Application No. 2004-287164).
JP 2004-301058 A JP 2004-090236 A

  When the phase angle is greatly retarded in the specific operation region of the low load low rotation region as in the variable valve device according to the above prior application, when shifting from there to another operation region on the high load side In addition, the variable lift mechanism is operated so that the lift amount of the intake valve increases with an increase in load, and the variable phase mechanism is also operated in synchronization so that the phase angle is advanced.

  However, in general, the variable lift mechanism is electrically operated, whereas the variable phase mechanism is hydraulically operated. When the engine speed is low, such as during idling, the amount of oil or hydraulic pressure is insufficient. It cannot be activated quickly. Therefore, for example, when the degree of increase in the engine load is larger than a predetermined value, for example, during acceleration operation, the lift angle of the intake valve can be increased without delay, but the phase angle is advanced as intended. I can't do that.

  Further, in such a state where the amount of oil or the hydraulic pressure is insufficient, the operation of the phase variable mechanism itself is likely to be inaccurate, and the control accuracy of the phase angle of the intake valve is also lowered.

  As a result, during the acceleration operation of the engine, the way in which the engine torque increases with respect to the accelerator pedal operation is inconsistent, and even with a certain operation, the torque fluctuates and the engine rotation Ascending is also jerky, and there is a problem that the driver who performs the operation feels uncomfortable.

  The present invention has been made in view of such a point, and an object of the present invention is, for example, in the case where the lift amount of the intake valve and the phase angle thereof are controlled in synchronization according to the operating state of the engine. Focusing on the fact that there is a delay in the control of the phase angle at the time of acceleration operation or the like, the engine torque fluctuation due to this is prevented and a smooth acceleration feeling is obtained.

  In order to achieve the above object, the first solution of the present invention is to devise a transitional control procedure when the engine shifts from a specific operating range of low load and low rotation such as idle to a high load side. As a result, at least if the degree of increase in load is greater than or equal to a predetermined level, the operation of the phase variable mechanism is restricted for a predetermined period.

  That is, the invention of claim 1 includes a lift variable mechanism capable of continuously changing the lift amount of the intake valve of the engine, and a phase variable mechanism capable of continuously changing the phase angle of the lift. It is assumed that the intake control device for an engine is such that the mechanism and the phase variable mechanism are controlled based on at least the operating state of the engine.

  The lift control means for controlling the lift variable mechanism so that the lift amount of the intake valve increases as the load increases from the high load to the high rotation side according to the operating state of the engine, and the low load according to the operating state of the engine. In the specific operation range of low rotation, the phase angle is retarded so that the intake valve is lifted in the middle of the intake stroke of the cylinder, while at least in the partial load operation region adjacent to the high load side of the specific operation range. Phase control means for controlling the phase variable mechanism so that the phase angle is relatively advanced, and when the engine shifts from the specific operating range to the high load side as the load increases, at least the degree of increase in the load Correction control means for correcting the control by the phase control means so that the operation of the phase variable mechanism is restricted for a predetermined period.

  With the above configuration, first, in the normal operation state of the engine, the lift amount of the intake valve is changed according to the load or the rotational speed of the engine by the control of the variable lift mechanism by the lift control means, so that the high load or the high rotation is achieved. The lift amount becomes larger toward the side, and the lift amount becomes smaller toward the low load or low rotation side. Further, by controlling the phase variable mechanism by the phase control means, the phase angle is relatively retarded so that the intake valve is in the lift peak state in the middle of the intake stroke of the cylinder in the specific operating range of low load and low rotation. Is done.

  Here, the phrase “higher load or higher rotation side” means that the higher load side is compared at the same rotation speed, and the higher rotation side is compared at the same load state. In addition, the lift characteristic of the intake valve is changed in accordance with the engine load and the rotational speed, so that an amount of air corresponding to the output request to the engine is filled into the cylinder.

  In other words, the intake valve lift amount and the valve opening period (crank angle) are relatively small on the low load or low rotation side where the output demand is relatively low, thereby reducing the efficiency of charging the cylinder with intake air. At this time, if the closing timing of the intake valve is set before the bottom dead center of the cylinder, the pumping loss can be reduced. On the other hand, on the high-load high-rotation side where the output demand is relatively high, the charging efficiency increases due to the increase in the lift amount and the valve opening period, and if the intake valve is opened after the bottom dead center of the cylinder, The filling efficiency is also improved by the inertia of the flow.

  Also, in a specific operating range of low load and low rotation such as idle, the phase angle is greatly retarded by the control of the phase variable mechanism by the phase control means, and the intake valve is in the middle stage of the intake stroke with the highest intake efficiency. Therefore, even if the lift amount is small, the required charging efficiency can be ensured and the combustion stability can be improved.

  On the premise of such basic control of the lift characteristic of the intake valve, when the engine shifts from the specific operating range to the high load side, if the degree of increase of the load is at least a predetermined level, the phase variable mechanism Although there is a possibility of delaying the control, at this time, the control by the phase control means of the phase variable mechanism is corrected by the correction control means, and its operation is restricted. If the phase variable mechanism does not operate for a predetermined period in this way, the adverse effect such as torque fluctuation does not occur due to the operation delay, and the driver does not feel a great sense of incongruity.

  However, restricting the operation of the phase variable mechanism in this manner means that the phase angle of the lift of the intake valve is controlled to the retard side as in the specific operating range, and this means that Since this means that the intake charging efficiency is relatively high, it is preferable to correct the lift variable mechanism control by the lift control means so that the lift amount of the intake valve becomes small during this period. .

  That is, if the phase variable mechanism is not operated for a predetermined period as described above, the phase angle of the lift of the intake valve is generally maintained at the state when the engine is in the specific operating range. Because there is no deviation from the control target value due to the operation delay of the phase variable mechanism, the amount of lift is corrected in accordance with the phase angle that is kept approximately constant, so that the intended target is achieved. Engine torque can be obtained, and the driver's uncomfortable feeling can be eliminated.

  If the period for restricting the operation of the phase variable mechanism elapses thereafter, the phase angle of the lift of the intake valve is advanced by the operation of the phase variable mechanism. Since the charging efficiency is lowered, to compensate for this, the correction amount of the lift amount can be reduced by the correction control means according to the advance angle of the phase angle, that is, the lift amount of the intake valve is gradually decreased. It is preferable to increase (Claim 3).

  The correction means is the correction described above when the degree of increase in the load is small and no delay occurs in the control of the phase variable mechanism even when the engine shifts from the specific operating range to the high load side. Control is not performed and the phase variable mechanism may be operated in synchronization with the lift variable mechanism.

  Alternatively, when the engine shifts from the specific operating range to the high load side, the correction control means may regulate the operation of the phase variable mechanism regardless of the degree of increase in the load (claim 4). In this way, if the operation of the phase variable mechanism is always restricted even during slow acceleration from a specific operating range, it is not necessary to switch control depending on the degree of increase in load. Control of characteristics can be simplified.

  In order to prevent the control delay of the phase variable mechanism as described above, the intake control device having the same premise configuration as that of the invention of claim 1 can be configured as in the invention of claim 5 below. That is, lift control means for controlling the lift variable mechanism so that the lift amount of the intake valve increases as the load increases or the rotation speed increases according to the engine operating state, and the phase variable mechanism is controlled according to the engine operating state. Phase control means and estimation means for estimating that the operation of the variable phase mechanism controlled by the phase control means is delayed with respect to the operation of the variable lift mechanism controlled by the lift control means in response to an increase in engine load. And a correction control means for correcting the control by the phase control means so that the operation of the phase variable mechanism is restricted when the estimation means estimates the operation delay of the phase variable mechanism. .

  According to this configuration, similarly to the first aspect of the invention, when the engine operating state changes, for example, from the idle operating state to the high load side, the estimation means may cause a delay in the control of the phase variable mechanism. Once estimated, the control by the phase control means of this phase variable mechanism is corrected by the correction control means so that the phase variable mechanism does not operate for a predetermined period of time. Will not feel great discomfort. That is, the same effect as that of the invention of claim 1 can be obtained.

  In this case as well, as in the second aspect of the invention, while the operation of the phase variable mechanism is restricted, the control of the lift variable mechanism by the lift control means is corrected so that the lift amount of the intake valve becomes small. (Claim 6).

  More specifically, the phase variable mechanism may be provided with a hydraulic actuator that is supplied with pressure oil from a pump driven by an engine. A sensor that detects the flow rate or pressure of oil may be included, and it may be estimated that the operation of the phase variable mechanism is delayed when the value detected by the sensor is less than a predetermined value.

  According to this configuration, the phase variable mechanism can be configured at low cost by using a hydraulic actuator that is relatively small and can obtain a large force. On the other hand, when the engine speed is low, such as during idling, the amount of oil or hydraulic pressure supplied from the pump is insufficient, so that the operation of the phase variable mechanism is slowed. Therefore, the adverse effect of the delay is eliminated. The action becomes particularly effective.

  As described above, according to the intake control device for an engine according to the present invention, the lift characteristics of the intake valve according to the operating state of the engine, basically, the lift amount increases from the high load to the high rotation side, Further, by changing the phase angle so as to be relatively retarded, it is possible to fill the cylinder with an amount of air corresponding to an output request to the engine without a throttle valve. This can reduce the pumping loss and reduce the fuel consumption of the engine.

  On the other hand, on the low-load, low-rotation side of the engine, the lift amount of the intake valve is reduced, and the closing timing is advanced to obtain a so-called intake early closing characteristic, thereby further reducing the pumping loss and improving the fuel efficiency. The reduction effect can be enhanced.

  Also, in a specific operating range of low load and low rotation, such as idle, the intake valve lift phase angle is significantly retarded so that the intake valve reaches a lift peak state in the middle of the intake stroke with the highest intake efficiency. By doing so, even if the lift amount is small, the required charging efficiency can be ensured and the combustion stability can be improved.

  In addition, when the phase angle is delayed with respect to the control of the lift amount of the intake valve, such as when accelerating from the specific operating range, or when it is estimated (Claim 5). In addition, by restricting the control of the phase variable mechanism for a predetermined period, it is possible to prevent adverse effects such as torque fluctuations and to suppress the driver's uncomfortable feeling.

  Further, by correcting so that the lift amount of the intake valve is reduced during the period in which the control of the phase variable mechanism is restricted (Claim 2), the engine torque as intended for the operation of the accelerator pedal can be reduced. It will be able to be obtained, and the uncomfortable feeling of the driver can be resolved.

In addition, when the phase angle of the lift of the intake valve is advanced by the operation of the phase variable mechanism after the lapse of the period, the lift amount is gradually increased so as to cancel the decrease in the charging efficiency due to this ( (3) The engine torque change can be made more natural.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.

(Basic configuration of intake control system)
FIG. 1 shows the configuration of an embodiment of an intake side valve system of an engine to which the present invention is applied. Although not shown, this engine is an in-line four-cylinder engine in which four cylinders are arranged in a line, and each cylinder has two intake valves 1 and 2 and two exhaust valves (not shown). A 4-valve double overhead cam system is used. In the figure, reference numeral 3 is arranged so as to extend in the longitudinal direction of the engine (the lateral direction in the figure) in which the four cylinders are arranged, and is rotated by a crankshaft of the engine via a cam chain (not shown). This is the intake side camshaft.

  A known phase variable mechanism 18 (Variable Cam Timing: hereinafter abbreviated as VCT) capable of changing the rotational phase of the camshaft 3 relative to the crankshaft within a predetermined angle range is attached to the front end portion of the camshaft 3. Has been. Although not described in detail, the VCT 18 includes a rotor fixed to the front end of the camshaft 3 that passes through the center hole of the sprocket 19 and a casing that is disposed so as to cover the rotor from the front of the engine and is fixed to the sprocket 19. A plurality of hydraulic working chambers are formed between the rotor and the casing side by side in the circumferential direction.

  Then, in response to the input of a control signal from the controller 17, the position of the solenoid valve 20 is switched, so that the direction of the hydraulic pressure supplied to the hydraulic pressure chamber of the VCT 18 is switched, so that the rotor and casing, The camshaft 3 and the sprocket 19 are rotated relative to each other. The solenoid valve 20 is a duty solenoid valve or the like capable of continuously changing the size of the hydraulic pressure, and thereby the amount of rotation of the rotor with respect to the casing is continuously changed within a predetermined range, whereby the camshaft 3 The opening / closing timing of the intake valves 1 and 2 in terms of the crank angle, that is, the lift phase angle of the intake valves 1 and 2 can be continuously changed by continuously changing the rotation phase with respect to the crankshaft.

  The VCT 18 is supplied with engine oil as hydraulic oil through the electromagnetic valve 20, and the hydraulic pressure source is an oil pump 26 driven by a crankshaft. An oil pressure sensor 27 is disposed in the oil passage from the oil pump 26 through the engine oil gallery to the solenoid valve 20 so as to detect the oil pressure of the engine oil.

  A pair of swing cams 4 and 5 are supported on the camshaft 3 so as to be swingable for each cylinder. The pair of swing cams 4, 5 are arranged so as to correspond to the two intake valves 1, 2, respectively, and are connected to each other by a cylindrical connecting portion 9 so as to swing integrally around the camshaft 3. It is supposed to be. As a result, the two intake valves 1 and 2 are lifted simultaneously for each cylinder. The outer peripheral surface of the connecting portion 9 is a cam journal portion that is in sliding contact with the cam bearing surface.

  In order to operate the swing cams 4 and 5 as described above, the camshaft 3 has four circular eccentric cams 6 that are eccentric from the axis X (the rotation center of the camshaft 3: see FIG. 2 and the like). They are integrally provided with a space therebetween. An outer ring 7 is fitted on each eccentric cam 6 so as to be rotatable. The swing cam 5 is connected to an eccentric convex portion provided so as to protrude from the outer periphery of the outer ring 7 via a connecting link 8. It is connected. That is, one end side of the outer ring 7 is rotatably fitted to the eccentric cam 6 of the camshaft 3, and the other end portion (eccentric convex portion) is connected to the swing cam 5 by the connecting link 8 (hereinafter referred to as “the outer ring 7”). This is called an offset link).

  A control shaft 11 is provided in parallel with the camshaft 3 obliquely above. Four control arms 12 are coupled and fixed to the control shaft 11, and the distal end portion of each control arm 12 and the other end portion of the offset link 7 are connected by a regulation link 13. The restriction link 13 restricts the displacement of the offset link 7 and reciprocates the other end when the one end side of the offset link 7 revolves around the camshaft 3 as the eccentric cam 6 rotates. Thus, the connecting link 8 connected to the other end of the offset link 7 swings the swing cams 4 and 5.

  Further, the control shaft 11 is coupled with a worm gear 14 having teeth formed on only a part of its circumference, and a worm 16 that is rotationally driven by an electric motor 15 meshes with the teeth of the worm gear 14. . Then, the motor 15 is actuated in response to the input of the control signal from the controller 17 and the control shaft 11 is rotated to change the position of the control arm 12, whereby the reciprocating motion of the other end of the offset link 7 is performed. The trajectory, that is, the swing trajectory of the connecting link 8 is changed, whereby the swing angle of the swing cams 4 and 5 is changed, and the lift characteristics such as the lift amount and opening / closing timing of the intake valves 1 and 2 are changed. It is supposed to be.

  In other words, the connecting link 8 and the restriction link 13 connect the swing cam 5 and the offset link 7 and also operate the offset link 7 accompanying the rotation of the eccentric cam 6 with the swing cam 5 (and the swing link 5). A link mechanism that restricts the moving cam 4) to swing is configured. Further, including the link mechanism, a variable lift mechanism capable of continuously changing the lift amount of the intake valves 1 and 2 by the eccentric cam 6, the offset link 7, the control shaft 11, the control arm 12 and the like of the cam shaft 3. (Variable Valve Lift: hereinafter also referred to as VVL).

  More specifically, the configuration of the VVL is as follows. First, as shown in FIG. 2 (b), a direct acting tappet 21 is provided at the upper end of the stem of the intake valve 2, and the swing cam 5 is applied to the tappet 21. Touching. In the intake valve 2, the intake port 25 is closed by a valve spring 24 provided between a retainer 22 provided in the tappet 21 and a retainer 23 provided in the cylinder head (intake valve 1, 2 lift direction). (Opposite direction). Note that the intake valve 1 has the same configuration as the intake valve 2.

  One end portion of the connection link 8 is rotatably connected to the swing cam 5 by a pin 31, while one end portion of the regulation link 13 is rotatably connected to a tip portion of the control arm 12 by a pin 32. ing. Thus, the connecting link 8 and the regulating link 13 are disposed on both sides of the offset link 7 and are linked with the offset link 7 interposed therebetween. That is, the other end of each of the connection link 8 and the restriction link 13 is connected to the other end of the offset link 7 coaxially and rotatably by the connection pin 33. The pins 31 to 33 all extend parallel to the camshaft 3.

  As shown in the figure, the connecting pin 33 between the offset link 7 and the connecting link 8 is located above the camshaft 3, and the rotation center of the control arm 12 (the axis of the control shaft 11) is located on the side of the connecting pin 33. positioned. The pin 32 at the tip of the control arm 12 is a rotation shaft of the restriction link 13, and by changing the position of the pin 32, the swing trajectory of the restriction link 13 and the connecting pin 33 is changed. , 2 can be changed.

  That is, the specific operation of each link or pin will be described in detail below. The control shaft 11 and the control arm 12 are rotated by the motor 15 so that the pin 32 is moved below the control shaft 11 as shown in FIG. In this case, the swing angle of the swing cams 4 and 5 becomes large, and the lift amount of the intake valves 1 and 2 at the lift peak becomes the largest lift control state. Further, when the pin 32 is moved upward by the rotation of the control arm 12 or the like, the swing angle of the swing cams 4 and 5 is reduced accordingly, and the pin 32 is moved to the camshaft as shown in FIG. If it is positioned above 3, the lift amount of the intake valves 1 and 2 becomes the smallest lift control state.

  In the large lift control state shown in FIG. 2, the swing cam 5 presses the direct acting tappet 21 on the tip side of the cam nose as shown in FIG. A lift peak state (a state where the swing cam 4 greatly lifts the intake valve 1 via the direct acting tappet) and a intake valve 2 (the intake valve 1) as shown in FIG. Oscillates between zero lift and no lift. Similarly, in the case of FIG. 3 which is a small lift control state, it swings between a lift peak state (pressing the tappet 21 on the base end side of the cam nose) and a zero lift state (FIGS. 3A and 3B). reference).

(Operation of variable lift mechanism)
Hereinafter, the operation of such links and cams will be described in detail with reference to FIGS. In both figures, the control arm 12, the connecting link 8, and the restricting link 13 are simply represented by straight lines, and the rotation trajectory of the center of the eccentric cam 6 (the center of the outer ring of the offset link 7) is indicated as T0. ing. As described above, the relationship between the intake valve 1 and the swing cam 4 is the same as the relationship between the intake valve 2 and the swing cam 5, and the swing cam 4 works in the same manner as the swing cam 5. Now, the relationship between the intake valve 2 and the swing cam 5 will be described.

  First, the profile of the oscillating cam 5 itself will be described with reference to FIG. 4. The circumferential surface of the oscillating cam 5 has a base circle surface (base circle section) θ1 having a constant radius of curvature within a predetermined angular range, A cam surface (lift section) θ2 having a gradually increasing radius of curvature is formed following θ1. The figure shows the large lift control state of FIG. 2, and the control arm 12 is in the large lift control position.

  The solid line in FIG. 2 shows the state of FIG. 2B in which the intake valve 2 is in the vicinity of the lift peak. At this time, the pin 31 is pulled up most by the connecting link 8, and the swing cam 5 is The cam nose tip side of the surface θ2 is in contact with the tappet 21. On the other hand, the phantom line shows a zero lift state (FIG. 2A). At this time, the base circle surface θ1 of the swing cam 5 is in contact with the tappet 21, and the intake valve 2 is not lifted (intake air). Valve 2 is closed).

  When the camshaft 3 (eccentric cam 6) rotates in the clockwise direction in the figure, one end side (lower end side in the figure) of the offset link 7 moves along the axis X of the camshaft 3 as indicated by the arrow in the figure. In this case, the displacement of the other end of the offset link 7 is regulated by the regulation link 13 connected thereto. That is, the restriction link 13 swings between the position of the solid line and the position of the phantom line around the pin 32 positioned below the control shaft 11, and accordingly, the other end side of the offset link 7. The (connecting pin 33) reciprocates around the pin 32 every time the eccentric cam 6 makes one revolution (the movement locus of the connecting pin 33 is shown as T1).

  With the reciprocating arc motion T1 of the connecting pin 33, the other end portion (pin 31) of the connecting link 8 whose one end portion is connected to the offset link 7 by the same connecting pin 33 is reciprocated along a locus shown as T2. The oscillating cam 5 that is circularly moved and is connected to the connecting link 8 by the pin 31 oscillates between the position of the solid line and the position of the phantom line in the figure. That is, when the connecting pin 33 moves upward, the pin 31 is pulled upward by the connecting link 8, and the cam nose of the swing cam 5 pushes down the tappet 21, thereby pushing the valve spring 24 (see FIG. 2). The intake valve 2 is lifted while shrinking.

  On the other hand, when the connecting pin 33 moves downward, the pin 31 is pushed downward by the connecting link 8 and the cam nose of the swing cam 5 rises. Therefore, the valve spring 24 compressed as described above. The tappet 21 is pushed up by the reaction force and moves upward so as to follow the rise of the cam nose. The intake valve 2 is pulled up by the retainer 22 in the tappet 21 and the intake port 25 is closed.

  That is, in the large lift control state, the swing cam 5 swings greatly so as to press the tappet 21 by substantially the entire base circle surface θ1 and cam surface θ2 of the peripheral surface, and thus corresponds to such a large swing angle. As a result, the lift amount of the intake valve 2 increases.

  Next, when the control arm 12 is turned upward from the large lift control state until it becomes substantially horizontal around the axis of the control shaft 11, as shown in FIG. 3 and FIG. The pin 32, which is the moving shaft, is positioned on the near side in the rotational direction of the camshaft 3 with respect to the large lift control state, and the small lift control state with a small lift amount is entered. In FIG. 5 as well, the state where the intake valve 2 is in the vicinity of the lift peak is indicated by a solid line, and the state of zero lift is indicated by a virtual line as in FIG.

  In this figure, when the camshaft 3 (eccentric cam 6) rotates, the displacement of the connecting pin 33 of the offset link 7 is restricted by the restricting link 13 and is located on the side of the control shaft 11 as in the large lift control state. A reciprocating arc motion T3 is performed around the pin 32 (the restriction link 13 reciprocates between the solid line position and the virtual line position in the figure). The pin 31 of the connecting link 8 performs a reciprocating arc motion T4 in accordance with the reciprocating arc motion T3 of the connecting pin 33, and the swing cam 5 connected to the connecting link 8 by the pin 31 is indicated by a solid line in the figure. The intake valve 2 is opened and closed by swinging between the position and the position of the virtual line.

  That is, in the small lift control state, the swing angle of the swing cam 5 is smaller than that in the large lift control state, and the swing cam 5 has a base circle surface θ1 on its peripheral surface and a cam surface continuous therewith. The tappet 21 is pressed only by a part of θ2, and the lift amount of the intake valve 2 is reduced.

(Change in lift characteristics)
FIG. 6 shows the lift curves of the intake valves 1 and 2 that are continuously changed from the large lift control state to the small lift control state by the operation of the variable lift mechanism VVL as described above. In the figure, a lift curve L1 indicates a large lift control state in which the swing cam 5 swings between the solid line position (near the lift peak in the large lift control state) and the virtual line position (zero lift) in FIG. L2 shows a small lift control state in which the swing cam 5 swings between the solid line position (near the lift peak in the small lift control state) and the virtual line position (zero lift) in FIG.

  As shown in the figure, according to the lift variable mechanism VVL of this embodiment, as the lift amount of the intake valves 1 and 2 increases, the valve opening period (the crank angle period from the opening timing to the closing timing, not including the buffer section). ) Also spreads, and the closing timing of the intake valves 1 and 2 is delayed. This is because, as described above, the lift amount of the intake valves 1 and 2 is changed in accordance with the change in the swing angle of the swing cam.

  In the example of the figure, the lift peak timing (crank angle position) is advanced as the lift amount of the intake valves 1 and 2 is smaller. As described above, in the transition from the large lift control state to the small lift control state, the position of the restriction link 13 is moved to the front side in the rotational direction of the camshaft 3 by the rotation of the control arm 12 or the like. This is because the trajectory of the reciprocating arc motion of the connecting pin 33 moves from the position T1 in FIG. 4 to the position T3 in FIG.

  That is, in the large lift control state shown in FIG. 4, the center of the eccentric cam 6 when the intake valves 1 and 2 are in the vicinity of the lift peak is located at the point Ta on the rotation locus T0. In the small lift control state shown in FIG. 2, the center position of the eccentric cam 6 in the vicinity of the lift peak moves to a point Tb shown in FIG. That is, when shifting from the large lift control state to the small lift control state, the lift peaks of the intake valves 1 and 2 advance by the center angle θ3 of the points Ta and Tb on the rotation locus T0 as shown in FIG. is there.

  In short, according to the variable lift mechanism VVL of this embodiment, the lift characteristics of the intake valves 1 and 2 indicate that the smaller the lift amount, the narrower the valve opening period, that is, the lift operating angle, and the earlier the closing timing. On the other hand, the so-called early closing characteristic is obtained, while the valve opening period is extended with the continuous increase of the lift amount, and the closing timing is changed to be retarded.

  Such a change in lift characteristics is consistent with general engine intake characteristics. That is, in general, the engine load is often increased on the high rotation side, but on the high rotation side, even if the valve opening periods of the intake valves 1 and 2 are the same as viewed from the crank angle, Since the interval becomes shorter, it is preferable not only to increase the flow passage cross-sectional area of the intake air by increasing the lift amount, but also to secure time for intake by increasing the valve opening period (crank angle). Further, if the closing timing of the intake valves 1 and 2 is retarded until after the bottom dead center of the cylinder, the charging efficiency can be increased by the inertia of the intake flow.

  On the other hand, in order to reduce the pumping loss of the cylinder, it is preferable to have the characteristics of early closing of the intake air as described above. Therefore, as the engine is at a low load or low rotation side, the lift amount of the intake valve is reduced and its phase is reduced. The angle should be advanced.

  Since the lift amount of the intake valves 1 and 2 can be continuously changed from the minimum lift to the maximum lift by the VVL having the characteristics as described above, the engine of this embodiment can respond to the output request to the engine without depending on the throttle valve. The cylinder can be filled with a sufficient amount of air, and the engine output can be controlled. Therefore, by not providing a throttle valve in the intake passage or by fully opening the throttle valve even in the partial load region, the pumping loss of the engine can be reduced and fuel consumption can be reduced.

  Specifically, in this embodiment, the lift amount of the intake valve by the lift variable mechanism VVL as described above is basically changed in accordance with the operating state of the engine. For example, referring to a control map as shown in FIG. 7, an appropriate lift amount corresponding to the engine target torque (engine load state) and the engine speed is obtained as a control target value, and this value (target lift amount) is obtained. Thus, the controller 17 controls the operation amount of the motor 15. The control shaft 11 is rotated by the operation of the motor 15, and the rotation position of the control arm 12 is controlled to an appropriate position between the large lift control position and the small lift control position.

  According to the control map of FIG. 7, the controller 17 determines that the lift amount increases at the higher rotation speed based on the target torque and rotation speed of the engine, and at the same engine rotation speed. If so, the rotational position of the control arm 12 is changed so that the lift amount increases as the target torque increases, that is, the lift amount increases as the load increases or increases. In other words, the controller 17 controls the lift variable mechanism VVL in accordance with the operating state of the engine as shown by the phantom line in FIG. 1 so that the intake valves 1 and 2 are relatively small on the low load or low rotation side. A lift control unit 17a (lift control means) is provided in the form of a program, which is a lift and a relatively large lift on the high rotation or high load side.

  In addition to the operation control of the variable lift mechanism VVL, in this embodiment, the lift phase angle of the intake valves 1 and 2 is changed according to the operating state of the engine by the operation control of the VCT 18. That is, when the lift phase angle of the intake valves 1 and 2 is advanced on the low load and low rotation side as described above, the engine load and the rotation speed are both extremely low as in the idling operation. In the region (specific operation region), the intake valves 1 and 2 are substantially closed in the first half of the intake stroke of the cylinder. Therefore, coupled with the very small lift amount, There is a possibility that the filling amount is insufficient and the combustion stability is impaired.

  Therefore, during idle operation in which the lift amount of the intake valves 1 and 2 is very small, the phase angle is relatively retarded by the operation of the VCT 18 so that the intake valves 1 and 2 have the highest intake efficiency. The lift peak is reached in the middle period of the engine, which makes it possible to secure a required intake charge amount even during idling and to improve combustion stability.

  Specifically, as shown in an example of the control map in FIG. 8, the controller 17 controls the VCT 18 according to the operating state of the engine and sets the maximum retard angle (advance amount 0 °) in the idle operation range. In most other operating ranges, the phase angle is relatively advanced. In the example shown in the figure, the phase angle gradually advances as the load increases from the idle operation range to the middle load range, and after reaching the maximum advance angle (60 ° adv), toward the high load or high rotation side. The angle is retarded, and again reaches the maximum retardation (advance amount 0 °) in a high load or high rotation range. The lift characteristics of the intake valves 1 and 2 are optimized by combining the control of the phase angle by the VCT 18 and the operation characteristics of the VVL described above.

  In other words, the controller 17 controls the VCT 18 in accordance with the operating state of the engine as shown by a virtual line in FIG. ), The phase angle is retarded so as to reach the lift peak state in the middle of the intake stroke of the cylinder, while the phase angle is relatively advanced at least in the operation region of the partial load adjacent to the high load side. A phase control unit 17b (phase control means) for controlling the VCT 18 is provided in the form of a program.

(Correction of lift characteristics during acceleration operation)
By the way, when the lift amount of the intake valves 1 and 2 is reduced and the phase angle is greatly retarded in the idle operation region as described above, the engine operating state is idle according to the depression operation of the accelerator pedal. When the operating range changes from a high load to a high rotation side, the lift variable mechanism VVL is operated in accordance with the increase in the load, and the lift amount of the intake valves 1 and 2 is increased and the phase angle is advanced. Thus, the VCT 18 is operated synchronously.

  However, in this embodiment, the variable lift mechanism VVL is driven by the electric motor 15, whereas the VCT 18 is hydraulically operated, and is driven by the crankshaft when the engine speed is low, such as during idle operation. Since the rotational speed of the oil pump 26 is also reduced, the amount of oil supplied to the VCT 18 cannot be increased too much. For this reason, for example, when the degree of increase in the engine load is larger than a predetermined value during acceleration operation, for example, the lift angle of the intake valves 1 and 2 can be increased without delay, but the phase angle is targeted. Cannot be advanced on the street.

  In addition, when the amount of oil supplied to the VCT 18 is insufficient, the hydraulic pressure is also insufficient, which tends to cause the operation control of the VCT 18 to be inaccurate. That is, during the acceleration operation of the engine, the oil amount and hydraulic pressure of the engine oil supplied from the oil pump 26 to the VCT 18 are insufficient, so that the operation is delayed and the operation becomes inaccurate. The controllability of the phase angle of the valves 1 and 2 is degraded.

  More specifically, for example, as schematically shown by the black arrows on the control maps of FIGS. 7 and 8, when the engine load and the rotational speed increase slowly, the control target value on the control map The VVL and the VCT 18 may be operated synchronously so as to follow the change. Then, as schematically shown by arrows in FIG. 9, the lift curves of the intake valves 1 and 2 gradually increase from the small lift control state L2 and the phase angle is advanced, so that the intermediate load is increased. After the maximum advance, the phase angle gradually retards as the lift amount increases.

  On the other hand, as schematically shown by the white arrows in FIGS. 7 and 8, when the degree of increase in the engine load is larger than a predetermined value, VVL and VCT 18 are operated in synchronization as described above. As a result, although the lift amount increases without delay with respect to the change in the target value on the control map, the change in the phase angle is delayed due to the shortage of the amount of oil supplied to the VCT 18 or the hydraulic pressure. Therefore, the lift amount becomes too high, and the torque is excessively generated.

  After that, when the phase angle changes beyond the maximum advance angle to the retarded angle side, the torque becomes short on the contrary, and the engine torque once becomes excessive for a certain stepping operation of the accelerator pedal. Later, it becomes deficient, resulting in large torque fluctuations and jerky increases in engine rotation.

  In other words, during acceleration operation from idle, the engine torque increase method with respect to the accelerator operation becomes inconsistent due to the operation delay of the VCT 18, etc., and the engine torque becomes harsh even though it is a constant accelerator operation. There was a risk that the driver would feel a great sense of incongruity due to fluctuations and an increase in engine rotation.

  On the other hand, in this embodiment, as described above, when the engine is in the acceleration operation state in the idle operation region, the rotation of the oil pump 26 is increased due to the increase of the engine rotation, and the supply of engine oil to the VCT 18 is insufficient. During the period until the cancellation (predetermined period), correction control such as regulation of the operation of the VCT 18 is performed.

  Hereinafter, a specific control procedure of VVL by the controller 17 will be described based on the flowchart of FIG. First, in step S1 after the start, signals from various sensors for mainly detecting the operating state of the engine are input, and data stored in the memory is read. In the subsequent step S2, for example, an engine target torque is obtained based on a signal from a sensor that detects the amount of depression of the accelerator pedal and a signal from an engine speed sensor (may be a crank angle sensor). The lift amount corresponding to the operating state of the engine is set with reference to the control map of FIG. 7 from the engine speed and the engine speed (setting of the target lift amount). Similarly, referring to the control map of FIG. 8, the phase angle of the lift corresponding to the engine operating state is set (setting of the target advance angle).

  Next, in step S3, it is determined whether or not the engine is in an acceleration operation state from the idle operation region based on the operation state of the engine and the change thereof. For example, when the engine is in the idling operation range, the target torque (engine load) increases at a predetermined level or more, and when the increased target torque is maintained at a predetermined level or larger, On the other hand, the process proceeds to steps S5 to S8, which will be described later, and otherwise, the process proceeds to step S4.

  In step S4, a control signal corresponding to the target lift amount set in step S2 is output to the motor 15 to rotate the control shaft 11 and the control arm 12 (operation of VVL), and in the same step S2. A control signal corresponding to the set target advance angle is output to the solenoid valve 20, the VCT 18 is operated, and then the process returns.

  Thus, if the engine is in a slowly accelerating state in which the degree of increase in load is relatively small, the intake valves 1 and 2 are operated as shown in FIG. 9 and the entire lift curve is shifted from the advance side to the retard side by the operation of the VCT 18, whereby the lift characteristics of the intake valves 1 and 2 change as shown in FIG. Will do.

  On the other hand, when the accelerator pedal is depressed when the engine is in the idling operation range and the target torque increases to a predetermined level or more, and the increased target torque is maintained, YES is determined in step S3. It judges and progresses to step S5, and it is judged whether the predetermined period has passed since acceleration operation started this time. This predetermined period is a period until the rotation of the oil pump 26 increases due to the increase in engine rotation due to the acceleration operation, and the shortage of supply of engine oil to the VCT 18 is resolved. What is necessary is just to set as a map in association with the magnitude | size of a target torque, the raise degree of engine rotation, etc.

  When it is determined NO in step S5 that the predetermined period has not elapsed, the process proceeds to step S6, the target advance angle set in step S2 is canceled, and this is forcibly set to zero, and the following step In S7, the target lift amount set in step S2 is corrected to decrease. That is, the operation of the VCT 18 is restricted when accelerating from the idling operation range, and the lift phase angle of the intake valves 1 and 2 is thereby delayed from the original target value (value set in the control map of FIG. 8). Corresponding to becoming the corner side, the target lift amount is corrected to decrease so as to cancel the increase in filling efficiency due to this. The lift amount decrease correction amount may be set in advance as a map in association with, for example, the target torque increased in response to the depression of the accelerator pedal or the degree of change.

  After correcting the target advance angle and the target lift amount as described above, the process proceeds to step S4, and a control signal corresponding to the corrected target lift amount is output to the motor 15 to operate the variable lift mechanism VVL. Since the target advance angle remains 0 °, the control signal is not output to the solenoid valve 20 of the VCT 18, that is, the VCT 18 returns without being operated.

  In this way, during the first period during which the control of the VCT 18 is likely to be caused by insufficient supply of engine oil during acceleration from the idle operation range, the operation of the VCT 18 is restricted and only the VVL is operated. As a result, as shown by the broken line in FIG. 11, the lift curves of the intake valves 1 and 2 change from the small lift control state L2 to the lift curve L3 on the high lift side with almost the same phase angle according to the characteristics of VVL.

  That is, by restricting the operation of the VCT 18, the phase angle of the intake valves 1 and 2 is maintained substantially in the same state as the idle operation region, and the actual phase angle may become unknown due to the operation delay of the VCT 18. Absent. Therefore, the target lift amount can be accurately reduced and corrected in accordance with the deviation from the target value in the phase angle control map (FIG. 8). It will be obtained.

  Then, when the predetermined period has elapsed, YES is determined in step S5 and the process proceeds to step S8. This time, only the target lift amount is corrected without correcting the target advance angle. That is, the correction amount used to decrease the target torque in the previous control cycle (for example, the value read from the map in step S7) is decreased by a preset value, and the correction amount after the decrease is reduced to step S2. Subtract from the target correction amount. In other words, the target lift amount is gradually increased at a substantially constant rate for each control cycle.

  Then, the process proceeds to step S4, where a control signal corresponding to the corrected target lift amount is output to the motor 15 to operate the lift variable mechanism VVL and to correspond to the target advance angle set in step S2. A control signal is output to the solenoid valve 20 to activate the VCT 18 and then return.

  Thus, the operation of the VCT 18 advances the lift phase angle of the intake valves 1 and 2 to the original target value, and the lift amount gradually increases corresponding to the advance angle of the phase angle. As shown by the broken line, the lift curves of the intake valves 1 and 2 change from L3 to L4 and converge to the original control characteristics (see FIG. 9).

  That is, when the shortage of oil supply to the VCT 18 is resolved and the operation restriction is released, the reduction in the cylinder filling efficiency caused by the advance of the lift phase angle of the intake valves 1 and 2 is reduced by the lift amount reduction correction amount. The engine torque can be obtained with no excess or deficiency with respect to the accelerator operation.

  Steps S2 and S4 in the flow shown in FIG. 10 correspond to the control by the lift control unit 17a and the phase control unit 17b that controls the lift variable mechanisms VVL and VCT18 according to the operating state of the engine.

  Further, when the engine shifts from the idle operation range to the high load side as the load increases by steps S3 to S8 of the same flow, if the increase degree of the load is at least a predetermined level, the operation of the VCT 18 is performed for a predetermined period. The correction control unit 17c is configured to correct the control by the phase control unit 17b so as to be regulated. That is, the controller 17 includes the correction control unit 17c (see FIG. 1) in the form of a program.

  In this embodiment, the correction control portion 17c controls the lift variable mechanism VVL by the lift control portion 17a while the operation amount of the VCT 18 is restricted as described above. Further, when the VCT 18 is operated after the lapse of the period and the phase angle of the lift of the intake valves 1 and 2 is advanced, the lift correction amount is decreased accordingly. It has become.

  Therefore, according to the intake control apparatus for an engine according to this embodiment, first, the intake variable valve mechanism VVL provided in the valve system on the intake side is controlled in accordance with the operating state (load and rotational speed) of the engine, and the intake valve By continuously changing the lift amounts of 1 and 2, it is possible to fill each cylinder with a necessary amount of air, so that the engine output can be controlled even if the throttle valve is eliminated. Therefore, the pumping loss can be reduced and the fuel consumption can be reduced.

  In addition, the VCT 18 that changes the rotational phase of the intake camshaft 3 controls the phase angle of the intake valves 1 and 2 according to the operating state of the engine. While further reducing fuel consumption as a closing characteristic, in the high-load high-rotation range where the lift amount increases, the intake flow inertia is maximized by delaying the closing timing of the intake valves 1 and 2 until after bottom dead center. The charging efficiency can be made sufficiently high by making effective use as much as possible, thereby obtaining a high engine output.

  Furthermore, in the idling operation region, the operation of the VCT 18 delays the lift phase angle of the intake valves 1 and 2 to increase the intake efficiency, thereby ensuring the required charging efficiency even if the lift amount is small, Combustion stability can be improved.

  Furthermore, when it is considered that the advance angle of the phase angle due to the operation of the VCT 18 is delayed with respect to the increase in the lift amount of the intake valves 1 and 2 due to the operation of the VVL as in acceleration from the idle operation range, By deliberately regulating the operation of the VCT 18 and correcting the lift amount accordingly, an engine torque appropriate for the driver's accelerator operation can be obtained. Thereby, a smooth acceleration feeling without a sense of incongruity is obtained.

  In addition, the structure of this invention is not limited to embodiment mentioned above, Other various structures are also included. That is, for example, the specific configuration of the variable lift mechanism VVL provided in the valve train of the engine is not limited to that of the above embodiment. For example, as shown in FIG. 12, the variable lift mechanism VVL does not change the lift peak timing even if the lift amount of the intake valves 1 and 2 changes, and the opening timing advances according to the increase in the lift amount. The closing time may be delayed. Also in this case, the VCT 18 is controlled according to the operating state of the engine, and the lift characteristics of the intake valves 1 and 2 are changed as shown in FIGS.

  Further, in the above-described embodiment, the operation of the VCT 18 is restricted because it is considered that the supply of hydraulic oil (engine oil) to the VCT 18 is insufficient during the acceleration operation in which the engine load increases at a predetermined level or more from the idle operation range. However, the present invention is not limited to this, and when the engine load increases from an idle operation range where the engine speed is low, the operation of the VCT 18 is regulated regardless of the degree of increase, that is, even during slow acceleration. Also good.

  More specifically, when the engine rotation including the idling region is below a predetermined value, the operation of the VCT 18 is stopped and the control map (FIG. 8) is set so that the phase angle of the intake valves 1 and 2 is always in the maximum retarded state. In addition, a lift amount control map (see FIG. 7) may be set so that an optimum lift amount corresponding to the reference lift amount is set. That is, the content of the correction control in the above-described embodiment may be incorporated in the basic control of the lift characteristics, and in this way, the lift control of the intake valves 1 and 2 is simplified.

  Furthermore, in the above-described embodiment, it is considered that the supply of hydraulic oil (engine oil) to the VCT 18 is insufficient for a predetermined period when accelerating from the idle operation range, and at this time, the operation of the VCT 18 is restricted. For example, the operation delay of the VCT 18 may be estimated based on the oil pressure detected by the oil pressure sensor 27, and the operation of the VCT 18 may be restricted at this time.

  That is, for example, as shown in the flow of FIG. 13, it is determined in step S30 whether the engine is accelerating, and in step S50, it is determined that the hydraulic pressure detected by the hydraulic sensor 27 is less than the required hydraulic pressure. At this time, the operation delay of the VCT 18 is estimated, and the operation of the VCT 18 is regulated in steps S6 and S7 so as to reduce and correct the target lift amount as in the above-described embodiment (see the flow of FIG. 10).

  In such a case, the operation of the VCT 18 controlled by the phase control unit 17b with respect to the operation of the variable lift mechanism VVL controlled by the lift control unit 17a of the controller 17 according to the increase of the engine load by the steps S30 and S50. Estimating means for estimating that the operation is delayed is configured. Further, in steps S6 and S7, when the operation delay of the VCT 18 is estimated by the estimating means, a correction control unit 17c for correcting the control of the VCT 18 by the phase control unit 17b is configured so that the operation is restricted. The

  The present invention relates to an engine intake control device including a variable lift mechanism and a variable phase mechanism for making the lift characteristics of an intake valve of an engine variable. For example, the variable phase control is possible during acceleration operation from an idle range. Even in a situation where the operation of the mechanism is delayed, a good acceleration feeling can be obtained, so that it is particularly useful for an automobile engine that requires high merchantability.

1 is a perspective view showing an embodiment in which an intake control device of the present invention is applied to an in-line four-cylinder engine. It is sectional drawing which shows the large lift control state of a lift variable mechanism, (a) shows the state of zero lift, (b) shows the state of a lift peak. FIG. 3 is a view corresponding to FIG. 2 showing a small lift control state. It is explanatory drawing of the action | operation of a large lift control state. FIG. 5 is a view corresponding to FIG. 4 related to a small lift control state. It is a characteristic view which shows the change of the lift curve by a lift variable mechanism. It is a figure which shows an example of the control map of lift amount. It is a figure which shows an example of the control map of a phase angle. It is explanatory drawing which shows the change of the lift curve at the time of slow acceleration. It is a flowchart figure which shows the control procedure at the time of an acceleration driving | operation. FIG. 10 is a diagram corresponding to FIG. 9 during acceleration operation. FIG. 7 is a view corresponding to FIG. 6 according to another embodiment having different lift curve change characteristics. FIG. 11 is a diagram corresponding to FIG. 10 according to another embodiment in which correction control is performed by estimating the operation delay of the phase variable mechanism.

Explanation of symbols

1, 2 Intake valve 3 Camshaft 4, 5 Oscillating cam (lift variable mechanism)
6 Eccentric cam (lift variable mechanism)
7 Offset link (lift variable mechanism)
8 Link (lift variable mechanism)
11 Control shaft (variable lift mechanism)
12 Control arm (lift variable mechanism)
13 Restriction link (lift variable mechanism)
17 Controller 17a Lift control unit (lift control means)
17b Phase control unit (phase control means)
17c Correction control unit (correction control means)
18 Phase variable mechanism (VCT)
26 Oil pump 27 Oil pressure sensor (estimating means)

Claims (7)

A lift variable mechanism capable of continuously changing the lift amount of the intake valve of the engine and a phase variable mechanism capable of continuously changing the phase angle of the lift are provided, and the lift variable mechanism and the phase variable mechanism are provided at least on the engine. In an intake control device for an engine that is controlled based on an operating state,
A lift control means for controlling the variable lift mechanism so that the lift amount of the intake valve increases in accordance with the operating state of the engine as the load increases from the high load to the high rotation side;
Depending on the operating state of the engine, in the specific operating range of low load and low rotation, the phase angle is retarded so that the intake valve is in the lift peak state in the middle of the intake stroke of the cylinder, while at least the high load of the specified operating range Phase control means for controlling the phase variable mechanism so that the phase angle is relatively advanced in the operating range of the partial load adjacent to the side;
When the engine shifts from the specific operating range to the high load side as the load increases, the phase is controlled so that the operation of the phase variable mechanism is regulated for a predetermined period, at least if the increase degree of the load is not less than a predetermined level. An engine intake control device comprising: correction control means for correcting control by the control means. The intake control device according to claim 1,
The correction control means corrects the control of the lift variable mechanism by the lift control means so as to reduce the lift amount of the intake valve while restricting the operation of the phase variable mechanism. . In the intake control device according to claim 1 or 2,
When a predetermined period for regulating the operation of the phase variable mechanism has elapsed and the phase angle of the lift of the intake valve is advanced by the operation of the phase variable mechanism, the correction control means adjusts the amount of correction of the lift amount accordingly. An intake control apparatus for an engine, characterized by being configured to reduce the engine. The intake control device according to any one of claims 1 to 3,
An engine intake control apparatus characterized in that the correction control means regulates the operation of the phase variable mechanism regardless of the degree of increase in engine load when shifting from a specific operating range to a high load side. A lift variable mechanism capable of continuously changing the lift amount of the intake valve of the engine and a phase variable mechanism capable of continuously changing the phase angle of the lift are provided, and the lift variable mechanism and the phase variable mechanism are provided at least on the engine. In an intake control device for an engine that is controlled based on an operating state,
A lift control means for controlling the variable lift mechanism so that the lift amount of the intake valve increases in accordance with the operating state of the engine as the load increases from the high load to the high rotation side;
Phase control means for controlling the phase variable mechanism according to the operating state of the engine;
Estimating means for estimating that the operation of the variable phase mechanism controlled by the phase control means is delayed with respect to the operation of the variable lift mechanism controlled by the lift control means in response to an increase in engine load;
Correction control means for correcting control by the phase control means so that the operation of the phase variable mechanism is restricted when the estimation means estimates the operation delay of the phase variable mechanism. Engine intake control device. In the intake control device of claim 5,
The correction control means corrects the control of the lift variable mechanism by the lift control means so as to reduce the lift amount of the intake valve while restricting the operation of the phase variable mechanism. . In the intake control device according to claim 5 or 6,
The phase variable mechanism includes a hydraulic actuator that is supplied with pressure oil from a pump driven by an engine,
The estimation means includes a sensor for detecting the flow rate or pressure of the pressure oil, and estimates that the operation of the phase variable mechanism is delayed when the detection value by the sensor is less than a predetermined value. Engine intake control device.

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