JP2008138634A - 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 capable of improving engine performance (performance of an internal combustion engine) in transition, and thereby improving the engine performance in actual use because responsiveness of a phase variable mechanism in transition is improved, and a response time until the phase of a lift center angle of an engine valve is changed to a control target value by a phase variable mechanism is reduced. <P>SOLUTION: This variable valve gear of an internal combustion engine includes: a first variable valve train 11 capable of simultaneously and continuously controlling expansion and reduction of lift/work angles of an intake valve 1; a second variable valve structure 21 retarding/advancing the phase of a lift center angle of the intake valve 1. When the phase of the lift center angle of the intake valve 1 is changed by the second variable valve structure 21, the variable valve gear executes a response assisting operation of once changing the lift/work angles of the intake valve 1 in a direction for improving responsiveness of the second variable valve structure 21 in changing the phase of the lift center angle by the first variable valve train 11. Thereby, the responsiveness of the second variable valve structure 21 in transition is improved, and a response time until the phase of the lift center angle of the intake valve is changed to the control target value by the second variable valve structure 21 is reduced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a variable valve operating apparatus for an internal combustion engine capable of continuously changing the lift / operation angle of the engine valve and the phase of the lift center angle of the engine valve in accordance with the operating state of the internal combustion engine.

  Patent Document 1 discloses a hydraulically driven first variable valve mechanism that can change a valve lift amount of an engine valve and a hydraulically driven second variable valve mechanism that can change a phase of a lift center angle of the engine valve. And detecting the oil pressure or the oil temperature of the hydraulic oil supplied to the first variable valve mechanism and the second variable valve mechanism, and when the detected oil pressure is lower than the set oil pressure, or the detected oil By prohibiting the supply of hydraulic pressure to at least one of the first variable valve mechanism and the second variable valve mechanism when the temperature is higher than the set oil temperature, the first and second oil pressure increases as the oil pressure decreases or the oil temperature increases. There has been disclosed a variable valve operating apparatus that avoids simultaneous deterioration of the operation responsiveness of both of the second variable valve operating mechanisms.

Further, Patent Document 2 includes a variable valve timing mechanism that continuously changes the phase of the valve opening / closing timing and a variable valve lift amount mechanism that continuously changes the valve lift amount. When both target values of the variable lift amount mechanism change at the same time, an operation priority is determined between the variable valve timing mechanism and the variable valve lift amount mechanism, and the variable valve timing mechanism is set according to the priority. A valve characteristic control device for an internal combustion engine in which a variable valve lift amount mechanism is controlled is disclosed.
Japanese Patent Laid-Open No. 2004-301101 JP 2000-87769 A

  However, in Patent Document 1 described above, the first variable valve mechanism and the second variable valve mechanism operate at the same time under the condition that the operation responsiveness is significantly deteriorated in order to guarantee a stable response of the variable valve device. Is only prohibited. Further, Patent Document 2 described above merely defines an operation order in a scene where the valve timing variable mechanism and the valve lift amount variable mechanism operate simultaneously.

  That is, as disclosed in Patent Document 1 and Patent Document 2, which are configured by combining an operating mechanism capable of changing the valve lift amount of the engine valve and an operating mechanism capable of changing the phase of the lift center angle of the engine valve. In such a known variable valve operating system, the structural response speed characteristics of each operating mechanism are not taken into consideration, and the change in changing the phase of the valve lift amount of the engine valve and the lift central angle of the engine valve is not considered. There is room for improving the responsiveness, and there is a problem that the engine performance is not sufficiently exhibited during the transition.

  Accordingly, the present invention provides a lift / working angle variable mechanism capable of simultaneously and continuously expanding and reducing the lift / working angle of the engine valve, and a phase variable mechanism for delaying the phase of the lift center angle of the engine valve. In a variable valve operating apparatus for an internal combustion engine that can change the valve characteristic of the engine valve by operating at least one of the lift / operating angle variable mechanism and the phase variable mechanism, the phase variable mechanism When changing the phase of the lift center angle of the engine valve, the lift / operating angle variable mechanism is used to improve the responsiveness when changing the lift center angle of the phase variable mechanism. It is characterized by performing a response assisting operation that is once changed.

  According to the present invention, the response of the phase variable mechanism at the time of transition is improved, and the response time until the phase of the lift center angle of the engine valve is changed to the control target value by the phase variable mechanism is shortened. Engine performance (performance of the internal combustion engine) can be improved, and as a result, engine performance in practical use can be improved.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an explanatory view schematically showing a schematic configuration of a variable valve operating apparatus for an internal combustion engine according to the present invention applied to an intake system. This variable valve operating apparatus is further operated by a first variable valve operating mechanism 11 as a lift / operating angle variable mechanism (VEL) capable of continuously expanding / reducing the lift / operating angle of the intake valve 1. The second variable valve mechanism 21 as a phase variable mechanism (VTC) capable of continuously delaying the central angle of the angle is combined.

  First, the first variable valve mechanism 11 will be described. This first variable valve mechanism has been previously proposed by the applicant of the present invention, but is known from, for example, Japanese Patent Application Laid-Open No. 11-107725, and only its outline will be described.

  The first variable valve mechanism 11 that variably controls the lift and operating angle includes a drive shaft 22 driven by a crankshaft (not shown) of an internal combustion engine, an eccentric cam 23 fixed to the drive shaft 22, and a rotation. A control shaft 32 that is freely supported, a rocker arm 26 that is swingably supported by an eccentric cam portion 38 of the control shaft 32, and a swing cam 29 that contacts the tappet 30 of the intake valve 1 are provided. The eccentric cam 23 and the rocker arm 26 are linked by a link arm 24, and the rocker arm 26 and the swing cam 29 are linked by a link member 28.

  The rocker arm 26 is supported by an eccentric cam portion 38 so as to be able to swing at the substantially central portion, and the arm portion of the link arm 24 is linked to one end portion thereof via the connecting pin 25 and the other end portion. The upper end portion of the link member 28 is linked via the connecting pin 27. The eccentric cam portion 38 is eccentric from the axis of the control shaft 32, and accordingly, the rocking center of the rocker arm 26 changes according to the angular position of the control shaft 32.

  The swing cam 29 is rotatably supported by being fitted to the outer periphery of the drive shaft 22, and the lower end portion of the link member 28 is linked to the end portion extending laterally via the connecting pin 37. . A base circle surface that forms a concentric arc with the drive shaft 22 and a cam surface extending in a predetermined curve from the base circle surface are continuously formed on the lower surface of the swing cam 29. These base circle surface and cam surface abut on the upper surface of the tappet 30 according to the swing position of the swing cam 29. When the cam surface presses the tappet 30, the intake valve 1 is pushed open against a valve spring reaction force (not shown). Along with this, the valve spring reaction force is transferred from the swing cam 29 to each part. Works.

  The control shaft 32 is configured to rotate within a predetermined angle range by a lift / operating angle control actuator 33 provided at one end. The lift / operating angle control actuator 33 is composed of, for example, an electric motor that drives the control shaft 32 via the worm gear 35, and is controlled by a control signal from the control unit 10. The rotation angle of the control shaft 32 is detected by the control shaft sensor 34.

  According to the first variable valve mechanism 11, the lift and the operating angle of the intake valve 1 are continuously expanded and reduced simultaneously according to the rotational angle position of the control shaft 32, and the lift and operating angle change in magnitude. Accordingly, the opening timing and closing timing of the intake valve 1 change substantially symmetrically. Since the magnitude of the lift / operating angle is uniquely determined by the rotation angle of the control shaft 32, the actual lift / operating angle at that time is indicated by the detection value of the control shaft sensor 34.

  Although only one cylinder is shown in FIG. 1, the drive shaft 22 and the control shaft 32 are common to a plurality of cylinders, and the other eccentric cam 23, link arm 24, rocker arm 26, link member 28 are provided. The link mechanism including the swing cam 29, the eccentric cam portion 38, and the like is provided for each cylinder. In a V-type internal combustion engine or the like, a drive shaft 22 and a control shaft 32 are provided for each bank.

  On the other hand, the second variable valve mechanism 21 that variably controls the center angle is configured so that the sprocket 42 provided at the front end of the drive shaft 22 and the sprocket 42 and the drive shaft 22 are relatively moved within a predetermined angle range. And a phase control actuator 43 to be rotated. The sprocket 42 is interlocked with the crankshaft via a timing chain or a timing belt (not shown). The phase control actuator 43 is a hydraulic rotary actuator, and is controlled by a control signal from the control unit 10 via a hydraulic control valve (not shown). The hydraulic control valve is supplied with hydraulic oil from an oil pump (not shown) driven by the rotation of the crankshaft. That is, the phase control actuator 43 is rotationally driven using the oil pump driven by the rotation of the crankshaft as a hydraulic pressure source. Then, the action of the hydraulic phase control actuator 43 causes the sprocket 42 and the drive shaft 22 to rotate relatively, and the lift center angle in the valve lift of the intake valve 1 is retarded. That is, the lift characteristic curve itself does not change, and the whole advances or retards. This change can also be obtained continuously. The control state of the second variable valve mechanism 21 is detected by a drive shaft sensor 36 that responds to the rotational position of the drive shaft 22.

  Accordingly, by combining the control of the first and second variable valve mechanisms 11 and 21, the opening timing and closing timing of the intake valve 1 can be variably controlled together with the lift amount. Further, the control unit 10 is provided with an oil temperature sensor 15 as an operating state detecting means for detecting the oil temperature of the hydraulic oil supplied to the second variable valve mechanism 21 and an engine speed (engine speed of the internal combustion engine). A signal is input from an engine speed sensor 16 as an operating state detecting means for detection.

  Here, since the second variable valve mechanism 21 described above is composed of a hydraulic rotary actuator, the response speed is affected by the viscosity of the hydraulic oil, the amount of oil, and the hydraulic pressure.

  FIG. 2 shows the correlation between the response speed of the second variable valve mechanism 21 and the hydraulic pressure of the hydraulic oil with respect to the hydraulic oil temperature. Since the viscosity of the hydraulic oil increases as the temperature of the hydraulic oil decreases, the flow rate of the hydraulic oil into the hydraulic actuator of the second variable valve mechanism 21 decreases as the temperature of the hydraulic oil decreases. Therefore, as shown in FIG. 2, when the oil temperature of the hydraulic oil is low, the response speed when the phase of the lift center angle of the intake valve 1 is changed to the advance side by the second variable valve mechanism 21 (FIG. 2) and the response speed when the phase of the lift center angle of the intake valve 1 is changed to the retard side by the second variable valve mechanism 21 (see the B line in FIG. 2). Is relatively slow. When the hydraulic oil temperature is high, the response speed when the phase of the lift center angle of the intake valve 1 is changed to the advance side by the second variable valve mechanism 21 (see the solid line A in FIG. 2). ) And the response speed (see the solid line B in FIG. 2) when the second variable valve mechanism 21 changes the phase of the lift center angle of the intake valve 1 to the retarded angle side. It is faster than when it is low.

  As is apparent from FIG. 2, the response speed when the phase of the lift center angle of the intake valve 1 is changed to the advance side by the second variable valve mechanism 21 and the intake valve 1 by the second variable valve mechanism 21. The response speed when changing the phase of the lift center angle to the retarded angle side has substantially the same tendency with respect to the oil temperature of the hydraulic oil. Also, the dotted line in FIG. 2 indicates the tendency of the hydraulic oil pressure (operating oil pressure) with respect to the hydraulic oil temperature, and the hydraulic pressure tends to decrease as the hydraulic oil temperature increases.

  Further, the oil pump serving as the hydraulic pressure source of the second variable valve mechanism 21 is driven by the rotation of the crankshaft as described above. Therefore, as shown in FIG. 3, the hydraulic pressure supplied from the oil pump to the second variable valve mechanism 21 is proportional to the engine speed, as indicated by the dotted line in FIG. Therefore, the response speed when the phase of the lift center angle of the intake valve 1 is changed by the second variable valve mechanism 21 is in a region where the engine speed is low, as shown by the solid line in FIG. Relatively slow.

  When the oil temperature of the hydraulic oil is high and the engine speed is low, the discharge amount of the hydraulic oil from the oil pump is small, and the viscosity of the hydraulic oil becomes low, so that the operation from the gaps in the oil passages Since the amount of oil leakage increases, the hydraulic pressure supplied to the second variable valve mechanism 21 becomes relatively low, and the amount of hydraulic oil supplied to the second variable valve mechanism 21 becomes relatively small. Therefore, the response speed when the phase of the lift center angle of the intake valve 1 is changed by the second variable valve mechanism 21 is reduced.

  Further, the response speed when the phase of the lift center angle of the intake valve 1 is changed by the second variable valve mechanism 21 is affected by the valve lift amount of the intake valve 1.

  The second variable valve mechanism 21 changes the phase of the lift center angle of the intake valve 1 while receiving the reaction force of the swing cam 29, and the phase of the lift center angle of the intake valve 1 is advanced. When changing, the reaction force of the swing cam 29 acts in a direction that inhibits the change to the advance side, and when changing the phase of the lift center angle of the intake valve 1 to the retard side, the swing cam 29 The reaction force 29 acts in the direction of promoting the change to the retard side.

  More specifically, as shown in FIG. 4, when the phase of the lift center angle of the intake valve 1 is changed to the advance side by the second variable valve mechanism 21, if the hydraulic pressure is constant, the swing cam 29 is The response speed of changing the lift center angle of the intake valve 1 to the advance side becomes slower as the lift valve becomes higher and the valve lift amount of the intake valve 1 is set larger. On the other hand, when the phase of the lift center angle of the intake valve 1 is changed to the retard side by the second variable valve mechanism 21, the swing cam 29 becomes a high lift cam and the intake valve 1 when the operating hydraulic pressure is constant. The larger the valve lift amount is, the faster the response speed of changing the lift center angle of the intake valve 1 to the retard side.

  Therefore, when the phase of the lift center angle of the intake valve 1 is changed by the second variable valve mechanism 21, the lift / operating angle of the intake valve 1 is changed by the second variable valve mechanism 21 by the first variable valve mechanism 11. A response assisting operation is performed to temporarily change the lift center angle in a direction to improve the response.

  Specifically, when the phase of the lift center angle of the intake valve 1 is changed to the advance side by the second variable valve mechanism 21, the intake valve is moved by the first variable valve mechanism 11 as shown in FIG. The lift / operating angle of 1 is once changed to the small lift / small operating angle side to increase the response speed of the change of the phase of the lift center angle of the intake valve 1 to the advance side. On the other hand, when the phase of the lift center angle of the intake valve 1 is changed to the retard side by the second variable valve mechanism 21, the lift / operating angle of the intake valve 1 is temporarily increased by the first variable valve mechanism 11. Change to the large operating angle side to increase the response speed of changing the phase of the lift center angle of the intake valve 1 to the retarded angle side.

  Here, the response assisting operation by the first variable valve mechanism 11 is started when a control command for changing the phase of the lift center angle of the intake valve 1 is issued to the second variable valve mechanism 21, and the drive shaft sensor 36. The process ends when it is determined from the detected value that the change of the phase of the lift center angle of the intake valve 1 by the second variable valve mechanism 21 has been completed. When the response assisting operation ends, the first variable valve mechanism 11 changes the lift / operation angle of the intake valve 1 toward the current control target value. Further, the amount of change of the lift / operating angle of the intake valve 1 in the response assisting operation is variably set according to the operation state and the control target value when the valve characteristic of the intake valve 1 is changed.

  In FIG. 5, thin lines S1 and S2 indicate control target values, thick lines T1 and T2 indicate actual measurement values by the sensors 34 and 36, and dotted lines U1 and U2 indicate the first variable valve without performing the response assisting operation. The measured value when the mechanism 11 and the second variable valve mechanism 21 are simultaneously operated toward the control target value is shown.

  By performing the response assisting operation by the first variable valve mechanism 11 in this way, the response of the second variable valve mechanism 21 at the time of transition is improved, and the lift of the intake valve 1 by the second variable valve mechanism 21 is improved. Since the response time until the phase of the central angle is changed to the control target value is shortened, the engine performance at the time of transition (the performance of the internal combustion engine) can be improved, and consequently the engine performance in practical use can be improved. it can. More specifically, practical fuel consumption can be improved by improving the response speed of the second variable valve mechanism 21 when the phase of the lift center angle of the intake valve 1 is changed to the advance side. By improving the response speed of the second variable valve mechanism 21 when the phase of the lift center angle is changed to the retard side, the acceleration of the vehicle on which the internal combustion engine is mounted can be improved.

  Since the response assisting operation by the first variable valve mechanism 11 can improve the responsiveness of the second variable valve mechanism 21 at the time of transition, the second variable valve can be operated without increasing the capacity of the oil pump. The responsiveness of the valve mechanism 21 can be improved. That is, the responsiveness of the second variable valve mechanism 21 can be improved while preventing an increase in cost, an increase in size of the engine (internal combustion engine), and deterioration of friction.

  The response assisting operation by the first variable valve mechanism 11 may be performed according to the operating state of the internal combustion engine. That is, when the phase of the lift center angle of the intake valve 1 is changed by the second variable valve mechanism 21, the response assisting operation is not always performed by the first variable valve mechanism 11, but the second variable valve mechanism The response assisting operation by the first variable valve mechanism 11 may be performed only when the response of the mechanism 21 is deteriorated. Specifically, when the temperature of the hydraulic oil supplied to the second variable valve mechanism 21 is lower than a first predetermined temperature set in advance (for example, a normal temperature of 20 ° C. or lower), the second variable valve is operated. At a high oil temperature (for example, 100 ° C. or higher) when the temperature of the hydraulic oil supplied to the mechanism 21 is equal to or higher than a preset second predetermined temperature, or at a low speed where the engine speed is equal to or lower than a preset predetermined speed By performing the response assisting operation only when the second variable valve mechanism 21 changes the phase of the lift center angle of the intake valve 1 in any state, the exhaust performance at start-up, fuel consumption, and the internal combustion The acceleration performance of the vehicle on which the engine is mounted can be improved. Here, when detecting the oil temperature of the working oil, the oil temperature of the working oil may be estimated using a detection value of a water temperature sensor for detecting the cooling water temperature of the internal combustion engine.

  The opening timing and closing timing of the intake valve 1 during the response assist operation by the first variable valve mechanism 11 are the opening / closing period of the intake valve 1 immediately before the response assist operation is performed, and the second variable valve operation. The mechanism 21 is controlled so as to be within at least one of the opening and closing periods of the intake valve 1 after the change of the valve characteristics including the change of the phase of the lift center angle of the intake valve 1. That is, when the phase of the lift center angle of the intake valve 1 is changed by the second variable valve mechanism 21 in accordance with the change of the valve characteristic of the intake valve 1, the opening period of the intake valve 1 before the change is opened before the change. Assuming that the opening period of the intake valve 1 after the change is the opening period after the change, the opening timing and closing timing of the intake valve 1 during the response assisting operation of the first variable valve mechanism 11 are the opening before the change. It is set to be within at least one of the valve period or the changed valve opening period.

  The response assisting operation by the first variable valve mechanism 11 may be terminated when a predetermined time elapses after the response assisting operation is started. Further, even if the phase of the lift center angle of the intake valve 1 is not changed to the control target value by the second variable valve mechanism 21, the response assisting operation is completed when the control target value is approached to some extent. It may be.

  In the above-described embodiment, the second variable valve mechanism 21 is hydraulically driven. However, the second variable valve mechanism 21 that delays the phase of the lift center angle of the intake valve 1 is hydraulically driven. It is not limited to this, and it may be driven by an electric motor or the like. Thus, even when the second variable valve mechanism 21 is driven by the electric motor, the response speed of the second variable valve mechanism 21 is affected by the valve lift amount of the intake valve 1. That is, as the swing cam 29 becomes a high lift cam and the valve lift amount of the intake valve 1 is set larger, the response of the second variable valve mechanism 21 to change the lift center angle of the intake valve 1 to the advance side. The speed tends to be slow, and as the swing cam 29 becomes a high lift cam and the valve lift amount of the intake valve 1 is set to be larger, the lift central angle of the intake valve 1 by the second variable valve mechanism 21 is retarded. The response speed of changes to the side tends to increase. Therefore, even when the second variable valve mechanism 21 is driven by an electric motor, when the second variable valve mechanism 21 changes the phase of the lift center angle of the intake valve 1, the first variable valve mechanism 21 is driven. The valve mechanism 11 performs a response assisting operation that temporarily changes the lift / operating angle of the intake valve 1 in a direction that improves the response when the lift center angle of the second variable valve mechanism 21 is changed, thereby providing the second variable valve operation. The responsiveness of the mechanism 21 can be improved.

  The variable valve operating apparatus for an internal combustion engine according to the present invention is not only applied to the intake system, but can also be applied to the exhaust system.

  The technical idea of the present invention that can be grasped from the above embodiment will be listed together with the effects thereof.

  (1) A lift / working angle variable mechanism capable of simultaneously and continuously expanding and reducing the lift / working angle of the engine valve, and a phase variable mechanism for delaying the phase of the lift center angle of the engine valve. In a variable valve operating apparatus for an internal combustion engine capable of changing the valve characteristic of the engine valve by operating at least one of the lift / operating angle variable mechanism and the phase variable mechanism, the phase variable mechanism When changing the phase of the lift center angle, the lift / operating angle variable mechanism temporarily changes the lift / operating angle of the engine valve in a direction that improves the responsiveness when changing the lift center angle of the phase variable mechanism. Performs a response assist operation. This improves the response of the phase variable mechanism during the transition, and the response time until the phase of the lift valve center angle of the engine valve is changed to the control target value by the phase variable mechanism is shortened. (Performance of the internal combustion engine) can be improved, and as a result, the engine performance in practical use can be improved.

  (2) The variable valve operating apparatus for the internal combustion engine according to (1), wherein the lift / operating angle variable mechanism is used when the phase of the lift center angle of the engine valve is changed to the advance side by the phase variable mechanism. Thus, the lift / operating angle of the engine valve is temporarily changed to the small lift / small operating angle side. Thereby, the practical fuel consumption of the internal combustion engine can be improved.

  (3) The variable valve operating apparatus for an internal combustion engine according to (1) or (2) described above, when the phase of the lift central angle of the engine valve is changed to the retard side by the phase variable mechanism. The lift / operating angle of the engine valve is once changed to the large lift / large operating angle side by the operating angle variable mechanism. As a result, the acceleration performance of the vehicle on which the internal combustion engine is mounted can be improved.

  (4) In the variable valve operating apparatus for an internal combustion engine according to any one of (1) to (3), the phase of the lift central angle of the engine valve is changed by the phase variable mechanism in accordance with the change of the valve characteristic of the engine valve. If the opening period of the engine valve before the change is the opening period before the change, and the opening period of the engine valve after the change is the opening period after the change, the lift / operating angle is variable. The opening timing and closing timing of the engine valve during the response assisting operation of the mechanism are set so as to be within at least one of the pre-change valve opening period and the post-change valve opening period.

  (5) In the variable valve operating apparatus for an internal combustion engine according to any one of (1) to (4), specifically, the lift / operating angle variable mechanism is set in advance after the start of the response assisting operation. When the predetermined condition is satisfied, the response assisting operation is terminated, and the lift / operating angle of the engine valve is changed toward the current control target value.

  (6) In the variable valve operating apparatus for an internal combustion engine according to (5), specifically, the predetermined condition is established when a predetermined time elapses from the start of the response assisting operation.

  (7) In the variable valve operating apparatus for an internal combustion engine according to (5), specifically, the predetermined condition is that the phase of the lift center angle of the engine valve reaches the current control target value by the phase variable mechanism. It is established when it is changed.

  (8) In the variable valve operating apparatus for an internal combustion engine according to any one of (1) to (7), specifically, the phase variable mechanism is oil driven by rotation of a crankshaft of the internal combustion engine. Driven by the hydraulic pressure of the hydraulic oil supplied from the pump, having operating state detecting means for detecting the operating state of the internal combustion engine, and changing the phase of the lift center angle of the engine valve by the phase variable mechanism. When the oil temperature of the hydraulic oil is lower than a first predetermined temperature set in advance by the operating state detecting means, the oil temperature of the hydraulic oil is equal to or higher than a preset second predetermined temperature. By the variable lift / operating angle when it is determined that the oil temperature is high or the engine speed of the internal combustion engine is low or lower than a predetermined value. The above response assisting action Hodokosuru. As a result, it is possible to improve the starting exhaust performance, the fuel consumption, and the acceleration performance of the vehicle on which the internal combustion engine is mounted.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which showed typically schematic structure of the variable valve operating apparatus of the internal combustion engine which concerns on this invention. The characteristic line figure which shows the correlation of the response speed of the 2nd variable valve mechanism with respect to the oil temperature of hydraulic fluid, and the hydraulic pressure of hydraulic fluid. The characteristic line figure which shows the correlation of the response speed of the 2nd variable valve mechanism with respect to engine speed, and the hydraulic pressure of hydraulic fluid. The characteristic line figure which shows the correlation of the response speed of a 2nd variable valve mechanism, the valve lift amount of an intake valve, and the working hydraulic pressure of a 2nd variable valve mechanism. The timing chart of the 1st and 2nd variable valve mechanism at the time of changing the phase of the lift center angle of an intake valve by a 2nd variable valve mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Intake valve 11 ... 1st variable valve mechanism (lift / operating angle variable mechanism)
21 ... Second variable valve mechanism (variable phase mechanism)

Claims (8)

A lift / working angle variable mechanism capable of simultaneously and continuously expanding and reducing the lift / working angle of the engine valve, and a phase variable mechanism for delaying the phase of the lift center angle of the engine valve, In a variable valve operating apparatus for an internal combustion engine capable of changing the valve characteristic of the engine valve by operating at least one of a lift / operating angle variable mechanism and the phase variable mechanism,
When the phase of the lift center angle of the engine valve is changed by the phase variable mechanism, the lift / operation angle of the engine valve is changed by the lift / operation angle variable mechanism when the lift center angle of the phase variable mechanism is changed. A variable valve operating apparatus for an internal combustion engine that performs a response assisting operation that temporarily changes in a direction to improve the performance.   When changing the phase of the lift center angle of the engine valve to the advance side by the phase variable mechanism, the lift / operating angle of the engine valve is once changed to the small lift / small operating angle side by the lift / operating angle variable mechanism. The variable valve operating apparatus for an internal combustion engine according to claim 1, wherein   When changing the phase of the lift center angle of the engine valve to the retarded side by the phase variable mechanism, the lift / operating angle of the engine valve is once set to the large lift / large operating angle side by the variable lift / operating angle mechanism. The variable valve operating apparatus for an internal combustion engine according to claim 1 or 2, wherein   When changing the phase of the lift center angle of the engine valve by the phase variable mechanism in accordance with the change of the valve characteristic of the engine valve, the opening period of the engine valve before the change is defined as the pre-change valve opening period. Assuming that the later opening period of the engine valve is a changed opening period, the opening timing and closing timing of the engine valve during the response assisting operation of the lift / operating angle variable mechanism are the opening period before the change or the change The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 3, wherein the variable valve operating apparatus is set so as to be within at least one of the post-opening periods.   The lift / operating angle variable mechanism terminates the response assisting operation when a predetermined condition is established after the response assisting operation is started, and sets the lift / operating angle of the engine valve toward the current control target value. The variable valve operating apparatus for an internal combustion engine according to claim 1, wherein the variable valve operating apparatus is changed.   6. The variable valve operating apparatus for an internal combustion engine according to claim 5, wherein the predetermined condition is satisfied when a predetermined time elapses from the start of the response assisting operation.   6. The variable valve operating system for an internal combustion engine according to claim 5, wherein the predetermined condition is satisfied when the phase of the lift center angle of the engine valve is changed to the current control target value by the phase variable mechanism. . The phase variable mechanism is driven by hydraulic pressure of hydraulic oil supplied from an oil pump driven by rotation of a crankshaft of the internal combustion engine,
Having an operating state detecting means for detecting the operating state of the internal combustion engine;
When the phase of the lift central angle of the engine valve is changed by the phase variable mechanism, the operating state detection means causes the oil temperature of the hydraulic oil to be equal to or lower than a first predetermined temperature set in advance. When the oil temperature of the hydraulic oil is higher than a preset second predetermined temperature or when the engine speed of the internal combustion engine is lower than a preset predetermined number of revolutions. 8. The variable valve operating apparatus for an internal combustion engine according to claim 1, wherein when the determination is made, the response assisting operation is performed by the lift / operating angle variable mechanism.

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