JP4433591B2 - Variable valve operating device for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an operating angle changing mechanism that changes an operating angle of an intake valve (hereinafter abbreviated as an intake operating angle if necessary) and a central phase of an operating angle of an intake valve (hereinafter abbreviated as an intake phase as required). And a phase change mechanism that changes the pressure control mechanism of the internal combustion engine.
[0002]
[Prior art]
Japanese Patent Laid-Open No. 2000-18056 discloses a valve lift amount changing mechanism that changes the valve lift amount and operating angle of the intake valve, a valve timing changing mechanism that changes the opening / closing timing of the intake valve (the center phase of the operating angle), Is disclosed. In this publication, only the intake phase is changed by the valve timing changing mechanism without changing the valve lift amount in the low rotation range.
[0003]
[Problems to be solved by the invention]
In an apparatus having two such change mechanisms, when changing both the operating angle and phase of the intake valve, such as during a transition period in which the engine operating state changes, particularly during acceleration to increase the engine speed, There is a possibility that the opening / closing timing of the intake valve temporarily becomes undesirable and the driving performance is deteriorated. For example, when only the operating angle is increased during acceleration from the idle state set to the minimum operating angle and the most retarded angle phase by both changing mechanisms, the closing timing of the intake valve becomes excessively late, and the torque temporarily May decrease.
[0004]
In addition, even when accelerating from the same load range, if both change mechanisms are driven and controlled in the same way at the time of cooling and after warming up, the torque may not be increased effectively during cooling or warming up. is there.
[0005]
The present invention has been made in view of such problems, and an object thereof is to increase torque quickly and efficiently during engine acceleration.
[0006]
[Means for Solving the Problems]
In view of this, the invention according to claim 1 provides a variable motion of an internal combustion engine having an operating angle changing mechanism that changes the operating angle of the intake valve and an electric phase changing mechanism that changes the center phase of the operating angle of the intake valve. In the valve device, in the extremely low load range when the engine is cold, the intake valve operating angle is set to the minimum operating angle, and the central phase of the intake valve operating angle is set to the most retarded angle phase. During acceleration of the engine, the phase change mechanism is preferentially driven to the advance side rather than the operating angle change mechanism.
[0007]
That is, even when accelerating from the same load range, the change mechanism that is driven preferentially is controlled based on the engine speed or the engine temperature. As a result, it is possible to prevent the torque from dropping during acceleration and improve the engine operating performance.
[0008]
The invention according to claim 2 is characterized in that the center phase of the operating angle of the intake valve in the extremely low load region is set to the retard side when the engine is cold than after the warm-up.
[0009]
According to the third aspect of the present invention, when accelerating from an extremely low load / ultra-low rotation range, the phase change mechanism is preferentially driven when cold, and the operating angle change mechanism is preferentially driven after warm-up. It is a feature.
[0010]
The invention according to claim 4 is characterized in that at the time of acceleration at the time of engine start, the phase change mechanism is preferentially driven when the engine is cold, and the operating angle change mechanism is preferentially driven after the engine is warmed up.
[0011]
The invention according to claim 5 preferentially drives the phase change mechanism in the extremely low rotation range and preferentially drives the operating angle change mechanism in the low rotation range when accelerating from the extremely low load range during cold operation. It is characterized by.
[0012]
The invention according to claim 6 is characterized in that the operating angle changing mechanism is electrically operated.
[0013]
The invention according to claim 7 is characterized in that the operating angle of the intake valve in the extremely low load region is set to be smaller at the time of cold operation than after warm-up.
[0014]
Driving invention of claim 8, the operating angle change mechanism, is fitted to be rotatable relative to the air intake drive shaft, a swing cam for opening and closing the intake valve, which is provided eccentrically on the intake drive shaft a cam, and a ring-shaped link fitted relatively rotatably to the drive cam, control and control shaft control cam provided eccentrically, as well as fitted as to be relatively rotatable to the control cam, one end of the ring-shaped It has a rocker arm connected to the link, and a rod-like link connected to the other end of the rocker arm and the swing cam.
[0015]
The invention according to claim 9 is a means for detecting the rotation angle of the intake drive shaft, a phase detection means for detecting the actual center phase of the operating angle of the intake valve based on the rotation angle of the intake drive shaft, and the control Means for detecting the rotation angle of the shaft, and operating angle detection means for detecting the actual operating angle of the intake valve based on the rotation angle of the control shaft, and the actual center phase is detected by the phase detection means. In this case, the actual operating angle is detected by the operating angle detecting means, and a target value of the operating angle of the intake valve is set.
[0016]
【The invention's effect】
According to the first aspect of the invention, the engine operability can be improved by efficiently increasing the torque during engine acceleration in accordance with the engine speed or the engine temperature.
[0017]
Moreover, since the phase change mechanism is an electric type, the phase can be reliably changed even when the engine is cold. Therefore, as in the invention according to claim 2, in the extremely low load region such as idle, the intake phase at the time of cooling can be further retarded than after warming up.
[0018]
According to the second aspect of the present invention, the opening timing of the intake valve can be greatly retarded at the time of cold start, etc., gas flow can be strengthened, combustion improvement and exhaust purification can be achieved. . On the other hand, after the warm-up, the intake phase is relatively advanced as compared with the cold-time, thereby suppressing the suction resistance and improving the fuel consumption. That is, it is possible to achieve both a high level of improvement in exhaust performance when cold and high fuel efficiency after warming up.
[0019]
According to the invention according to claim 3 or 4, torque during acceleration transient can be obtained by preferentially advancing the phase by the phase change mechanism during cold, when accelerating from an extremely low load / ultra low rotation range or starting. Can be reliably avoided. In addition, during warm-up when the phase is advanced compared to when cold, the operating angle can be increased quickly and efficiently by preferentially increasing the operating angle by the operating angle changing mechanism.
[0020]
According to the fifth aspect of the present invention, when accelerating from an extremely light load range during cold operation, the phase change mechanism is preferentially driven and the retardation of the intake phase is quickly performed at the time of extremely low rotation with sufficient intake time. When the engine speed is low and the intake time decreases, the operating angle change mechanism is preferentially driven to increase the operating angle to increase the intake air volume, thereby effectively increasing the torque during the transition. Can do.
[0021]
According to the sixth aspect of the invention, the operating angle of the intake valve can be quickly changed by the operating angle changing mechanism regardless of the engine temperature or the like. For this reason, for example, the minimum operating angle at the time of cooling can be set sufficiently small as compared with the case of the hydraulic drive type that tends to cause a delay in the increase of the operating angle at the time of starting the cold machine. This further enhances the gas flow, improving combustion and further purifying exhaust gas.
[0022]
According to the seventh aspect of the present invention, since the operating angle at the time of cold start is further smaller than that at the time of warm start, the gas flow is further strengthened to improve the combustion, and the exhaust performance can be further improved. it can. On the other hand, at the time of warm-up start, the operating angle becomes relatively larger than that at the time of cold start, and the suction resistance is suppressed, so that fuel efficiency can be improved.
[0023]
According to the invention which concerns on Claim 8, it is possible to arrange | position both change mechanisms of a comparatively simple structure, without interfering with each other. In particular, in this operating angle changing mechanism, since the connecting portions of the members such as the bearing portion of the drive cam and the bearing portion of the control cam are in surface contact, lubrication is easy, and durability and reliability are excellent. At the same time, the resistance when changing the operating angle is also kept low. In addition, since the swing cam that drives the intake valve is disposed coaxially with the intake drive shaft, for example, compared to a configuration in which the swing cam is supported by another support shaft different from the intake drive shaft, In addition to excellent control accuracy, the device itself is compact and has good vehicle mountability.
[0024]
According to the ninth aspect of the present invention, the actual intake phase is detected every time the intake drive shaft rotates in conjunction with the crankshaft, while the actual operating angle is detected based on the angle of the control shaft. Therefore, it can be detected at an arbitrary timing. Therefore, by detecting the actual operating angle at the timing when the actual intake phase is detected and setting the target value of the operating angle, it is possible to accurately detect the operating angle and phase at the same time, and the control Accuracy is improved.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
[0026]
FIG. 1 shows a variable valve operating apparatus according to an embodiment of the present invention. Each cylinder is provided with a pair of intake valves 2. A hollow intake drive shaft 3 extends in the cylinder row direction above the intake valves 2. A swing cam 4 that contacts the valve lifter 2a of the intake valve 2 and opens and closes the intake valve 2 is fitted on the intake drive shaft 3 so as to be relatively rotatable.
[0027]
Then, between the intake drive shaft 3 and the swing cam 4, electric operation is performed to change the operation angle and valve lift amount of the intake valve 2 while keeping the central phase (intake phase) of the operation angle of the intake valve 2 substantially constant. An operating angle changing mechanism 10 of the type is provided. Further, an electric phase changing mechanism 20 that changes the intake phase by changing the phase of the intake drive shaft 3 with respect to a crankshaft (not shown) is disposed at one end of the intake drive shaft 3.
[0028]
As shown in FIGS. 1 and 2, the operating angle changing mechanism 10 includes a drive cam 11 that is eccentrically provided on the intake drive shaft 3, a ring-shaped link 12 that is externally fitted to the drive cam 11 so as to be relatively rotatable, and an intake air A control shaft 13 extending substantially parallel to the drive shaft 3 in the cylinder row direction, a control cam 14 provided eccentric to the control shaft 13, and externally fitted to the control cam 14 so as to be rotatable relative to each other. The rocker arm 15 is connected to the tip of the link 12, and the rod-like link 16 is connected to the other end of the rocker arm 15 and the swing cam 4.
[0029]
The control shaft 13 is driven to rotate within a predetermined control range via the gear train 18 by the electric actuator 17. The ECU 30 as an engine control unit includes an angle of the intake drive shaft 3 and the control shaft 13 detected by the angle detection sensors 31 and 32, a crank angle detected or estimated by various sensors, an engine speed, a load, and a water temperature. In addition to performing general engine control such as fuel injection and ignition timing control based on the engine operating conditions such as the above, the electric actuator 17 is driven and controlled, and the phase changing mechanism 20 described later is driven and controlled, and the intake valve 2 Controls opening and closing timing and operating angle.
[0030]
With the above configuration, when the intake drive shaft 3 rotates in conjunction with the crankshaft, the ring-shaped link 12 moves substantially in translation through the drive cam 11 and the rocker arm 15 swings around the axis of the control cam 14. Then, the swing cam 4 swings via the rod-shaped link 16 and the intake valve 2 is driven to open and close.
[0031]
Further, by changing the rotation angle of the control shaft 13, the axial center position of the control cam 14 that becomes the swing center of the rocker arm 15 is changed, and the posture of the swing cam 4 is changed. As a result, the operating angle (opening / closing period) and the valve lift amount of the intake valve 2 continuously change while the central phase of the operating angle of the intake valve 2 remains substantially constant.
[0032]
In such an operating angle changing mechanism 10, since the connecting portions of the members such as the bearing portion of the drive cam 11 and the bearing portion of the control cam 14 are in surface contact, lubrication is easy and durability and reliability are improved. While being excellent, the resistance at the time of changing an operating angle is also suppressed low. In addition, since the swing cam 4 that drives the intake valve 2 is arranged coaxially with the intake drive shaft 3, for example, the swing cam is supported by another support shaft different from the intake drive shaft 3. In comparison, the control accuracy is excellent, the device itself is compact, and the vehicle mountability is good.
[0033]
FIG. 3 shows an electric phase change mechanism 20. The configuration of the phase changing mechanism 20 is known as disclosed in Japanese Patent Application Laid-Open No. 10-153105. Briefly, the first rotating body 21 that rotates in synchronization with the crankshaft, the intake air, Between the 2nd rotary body 22 rotated with the drive shaft 3, the cyclic | annular piston 23 meshed with both 21 and 22 via the helical spline is interposed. Then, by driving the piston 23 in the axial direction by the electromagnetic solenoid 24, the relative phase of the rotating bodies 21 and 22 changes, and the phase of the intake drive shaft 3 with respect to the crankshaft is variably controlled. The electromagnetic solenoid 24 is driven and controlled according to the engine operating state by the control signal from the ECU 30 described above.
[0034]
Next, a setting example of the intake operation angle and the intake phase according to the present embodiment will be described with reference to FIG. Note that the value of the intake phase to be described later has a relationship of P1 <P2 <P3 <P4 <P5 when the advance side is positive.
[0035]
First, the valve lift characteristics after warming up will be described. In an extremely low load range (a2) such as idling, the intake phase is set to a predetermined retarded phase P2, the intake operating angle is set to the minimum operating angle, and the intake valve is opened after top dead center. The valve closing timing is near the bottom dead center. As a result, the residual gas is reduced and the upper surface of the piston is not exposed to the negative intake pressure from the top dead center, and the intake valve is opened after the piston is displaced to some extent and the cylinder becomes negative pressure. , Pump loss is reduced. Further, since the intake operating angle is minimized, the friction is reduced, the gas flow is enhanced, and the atomization of fuel is promoted. As a result, fuel efficiency and exhaust performance are improved.
[0036]
In the middle load range (c), in order to reduce pump loss mainly due to an increase in residual gas and improve combustion due to high-temperature residual gas, the intake valve opening timing is set to before the top dead center, and mainly the intake air In order to reduce pump loss by reducing the amount (filling efficiency), the intake valve closing timing is set before the bottom dead center. Therefore, a predetermined small operating angle larger than the minimum operating angle is set, and the intake phase is set to the most advanced angle phase P5.
[0037]
In the low load range (b) where the intake air amount is smaller than the middle load range (c), the intake operating angle is reduced from the minimum operating angle to a small operating angle in order to prevent combustion deterioration and reduce residual gas. And the intake phase is set to a predetermined advance phase P4. As a result, fuel efficiency is improved by reducing pump loss accompanying an increase in effective compression ratio.
[0038]
In the fully open areas (d) to (f), in order to mainly improve the charging efficiency, the intake phase is set at or near the predetermined intermediate phase P3, and the intake operating angle is increased as the engine speed increases. . For example, in the fully open / low speed range (d), IVO is set to approximately the top dead center, and IVC is set after the bottom dead center.
[0039]
On the other hand, in an extremely low load region (a1) such as an idling in a cold state where the engine temperature is equal to or lower than a predetermined value, such as at the time of cold start, catalyst warm-up is insufficient, so exhaust purification and exhaust temperature increase due to combustion improvement Therefore, the intake operating angle is set to the minimum operating angle, the intake phase is set to the most retarded angle phase P1, and the IVO is significantly retarded from the top dead center. With this setting, fuel atomization by gas flow enhancement is promoted, and the intake valve opens after the cylinder negative pressure is sufficiently developed by retarding the IVO. The flow is further strengthened.
[0040]
Although not shown in the figure, in the low / medium load range in the cold state, combustion may deteriorate if the lift characteristics (b) and (c) in the warm state are the same. The lift characteristics (d) must be set substantially the same.
[0041]
The flow of setting control of the intake operating angle and intake phase in the idling region described above will be described in detail with reference to the flowchart of FIG. If it is determined in S (step) 1 that the engine is in the idling state, the process proceeds to S2, where it is determined whether the engine is cold or warmed based on the engine temperature or the like. If it is cold, the process proceeds to S3, where the intake operation angle is set to the minimum operation angle, and the intake phase is set to the most retarded angle phase P1. On the other hand, at the time of warm-up, the intake operation angle is set to a predetermined small operation angle larger than the minimum value, and the intake phase is set to the retard angle phase P2.
[0042]
In this flowchart, unlike the setting shown in FIG. 4 (a2), the operating angle of the intake valve in an extremely low load region such as when the engine is started is set to be smaller when the engine is cold than after warming up. . In this case, since the operating angle becomes smaller at the time of cold start than at the time of warm-up, the gas flow is strengthened and combustion is improved. On the other hand, at the time of warm-up start, the operating angle becomes relatively larger than that at the time of cold start, and the suction resistance is suppressed, so that fuel efficiency can be improved.
[0043]
Next, with reference to FIGS. 5-7, the case where it accelerates from each driving | running state is considered. Note that L1 in the figure represents a reference characteristic corresponding to the reference setting of the intake operation angle and the intake phase in the driving state before acceleration. L2 is a target characteristic corresponding to the target operating angle and target phase, and L3 is a characteristic in a state where only the intake operating angle is changed by a predetermined amount toward the target operating angle with respect to the reference characteristic L1. L4 represents a characteristic in a state in which only the intake phase is changed by a predetermined amount toward the target phase with respect to the reference characteristic L1.
[0044]
First, with reference to FIG. 5, the acceleration from the extremely low load region (cold idle state) during cold operation will be considered. In the cold machine idle state, as described above, the intake phase is set to the most retarded phase P1. Therefore, when only the intake operating angle is increased in the extremely low load region, there is a possibility that the torque may temporarily decrease because the intake valve closing timing is excessively delayed. For example, in the rotation range lower than the first rotation speed N1 shown in FIG. 5, the torque of the characteristic L3 after the increase of the operating angle is lower than the reference characteristic L1, and therefore the torque is temporarily changed when only the operating angle is changed. Will be reduced.
[0045]
On the other hand, even if only the intake phase is advanced during acceleration from such an extremely low load, the torque surely goes in the increasing direction. Therefore, at the time of acceleration from such an extremely low load and extremely low rotation range, the phase change mechanism 20 preferentially advances the intake phase. That is, only the phase change mechanism 20 is driven, or the change amount of the intake phase by the phase change mechanism 20 is controlled to be sufficiently larger than the change amount of the operating angle by the operating angle changing mechanism 10. As a result, the torque during the acceleration transition is surely moved in the increasing direction, and the torque drop during the transition can be reliably avoided.
[0046]
By the way, the reference setting (minimum operating angle and most retarded angle phase) L1 of the cold idle state is used also in a low rotational speed range where the rotational speed is somewhat higher than the extremely low rotational speed range, mainly for the purpose of improving combustion. However, as the engine speed increases, the intake time decreases at the same operating angle, so that the fully open torque cannot be increased effectively even if only the intake phase is advanced. Therefore, in the extremely low rotation range (for example, the rotation range below the second rotation speed N2 in which the torque is reversed between the characteristic L3 in the increased operating angle state and the characteristic L4 in the phase advance state shown in FIG. 5), as described above. Torque can be increased most efficiently by preferentially advancing the intake phase and preferentially increasing the intake operation angle in a low rotation range (for example, a rotation range exceeding the second rotation speed N2). it can.
[0047]
Next, a case where acceleration is performed from an extremely low load range in a state after warm-up will be considered with reference to FIG. In the extremely low load range after warming up, the intake phase is set to the post-warming retarded phase P2 that is advanced from the most retarded phase P1, as described above, mainly in order to suppress the intake resistance and improve fuel efficiency. is doing. That is, in order to improve the combustion mainly by increasing the effective compression ratio, the intake valve closing timing is advanced more than the cold engine. Therefore, if only the intake phase is advanced, the effective compression ratio and the charging efficiency may be reduced, and the torque may not be increased effectively. Therefore, during acceleration from such an extremely low load range after warm-up, the torque can be efficiently increased by preferentially increasing the intake operating angle.
[0048]
Thus, even when acceleration is performed from the same load range, priority is given to one of the operating angle changing mechanism 10 or the phase changing mechanism 20 based on at least one of the engine speed or the engine temperature (cold or warmed up). By driving automatically, the torque can be increased efficiently and drivability can be improved.
[0049]
Next, a case where acceleration is performed from a low load range in a state after warm-up will be considered with reference to FIG. When accelerating from the low load range, as is apparent from the fact that both the characteristics L3 and L4 have higher torque than the reference characteristic L1 in FIG. 7, the torque increases even if the operating angle is increased or the phase is retarded. . However, in FIG. 7, as apparent from the fact that the characteristic L3 in the increased operating angle state is always higher in torque than the characteristic L4 in the retarded phase state, the intake operating angle by the operating angle changing mechanism 10 regardless of the engine speed. The torque can be increased efficiently by giving priority to the increase in the acceleration to the retardation of the intake phase by the phase change mechanism 20.
[0050]
Although not shown, for acceleration from the middle load region as shown in FIG. 4C, if priority is given to an increase in the operating angle, there is a possibility that the IVO becomes excessively fast and the intake valve and the piston interfere with each other. Therefore, preferably, the phase change mechanism 20 preferentially retards the intake phase.
[0051]
As described above, in the present embodiment, since the phase change mechanism 20 has an electric configuration, the intake phase can be quickly changed regardless of the engine temperature (when cold or hot). That is, the phase can be changed quickly even when the engine is cold, as opposed to the hydraulic drive that tends to cause a phase change delay when the engine is cold. As a result, the intake valve opening timing is greatly retarded at the time of cold start to enhance the gas flow, thereby improving combustion and purifying exhaust. Also, after warming up, the intake phase is slightly advanced to reduce intake resistance and improve fuel efficiency. As a result, it is possible to achieve both a high level of purification of exhaust gas when cold and improved fuel efficiency after warming up.
[0052]
Further, since the operating angle changing mechanism 10 is also of an electric type, the intake operating angle can be changed reliably and quickly even when the cold machine is started or at extremely low speed. That is, by employing such an electric operating angle changing mechanism 10, for example, the operating angle changing mechanism 10 can be preferentially driven even in a low speed range. In addition, the operating angle can be quickly increased regardless of the engine temperature (during cold or after warm-up). For this reason, it is possible to set the minimum operating angle sufficiently small compared to the hydraulic drive type configuration that tends to cause an increase in operating angle during cold operation. It is possible to improve the combustion and improve the exhaust emission.
[0053]
Thus, since both the change mechanisms 10 and 20 are motorized, as described above, control can be performed so as to switch the priority of both the change mechanisms 10 and 20 even during the acceleration transition period. .
[0054]
By the way, as in this embodiment, based on the detection signal from the angle detection sensor 31 of the intake drive shaft 3, the actual value (actual center phase) of the center phase of the intake drive shaft 3 with respect to the crank angle is detected. The intake phase is detected every rotation of the intake drive shaft 3. On the other hand, in the case of a configuration in which an actual measured value (actual operating angle) of the intake operating angle is detected based on a detection signal from the angle detection sensor 32 of the control shaft 13, the detection interval is free and the actual operation is performed at an arbitrary timing. Corners can be detected. Therefore, by detecting the actual operating angle in accordance with the timing at which the actual intake phase is detected, setting the target value for the intake operating angle and the intake phase based on the actual intake phase and actual operating angle detected at the same time The control accuracy can be improved.
[0055]
The flow of such control will be described in detail with reference to the flowchart of FIG. In S11, when the actual intake phase is detected based on the detection signal from the angle detection sensor 31 of the intake drive shaft 3, the process proceeds to S12, and the actual operating angle is determined based on the detection signal of the angle detection sensor 32 of the control shaft 13. Is detected. In subsequent S13, if it is determined that the vehicle is in the acceleration state, the process proceeds to S14, and it is determined whether the engine is in the cold state or after the warm-up based on the engine temperature or the like. When the engine is cold, the process proceeds to S16, and it is determined whether the engine is in the extremely low speed range or the low speed range based on the engine speed. In the case of the extremely low rotation range, the process proceeds to S17, and control for preferentially driving the phase changing mechanism 20 is performed. On the other hand, in the case of the low rotation range, the process proceeds to S18, and the control for preferentially driving the operating angle changing mechanism 10 is performed.
[0056]
If it is determined in S14 that the engine has been warmed up, the process proceeds to S15 to determine whether the intake valve opening timing (IVO) is excessively early. If it is too early, the process proceeds to S17 described above, and control for preferentially driving the phase change mechanism 20 is performed. If it is determined that it is relatively slow, the process proceeds to S16, and it is determined which of the change mechanisms 10 and 20 is preferentially driven according to the engine speed.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing a variable valve operating apparatus according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing an operating angle changing mechanism of the variable valve operating apparatus.
FIG. 3 is a sectional view showing a phase changing mechanism of the variable valve operating apparatus.
FIG. 4 is an operation explanatory diagram of the embodiment.
FIG. 5 is an explanatory diagram at the time of acceleration from a cold machine idle region.
FIG. 6 is an explanatory diagram during acceleration from a warm-up idle range.
FIG. 7 is an explanatory diagram during acceleration from a warm-up low load region.
FIG. 8 is a flowchart showing a flow of setting control of an intake operation angle and an intake phase in an idle range.
FIG. 9 is a flowchart showing a flow of priority setting control of the change mechanism.
[Explanation of symbols]
2 ... Intake valve 3 ... Intake drive shaft 4 ... Oscillating cam 10 ... Operating angle changing mechanism 11 ... Drive cam 12 ... Ring link 13 ... Control shaft 14 ... Control cam 15 ... Rocker arm 16 ... Rod link 20 ... Phase changing mechanism

Claims (9)

In a variable valve operating apparatus for an internal combustion engine having an operating angle changing mechanism that changes the operating angle of the intake valve and an electric phase changing mechanism that changes the center phase of the operating angle of the intake valve,
In the extremely low load range when the engine is cold, the intake valve operating angle is set to the minimum operating angle, and the center phase of the intake valve operating angle is set to the most retarded angle phase.
The engine when the engine is accelerating from cold extremely low load region at the time, the variable valve device for an internal combustion engine, characterized in that to drive the phase change mechanism to preferentially advance side of the operating angle altering mechanism. 2. The variable valve operating system for an internal combustion engine according to claim 1, wherein the center phase of the operating angle of the intake valve in the extremely low load region is set to a retarded angle side after warming up when the engine is cold. 3. The acceleration according to claim 2, wherein when accelerating from an extremely low load / ultra-low rotation range, the phase change mechanism is preferentially driven when the engine is cold, and the operating angle changing mechanism is preferentially driven after the engine is warmed up. The variable valve operating apparatus for an internal combustion engine. 3. The variable motion of the internal combustion engine according to claim 2, wherein at the time of acceleration at the time of starting the engine, the phase change mechanism is preferentially driven when the engine is cold, and the operating angle change mechanism is preferentially driven after the engine is warmed up. Valve device. The first aspect of the invention is characterized in that when accelerating from an extremely low load region during cold machine, the phase change mechanism is preferentially driven in the extremely low rotation region, and the operating angle changing mechanism is preferentially driven in the low rotation region. 5. The variable valve operating apparatus for an internal combustion engine according to any one of 4 above. 6. The variable valve operating apparatus for an internal combustion engine according to claim 1, wherein the operating angle changing mechanism is an electric type. The variable valve for an internal combustion engine according to any one of claims 1 to 6, wherein the operating angle of the intake valve in an extremely low load range is set to be smaller when the engine is cold than after the engine is warmed up. apparatus. The working angle changing mechanism, it is fitted to be rotatable relative to the air intake drive shaft, a swing cam for opening and closing the intake valve, a drive cam provided eccentrically to the intake drive shaft, relative to the drive cam a ring-shaped link rotatably fitted, braking control cam eccentrically provided on your axis, as well as fitted as to be relatively rotatable to the control cam, a rocker arm having one end connected to the ring shaped link, The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 7, further comprising: a rod-shaped link connected to the other end of the rocker arm and the swing cam. Means for detecting the rotation angle of the intake drive shaft;
Phase detection means for detecting the actual center phase of the operating angle of the intake valve based on the rotation angle of the intake drive shaft;
Means for detecting the rotation angle of the control shaft;
An operating angle detecting means for detecting the actual operating angle of the intake valve based on the rotation angle of the control shaft,
9. The target value of the intake valve operating angle is set by detecting the actual operating angle by the operating angle detecting means when the actual center phase is detected by the phase detecting means. The variable valve operating apparatus for an internal combustion engine.

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