JP4590746B2 - Variable valve operating device for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a variable valve operating apparatus for an internal combustion engine.
[0002]
[Prior art]
For example, Japanese Patent Laid-Open No. 2000-220420 discloses a lift / working angle switching mechanism that switches a lift / working angle of a valve of an internal combustion engine between a low speed operation and a high speed operation of the internal combustion engine, and a phase of a lift center angle of the valve. A so-called variable valve operating apparatus is disclosed that includes a phase variable mechanism that variably controls the motor.
[0003]
In the variable valve operating apparatus, the lift / operating angle switching mechanism and the phase variable mechanism are controlled by hydraulic pressure.
[0004]
[Problems to be solved by the invention]
In such a variable valve system, the lift / operating angle switching mechanism has two types of cams, a low-speed operation cam and a high-speed operation cam, and these cams are simply used in accordance with operating conditions. Therefore, there is a possibility that it cannot cope with a wide range of operating conditions.
[0005]
For example, one of the cams is a R / L cam with a small lift and a small operating angle that improves fuel efficiency during steady running (R / L). Since this R / L cam cannot obtain a sufficient driving torque during low-speed full-open running, the other cam is a low-speed full-open running cam having a higher lift and operating angle than the R / L cam. As a result, it becomes impossible to cope with high-speed full-open travel that requires a larger lift and a larger operating angle than during low-speed full-open travel.
[0006]
In addition, the phase variable mechanism is combined with a variable lift / operating angle mechanism that continuously increases and decreases the valve lift / operating angle of the internal combustion engine, so that the valve lift / operate to meet all operating conditions. Although variable control of the angle can be considered, in order to make full use of the variable amount of valve lift and operating angle under all operating conditions, the lift / operating angle variable mechanism is not driven by hydraulic control, There is a problem that it is necessary to drive by control, and the performance effect is large, but the cost increases.
[0007]
[Means for Solving the Problems]
  In view of this, the invention according to claim 1 delays the phase of the lift / working angle variable mechanism that can simultaneously and continuously enlarge and reduce the lift / working angle of the valve of the internal combustion engine and the lift center angle of the valve. In the variable valve operating apparatus for an internal combustion engine having a variable phase mechanism, the ratio of the amount of change allowed from the minimum lift / minimum operating angle to the maximum variable amount variable in the lift / operating angle variable mechanism Is defined as a variable ratio, and in the phase variable mechanism, when the ratio of the amount of change allowed from the most retarded angle position is defined as the variable ratio with respect to the maximum variable amount that can be varied, the variable lift / operating angle mechanism Variable ratio and variable ratio of phase variable mechanism are changed by engine temperatureThe lift / operating angle variable mechanism is hydraulically driven, and the phase variable mechanism is electrically driven.It is characterized by doing. As a result, the lift / operating angle variable mechanism and the phase variable mechanism need not always be variably controlled by the maximum variable amount.In addition, if the lift / operating angle variable mechanism and the phase variable mechanism are both electrically driven, the manufacturing cost increases. In addition, if both the lift / operating angle variable mechanism and the phase variable mechanism are hydraulically driven, fuel consumption performance deteriorates due to a delay in hydraulic response. However, the variable requirement of the lift / operating angle variable mechanism is substantially proportional to the engine speed, and the variable requirement of the phase variable mechanism is proportional to the valve overlap setting and the engine load. That is, the variable lift / operating angle mechanism can be handled by a hydraulic drive with relatively low response.
[0008]
  According to the second aspect of the present invention, there is provided a lift / working angle variable mechanism capable of simultaneously and continuously expanding and reducing the lift / working angle of the intake valve, and a phase variable for delaying the phase of the lift center angle of the intake valve. In the variable valve operating apparatus for an internal combustion engine having the mechanism, in the variable lift / operating angle mechanism, the variable ratio is defined as the ratio of the amount of change allowed from the minimum lift / minimum operating angle to the maximum variable variable. In the phase variable mechanism, when the ratio of the amount of change allowed from the most retarded position is defined as the variable ratio with respect to the maximum variable amount that can be changed, Variable ratio of phase variable mechanism is changed by engine temperatureThe lift / operating angle variable mechanism is hydraulically driven, and the phase variable mechanism is electrically driven.It is characterized by doing.
[0009]
  According to a third aspect of the present invention, in the second aspect of the invention, when the engine is cold, the lift center angle of the intake valve is substantially fixed to a retarded state, and the lift / operation angle of the intake valve is reduced. The variable range of the lift / operation angle variable mechanism is variable from the lift / small operation angle to the intermediate lift / medium operation angle, and the variable ratio of the lift / operation angle variable mechanism is larger than the variable ratio of the phase variable mechanism. When the internal combustion engine is cold, the in-cylinder temperature is low and atomization of fuel is not promoted. Therefore, if the valve overlap of the intake and exhaust valves is increased, combustion becomes unstable and operability deteriorates. That is, it is not necessary to drive the phase variable mechanism with the maximum variable amount. On the other hand, the variable lift / operating angle mechanism stabilizes combustion and increases the ignition timing delay limit by increasing the gas flow in a state where the air flow rate is low during cold operation, which is an operating condition of low rotation and low load. Since it is necessary to expand and promote catalyst warm-up, it is desirable to make the intake valve a small lift and a small operating angle. However, with a small lift and small operating angle, even if the rotation is low, the full opening torque will decrease, so operationSexGetting worse. When the lift / operating angle variable mechanism is driven by a hydraulic actuator, the responsiveness deteriorates when the engine is cold. Further, when the lift / operating angle variable mechanism is driven by an electric actuator, low temperature demagnetization occurs during cold operation. For this reason, when the engine is cold, the drive range of the lift / operating angle variable mechanism by the actuator is desired to be the minimum range. Therefore, considering the fully open performance, the minimum required intake valve opening time is secured by making the variable lift / operating angle mechanism variable in the range from small lift / small operating angle to medium lift / medium operating angle. To do.
[0010]
  According to a fourth aspect of the present invention, in the invention of the second aspect, at the time of cold start, the lift central angle of the intake valve is retarded and the lift / operating angle of the intake valve is reduced by a small lift / small operating angle. And the variable ratio of the variable lift / operating angle mechanism is greater than the variable ratio of the phase variable mechanism.bigIt is characterized by doing. At the time of cold start, the gas flow is increased with a small lift and small operating angle and a small air flow rate to stabilize combustion, and at the same time, the ignition timing retardation limit is expanded to promote catalyst warm-up. Therefore, the variable ratio of the lift / operating angle variable mechanism becomes small. On the other hand, we want to retard the intake valve opening timing as much as possible to increase the in-cylinder negative pressure and further increase the gas flow at the intake valve opening timing.. TheIn other words, the variable ratio of the phase variable mechanism is less than the variable ratio of the lift / operating angle variable mechanism at the time of cold start.smallBecome.
[0011]
  The invention according to claim 5. In the third aspect of the present invention, when the engine is cold, the lift / operating angle of the intake valve is set to the medium lift / operating angle by the lift / operating angle variable mechanism after a predetermined time has elapsed after the engine is started, regardless of the required load on the internal combustion engine. It is characterized by expanding and holding to a medium operating angle. When cold, we want to minimize actuator drive and ensure full opening performance. On the other hand, the small lift and small operating angle can generate a strong gas flow even at the start of a small amount of gas, so that combustion is stabilized and the ignition timing can be retarded to raise the exhaust temperature and warm the catalyst. The machine can be promoted. Also, when the lift / operating angle variable mechanism is driven and controlled by a hydraulic actuator during cold operation, the operation slows down due to a delay in hydraulic response.Become. For this reason, it is determined that the catalyst has been warmed up after a certain period of time since the start of the internal combustion engine, and the response of the hydraulic valve is delayed by maintaining the lift / operating angle of the intake valve at the medium lift / medium operating angle.ThisTo prevent. The intermediate lift / medium operating angle in claim 5 is relatively smaller than the intermediate lift / medium operating angle in claim 3.
[0014]
  Claim6The invention described in claimAny one of 1-5The lift / operating angle variable mechanism is variably controlled at a lower temperature than the phase variable mechanism. As a result, it is possible to prevent the drive torque from being lowered when the machine is cold. It should be noted that the lift / operating angle variable mechanism can be hydraulically operated even though the hydraulic response is deteriorated during cold operation.
[0015]
  Claim7The invention described in claimAny one of 1-5In the invention described in (1), during the warm-up, the variable ratio of the lift / operating angle variable mechanism is made smaller than the variable ratio of the phase variable mechanism. In the middle of warming up, the in-cylinder temperature is rising, so fuel atomization is promoted more than when cold. Therefore, the valve overlap of the intake / exhaust valve can be increased. Therefore, it is possible to improve the fuel efficiency by increasing the variable ratio of the phase variable mechanism. On the other hand, even if the responsiveness of the lift / operating angle variable mechanism by hydraulic drive is improved at the intermediate temperature than when cold, there is no responsiveness and controllability such as overshoot after warming up. Control within the range of operating angle to medium lift / medium operating angle. For this reason, transient engine control stability, fuel efficiency and exhaust performance can be improved by the lift / operating angle variable mechanism and the phase variable mechanism.
[0016]
  Claim8The invention described in claimAny one of 1-5In the invention described in (1), the variable ratio of the lift / operating angle variable mechanism is smaller than the variable ratio of the phase variable mechanism at a high temperature after completion of warm-up. If the output is high and the rotation is high at high temperatures, there is a possibility of overheating. At high temperatures, the variable ratio of the lift / operating angle variable mechanism is reduced to prevent overheating. In addition, the hydraulic viscosity is low at high temperatures, and leakage from the clearance of each part of the engine increases. Therefore, it is possible to reduce the size of the hydraulic pump used to operate the lift / operation angle variable mechanism by slightly reducing the variable ratio of the lift / operation angle variable mechanism at a high temperature compared to the variable ratio after warm-up. Become.
[0017]
【The invention's effect】
According to the present invention, the lift / operating angle variable mechanism and the phase variable mechanism do not always need to be variably controlled with the maximum variable amount. Each actuator that drives the mechanism and the phase variable mechanism can be made inexpensive.
[0018]
According to another aspect of the present invention, the variable ratio of the lift / operating angle variable mechanism is set to the phase variable mechanism in order to secure the minimum opening time of the intake valve that does not deteriorate the operability during cold operation. If it is larger than the variable ratio, each actuator for driving the lift / operating angle variable mechanism and the phase variable mechanism can be made inexpensively and miniaturized while minimizing the decrease in engine performance.
[0019]
According to the fourth aspect, by making the intake valve a small lift and a small operating angle, the gas flow is increased and the intake valve closing timing is advanced, whereby the effective compression ratio is increased and the combustion performance is improved. The
[0020]
  According to claim 5, even if the lift / operating angle variable mechanism is driven and controlled by the hydraulic actuator, a response delay due to the hydraulic pressure may occur.Absent.
[0021]
  Claim7According to the present invention, transient engine control stability, fuel efficiency and exhaust performance can be improved by the lift / operating angle variable mechanism and the phase variable mechanism.
[0022]
  Claims8As described above, if the variable ratio of the variable lift / operating angle mechanism is reduced at a high temperature, the hydraulic pump that drives the hydraulic actuator of the variable lift / operating angle mechanism can be downsized.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
[0024]
FIG. 1 is a configuration explanatory view showing the configuration of an intake valve side variable valve operating device of an internal combustion engine. This variable valve operating device changes a lift / operating angle variable mechanism (VEL) that changes a lift / operating angle of an intake valve 3. ) 1 and a phase variable mechanism (VTC) 2 that advances or retards the phase of the center angle of the lift (phase with respect to a crankshaft (not shown)). The lift / operating angle variable mechanism 1 has been previously proposed by the applicant of the present invention. However, since it has been publicly known, for example, in Japanese Patent Application Laid-Open No. 11-107725, only the outline thereof will be described.
[0025]
The variable lift / operating angle mechanism 1 includes an intake valve 3 slidably provided on a cylinder head (not shown) via a valve guide (not shown), and a cam bracket on the cylinder head (not shown). A hollow drive shaft 4 rotatably supported by (not shown), an eccentric cam 5 fixed to the drive shaft 4 by press-fitting or the like, and the same cam bracket (see FIG. A control shaft 6 that is rotatably supported by the drive shaft 4, a rocker arm 8 that is swingably supported by an eccentric cam portion 7 of the control shaft 6, and each intake valve 3. And a swing cam 10 that contacts the valve lifter 9 disposed at the upper end of the. The eccentric cam 5 and the rocker arm 8 are linked by a link arm 11, and the rocker arm 8 and the swing cam 10 are linked by a link member 12.
[0026]
The drive shaft 4 is driven by a crankshaft of the engine via a timing chain or a timing belt, as will be described later.
[0027]
The eccentric cam 5 has a circular outer peripheral surface, the center of the outer peripheral surface is offset from the axis of the drive shaft 4 by a predetermined amount, and the link arm 11 is rotatably fitted to the outer peripheral surface. ing.
[0028]
The rocker arm 8 is supported substantially at the center by the eccentric cam portion 7, the link arm 11 is linked to one end thereof, and the upper end of the link member 12 is linked to the other end. is doing. The eccentric cam portion 7 is eccentric from the axis of the control shaft 6, and therefore the rocking center of the rocker arm 8 changes according to the angular position of the control shaft 6.
[0029]
The swing cam 10 is fitted to the outer periphery of the drive shaft 4 and is rotatably supported, and the lower end portion of the link member 12 is linked to the end portion extending sideways.
[0030]
The lower surface of the swing cam 10 is in contact with the upper surface of the valve lifter 9 according to the swing position of the swing cam 10.
[0031]
The control shaft 6 is configured to rotate within a predetermined rotation angle range by a lift / operating angle control hydraulic actuator 13 provided at one end.
[0032]
The lift / working angle control hydraulic actuator 13 has a piston structure (not shown), and the control shaft of the lift / working angle variable mechanism 1 is adjusted by adjusting the hydraulic pressure before and after the piston with the control valve 14. The angle, that is, the lift / operating angle is determined.
[0033]
The control valve 14 is controlled by the engine control unit 15. The engine control unit 15 receives detection values such as the engine speed, the engine load, and the water temperature. The engine control state is detected based on these detection values, and the control valve 14 is controlled.
[0034]
The operation of the variable lift / operating angle mechanism 1 will be described. When the drive shaft 4 rotates, the link arm 11 moves up and down by the cam action of the eccentric cam 5, and the rocker arm 8 swings accordingly. The swing of the rocker arm 8 is transmitted to the swing cam 10 via the link member 12, and the swing cam 10 swings. Due to the cam action of the swing cam 10, the valve lifter 9 is pressed and the intake valve 3 is lifted.
[0035]
Here, when the angle of the control shaft 6 changes via the lift / operating angle control hydraulic actuator 13, the initial position of the rocker arm 8 changes, and consequently, the initial swing position of the swing cam 10 changes.
[0036]
Since the position of the eccentric cam portion 7 can be continuously changed, the lift and the operating angle can be continuously enlarged and reduced simultaneously with this. In particular, in this case, the opening timing and closing timing of the intake valve 3 change substantially symmetrically as the lift and operating angle change.
[0037]
Next, the phase variable mechanism 2 includes a sprocket 16 provided at the front end of the drive shaft 4 and a phase control electromagnetic that relatively rotates the sprocket 16 and the drive shaft 4 within a predetermined angle range. Type actuator 17. The sprocket 16 is linked to the crankshaft via a timing chain or timing belt (not shown). The phase control electromagnetic actuator 17 is controlled based on a control signal from the engine control unit 15. The sprocket 16 and the drive shaft 4 are relatively rotated by the phase control electromagnetic actuator 17 and the lift center angle 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.
[0038]
Here, the lift / operation angle variable mechanism 1 and the phase variable mechanism 2 are feedback-controlled by sensors 18 and 19 that detect the actual lift / operation angle or phase operation amount.
[0039]
2 and 3 show a control map of the lift / operating angle variable mechanism 1 after engine warm-up and a control map of the phase variable mechanism 2 after engine warm-up.
[0040]
The lift / operating angle variable mechanism 1 controls the enlargement of the lift / operating angle substantially in proportion to the engine rotation. At low rotation and low load, small lift and small operating angle reduces drive friction of the valve operating system, delays intake valve opening timing (IVO) to reduce pump loss and residual gas in cylinder, and intake valve closing timing Improving fuel efficiency by speeding up (IVC) and reducing pump loss. At high speeds, a large lift and a large operating angle are used to increase intake volume and improve output.
[0041]
On the other hand, the phase variable mechanism 2 is operated in the load direction by normal engine rotation. In order to stabilize combustion at low loads and to improve charging efficiency at high loads, the valve overlap of the intake and exhaust valves is made small. At medium loads where combustion is stable, in order to reduce pump loss and improve combustion due to internal EGR, the valve overlap of intake and exhaust valves is increased to improve fuel efficiency.
[0042]
Therefore, after warm-up, as shown in FIG. 4, both the lift / operating angle variable mechanism 1 and the phase variable mechanism 2 are operated within the maximum setting variable width range. In other words, the variable ratio (details will be described later) of the lift / operating angle variable mechanism 1 and the phase variable mechanism 2 is 100%.
[0043]
In this case, the phase variable mechanism 2 needs to be variably controlled in accordance with load change and accelerator pedal change, and high response is required. Therefore, in this embodiment, an electromagnetic actuator is used. Further, since the lift / operating angle variable mechanism 1 is substantially proportional to the engine rotation, the responsiveness like the phase variable mechanism 2 is not necessary, and in this embodiment, an inexpensive hydraulic actuator is used.
[0044]
Next, operations of the lift / operating angle variable mechanism 1 and the phase variable mechanism 2 other than the normal state in which the engine temperature is warmed up will be described.
[0045]
When cold, the in-cylinder temperature is low and fuel atomization worsens. Therefore, if the valve overlap of the intake / exhaust valve is increased, the combustion becomes unstable and the drivability deteriorates. That is, the phase variable mechanism 2 does not need to be driven to the maximum setting variable width. Therefore, the lift center angle of the intake valve 3 is substantially fixed in a state where it is retarded so that the valve overlap of the intake and exhaust valves does not become large.
[0046]
On the other hand, the variable lift / operating angle mechanism 1 is a small lift / small operating angle with low rotation and low load, and the gas flow is large when the air flow rate is low, such as at the time of starting, to stabilize combustion, and to limit the ignition timing retardation. Since it is necessary to expand the catalyst and promote catalyst warm-up, it is desirable to use a small lift and a small operating angle. However, with a small lift and a small operating angle, even if the rotation is low, the fully open torque is reduced, so the drivability is deteriorated. Therefore, the lift / working angle varying mechanism 1 needs to be varied in a range from a small lift / small working angle to a medium lift / medium working angle. Since the hydraulic pressure of the lift / operating angle control hydraulic actuator 13 is high even when the oil viscosity is cold, the hydraulic actuator 13 can be switched unless the response is high such as load switching.
[0047]
Here, the ratio of the controllable range of each variable mechanism at that time with respect to the maximum variable amount variable by the lift / operation angle variable mechanism 1 and the phase variable mechanism 2 is defined as a variable ratio. For example, if the phase variable mechanism can change the crank angle by 60 °, but only allows 6 ° operation at low temperatures, the variable ratio at that time is 10%. The variable ratio is 100%.
[0048]
In other words, in this embodiment, the variable ratio of the lift / operating angle variable mechanism 1 is controlled to be larger than the variable ratio of the phase variable mechanism 2 when the engine is cold.
[0049]
In this embodiment, the variable lift / operating angle mechanism 1 is driven by a hydraulic actuator. However, even if the lift / operating angle variable mechanism 1 is driven by an electromagnetic actuator, a high response is required when the engine is cold. Then, low temperature demagnetization occurs, and the output of the electromagnetic actuator may be reduced. Therefore, if the variable ratio of the lift / operating angle variable mechanism 1 during cooling is reduced, even if an electromagnetic actuator is applied to the lift / operating angle variable mechanism 1, there is an advantage that the actuator can be reduced in size.
[0050]
As described above, even when the engine is cold, it is necessary to expand the lift / operating angle of the intake valve 3 to a medium lift / medium operating angle due to an acceleration request. However, considering the deterioration of hydraulic response and the occurrence of low temperature demagnetization, I want to respond with slow response. Therefore, it is determined that the catalyst has been warmed up after a certain period of time has elapsed since the start of the cold engine, and the lift / operating angle of the intake valve 3 is set to the medium lift / medium operating angle regardless of whether or not acceleration is requested. The control is expanded and maintained until the deterioration of responsiveness during cold operation is prevented.
[0051]
In the middle of warming up, the in-cylinder temperature also rises and fuel atomization is improved. Therefore, the valve overlap of the intake / exhaust valve can be increased to improve fuel efficiency. On the other hand, the lift / operating angle variable mechanism 1 does not have controllability such as response after over-warming, overshoot, etc., even if the switching responsiveness is improved at the intermediate temperature from when cold. ~ Control within the range of medium lift and medium working angle. That is, the variable ratio of the phase variable mechanism 2 is made larger than the variable ratio of the lift / operation angle variable mechanism 1. The intermediate lift / medium operating angle during warm-up is relatively larger than the intermediate lift / medium operating angle during cold-up (see FIG. 4), but may be the same.
[0052]
At high temperatures, if the output is large and the rotation is high, there is a possibility of overheating. Therefore, the variable ratio of the lift / operating angle variable mechanism 1 is slightly reduced as compared with the variable ratio after warming up to prevent overheating. The phase variable mechanism 2 is operated within the maximum setting variable width range, similar to after warm-up.
[0053]
That is, the lift / operating angle variable mechanism 1 is operated within the range of the small lift / small operating angle to the large lift / large operating angle slightly smaller than the maximum variable amount, and the phase variable mechanism 2 is the same as that after the warm-up described above. And within the maximum setting variable width range.
[0054]
Therefore, at a high temperature, the variable ratio of the variable lift / operating angle mechanism 1 is smaller than the variable ratio of the phase variable mechanism 2.
[0055]
Further, since the hydraulic viscosity becomes low and the leakage from the clearance of each part of the engine increases at high temperatures, it is possible to reduce the size of the pump that supplies hydraulic pressure to the lift / operating angle control hydraulic actuator 13.
[0056]
As described above, as shown in FIG. 4, the variable ratio of the lift / operating angle variable mechanism 1 and the phase variable mechanism 2 is changed depending on the engine temperature. It becomes possible. In addition, when the variable ratio is set according to the temperature, it is not necessary to prepare a plurality of valve timing maps for each temperature, and there is an advantage that the memory of the engine control unit can be reduced in size.
[0057]
As can be seen from FIG. 4, the variable ratio of the lift / operating angle variable mechanism 1 during the cool-down and the variable ratio of the lift / operating angle variable mechanism 1 during the warm-up include the variable ratio during the warm-up. The variable ratio of the lift / operating angle variable mechanism 1 during warm-up and the variable ratio of the lift / operating angle variable mechanism 1 at high temperatures are larger in the variable ratio at high temperatures.
[0058]
FIG. 5 shows a flowchart of the control of this embodiment.
[0059]
In step 1, the engine temperature T is read, and in step 2, it is determined whether or not the engine is cold.
[0060]
If it is determined that the engine is in the cold state, the process proceeds to step 3 where the elapsed time ts after engine start is read and the process proceeds to step 4.
[0061]
If it is determined in step 4 that the elapsed time ts after engine start ≤ the constant time tc, the process proceeds to step 5 where the lift / operating angle of the intake valve 3 is set to a small lift / small operating angle, and the lift central angle of the intake valve 3 is intake / exhaust. The valve is substantially fixed in a state of being retarded so that the valve overlap of the valve becomes small (see the time of cooling in FIG. 4).
[0062]
In step 4, if the elapsed time ts after engine start is greater than the predetermined time tc, the process proceeds to step 6 where the lift / operating angle of the intake valve 3 is expanded and held to the middle lift / medium operating angle. The lift center angle is generally fixed in a state of being retarded so that the valve overlap becomes smaller (see the time of cooling in FIG. 4).
[0063]
If it is determined in step 2 that the engine is not in the cold state, the process proceeds to step 7.
[0064]
If it is determined in step 7 that the engine is warming up, the process proceeds to step 8. If it is determined that the engine is warmed up, the process proceeds to step 9;
[0065]
In step 8, the lift / operating angle of the intake valve 3 is controlled within the range of small lift / small operating angle to medium lift / medium operating angle, and the lift center angle of the intake valve 3 is controlled with the maximum setting variable width (FIG. (See 4 in the middle of warming up).
[0066]
In step 9, the lift / operating angle and the lift center angle of the intake valve 3 are controlled at the maximum setting variable width (see after warm-up in FIG. 4).
[0067]
In step 10, the lift / operating angle of the intake valve 3 is controlled within a range from a small lift / small operating angle to a large lift / large operating angle slightly reduced from the set variable width. Control is performed with the maximum variable width (see the high temperature in FIG. 4).
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a variable valve operating apparatus for an internal combustion engine according to the present invention.
[Fig. 2] Control map of lift / operating angle variable mechanism
Fig. 3 Control map of phase variable mechanism
FIG. 4 is an explanatory diagram showing variable ratios by engine temperature of a lift / operating angle variable mechanism and a phase variable mechanism.
FIG. 5 is a flowchart of variable ratio control of the lift / operating angle variable mechanism and the phase variable mechanism.
[Explanation of symbols]
1 ... Lift / operating angle variable mechanism
2 ... Phase variable mechanism
13 ... Hydraulic actuator for lift / operation angle control
14 ... Control valve
15 ... Engine control unit
17 ... Electromagnetic actuator for phase control

Claims (8)

An internal combustion engine having a lift / working angle variable mechanism capable of simultaneously and continuously expanding and reducing the valve lift / working angle of the internal combustion engine and a phase variable mechanism for delaying the phase of the lift center angle of the valve. In the variable valve gear of
In the variable lift / operating angle mechanism, the ratio of the amount of change allowed from the minimum lift / minimum operating angle is defined as the variable ratio with respect to the maximum variable variable, and the variable variable maximum variable in the phase variable mechanism. When the ratio of the amount of change allowed from the most retarded angle position relative to the amount is defined as a variable ratio, the variable ratio of the lift / operating angle variable mechanism and the variable ratio of the phase variable mechanism are changed according to the engine temperature ,
A variable valve operating apparatus for an internal combustion engine, wherein the lift / operating angle variable mechanism is hydraulically driven and the phase variable mechanism is electrically driven . A variable lift / operating angle mechanism that can simultaneously and continuously expand and contract the lift / operating angle of the intake valve, a phase variable mechanism that retards the phase of the lift central angle of the intake valve, and a variable operation of the internal combustion engine. In the valve device,
In the variable lift / operating angle mechanism, the ratio of the amount of change allowed from the minimum lift / minimum operating angle is defined as the variable ratio with respect to the maximum variable variable, and the variable variable maximum variable in the phase variable mechanism. When the ratio of the amount of change allowed from the most retarded angle position relative to the amount is defined as a variable ratio, the variable ratio of the lift / operating angle variable mechanism and the variable ratio of the phase variable mechanism are changed according to the engine temperature ,
A variable valve operating apparatus for an internal combustion engine, wherein the lift / operating angle variable mechanism is hydraulically driven and the phase variable mechanism is electrically driven .   When the engine is cold, the intake valve lift center angle is generally fixed at a retarded angle, and the intake valve lift / operation angle can be varied from small lift / small operation angle to medium lift / medium operation angle. The variable valve operating apparatus for an internal combustion engine according to claim 2, wherein a variable ratio of the lift / operating angle variable mechanism is larger than a variable ratio of the phase variable mechanism.   At the time of cold start, the lift central angle of the intake valve is retarded and the lift / operation angle of the intake valve is set to a small lift / small operation angle, and the variable ratio of the lift / operation angle variable mechanism is set to the phase variable mechanism. The variable valve operating apparatus for an internal combustion engine according to claim 2, wherein the variable ratio is greater than the variable ratio.   When the engine is cold, regardless of the required load on the internal combustion engine, the lift / working angle of the intake valve is expanded to the middle lift / medium working angle by the lift / working angle variable mechanism after the engine has been started for a certain period of time. The variable valve operating apparatus for an internal combustion engine according to claim 3. 6. The variable valve operating apparatus for an internal combustion engine according to claim 1, wherein the lift / operating angle variable mechanism is variably controlled from a lower temperature than the phase variable mechanism. The variable operation of the internal combustion engine according to any one of claims 1 to 5 , wherein during the warm-up, the variable ratio of the lift / operating angle variable mechanism is made smaller than the variable ratio of the phase variable mechanism. Valve device. During high temperature after the warm-up completion, an internal combustion according to the variable ratio of the lift operating angle variable mechanism, in any one of claims 1 to 5, characterized in that less than the variable ratio of the phase variable mechanism Variable valve gear for engine.

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