JP2004285855A - Variable valve system of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To practically operate an internal combustion engine, even if an adjusting mechanism for a valve lift amount is in failure. <P>SOLUTION: When it is determined that normal adjustment of the lift amount of an intake valve is impossible (step S200), valve timing preset for use in abnormality is extracted (step S230), and the valve timing of the intake valve 10 depending on operational statuses is controlled. Therefore, although the lift amount is maximum as the valve timing for use in abnormality, a piston is not collided with the intake valve, or the piston is not collided with an exhaust valve. Further, by presetting the valve timing depending on the operational statuses of the engine, the engine can be practically operated by using only valve timing control function. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a variable valve operating device for an internal combustion engine.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a variable valve operating device for an internal combustion engine including both a valve lift adjusting mechanism and a valve timing adjusting mechanism, there has been proposed a control method in the case where these mechanisms have failed (for example, see Patent Document 1). According to the variable valve operating device for an internal combustion engine disclosed in Patent Document 1, for example, when a failure of at least one of the valve lift adjustment mechanism and the valve timing adjustment mechanism is detected, the following control is performed.
[0003]
That is, when the valve lift adjusting mechanism fails, the electromagnetic switching valve for switching between the high-speed cam having a large valve lift and the low-speed cam having a small valve lift is turned off and fixed to the low-speed cam. If the valve timing adjustment mechanism breaks down, the electromagnetic switching valve that switches the valve opening / closing timing is turned off so that the valve lift operating center angle (the crank angle at which the valve lift amount becomes maximum) moves away from the top dead center. Fix it.
[0004]
With this, even if the valve lift operation center angle is fixed near the top dead center due to some kind of failure and the switching mechanism of the high-speed cam is fixed as the high-speed cam, the piston and the intake valve are fixed. Of the mechanism due to collision with the exhaust valve and interference between the exhaust valve and the intake valve.
[0005]
[Patent Document 1]
JP-A-8-177434
[0006]
[Problems to be solved by the invention]
However, as described above, the control method at the time of failure of the valve lift adjustment mechanism and the valve timing adjustment mechanism prevents damage to the mechanisms, and the valve lift amount and the valve timing set by this control are different from those of the internal combustion engine. It is not set to enable practical operation of the engine.
[0007]
The present invention has been made in view of such a problem, and has a variable valve actuation device including both a valve lift adjustment mechanism and a valve timing adjustment mechanism that enable a practical operation of an internal combustion engine even at the time of failure. The purpose is to provide.
[0008]
[Means for Solving the Problems]
A variable valve operating apparatus for an internal combustion engine according to claim 1, wherein a valve lift adjusting means for adjusting a lift amount of an intake valve or an exhaust valve of the internal combustion engine; a valve timing adjusting means for adjusting opening / closing timing of the valve; Operating state detecting means for detecting an operating state of the internal combustion engine, target value setting means for setting a target value of the lift amount and opening / closing timing in accordance with the operating state, and setting the lift amount and the opening / closing timing to coincide with the target values. A valve lift adjusting means, a control means for controlling the valve timing adjusting means, and a determining means for determining whether or not the valve lift adjusting means can normally execute the adjustment of the lift amount. When the adjustment of the lift amount by the lift adjustment means cannot be performed normally, the valve timing adjustment means changes according to the operating state to be adjusted. A target value for abnormal timing of the closing timing is set in advance, and the control unit sets the opening / closing timing to coincide with the target value for abnormal time when the determining unit determines that the adjustment of the lift amount cannot be normally performed. It is characterized by controlling.
[0009]
2. Description of the Related Art A variable valve apparatus that controls the lift amount of an intake valve in cooperation with the opening / closing timing of the intake valve in accordance with the operating state of an internal combustion engine is used to achieve the following objects. For example, during low-speed rotation, the exhaust valve and the intake valve are both opened (hereinafter referred to as valve overlap), and the lift amount of the intake valve is reduced to improve fuel efficiency and improve stability. To achieve improved driving performance.
[0010]
Also, at the time of medium-speed rotation, by increasing the valve overlap, the amount of so-called internal EGR, in which exhaust gas to be discharged to the outside flows back into the combustion chamber due to intake negative pressure, becomes appropriate. And fuel efficiency is improved. Furthermore, during high-speed rotation, the valve overlap is made smaller than during medium-speed rotation, and by increasing the lift amount of the intake valve, the intake charging efficiency is improved and sufficient output can be exhibited. it can.
[0011]
However, for example, when the lift amount adjusted during high-speed rotation is fixed due to some abnormality, the valve opening / closing timing (hereinafter referred to as valve timing) is the same as when the valve lift adjusting means can normally execute the lift amount adjustment. ) Is adjusted by the valve timing adjusting means, the valve overlap becomes excessive at the time of medium-speed rotation, resulting in an inappropriate internal EGR amount. As a result, improvement in emission and fuel efficiency cannot be expected. Further, interference between the exhaust valve and the intake valve may occur. In addition, at low speed rotation, fuel economy is deteriorated due to occurrence of valve overlap, and a stable combustion state cannot be maintained.
[0012]
Therefore, in the variable valve apparatus for an internal combustion engine of the present invention, when the adjustment of the lift amount by the valve lift adjustment means cannot be normally performed, the valve timing adjusted by the valve timing adjustment means is set in advance for an abnormal time. The valve timing is controlled.
[0013]
For example, as the valve timing for this abnormality, the piston is not caused to collide with the intake valve or the exhaust valve even if the lift amount is the maximum, and is set according to the operating state of the internal combustion engine. Thus, practical operation of the internal combustion engine can be performed using only the function of the valve timing adjusting means.
[0014]
In the variable valve operating device for an internal combustion engine according to the second aspect, when the determination unit determines that the adjustment of the lift amount cannot be normally performed, the failure time control unit that fixes the valve lift adjustment unit to the predetermined lift amount is provided. It is characterized by having.
[0015]
As described above, when the valve lift adjusting means cannot be executed normally, even if the valve is adjusted to the predetermined lift amount, the internal combustion engine is controlled by the valve timing suitable for the operating state of the internal combustion engine at the fixed lift amount. Can be driven.
[0016]
According to the variable valve operating apparatus for an internal combustion engine according to the third aspect, the target value setting unit divides the length of the lift amount adjusted by the valve lift adjusting unit into a plurality of regions, and sets the lift by the valve lift adjusting unit. A target value for an abnormal opening / closing timing when the adjustment of the amount cannot be normally performed is set in association with each of the plurality of regions, and the control unit determines that the adjustment of the lift amount cannot be normally performed by the determination unit. In this case, the valve timing adjusting means is controlled so that the opening / closing timing coincides with the target value for an abnormality corresponding to the area to which the lift amount at that time belongs.
[0017]
For example, an optimal valve timing at a lift amount corresponding to an intermediate position or the like of the region is set as an abnormal valve timing set for each of a plurality of regions. Accordingly, the valve timing adjustment unit adjusts the valve timing at a valve timing suitable for the lift amount when it is determined that the adjustment of the lift amount cannot be normally performed by the determination unit, so that a practical operation of the internal combustion engine becomes possible.
[0018]
In the variable valve operating apparatus for an internal combustion engine according to the fourth aspect, the target value setting unit sets a representative lift amount representing the region for each of the plurality of regions, and the adjustment of the lift amount cannot be normally performed by the determination unit. If it is determined that the adjustment of the lift amount is not completely executable, the control means controls the valve timing adjustment means to match the representative lift amount of the region to which the lift amount belongs at that time, and thereafter, the representative lift amount It is characterized in that the amount is fixed.
[0019]
As a result, there is no deviation between the lift amount and the representative lift amount when the determination unit determines that the lift amount adjustment cannot be performed normally. As a result, the valve timing adjustment unit performs optimal opening / closing timing at the representative lift amount. Is adjusted. Note that, even when the lift amount cannot be adjusted to the lift amount that matches the representative lift amount, the shift amount of the lift amount can be reduced by adjusting the lift amount closer to the representative lift amount.
[0020]
According to the variable valve actuation device for an internal combustion engine according to the fifth aspect, when the determination means determines that the adjustment of the lift amount can be normally performed, and when the operation of the internal combustion engine is stopped, the control means The lift amount is adjusted to a predetermined lift amount.
[0021]
Thereby, even when the determination unit determines that the valve lift adjustment unit cannot perform the lift amount adjustment normally at the next start-up or operation of the internal combustion engine, the practical operation of the internal combustion engine can be performed. Will be possible.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a variable valve apparatus for an internal combustion engine according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a gasoline engine (hereinafter, referred to as an engine) 1 as an internal combustion engine to which the above-described invention is applied, and a peripheral configuration. FIG. 2 is a longitudinal sectional view of the engine 1.
[0023]
As shown in FIG. 2, the engine 1 includes a cylinder block 2, a piston 4 reciprocating in the cylinder block 2, a cylinder head 6 mounted on the cylinder block 2, and the like. A plurality of cylinders are formed in the cylinder block 2, and a combustion chamber 8 defined by the cylinder block 2, the piston 4, and the cylinder head 6 is formed in each cylinder.
[0024]
An intake valve 10 and an exhaust valve 11 are arranged in each combustion chamber 8. The intake valve 10 opens and closes an intake port 12, and the exhaust valve 11 opens and closes an exhaust port 13. The intake port 12 is connected to an air cleaner (not shown) via an intake passage.
[0025]
In the intake passage, a fuel injector (not shown) is arranged for each intake port 12, and a required amount of fuel is injected into the intake port 12. It should be noted that no throttle valve is disposed in the intake passage, and intake air amount control according to the magnitude of accelerator operation by the driver and the level of the engine speed is achieved by adjusting the lift amount of the intake valve 10. You.
[0026]
The adjustment of the lift amount of the intake valve 10 is performed by driving a drive mechanism 120 existing between the intake cam 15 provided on the intake camshaft 14 and the rocker arm 16 by the valve lift control actuator 108. . The valve timing of the intake valve 10 is adjusted by the valve timing control actuator 109 in accordance with the operating state of the engine 1.
[0027]
An exhaust valve 11 that opens and closes an exhaust port 13 of each cylinder controls a rocker arm 19 by an exhaust cam 18 provided on an exhaust camshaft 17 that rotates with the rotation of a crankshaft (not shown) of the engine 1. It is opened and closed with a constant lift amount through. The exhaust port 13 of each cylinder is connected to an exhaust manifold (not shown). As a result, exhaust gas is discharged to the outside.
[0028]
The engine ECU 100 shown in FIG. 1 is configured as a normal computer, and includes a well-known CPU, ROM, RAM, I / O, and a bus line connecting these components. A program to be executed by the engine ECU 100 is written in the ROM, and the CPU and the like execute predetermined arithmetic processing according to the program.
[0029]
An accelerator pedal sensor 101 is attached to the accelerator pedal operated by the driver, and the accelerator pedal sensor 101 outputs a signal proportional to the amount of depression of the accelerator pedal (hereinafter referred to as accelerator pedal) to the engine ECU 100. I do. The top dead center sensor 103 generates an output pulse when the first cylinder of the plurality of cylinders reaches the intake top dead center, for example, and outputs this output pulse to the engine ECU 100.
[0030]
The crank angle sensor 102 generates an output pulse each time the crankshaft rotates by a predetermined angle, and outputs the output pulse to the engine ECU 100. The engine ECU 100 calculates the current crank angle from the output pulse of the top dead center sensor 103 and the output pulse of the crank angle sensor 102, and calculates the current engine speed from the frequency of the output pulse of the crank angle sensor 102. Further, the load applied to the engine 1 is grasped from the relationship between the engine speed and the accelerator opening.
[0031]
The shaft position sensor 104 detects the axial displacement of the control shaft 20 moved by the valve lift control actuator 108, and outputs a signal corresponding to the magnitude of the axial displacement to the engine ECU 100. The cam angle sensor 105 detects the rotation angle of the intake cam 15 that drives the intake valve 10 via the drive mechanism 120, and generates an output pulse every time the intake cam 15 rotates a predetermined angle. The pulse is output to engine ECU 100.
[0032]
The engine ECU 100 grasps the operating state of the engine 1 from signals from these sensors, performs valve opening control of fuel injectors disposed in each intake port 12 according to the operating state, and controls fuel injection timing and fuel injection. Execute quantity control.
[0033]
An oil control valve (hereinafter, referred to as OCV) 106 is connected to the engine ECU 100, and the engine ECU 100 controls a valve lift control actuator 108 according to an operating state of the engine 1 such as a required intake air amount. I do. Further, an OCV 107 is connected to the engine ECU 100, and the engine ECU 100 controls the valve timing control actuator 109 according to the operating state of the engine 1.
[0034]
In the engine 1, as shown in FIG. 2, the intake camshaft 14 rotates with the rotation of the crankshaft of the engine 1, and the rotation of the intake cam 15 provided on the intake camshaft 14 causes the drive mechanism 120 and the rocker The intake valve 10 opens and closes via the arm 16.
[0035]
That is, when the intake cam 15 rotates clockwise, it comes into contact with the roller 22, and when the intake cam 15 further rotates, the roller 22 is pushed down about the axis of the pipe 23. The control shaft 20 does not rotate with the pipe 23.
[0036]
The nose 21 rotates counterclockwise around the axis of the pipe 23 in conjunction with the depression of the roller 22, and comes into contact with the upper surface of the rocker arm 16. Then, as the intake cam 15 continues to rotate, the roller 22 is pushed down further, and the nose 21 pushes down the left end of the rocker arm 16, and as a result, the intake valve 10 is opened.
[0037]
On the other hand, when the intake cam 15 further rotates clockwise from the state in which the intake valve 10 is opened, the roller 22 is pushed upward by the repulsive force of the spring 24, and accordingly, the nose 21 is also pushed upward. Then, the left end of the rocker arm 16 is also pushed upward, and the intake valve 10 is closed. By repeating this process, the intake valve 10 is opened and closed.
[0038]
Here, the operations of the lift amount control of the intake valve 10 by the valve lift control actuator 108 and the valve timing control of the intake valve 10 by the valve timing control actuator 109 will be briefly described.
[0039]
The lift amount of the intake valve 10 is continuously adjusted by moving the control shaft 20 of the drive mechanism 120 shown in FIG. 2 in the axial direction by a valve lift control actuator 108. That is, when the control shaft 20 moves in the axial direction, the nose 21 of the drive mechanism 120 is formed so as to rotate about the axis of the control shaft 20 with the movement. Due to the magnitude of the counterclockwise rotation angle of the nose 21, the size of the nose 21 contacting the rocker arm 16 and pushing down the left end of the rocker arm 16 by the rotation of the intake cam 15 changes. As a result, the intake valve Ten lift amounts are adjusted.
[0040]
On the other hand, in the valve timing control, the valve timing is adjusted by driving the valve timing control actuator 109. That is, the valve timing control actuator 109 is arranged at a position where the rotational force of the crankshaft is transmitted to the intake camshaft 14, and changes the rotational phase difference of the intake camshaft 14 with respect to the crankshaft. Thereby, the valve timing with the exhaust cam 18 is adjusted.
[0041]
Although different depending on the type of the engine 1, the engine ECU 100 controls the lift amount and the valve timing of the intake valve 10 according to the operating state. For example, as shown in FIG. 3A, when the engine speed is low (Lo), the valve overlap is eliminated, and the lift amount of the intake valve 10 is reduced, so that the fuel efficiency is improved and stable operation is performed. Sexuality.
[0042]
Also, as shown in FIG. 3A, when the engine speed is medium (Mid), the internal EGR amount is increased by increasing the valve overlap and setting the lift amount of the intake valve 10 to medium. The right amount, resulting in improved emissions and fuel economy.
[0043]
Further, as shown in FIG. 3A, when the engine speed is high (Hi), the valve overlap is made smaller than that at the time of middle rotation, and the lift amount of the intake valve 10 is made larger, so that the intake air is increased. The filling efficiency has been improved and sufficient output has been secured.
[0044]
However, for example, when the lift amount adjusted at the time of high-speed rotation (Hi) is fixed by the abnormality of the valve lift control actuator 108 or the like, the lift amount of the intake valve 10 is normally adjusted by the valve timing control. If the valve timing is adjusted in the same manner as in the case where it can be executed, as shown in FIG. 3B, the valve overlap becomes excessive during the middle rotation (Mid), so that the internal EGR amount becomes inappropriate. As a result, improvements in emissions and fuel economy cannot be expected. Further, interference between the exhaust valve 11 and the intake valve 10 may occur. In addition, at the time of low speed rotation (Lo), fuel consumption is deteriorated due to occurrence of valve overlap, and a stable combustion state cannot be maintained.
[0045]
FIG. 4B shows a case where the lift amount of the intake valve 10 shown in FIG. 4A is normally adjusted by the valve timing control when the lift amount adjusted during the middle-speed rotation (Mid) is fixed. This is the valve timing when the adjustment is performed at the same valve timing as the case where the adjustment can be performed. Further, FIG. 5B shows that the lift amount of the intake valve 10 shown in FIG. 5A is adjusted by valve timing control when the lift amount adjusted during the low-speed rotation (Lo) is fixed. This is the valve timing when the adjustment is performed at the same valve timing as when the normal execution is possible. In any case, the effect of controlling the lift amount and valve timing of the intake valve 10 described above cannot be expected.
[0046]
Therefore, the variable valve operating device according to the present embodiment is designed for the purpose of enabling a practical operation of the engine 1 even when the adjustment of the lift amount of the intake valve 10 cannot be normally performed. Is set in advance, and if the adjustment of the lift amount cannot be normally performed, the valve timing of the intake valve 10 is adjusted so as to achieve the preset valve timing.
[0047]
For example, as shown in FIG. 6, the lift amount of the intake valve 10 adjusted by the valve lift control actuator 108 is divided into three regions (A, B, C), and a representative lift amount ( L, M, S) are set. Although the representative lift amounts (L, M, S) in the figure set the maximum lift amounts of the respective regions, for example, the lift amounts corresponding to the intermediate positions of the respective regions may be used.
[0048]
Also, as shown in FIGS. 7 (a) to 7 (c), the optimal valve timing is set in advance so that the optimal valve timing can be determined according to the operating state of the engine 1 such as the rotation speed and the load. Keep it. For example, a map in which the valve timing is determined from the engine speed and the load is stored in advance in the ROM in the engine ECU 100, and the valve speed is determined by applying the engine speed and the load to the map.
[0049]
FIG. 3C shows an example in which the valve timing is set in the representative lift amount (L) and is determined by the rotation speed (Hi, Mid, Lo) of the engine 1. As shown in FIG. 3C, at the time of middle speed rotation (Mid), the valve timing is set such that the valve overlaps to realize an appropriate internal EGR amount even with a large lift amount. In addition, it is possible to minimize a decrease in the output of the engine 1 and a deterioration in the emission. In addition, during low-speed rotation (Lo), stable operation of the engine 1 is realized by setting the valve timing to eliminate the valve overlap.
[0050]
FIG. 4C shows an example in which the valve timing is set in the representative lift amount (M) and is determined by the rotation speed (Hi, Mid, Lo) of the engine 1. As shown in FIG. 9C, the valve timing at the time of high-speed rotation (Hi) is set so that the inertia effect of the intake air can be obtained, so that the charging efficiency of the intake air can be ensured.
[0051]
FIG. 5C shows an example in which the valve timing is set in the representative lift amount (L) and is determined by the rotation speed (Hi, Mid, Lo) of the engine 1. As shown in FIG. 3C, the valve timings at the time of medium speed rotation (Mid) and at the time of high speed rotation (Hi) are set so that the operation of the engine 1 is prioritized so that a high intake efficiency can be secured with a small lift amount. By doing so, the operation of the engine 1 becomes possible.
[0052]
As a result, when the lift amount cannot be normally adjusted normally, the lift amount of the intake valve 10 at that time is grasped, and the representative lift amount is determined from the area to which the lift amount belongs. Then, a map corresponding to the determined representative lift amount is extracted, and the valve timing is determined by applying the engine speed and the load to the map.
[0053]
Next, a valve timing control process in a case where the adjustment of the lift amount of the intake valve 10 cannot be normally performed according to the characteristic portion of the present embodiment will be described with reference to flowcharts shown in FIGS. 8 and 9.
[0054]
In step S100 shown in FIG. 8, it is determined whether or not a key has been inserted into a key cylinder (not shown) provided near the driver's seat in the vehicle compartment, and a key operation (IG_ON) for starting engine 1 has been performed. . Here, if an affirmative determination is made, the process proceeds to step S110; if a negative determination is made, the process enters a standby state.
[0055]
In step S110, a determination process (abnormality determination) as to whether the lift amount of the intake valve 10 can be normally adjusted is performed. For example, a test signal is transmitted from the engine ECU 100, and a determination process is performed to determine whether the valve lift control actuator 108 operates according to the test signal.
[0056]
In step S120, it is determined whether it is determined in step S110 that an abnormality has occurred. If the determination is affirmative, the process proceeds to step S140. If the determination is negative, the process proceeds to step S130.
[0057]
In step S130, preparation is made for starting the engine 1 by the normal lift amount / valve timing control processing. For example, when the program of the valve timing control is different between the normal control and the abnormal control of the lift amount, a program for the valve timing control for the normal operation is read.
[0058]
In step S140, since the adjustment of the lift amount is not performed normally, preparation is made for starting the engine 1 by the valve timing control process for an abnormal time. For example, a program for valve timing control for abnormal time is read.
[0059]
In step S120, if it is determined that the lift amount adjustment cannot be performed normally, but the lift amount adjustment is not completely impossible, if the lift amount adjustment is not completely performed, the lift amount adjustment is not performed. The lift amount of the intake valve 10 is adjusted in such a manner as to perform the adjustment, and is fixed at the representative lift amount.
[0060]
As a result, there is no difference between the lift amount and the representative lift amount when it is determined that the adjustment of the lift amount cannot be performed normally. As a result, the engine 1 can be operated at the optimal valve timing at the representative lift amount. it can. Note that, even when the lift amount cannot be adjusted to the lift amount that matches the representative lift amount, the shift amount of the lift amount can be reduced by adjusting the lift amount closer to the representative lift amount.
[0061]
In step S150, it is determined to which region in FIG. 6 the current lift amount of the intake valve 10 belongs, and a representative lift amount of the region to which the lift amount belongs is extracted. Then, a valve timing map of the intake valve 10 at the time of the representative lift amount is extracted. In step S160, the engine 1 is started.
[0062]
In step S170, it is determined whether the engine 1 is operating. If the determination is affirmative, the process proceeds to step S190. If the determination is negative, the process proceeds to step S180.
[0063]
In step S180, when stopping the engine 1, the lift amount of the intake valve 10 is stopped after fixing the lift amount to a predetermined lift amount. For example, the operation of the engine 1 is stopped after the lift amount is adjusted so that the medium / low-speed torque generated by the engine 1 can be widely realized.
[0064]
Thereby, even when the adjustment of the lift amount cannot be normally performed at the time of starting or operating the engine 1 next time, the practical operation of the engine 1 becomes possible. The processing in step S180 is performed except when the adjustment of the lift amount cannot be completely performed.
[0065]
In step S190 shown in FIG. 9, a determination process (abnormality determination) is performed again to determine whether the lift amount of the intake valve 10 can be adjusted normally. That is, after the start of the engine 1, a difference occurs in the power state and the like before the start, and this difference may affect the lift amount control and the valve timing control.
[0066]
In step S200, it is determined whether it is determined in step S190 that an abnormality has occurred. If the determination is affirmative, the process proceeds to step S220. If the determination is negative, the process proceeds to step S210.
[0067]
In step S210, normal lift amount / valve timing control processing according to the operating state of the engine 1 is executed. In step S220, since the adjustment of the lift amount is not performed normally, a valve timing control process for an abnormal time is executed. In step S230, a representative lift amount corresponding to the current lift amount of the intake valve 10 is extracted, and a valve timing map of the intake valve 10 at the time of the representative lift amount is extracted. Thereafter, during the operation of the engine, the processing in steps S190 to S230 is repeatedly performed.
[0068]
As described above, when the adjustment of the lift amount of the intake valve 10 cannot be normally performed, the variable valve operating apparatus according to the present embodiment adjusts the valve timing of the intake valve 10 by using the valve timing preset for an abnormal time. Control. Thereby, for example, as the valve timing for this abnormality, even if the lift amount is the maximum, the collision between the piston 4 and the intake valve 10 or the exhaust valve 11 does not occur, and the operation state of the engine 1 is reduced. By setting the corresponding valve timing in advance, practical operation of the engine 1 can be performed using only the valve timing control function.
[0069]
(Modification 1)
If it is determined in step S120 shown in FIG. 8 that the adjustment of the lift amount of the intake valve 10 cannot be performed normally, the variable valve operating device having a mechanism for fixing the lift amount of the intake valve 10 to a predetermined lift amount In this case, a valve timing map corresponding to the fixed lift amount is set in advance.
[0070]
Thus, even when the adjustment of the lift amount of the intake valve 10 cannot be normally performed, the operation can be performed at a fixed lift amount at a valve timing suitable for the operation state of the engine 1.
[0071]
(Modification 2)
For example, in a variable valve operating apparatus that controls the fuel injection timing of the fuel injector, the ignition timing of the engine 1, and the like together with the lift amount control and the valve timing control, if the lift amount cannot be adjusted normally, the lift amount is reduced. It is preferable to set in advance control values of the injection timing and the ignition timing that are suitable for the abnormal valve timing used when fixed. Thereby, more practical operation of the engine 1 becomes possible.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of an engine 1 and peripheral components according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of the engine 1 according to the embodiment of the present invention.
3A is a diagram showing an optimal lift amount and valve timing of the intake valve 10 according to an engine speed, and FIG. 3B is a diagram showing a lift adjusted at a high rotation speed (Hi); It is a figure showing valve timing in the state where it was fixed as it was, and (c) is a figure showing valve timing for an abnormal time in representative lift (L) according to engine speed.
4A is a diagram showing an optimal lift amount and valve timing of the intake valve 10 according to the engine speed, and FIG. 4B is a diagram showing a lift adjusted at the time of middle rotation (Mid); It is a figure showing valve timing in the state where it was fixed as it was, and (c) is a figure showing valve timing for an abnormal time in representative lift amount (M) according to engine speed.
FIG. 5A is a diagram showing an optimal lift amount and valve timing of the intake valve 10 according to the engine speed, and FIG. 5B is a diagram showing a lift adjusted at the time of low rotation (Lo). It is a figure showing valve timing in the state where it was fixed as it was, and (c) is a figure showing valve timing for an abnormal time in representative lift amount (S) according to engine speed.
FIG. 6 shows an example of setting each of the lift amount regions (A, B, C) of the intake valve 10 and representative lift amounts (L, M, S) representing the respective regions according to the embodiment of the present invention. FIG.
7A is a valve timing map for a representative lift amount (L), FIG. 7B is a valve timing map for a representative lift amount (M), and FIG. 7C is a representative lift amount. It is a valve timing map at (S) time.
FIG. 8 is a flowchart illustrating a first half of a valve timing control process when the adjustment of the lift amount of the intake valve 10 cannot be normally performed according to the embodiment of the present invention.
FIG. 9 is a flowchart illustrating the latter half of the valve timing control process when the adjustment of the lift amount of the intake valve 10 cannot be normally performed according to the embodiment of the present invention.
[Explanation of symbols]
1 engine
10 Intake valve
11 Exhaust valve
14 Intake camshaft
15 Intake cam
16, 19 rocker arm
20 Control shaft
100 Engine ECU
106, 107 OCV
108 Valve lift control actuator
109 Actuator for Valve Timing Control
120 drive mechanism

Claims (5)

Valve lift adjustment means for adjusting the lift of the intake valve or exhaust valve of the internal combustion engine,
Valve timing adjusting means for adjusting the opening and closing timing of the valve,
Operating state detecting means for detecting an operating state of the internal combustion engine,
Target value setting means for setting a target value of the lift amount and the opening / closing timing according to the operating state,
Control means for controlling the valve lift adjustment means and the valve timing adjustment means so that the lift amount and the opening / closing timing coincide with the target value;
Judgment means for judging whether or not the valve lift adjustment means can normally execute the adjustment of the lift amount,
The target value setting unit is a target for abnormalities of the opening / closing timing that changes according to the operating state to be adjusted by the valve timing adjusting unit when the adjustment of the lift amount by the valve lift adjusting unit cannot be normally performed. Set the value in advance,
An internal combustion engine, wherein the control means controls the opening / closing timing to coincide with the abnormal time target value when the determination means determines that the adjustment of the lift amount cannot be normally performed. Variable valve gear. 2. The internal combustion engine according to claim 1, further comprising a failure control unit that fixes the valve lift adjustment unit to a predetermined lift amount when the determination unit determines that the adjustment of the lift amount cannot be normally performed. Variable valve gear of the engine. The target value setting unit divides the length of the lift amount adjusted by the valve lift adjustment unit into a plurality of regions, and adjusts the opening / closing timing when the adjustment of the lift amount by the valve lift adjustment unit cannot be normally performed. Set a target value for abnormal time in association with each of the plurality of areas,
The control unit, when the determination unit determines that the lift amount adjustment cannot be normally performed, matches the abnormal time target value corresponding to the area to which the lift amount belongs at the time with the opening / closing timing. 2. The variable valve operating apparatus for an internal combustion engine according to claim 1, wherein the valve timing adjusting means is controlled to perform the control. The target value setting means sets a representative lift amount representing the region for each of the plurality of regions,
If the determination unit determines that the adjustment of the lift amount cannot be normally performed, but the adjustment of the lift amount is not completely impossible, the control unit determines the representative lift amount of the area to which the current lift amount belongs. 4. The variable valve actuation device for an internal combustion engine according to claim 3, wherein the valve timing adjusting means is controlled so as to coincide with the following, and thereafter, the valve lift is fixed at the representative lift amount. The control unit may adjust the lift amount to a predetermined lift amount when stopping the operation of the internal combustion engine when the determination unit determines that the adjustment of the lift amount can be normally performed. The variable valve train for an internal combustion engine according to any one of claims 1 to 4, characterized in that:

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