JP2000314329A - Management device for variable valve system of internal combustion engine at operating sensor failure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable engine start, idling operation, and evacuation traveling at the time of the failure of operating angle detecting means for control by drivingly controlling a control shaft, so that a real operating angle decided by an operation parameter of an internal combustion engine to a target-at-failure operating angle, when the operating angle detecting means for control fails. SOLUTION: In the case, where a variable valve system including an actuator 101 for varying a lift quantity of an intake and exhaust valves of an internal combustion engine according to an operating condition is controlled by a CPU, output signals of an air flow meter 104 and an engine rotating speed sensor 106 are taken in, and management control is performed, when an operating angle sensor 102 fails. Namely, the output voltage of the operating angle sensor 102 is fetched, a negative maximum torque quantity is taken to a control shaft 16 in the case where failure of the sensor 102 is decided, and an operating angle is once returned to a level which is near zero. A torque added to a solenoid actuator 101 is estimated on the basis of an operating parameter, such as engine rotation speed and an intake quantity, and a current-carrying quantity to the actuator 101 is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a malfunction of an operating angle sensor in a variable valve operating device of an internal combustion engine which can vary the lift amount (operating angle of a control shaft) of an intake / exhaust valve of the internal combustion engine in accordance with the operating state of the engine. Time processing device.

[0002]

2. Description of the Related Art As is well known, in order to improve fuel efficiency at low engine low speed and low load, to ensure stable driving performance, and to secure sufficient output by improving intake air filling efficiency at high speed and high load, intake air intake and air intake are controlled. Various variable valve devices for variably controlling the opening / closing timing of an exhaust valve and the valve lift amount according to the engine operating state have been conventionally provided.
Japanese Patent No. 137305 is known.

[0005] Referring to FIG. 18, the outline thereof will be described. A cam shaft 2 is provided at a position substantially above the center of the upper deck of the cylinder head 1, and a cam 2 a is integrally provided on the outer periphery of the cam shaft 2. ing. A control shaft 3 is arranged in parallel on the side of the cam shaft 2.
A rocker arm 5 is pivotally supported via an eccentric cam 4.

On the other hand, at the upper end of an intake valve 6 slidably provided on the cylinder head 1, a swing cam 8 is arranged via a valve lifter 7. The swing cam 8 is swingably supported by a support shaft 9 disposed above the valve lifter 7 in parallel with the cam shaft 2, and a lower cam surface 8 a is in contact with the upper surface of the valve lifter 7. . The rocker arm 5 has one end 5a abutting on the outer peripheral surface of the cam 2a and the other end 5b abutting on the upper end surface 8b of the swing cam 8, thereby lifting the lift of the cam 2a. And, it transmits to the intake valve 6 via the valve lifter 7.

Further, as shown in FIG. 19, the control shaft 3 is controlled by an electromagnetic actuator such as a DC servomotor.
The eccentric cam 4 is rotated and driven within a predetermined angle range via a reduction gear, thereby controlling the rotation position of the eccentric cam 4, thereby changing the swing fulcrum of the rocker arm 5.

In FIG. 18, when the eccentric cam 4 is controlled to a predetermined forward / reverse rotation position, the swing fulcrum of the rocker arm 5 changes, and the upper end face 8b of the swing cam 8 at the other end 5b.
Is changed in the vertical direction in the figure, whereby the swing locus of the swing cam 8 changes with the change of the contact position of the cam surface 8a of the swing cam 8 with the upper surface of the valve lifter 7. The opening / closing timing of the intake valve 6 and the valve lift amount are variably controlled with a change in the operating angle of the control shaft 3. Reference numeral “10” in the drawing indicates a spring that constantly biases the upper end surface 8b of the swing cam 8 against the other end 5b of the rocker arm 5.

FIG. 19 shows a variable valve operating apparatus in which the opening / closing timing and valve lift of the intake valve 6 are variably controlled by changing the swing fulcrum of the rocker arm 5 as described above. As described above, the operating angle (rotational position) of the control shaft 3 for changing the swing fulcrum is detected by an operating angle sensor (for control) such as a potentiometer, and based on the detected operating angle signal, the control unit CPU In, comparing the detection result and the target,
The drive control signal is feedback-controlled so that the operation angle (rotational position) of the control shaft 3 is accurately controlled to a target operation angle (rotational position) corresponding to a target valve characteristic.

[0008]

However, in the above-mentioned conventional apparatus, no measures have been taken when an operating angle sensor (for control) for detecting the operating angle of the control shaft 3 has failed. If the operating angle sensor fails, the actual operating angle position information of the control shaft 3 cannot be obtained, and the variable valve control cannot be performed. Then, depending on the stop position of the control shaft 3 at that time, there is a problem that a valve lift amount for performing engine start, idling operation, and evacuation traveling cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems. Even when a control operating angle sensor fails, a variable operation of an internal combustion engine that enables engine start, idling operation, and limp-home operation is possible. It is an object of the present invention to provide a processing device when an operating angle sensor fails in a valve device.

[0010]

In order to achieve the above-mentioned object, an apparatus for processing a failure of an operating angle sensor in a variable valve apparatus for an internal combustion engine according to the present invention is arranged substantially parallel to a cam shaft. Control shaft, a control cam eccentrically fixed to the outer periphery of the control shaft, a rocker arm pivotally supported by the control cam, and one end of the rocker arm according to the rotation of the cam shaft. Swing drive means for swinging drive, a swing cam linked to the other end of the rocker arm for swinging to open an engine valve, and control operating angle detecting means for detecting an operating angle of the control shaft An electromagnetic actuator for rotating the control shaft to a target operating angle, and a target operation corresponding to the operating state of the engine based on an operating state of the engine based on an operating angle signal of the control shaft detected by the control operating angle detecting means. Control means for rotating and driving to an angular position A variable valve operating device for an internal combustion engine, comprising: a failure detecting means for detecting a failure of the control operating angle detecting means; and an internal combustion engine operating state detecting means for detecting a predetermined parameter relating to an operating state of the internal combustion engine. ,
When the failure detecting means detects a failure of the control operating angle detecting means, the actual operating angle determined by a predetermined parameter relating to the operating state of the internal combustion engine detected by the internal combustion engine operating state detecting means is a failure. Failure control means for rotationally controlling the control shaft so as to attain the target operating angle.

According to a second aspect of the present invention, in the first aspect of the present invention, the predetermined parameter detected by the internal combustion engine operating state detecting means is the internal combustion engine operating state detecting means. The engine speed and intake air volume were used.

According to a third aspect of the present invention, there is provided a processing device when an operating angle sensor fails in a variable valve train of an internal combustion engine, wherein the lift amount of the engine valve is determined based on the rotational speed of the internal combustion engine and the intake air amount. A lift calculation map calculated in advance, the operating angle of the control shaft, which is converted from the rotation speed of the internal combustion engine and the intake air amount based on the lift amount of the engine valve obtained by the lift amount calculation map, It is a means configured to be a corner.

According to a fourth aspect of the present invention, there is provided an apparatus for processing a malfunction of an operating angle sensor in a variable valve apparatus for an internal combustion engine.
In the invention according to any one of the above, in the rotational drive control of the control shaft in the failure control means, the amplitude of the drive current output to the electromagnetic actuator is initially increased with respect to the square wave input, and then gradually reduced. did.

According to a fifth aspect of the present invention, there is provided an apparatus for processing a malfunction of an operating angle sensor in a variable valve train of an internal combustion engine.
In the invention according to any one of the above, in the rotational drive control of the control shaft in the failure time control means, a frequency of a drive current output to the electromagnetic actuator is initially reduced with respect to a sine wave input, and then gradually increased.

[0015]

According to the first aspect of the present invention, the operation angle sensor failure processing device in the variable valve operating apparatus for an internal combustion engine according to the first aspect of the present invention operates as described above when the failure of the control operating angle detection means is detected by the failure detection means. And controlling the rotation of the control shaft so that the actual operating angle determined by a predetermined parameter relating to the operating state of the internal combustion engine detected by the internal combustion engine operating state detecting means becomes the target operating angle at the time of failure. Things
Thus, even when the control operating angle sensor fails,
Start of the engine, idling operation, and evacuation traveling become possible.

According to a second aspect of the present invention, the actual operating angle is determined based on the rotational speed of the internal combustion engine and the amount of intake air. Accordingly, a somewhat accurate actual operating angle can be obtained.

According to a third aspect of the present invention, there is provided a processing device when an operating angle sensor fails in a variable valve operating device for an internal combustion engine. Is determined, and the operating angle of the control shaft converted based on the lift amount is determined as the actual operating angle. By using the map in this manner, the control is simplified.

According to a fourth aspect of the present invention, there is provided an apparatus for processing a malfunction of an operating angle sensor in a variable valve operating apparatus for an internal combustion engine.
In the invention according to any one of the above, in the rotational drive control of the control shaft in the failure control means, the drive current output to the electromagnetic actuator is controlled so that the amplitude is initially large with respect to the square wave input and then gradually reduced. Accordingly, even in the case of the failure process control in which the feedback control cannot be performed, the actual operation angle of the control axis can be controlled to converge to the failure-time target operation angle.

According to a fifth aspect of the present invention, there is provided an apparatus for processing a failure of an operating angle sensor in a variable valve operating apparatus for an internal combustion engine.
In the invention according to any one of the above, in the rotational drive control of the control shaft in the failure time control means, the drive current output to the electromagnetic actuator is controlled so that the frequency is initially low with respect to the sine wave input and gradually increases thereafter. Therefore, even in the process control at the time of failure in which the feedback control cannot be performed, the actual operation angle of the control axis can be controlled to converge to the target operation angle at the time of failure.

[0020]

Embodiments of the present invention will be described below. (First Embodiment of the Invention) FIGS. 1 to 3 show a variable valve operating device of an engine (internal combustion engine) according to a first embodiment of the present invention, in which two intake valves are provided for each cylinder. The valve mechanism VEL will be described below. However, it is clear that the engine valve is not limited to the intake valve and the number of intake valves is not limited.

The variable valve apparatus shown in FIGS. 1 to 3 includes a pair of intake valves 12 and 12 which are provided on a cylinder head 11 via a valve guide (not shown) so as to be slidable, and an upper portion of the cylinder head 11. A hollow camshaft 13 rotatably supported by a cam bearing 14 and two eccentric cams 15, 15 which are rotating cams fixed to the camshaft 13 by press fitting or the like.
A control shaft 16 rotatably supported by the same cam bearing 14 above the cam shaft 13, and a pair of rocker arms 18, 18 rotatably supported by the control shaft 16 via a control cam 17. And a pair of independent swing cams 20, 20 disposed at the upper ends of the intake valves 12, 12 via valve lifters 19, 19, respectively.

The eccentric cams 15, 15 and the rocker arms 18, 18 are linked by link arms 25, 25, while the rocker arms 18, 18 and the swing cam 2
0 and 20 are linked by link members 26 and 26. The camshaft 13 is disposed along the engine front-rear direction (cylinder row direction), and also via a driven sprocket (not shown) provided at one end or a timing chain wound around the driven sprocket. Torque is transmitted from the crankshaft of the engine.

The cam bearing 14 is provided on the cylinder head 11.
A main bracket 14a provided at an upper end portion of the main bracket 14 and supporting an upper portion of the camshaft 13, and a sub-bracket 14b provided at an upper end portion of the main bracket 14a and rotatably supporting the control shaft 16; 14a, 14
b is fixed together from above by a pair of bolts 14c, 14c.

As shown in FIG. 4, the two eccentric cams 15 have a substantially ring shape, and have a small-diameter cam body 15a and a flange 1 provided integrally on the outer end face of the cam body 15a.
5b, the cam shaft insertion hole 15c is formed in the inner axial direction, and the axis X of the cam body 15a is eccentric by a predetermined amount in the radial direction from the axis Y of the cam shaft 13.

Each of the eccentric cams 15 has a camshaft 13
, Are press-fitted and fixed via cam shaft insertion holes 15c on both outer sides not interfering with the valve lifters 19, 19, and the outer peripheral surfaces 15 of both cam bodies 15a, 15a.
d and 15d are formed in the same cam profile.

As shown in FIG. 3, each rocker arm 18 is bent substantially in a crank shape when viewed from a plane, and a base 18a provided at the center is supported by the control cam 17 so as to rotate independently. A pin hole 18d into which the pin 21 connected to the distal end of the link arm 25 is press-fitted is formed through one end 18b protruding from each outer end of each base 18a, while each cylindrical shape is formed. A pin hole 18e into which a pin 28 connected to one end 26a of each link member 26 described later is press-fitted is inserted into the other end 18c protruding from each inner end of the base 18a.
Are formed.

Each of the control cams 17 has a cylindrical shape and is fixed to the outer periphery of the control shaft 16 and the position of the axis P1 is eccentric from the axis P2 of the control shaft 16 by α as shown in FIG. I have.

The oscillating cam 20 is shown in FIGS.
As shown in the figure, the base end portion 2 has a substantially horizontal U-shape and is substantially annular.
2 has a support hole 22a through which the camshaft 13 is inserted and rotatably supported.
8 is provided with a pin hole 23a at the end 23 located on the other end 18c side.
Are formed through.

The lower end of the oscillating cam 20 has a base end 2.
A base circular surface 24a on the two sides and a cam surface 24b extending in an arc shape from the base circular surface 24a toward the end edge of the end portion 23 are formed.
The base circular surface 24a and the cam surface 24b abut on a predetermined position on the upper surface of each valve lifter 19 according to the swing position of the swing cam 20.

That is, in view of the valve lift characteristics shown in FIG. 5, a predetermined angle range θ1 of the base circular surface 24a is a base circle section as shown in FIG. 1, and a predetermined angle range from the base circle section θ1 of the cam surface 24b. The range θ2 is set to be a so-called ramp section, and the predetermined angle range θ3 from the ramp section θ2 of the cam surface 24b is set to be a lift section.

The link arm 25 has a relatively large annular base 25a and a protruding end 25b protruding at a predetermined position on the outer peripheral surface of the base 25a. The eccentric cam 15 has a cam hole 15c rotatably fitted on the outer peripheral surface of the cam main body 15a, while a protruding end 25b has a pin hole 25d through which the pin 21 is rotatably inserted. Is formed. Note that the link arm 25 and the eccentric cam 15 constitute a swing drive unit.

Further, as shown in FIG. 1, the link member 26 is formed in a linear shape having a predetermined length, and the other ends 26a and 26b of the circular shape have the other end 1 of the rocker arm 18.
8c and each pin hole 18d, 23 of the end 23 of the swing cam 20.
Pin insertion holes 26c and 26d through which the ends of the pins 28 and 29 press-fitted into a are rotatably inserted are formed.
At one end of each of the pins 21, 28, 29, snap rings 30, 31, 32 for regulating the axial movement of the link arm 25 and the link member 26 are provided.

The control shaft 16 includes a D shaft provided at one end.
The electromagnetic actuator 101 is rotationally driven within a predetermined rotation angle range by an electromagnetic actuator 101 such as a C servo motor. As shown in FIG.
Are controlled by a control signal from a control unit CPU as control means. The control unit CPU includes a crank angle sensor 10
3, detecting the current engine operating state based on detection signals from various sensors such as the air flow meter 104 and the water temperature sensor 105, and determining a target valve characteristic in accordance with the detected engine operating state; A control signal is output to the electromagnetic actuator 101 to drive the control shaft 16 to an angular position corresponding to a target valve characteristic.

In the following, the operation of the variable valve apparatus will be described. First, when the engine is running at low speed and low load, the electromagnetic actuator 101 is driven to rotate to one side by a control signal from the control unit CPU. Therefore, the control cam 1
6A and 7B, the axis P1 is held at the upper left rotation position from the axis P2 of the control shaft 16 as shown in FIGS.
a moves upward away from the camshaft 13. For this reason,
The entire rocker arm 18 moves upward with respect to the camshaft 13, whereby each swing cam 20 is slightly lifted at its end 23 via the link member 26, and the entire rocker arm 20 moves leftward. Rotate.

6A and 6B, when the eccentric cam 15 rotates and pushes up one end 18b of the rocker arm 18 via the link arm 25, the lift amount of the eccentric cam 15 is increased via the link member 26. The lift amount L1 is relatively small as shown in FIG. 6B.

Therefore, in such a low-speed and low-load region, the valve lift becomes small as shown by the broken line in FIG.
The opening timing of each intake valve 12 is delayed (operating angle is reduced), and the valve overlap with the exhaust valve is reduced. For this reason, improvement in fuel consumption and stable rotation of the engine can be obtained.

On the other hand, when the engine shifts at the time of high speed and high load of the engine, the electromagnetic actuator 101 is rotationally driven in the opposite direction by a control signal from the control unit CPU. Therefore, as shown in FIGS. 7A and 7B, the control shaft 16 rotates the control cam 17 clockwise from the position shown in FIG.
The axis P1 (thick portion 17a) is moved downward. For this reason, the rocker arm 18 is now moved in its entirety in the direction of the camshaft 13 (downward), and the other end 18 c is
The upper end 23 of the swing cam 20 is pressed downward via the link member 26 to rotate the entire swing cam 20 clockwise by a predetermined amount.

Accordingly, the valve lifter 1 of the swing cam 20
The contact position of the lower surface with respect to the upper surface 9 moves to the left position as shown in FIGS. 7A and 7B. For this reason, the eccentric cam 15 rotates as shown in FIG.
When b is pushed up via the link arm 25, the lift amount L2 with respect to the valve lifter 19 increases as shown in FIG. 7B.

Therefore, in such a high-speed, high-load region, the cam lift characteristics are larger than those in the low-speed, low-load region, and the valve lift (operating angle) is increased as shown by the solid line in FIG. The opening timing is earlier and the closing timing is later. As a result, the intake charging efficiency is improved, and a sufficient output can be secured.

As described above, in the above-described variable valve apparatus, not only the opening / closing timing of each intake valve 12 and the valve lift (operating angle) can be varied, but also each eccentric cam 15 and each swing Since the moving cam 20 and the moving cam 20 are provided coaxially, the arrangement space in the engine width direction can be sufficiently reduced.
Further, since each rocker arm 18 does not need to be installed in the width direction of the engine, it can be formed in a small "H" shape just above the camshaft, so that the entire apparatus can be made compact. As a result, the mountability of the device on the engine is improved. Further, since the apparatus can be mounted according to the current arrangement of the camshafts 13 without changing the arrangement of the camshafts 13, the mountability to the engine is also improved in this respect.

Further, by providing the eccentric cam 15 and the swing cam 20 coaxially with the cam shaft 13, the swing cam 20
A dedicated support shaft for supporting the shaft is not required, and the number of parts can be reduced, and the cam shaft 13 and the oscillating cam 20 are not displaced from each other. Can be prevented.

Further, since the eccentric cams 15 are offset from the valve lifters 19 and arranged at positions where they do not interfere with each other, the outer shape of each cam 15 can be made large.
The degree of freedom in designing the outer peripheral surface 15a of the eccentric cam 15 can be improved, whereby a sufficient lift amount for securing the swing amount of the swing cam 20 can be secured.
A sufficient cam width for reducing the driving surface pressure of the eccentric cam 15 can be secured.

In particular, the eccentric cam 15 is formed in a ring shape, and the entire outer peripheral surface is formed in the fitting hole 25 of the link arm base 25a.
Since the entire inner peripheral surface of c is in sliding contact, the surface pressure on the outer peripheral surface is dispersed, and the surface pressure can be sufficiently reduced. Therefore, the fitting hole 25
The occurrence of abrasion between the inner peripheral surfaces of c can be suppressed and lubrication can be easily performed. Further, the degree of freedom in selecting the material of the eccentric cam 15 is improved with a decrease in the surface pressure, and a material that is easy to process and can be selected at a low cost can be selected. The swing cams 20 corresponding to the respective intake valves 12 are integrated. , So that the eccentric cam 15 and the rocker arm 18 are united, and each intake valve 1
It may be configured to be shared between the two.

By the way, in the above-mentioned variable valve, the control shaft 16 is driven to the angular position corresponding to the target valve characteristic, and the actual valve characteristic is controlled to the target valve characteristic. If the accuracy or the relationship between the angular position of the control shaft 16 and the valve characteristics varies, it becomes impossible to accurately control the actual valve characteristics to the target valve characteristics. Therefore, Embodiment 1 of the present invention
Then, as shown in the block diagram of FIG. 10, the operating angle (rotational position) of the control shaft 16 for changing the swing fulcrum is detected by an operating angle sensor (control operating angle detecting means) 102 such as a potentiometer. Based on the detected operating angle signal, the control unit CPU compares the detected operating angle with the target operating angle, and sets the operating angle (rotational position) of the control shaft 16 to a target value corresponding to the target valve characteristic. A drive control signal for the electromagnetic actuator 101 such as a DC servomotor is feedback-controlled so that the operating angle (rotational position) is obtained. Note that a reduction gear 107 is interposed between the electromagnetic actuator 101 and the control shaft 16.

However, if the operating angle sensor 102 for detecting the operating angle of the control shaft 16 fails, the control shaft 16
The actual operating angle position information cannot be obtained, and the variable valve control cannot be performed.
However, depending on the stop position, there is a problem that it is not possible to obtain a valve lift for starting the engine, idling, and evacuation.

Therefore, in the variable valve apparatus according to Embodiment 1 of the present invention, even when the control operating angle sensor 102 fails, the failure control circuit that enables the engine start, idling operation, limp-home running, and the like is controlled. Unit CP
Prepared for U.

Next, the contents of the fault control circuit will be described with reference to FIG.
This will be described based on １５15. First, FIG. 10 is a system block diagram mainly showing the content of the processing control at the time of failure. As shown in this figure, the control unit CPU has an engine speed N signal from the engine speed sensor 106, and , The intake air amount Q signal from the air flow meter 104 is input, and based on the two signals, the processing control at the time of failure of the operating angle sensor 102 is performed. The failure of the control operating angle sensor 102 is determined by the operating angle sensor 102.
This is performed due to a decrease in the output voltage or the like.

Next, the contents of the processing control at the time of failure (abnormal) judgment of the control operating angle sensor 102 will be described with reference to FIG.
1 will be described. First, in A1,
A lift return operation of the intake valve 12 is performed. That is, after the failure (abnormality) of the control operating angle sensor 102 is determined, as shown in the operating angle θ-torque T characteristic in FIG. First, as shown in FIG. 1A, the negative maximum torque amount (Tma
By giving x) to the control shaft 16, a process for temporarily returning the operating angle to near zero is performed.

At A2, the torque Tm applied to the electromagnetic actuator 101 is estimated using various parameters (engine speed N, intake air amount Q). That is, based on the engine speed N and the intake air amount Q at that time, the lift amount (actual operating angle) of the intake valve 12 is estimated based on the lift amount calculation map shown in FIG. Target operating angle of shaft 16 (operating angle target value) θs
Then, the torque Tm of the electromagnetic actuator 101 necessary for driving the motor is estimated.

At A3, the electromagnetic actuator 101
By outputting the drive current I corresponding to the torque Tm, the operating angle θ-torque T characteristic (2) in FIG.
As shown in (5), the drive of the control shaft 16 is controlled to the target operating angle. The relationship between the target torque Tm and the drive current I can be expressed by the following equation. Tm = Km × I (Km: motor torque multiplier)

Next, a method of outputting the drive current I to the electromagnetic actuator 101 will be described. That is, in this failure process control, the control operating angle sensor 10
2 cannot perform feedback control based on the actual operating angle signal, and since the drive system of the control shaft 16 including the electromagnetic actuator 101 has static friction and dynamic friction, simply outputting the target drive current I is not sufficient. However, the control shaft 16 cannot be rotated to the target operating angle θs.

Therefore, in the first embodiment of the present invention, as shown in the time chart of FIG. 14, the amplitude of the drive current I to be output to the electromagnetic actuator 101 is initially large with respect to the square wave input and then gradually reduced. As a result, as shown in the time chart of FIG. 15, the operation angle of the control shaft 16 can be controlled to converge to the target operation angle θs.

As described above, according to the first embodiment of the present invention, when a malfunction of the control operating angle sensor 102 is detected, the actual operating angle determined from the engine speed N and the intake air amount Q is determined. By performing the rotational drive control of the control shaft 16 so that the target operation angle at the time of failure is obtained, even when the control operation angle sensor 102 fails, the engine start, the idling operation, and the limp-home operation can be performed. can get.

As described above, the engine speed N
By obtaining the actual operation angle from the intake air amount Q, the actual operation angle to some extent can be obtained. Further, by providing a lift amount calculation map for obtaining the lift amount of the intake valve 12 from the engine speed N and the intake air amount Q, the control can be simplified.

Further, the drive current I to be output to the electromagnetic actuator 101 is initially increased in amplitude with respect to the square wave input, and is gradually reduced thereafter. The actual operating angle of the shaft 16 can be controlled to converge to the target operating angle θs at the time of failure.

(Embodiment 2) Next, a description will be given of an operating angle sensor failure processing device in a variable valve apparatus for an internal combustion engine according to Embodiment 2 of the present invention. The second embodiment of the present invention shows another example of a method of outputting the drive current I to the electromagnetic actuator 101 in the process control at the time of failure. Other configurations are the same as those of the first embodiment of the present invention.
Therefore, only the differences will be described.

In the process control at the time of failure according to the second embodiment of the present invention, as shown in the time chart of FIG. The control is performed so as to be gradually increased, so that the operation angle of the control shaft 16 can be controlled to converge to the target operation angle θs as shown in the time chart of FIG.

As described above, according to the second embodiment of the present invention, the actual operation angle of the control shaft 16 is changed to the target operation angle θs in the failure even in the failure process control in which the feedback control cannot be performed.
Can be controlled to converge.

Although the embodiment of the present invention has been described above, the specific configuration is not limited to the embodiment of the present invention, and there are design changes and the like without departing from the gist of the present invention. This is also included in the present invention.

For example, in the embodiment of the present invention, an intake valve is taken as an example of an engine valve, but the invention can also be applied to an exhaust valve. Further, the variable valve mechanism to which the present invention is applied is not limited to the structure illustrated in the embodiment of the present invention, but may be the structure illustrated in the conventional example or other variable valve mechanisms. The present invention can be applied to all mechanisms.

[0061]

As described in detail above, the operating angle sensor failure processing device in the variable valve operating apparatus for an internal combustion engine according to the first aspect of the present invention, as described above, has the control operating angle detecting means as described above. Failure detection means for detecting a failure of the internal combustion engine, an internal combustion engine operating state detection means for detecting a predetermined parameter relating to the operation state of the internal combustion engine, and when the failure of the control operating angle detection means is detected by the failure detection means, Failure control means for rotationally controlling a control shaft such that an actual operation angle determined by a predetermined parameter relating to an operation state of the internal combustion engine detected by the internal combustion engine operation state detection means becomes a failure target target operation angle; By having a means that has
Even when the control operating angle sensor fails, the effect that the engine can be started, the idling operation, and the limp-home mode can be performed is obtained.

According to a second aspect of the present invention, in the first aspect of the present invention, the predetermined parameter detected by the internal combustion engine operating state detecting means is the internal combustion engine operating state detecting means. By adopting the configuration of the number of rotations of the engine and the amount of intake air, a somewhat accurate actual operating angle can be obtained.

According to the third aspect of the present invention, in the processing device for operating the angle sensor failure in the variable valve apparatus for an internal combustion engine, the lift amount of the engine valve is determined based on the rotational speed of the internal combustion engine and the intake air amount. A lift calculation map calculated in advance, the operating angle of the control shaft, which is converted from the rotation speed of the internal combustion engine and the intake air amount based on the lift amount of the engine valve obtained by the lift amount calculation map, By adopting a means configured to be a corner, control can be simplified by using a map.

According to a fourth aspect of the present invention, there is provided an apparatus for processing a malfunction of an operating angle sensor in a variable valve system for an internal combustion engine.
In the invention according to any one of the above, in the rotational drive control of the control shaft in the failure control means, the amplitude of the drive current output to the electromagnetic actuator is initially increased with respect to the square wave input, and then gradually reduced. By doing so, it becomes possible to control the actual operating angle of the control axis to converge to the target operating angle at the time of failure, even in the case of failure processing control in which feedback control cannot be performed.

The operating angle sensor failure processing device in the variable valve apparatus for an internal combustion engine according to the fifth aspect of the present invention.
In the invention according to any one of the first to third aspects, in the rotational drive control of the control shaft in the failure control means, the frequency of the drive current output to the electromagnetic actuator is initially lowered with respect to a sine wave input, and then gradually increased. Thus, even in the processing control at the time of failure in which the feedback control cannot be performed, the actual operating angle of the control axis can be controlled to converge to the target operating angle at the time of failure.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view (a cross-sectional view taken along line AA in FIG. 2) showing a variable valve operating device according to Embodiment 1 of the present invention.

FIG. 2 is a side view of the variable valve device.

FIG. 3 is a plan view of the variable valve device.

FIG. 4 is a perspective view showing an eccentric cam used in the variable valve device.

FIG. 5 is a valve lift characteristic diagram corresponding to a base end surface and a cam surface of an oscillating cam in the variable valve operating device.

FIG. 6 is a cross-sectional view (cross-sectional view taken along the line BB in FIG. 2) showing the operation of the variable valve device at low speed and low load.

FIG. 7 is a cross-sectional view (a cross-sectional view taken along the line BB of FIG. 2) illustrating an operation of the variable valve device at the time of high speed and high load.

FIG. 8 is a characteristic diagram of valve timing and valve lift of the variable valve operating device.

FIG. 9 is a block diagram mainly showing an operating angle control system of the variable valve operating device.

FIG. 10 is a system block diagram mainly showing the contents of a control circuit when an operating angle sensor fails in the variable valve operating device.

FIG. 11 is a block diagram showing the contents of processing control at the time of failure of the operating angle sensor of the variable valve operating device.

FIG. 12 is an operating angle-torque characteristic diagram of the variable valve device.

FIG. 13 is a lift amount calculation map used in processing control at the time of failure of the operating angle sensor of the variable valve operating device.

FIG. 14 is a time chart showing a method of outputting a drive current in the process control at the time of failure of the operating angle sensor of the variable valve operating device.

FIG. 15 is a time chart showing an operating angle control state in the processing control at the time of failure of the operating angle sensor of the variable valve operating device.

FIG. 16 is a time chart showing a method of outputting a drive current in processing control when an operating angle sensor fails in the variable valve apparatus according to Embodiment 2 of the present invention;

FIG. 17 is a time chart showing an operating angle control state in the processing control at the time of an operating angle sensor failure of the variable valve operating device.

FIG. 18 is a sectional view showing a conventional variable valve operating device.

FIG. 19 is a block diagram mainly showing an operation angle control system of a conventional variable valve apparatus.

[Explanation of symbols]

Reference Signs List 12 intake valve (engine valve) 13 cam shaft 15 eccentric cam (oscillation driving means) 16 control shaft 17 control cam 18 rocker arm 20 oscillation cam 25 link arm (oscillation driving means) CPU control unit (control means, failure control) Means 101 Electromagnetic actuator 102 Operating angle sensor (operating angle detecting means for control) 104 Air flow meter (internal combustion engine operating state detecting means) 106 Engine speed sensor (internal combustion engine operating state detecting means)

 ──────────────────────────────────────────────────続 き Continued on front page F-term (reference) 3G084 BA23 CA01 CA02 CA05 DA09 DA30 EB08 EC05 EC07 FA07 FA20 FA33 FA38 3G092 AA11 DA01 DA05 DG08 DG09 EA01 EA02 EA22 EC09 FA31 FB02 FB05 GA01 GA04 HA01Z HA13X HA13Z HE08Z

Claims (5)

[Claims] A control shaft disposed substantially parallel to a cam shaft; a control cam eccentrically fixed to an outer periphery of the control shaft; a rocker arm pivotally supported by the control cam; Rocking drive means for rocking one end of the rocker arm in response to rotation of a camshaft; rocking cam for linking with the other end of the rocker arm and rocking to open an engine valve; Control operating angle detecting means for detecting the operating angle of the shaft; an electromagnetic actuator for driving the control shaft to rotate to the target operating angle; and an operating angle signal of the control axis detected by the control operating angle detecting means. Control means for rotating the control shaft to a target operating angle position in accordance with the operating state of the engine. A variable valve actuation device for an internal combustion engine, comprising: Means and operating conditions of the internal combustion engine An internal combustion engine operating state detecting means for detecting a predetermined parameter regarding the internal combustion engine, wherein when the failure detecting means detects a failure of the control operating angle detecting means, the internal combustion engine detected by the internal combustion engine operating state detecting means is detected. Failure control means for rotationally controlling a control shaft so that an actual operation angle determined by a predetermined parameter relating to an operating state becomes a target operation angle at the time of a failure. Processing device for operating angle sensor failure in valve device. 2. A variable valve operating apparatus for an internal combustion engine according to claim 1, wherein said predetermined parameters detected by said internal combustion engine operating state detecting means are a rotational speed of the internal combustion engine and an intake air amount. Processing device for operating angle sensor failure. 3. A lift calculation map in which a lift amount of an engine valve is calculated in advance from a rotation speed of the internal combustion engine and an intake air amount, and the lift calculation map is obtained from the rotation speed of the internal combustion engine and an intake air amount. 3. The operation of the variable valve apparatus for an internal combustion engine according to claim 2, wherein an operation angle of the control shaft, which is converted based on the lift amount of the engine valve, is set as the actual operation angle. Angle sensor failure processing device. 4. The rotary drive control of the control shaft by the failure time control means, wherein a drive current to be output to the electromagnetic actuator is initially increased in amplitude relative to a square wave input, and then gradually reduced. 4. An apparatus for processing an operating angle sensor failure in a variable valve apparatus for an internal combustion engine according to claim 1, wherein 5. A control method according to claim 1, wherein said control means controls the rotation of said control shaft so that a frequency of a drive current to be output to said electromagnetic actuator is initially reduced with respect to a sine wave input, and then gradually increased. Claim 1
4. An apparatus for processing a malfunction of an operating angle sensor in a variable valve operating device for an internal combustion engine according to any one of claims 1 to 3.