JP3132326B2 - Abnormality detection device for valve timing control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abnormality detecting device for a valve timing control device of an internal combustion engine for controlling at least one of an intake valve and an exhaust valve of the internal combustion engine in accordance with an operation state.

[0002]

2. Description of the Related Art Hitherto, a variable valve timing mechanism for changing at least one of an intake valve and an exhaust valve in accordance with an operating state of an engine has been put to practical use. As this type of variable valve timing mechanism, for example, a variable valve timing mechanism that continuously displaces a rotational phase difference (displacement angle) of a camshaft with respect to a crankshaft is known.

In an engine having such a variable valve timing mechanism, feedback control is performed to converge an actual rotational phase difference (actual displacement angle) to a target rotational phase difference (target displacement angle) determined based on the operating state of the engine. Have been. Therefore, using a phase difference detection device as described in JP-A-59-105911,
It is necessary to accurately detect the actual displacement angle.

Here, Japanese Patent Application Laid-Open No. 59-105911 measures the interval between a first pulse signal output every one rotation of a crankshaft and a second pulse signal output every one rotation of a camshaft. Thus, an apparatus for accurately detecting an actual displacement angle is described.

When a failure such as a foreign matter bite occurs in the variable valve timing mechanism, the actual displacement angle cannot be converged to the target displacement angle. However, when it is determined to correspond to the above, problems such as deterioration of the output characteristics of the engine occur. Therefore, it is necessary to determine whether or not a failure has occurred in the variable valve timing mechanism. If a failure has occurred, it is necessary to correct various control amounts to prevent a decrease in engine output characteristics and the like.

Here, a general fail detecting means uses an absolute value of a difference between a target displacement angle and an actual displacement angle, and when the absolute value is larger than a predetermined threshold value, a variable valve timing mechanism is used. A failure detecting means for determining that a failure has occurred in the above is considered.

[0007]

However, if the absolute value of the difference between the target displacement angle and the actual displacement angle is larger than a predetermined threshold value, it is determined that a failure has occurred in the variable valve timing mechanism. However, there is a problem that a failure is easily erroneously detected. That is, in the initial stage of control for displacing the actual displacement angle toward the determined target displacement angle, the absolute value of the difference between the target displacement angle and the actual displacement angle is generally large.

Therefore, if the threshold value of the fail determination is reduced, the failure is frequently determined. On the other hand, if the threshold value is increased, there is a problem that effective failure determination cannot be performed.

If the target displacement angle is a displacement angle near the most advanced angle or the most retarded angle, the displacement at the actual displacement angle stops at a displacement angle smaller or larger than the target displacement angle. Sometimes. That is, since the operable range of each variable valve timing mechanism varies due to the tolerance of the components, etc., the actual displacement angle is physically changed to the maximum displacement state (the component Contact state), and it may not be possible to converge to the target displacement angle.

Therefore, when the threshold value used for failure determination is a fixed value, a failure occurs on the variable valve timing mechanism even though the actual displacement angle is the most displaced. There is a problem that it is erroneously determined that.

Further, if it is determined that the variable valve timing mechanism returns to normal from a failure when the absolute value of the difference between the target displacement angle and the actual displacement angle becomes smaller than the threshold value for the failure determination, There is a case where the normal return judgment is erroneously made. That is, the target displacement angle changes every moment according to the operating state of the engine, and the absolute value of the difference between the target displacement angle and the actual displacement angle also changes accordingly.

The absolute value of the difference calculated in this manner merely indicates the transient operating state of the variable valve timing mechanism, and does not indicate the steady operating state necessary for the failure determination. As a result, there is a case where the determination of the normal return may be made even though the state is normally in the fail state.

Further, if the fail determination and the normal return determination are performed with a normal determination time under the condition that the responsiveness of the variable valve timing mechanism is low, the respective determinations may be erroneous. For example, when the variable valve timing mechanism is a mechanism driven by hydraulic pressure, the operating resistance is large in a state where the oil viscosity is low, so that
Compared to the case of normal oil viscosity, it takes more time for the actual displacement angle to converge on the target displacement angle.

Therefore, if the fail determination time is determined based on the case of normal oil viscosity,
In some cases, it is determined that the vehicle is in a fail state even though the actual displacement angle is being displaced toward the target displacement angle.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has as its object to suppress erroneous detection in detecting whether or not an abnormality has occurred in a variable valve timing mechanism. I do.

[0016]

According to a first aspect of the present invention, there is provided a valve timing control apparatus for detecting an abnormality in a crankshaft M of an internal combustion engine M1.
In order to detect the operating state of the internal combustion engine M1 and the intake valve M6 and the exhaust valve M7, which are driven at a predetermined timing in synchronization with the rotation of the engine 2 to open and close the intake passage M4 and the exhaust passage M5 respectively leading to the combustion chamber M3. Operating state detecting means M8 and target valve timing determining means M for determining a target valve timing according to the operating state of the internal combustion engine M1 detected by the operating state detecting means M8.
9, a variable valve timing mechanism M10 for changing the valve timing of at least one of the intake valve M6 and the exhaust valve M7, and the actual valve timing of the valve on the side where the variable valve timing mechanism M10 is provided. And a variable valve timing mechanism for converging the actual valve timing detected by the valve timing detecting means M11 to the target valve timing determined by the target valve timing determining means M9. A valve timing control means M12 for controlling M10, a target valve timing determined by the target valve timing determination means M9, and an actual valve timing detected by the valve timing detection means M11. If the absolute value of the difference between the actual valve timing and the absolute value of the change amount of the actual valve timing detected by the valve timing detecting means M11 is equal to or less than a second predetermined value, the variable An abnormality determining means M13 for determining that an abnormality has occurred in the valve timing mechanism M10 is provided as a configuration.

According to a second aspect of the present invention, in the valve timing control device abnormality detecting device according to the first aspect, the first predetermined value is the valve timing detection value. Means M11
When the actual valve timing detected by the above is the valve timing near the maximum displacement valve timing, the actual valve timing detected by the valve timing detecting means M11 is compared with the case where the actual valve timing is other than the valve timing near the maximum displacement valve timing. Then, it is provided as a configuration that the value is set to a large value.

Further, according to a third aspect of the present invention, in the valve timing control device abnormality detecting device according to the first or second aspect, the abnormality determining means M13 controls the abnormality. After it is determined that an abnormality has occurred in the variable valve timing mechanism M10, the valve timing detection means M11
The change amount of the actual valve timing detected by
The variable valve timing mechanism M10 includes a normal return determination unit M14 that determines that the variable valve timing mechanism M10 has returned to a normal state when the predetermined value is exceeded.

According to a fourth aspect of the present invention, in the valve timing control device abnormality detecting apparatus according to the third aspect, the third predetermined value is the second predetermined value. It is provided as a configuration that the value is set to be larger than the value.

According to a fifth aspect of the present invention, there is provided an abnormality detecting apparatus for a valve timing control apparatus according to any one of the first to fourth aspects. The variable valve timing mechanism M10 is a variable valve timing mechanism driven by hydraulic pressure, and the operating state detecting means M8 is provided with an oil temperature detecting means M15 for detecting the temperature of oil driving the variable valve timing mechanism M10. When it is determined that the oil temperature detected by the oil temperature detecting means M15 is not within the predetermined range, the abnormality determining means M13 determines whether there is an abnormality in the variable valve timing mechanism M10, or the normal return determining means M14. At least one of the normal return determination in the variable valve timing mechanism M10 Comprising a first determination inhibiting means M16 for prohibiting the determination of the configuration.

According to a sixth aspect of the present invention, there is provided an abnormality detecting device for a valve timing control device according to any one of the first to fourth aspects. The variable valve timing mechanism M10 is a variable valve timing mechanism driven by hydraulic pressure, and the operating state detecting means M8 is provided with an oil temperature detecting means M15 for detecting the temperature of oil driving the variable valve timing mechanism M10. When it is determined that the oil temperature detected by the oil temperature detecting means M15 is not within the predetermined range, the abnormality determining means M13 determines whether there is an abnormality in the variable valve timing mechanism M10, or the normal return determining means M14. At least one of the normal return determinations in the variable valve timing mechanism M10 Comprising a configuration determination time extension unit M17 to extend the constant time.

Further, according to a seventh aspect of the present invention, there is provided an abnormality detecting device for a valve timing control device, wherein the oil temperature detecting means M15 is provided with an oil temperature detecting means M15. And detecting the oil temperature via the water temperature.

An abnormality detecting device for a valve timing device according to the invention according to claim 8 is the abnormality detecting device for a valve timing control device according to any one of claims 1 to 7. The operating state detection means M8 includes an engine speed detection means M18 for detecting the rotation speed of the internal combustion engine M1, and the rotation speed of the internal combustion engine M1 detected by the engine speed detection means M18 is within a predetermined range. If not, a second prohibition of at least one of the abnormality determination in the variable valve timing mechanism M10 by the abnormality determination means M13 and the normal return determination in the variable valve timing mechanism M10 by the normal return determination means M14 is prohibited. Judgment prohibition means M
19 as a configuration.

[0024]

In the valve timing control device abnormality detecting device according to the first aspect of the present invention, when the internal combustion engine M1 is started, the intake valve M6 and the exhaust valve M7 are connected to the crankshaft M2 of the internal combustion engine M1. It is driven at a predetermined timing in synchronization with the rotation of the intake passage M4, and opens and closes an intake passage M4 and an exhaust passage M5 communicating with the combustion chamber M3.

The variable valve timing mechanism M10
Changes the valve timing of at least one of the intake valve M6 and the exhaust valve M7. further,
The operating state detecting means M8 detects the operating state of the internal combustion engine M1, and the target valve timing determining means M9 determines the target valve timing according to the operating state of the internal combustion engine M1.

The valve timing detecting means M11 detects the actual valve timing of the valve on the side where the variable valve timing mechanism M10 is provided. Then, the valve timing control means M12 controls the variable valve timing mechanism M10 such that the actual valve timing detected by the valve timing detection means M11 converges on the target valve timing determined by the target valve timing determination means M9.

At this time, the abnormality determining means M13 determines the absolute value of the difference between the target valve timing determined by the target valve timing determining means M9 and the actual valve timing detected by the valve timing detecting means M11 as the first value.
The valve timing detecting means M
When the absolute value of the change amount of the actual valve timing detected by 11 is equal to or smaller than the second predetermined value, it is determined that an abnormality has occurred in the variable valve timing mechanism M10.

Therefore, it is not determined that an abnormality has occurred in the variable valve timing mechanism M10 simply because the absolute value of the difference between the target valve timing and the actual valve timing is large. As a result, it is determined that an abnormality has occurred in the variable valve timing mechanism M10 even though the actual valve timing is in the convergence process toward the target valve timing in the initial stage of control by the valve timing control means M12. Never.

In the abnormality detecting device for a valve timing control device according to the second aspect of the present invention, when the actual valve timing is a valve timing near the maximum displacement valve timing, the actual valve timing is set to the maximum displacement valve timing. The first predetermined value is set larger than when the valve timing is other than the vicinity.

Therefore, even though the actual valve timing is displaced to the maximum displacement valve timing, the absolute value of the difference between the target valve timing and the actual valve timing does not decrease due to the physical restriction in the variable valve timing mechanism M10. , Variable valve timing mechanism M10
Is not determined to be in an abnormal state.

Further, in the abnormality detecting device for the valve timing control device according to the third aspect of the present invention, the normal return determining means M14 determines that the change amount of the actual valve timing detected by the valve timing detecting means M11 is a third predetermined value. If the value exceeds the value, the variable valve timing mechanism M1
0 is determined to have returned from the abnormal state to the normal state.

Therefore, the variable valve timing mechanism M
Despite the occurrence of an abnormality in 10, it is not erroneously determined that the normal recovery has been achieved when the absolute value of the difference between the target valve timing and the actual valve timing transiently exceeds the first predetermined value. .

Further, in the abnormality detecting device for the valve timing control device according to the fourth aspect of the present invention, since the third predetermined value is set to a value larger than the second predetermined value, the normal return determining means M14 As a result, a situation in which an abnormality determination is made immediately after the normal return determination is made is avoided. As a result, chattering in various controls affected by the abnormality determination of the variable valve timing mechanism M10 is prevented.

Further, in the abnormality detecting device for the valve timing control device according to the fifth aspect of the present invention, the variable valve timing mechanism M10 is driven by hydraulic pressure.
Further, the oil temperature detecting means M15 detects the temperature of the oil driving the variable valve timing mechanism M10. And the first
When the detected oil temperature is not within the predetermined range, the determination prohibition unit M16 prohibits at least one of the abnormality determination by the abnormality determination unit M13 and the normal return determination by the normal return determination unit M14.

As a result, the variable valve timing mechanism M1
Under the condition that the operation of the variable valve timing mechanism M10 is unstable, the abnormality determination and the normal return determination in the variable valve timing mechanism M10 are not executed, and each erroneous determination due to the unstable operation of the variable valve timing mechanism M10 is prevented. .

In the abnormality detecting device for a valve timing control device according to the invention, the variable valve timing mechanism M10 is driven by hydraulic pressure. Also,
The oil temperature detecting means M15 is provided with a variable valve timing mechanism M1.
The temperature of the oil driving the zero is detected. When the detected oil temperature is not in the predetermined region, the determination time extending means M17 sets at least one of the determination time of the abnormality determination by the abnormality determination means M13 or the normal return determination by the normal return determination means M14. Extend.

As a result, the variable valve timing mechanism M1
Under the condition that the operation of “0” is unstable, the determination time for performing the abnormality determination and the normal return determination is extended. It is avoided that the determination and the normal return determination are made.

Further, in the abnormality detecting device for the valve timing control device according to the present invention, the oil temperature detecting means M15 detects the temperature of the oil driving the variable valve timing mechanism M10 through the water temperature. .

In the abnormality detecting device for a valve timing control device according to the present invention, the engine speed detecting means M18 included in the operating state detecting means M8 detects the rotational speed of the internal combustion engine M1. When the engine speed of the internal combustion engine M1 detected by the engine speed detecting unit M18 is not in the predetermined range, the second determination prohibiting unit M19 determines that
At least one of the abnormality determination by the abnormality determination means M13 and the normality return determination by the normality return determination means M14 is prohibited.

Therefore, an erroneous determination due to a variation in the engine speed and a variation in the valve timing detected by the valve timing detecting means M11 is prevented.

[0041]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention applied to an abnormality detection device of a valve timing control device will be described below with reference to the drawings.

First, the configuration of the abnormality detection device VC of the valve timing control device according to the first embodiment will be described with reference to FIGS. FIG. 2 is a schematic configuration diagram showing a gasoline engine system including the abnormality detection device VC of the valve timing control device.

An engine 10 as an internal combustion engine includes a cylinder block 11 in which a plurality of cylinders are formed, and a cylinder head 1 connected to an upper portion of the cylinder block 11.
2 and a piston 13 that reciprocates up and down in each cylinder of the cylinder block 11. Further, a crankshaft 14 is connected to a lower end portion of the piston 13, and the crankshaft 14 is rotated by moving the piston 13 up and down.

Further, a crank angle sensor 40 is provided near the crankshaft 14, and the crank angle sensor 40 includes a magnetic rotor (not shown) connected to the crankshaft 14 and an electromagnetic pickup (not shown). (Not shown). Here, equiangular teeth are formed on the outer periphery of the rotor, and every time the equiangular teeth of the rotor pass in front of the electromagnetic pickup, a pulse-like crank angle signal is detected.

After a reference position signal is generated by a cylinder discriminating sensor 42, which will be described later, the number of generated crank angle signals from the crank angle sensor 40 is measured to detect the rotation angle (crank angle) of the crankshaft 14. You.

The space defined by the inner wall of each cylinder block 11 and the cylinder head 12 and the top of the piston 13 functions as a combustion chamber 15 for burning an air-fuel mixture. Is provided with a spark plug 16 for igniting the air-fuel mixture so as to protrude into the combustion chamber 15.

Each ignition plug 16 is connected to a distributor 18 via a plug cord or the like (not shown), and the high voltage output from the igniter 19 is synchronized with the crank angle by the distributor 18 to each of the ignition plugs 16. It is distributed to the spark plug 16.

Further, the distributor 18 is connected to the exhaust-side camshaft 33 and is connected to the crankshaft 1.
An engine speed sensor 41 for detecting the speed of the engine 4 is provided.

The engine speed sensor 41 includes a magnetic rotor (not shown) that rotates in synchronization with the crankshaft 14 and an electromagnetic pickup (not shown). The electromagnetic pickup detects the rotation speed of the rotor. Thus, the rotation speed of the crankshaft 14 (engine speed NE) is detected. Further, the distributor 18 is provided with a cylinder discriminating sensor 42 for detecting a reference position of the crank at a predetermined ratio from the rotation of the rotor.

The cylinder block 11 is provided with a water temperature sensor 43 for detecting the temperature (cooling water temperature) THW of the cooling water flowing through the cooling water passage. Cylinder head 1
2 has an intake port 22 and an exhaust port 32. The intake port 22 is connected to the intake passage 20, and the exhaust port 32 is connected to the exhaust passage 30. In addition, the intake port 22 of the cylinder head 12 includes:
An intake valve 21 is provided, and an exhaust port 31 is provided with an exhaust valve 31.

An intake camshaft 2 for opening and closing the intake valve 21 is provided above the intake valve 21.
The exhaust side camshaft 33 for opening and closing the exhaust valve 31 is disposed above the exhaust valve 31. At one end of each of the camshafts 23 and 33, an intake-side timing pulley 27 and an exhaust-side timing pulley 34 are mounted.
7 and 34 are connected to the crankshaft 14 via a timing belt 35.

Therefore, when the engine 10 is operated, the camshaft 2 is transmitted from the crankshaft 14 via the timing belt 35 and the timing pulleys 27 and 34.
The rotational driving force is transmitted to each of the camshafts 2 and 3.
The rotation of 3, 33 causes the intake valve 21 and the exhaust valve 31 to open and close. Each of these valves 21,
31 is the rotation of the crankshaft 14 and the piston 13
In synchronization with the vertical movement of
The engine 10 is driven at a predetermined opening / closing timing in synchronization with a series of four strokes of the engine 10 including an explosion / expansion stroke and an exhaust stroke.

Further, a cam angle sensor 44 for detecting the valve timing of the intake valve 21 is provided near the intake side camshaft 23. The cam angle sensor 44 is connected to the intake side camshaft 23. It is composed of a connected magnetic rotor (not shown) and an electromagnetic pickup (not shown). Further, a plurality of teeth are formed at equal angles on the outer circumference of the magnetic rotor, for example,
Before the compression TDC of the predetermined cylinder, a pulse-like cam angle signal accompanying the rotation of the intake camshaft 23 is detected between BTDC 90 ° to 30 °.

An air cleaner 24 is connected to the air intake side of the intake passage 20, and a throttle valve 26 which is opened and closed in conjunction with an accelerator pedal (not shown) is provided in the middle of the intake passage 20. ing. The intake air amount is adjusted by opening and closing the accelerator pedal.

In the vicinity of the throttle valve 26, a throttle sensor 4 for detecting the throttle opening TA is provided.
5 are provided. Further, a surge tank 2 for suppressing intake pulsation is provided downstream of the throttle valve 26.
5 are formed. And in the surge tank 25,
An intake pressure sensor 46 for detecting an intake pressure in the surge tank 25 is provided. An injector 17 for supplying fuel to the combustion chamber 15 is provided near the intake port 22 of each cylinder. Each injector 17 is an electromagnetic valve that is opened by energization, and each injector 17 is supplied with fuel pumped from a fuel pump (not shown).

Therefore, when the engine 10 is operating,
The air filtered by the air cleaner 24 is taken into the intake passage 20, and fuel is injected from each injector 17 toward the intake port 22 simultaneously with the intake of the air. As a result, an air-fuel mixture is generated at the intake port 22, and the air-fuel mixture is sucked into the combustion chamber 15 with the opening of the intake valve 21 that is opened during the intake stroke.

A catalytic converter 36 containing a three-way catalyst for purifying exhaust gas is disposed in the exhaust passage 30. In the middle of the exhaust passage 30, an oxygen sensor 47 for detecting the oxygen concentration in the exhaust gas is provided.

In the gasoline engine system of this embodiment, the variable valve timing mechanism 50 (hereinafter referred to as “VV”) driven by hydraulic pressure is used to change the valve opening / closing timing by changing the opening / closing timing of the intake valve 21.
T ". ) Are arranged. This VVT50 is
Crankshaft 14 (intake side timing pulley 27)
This is a mechanism for continuously changing the valve timing of the intake valve 21 by changing the phase of rotation of the intake-side camshaft 23 with respect to the rotation of the intake-side camshaft 23.

The system configuration of the VVT 50 will be described with reference to FIG. Here, FIG.
FIG. 5 is an explanatory diagram showing a cross section near the intake side camshaft 23 where 0 is disposed, and an entire control system of the VVT 50.

The control system of the VVT 50 includes a VVT 5
0, an oil control valve 80 (hereinafter referred to as "OCV") for applying a driving force to the VVT 50, a cam angle sensor 44 for detecting a cam angle signal, and a cam angle sensor 44.
And an ECU 70 that controls the drive of the OCV 80 based on input signals from various sensors such as the above.

The VVT 50 is disposed between the intake side camshaft 23 and the intake side timing pulley 27,
The intake camshaft 23 is rotatably supported between the cylinder head 12 and the bearing cap 51. An intake-side timing pulley 27 is mounted in the vicinity of the distal end of the intake-side camshaft 23 so as to be relatively rotatable, and an inner cap 52 is provided with a hollow bolt 53 and a pin 54 at the distal end of the intake-side camshaft 23. Are attached so as to be integrally rotatable.

A housing 56 having a cap 55 is attached to the intake-side timing pulley 27 so as to be integrally rotatable by bolts 57 and pins 58. By this housing 56, the tip of the intake-side camshaft 23 and the inner The entire cap 52 is covered. Further, on the outer periphery of the intake-side timing pulley 27, a number of external teeth 27a for mounting the timing belt 35 are formed.

The intake camshaft 23 and the intake timing pulley 27 are connected by a ring gear 59 interposed between the housing 56 and the inner cap 52. The ring gear 59 has a substantially annular shape, and is housed in a space S surrounded by the intake-side timing pulley 27, the housing 56, and the inner cap 52 so as to be able to reciprocate in the axial direction of the intake-side camshaft 23. . A large number of teeth 59 are provided on the inner and outer circumferences of the ring gear 59.
a, 59b are formed.

Correspondingly, a large number of teeth 52a are provided on the outer circumference of the inner cap 52 and the inner circumference of the housing 56.
56b are formed. These teeth 59a, 59b,
Both 52a and 56b are helical teeth whose tooth traces intersect at a predetermined angle with respect to the axis of the intake-side camshaft 23. That is, the teeth 52a and the teeth 59a mesh with each other, and the teeth 56b and the teeth 59b mesh with each other to form a helical spline.

The rotation of the intake-side timing pulley 27 is transmitted to the intake-side camshaft 23 via the housing 56 and the inner cap 52 due to the meshing of these. Also, each tooth 59a, 59b, 52a, 56
Since b is a helical tooth, when the ring gear 59 moves in the axial direction of the intake side camshaft 23, a twisting force is applied to the inner cap 52 and the housing 56, and the intake side camshaft 23 is attached to the intake side timing pulley 27. Move relative to

The space S has a first hydraulic chamber 60 at the distal end of the ring gear 59 for moving the ring gear 59 in the axial direction, and a second hydraulic chamber 61 at the proximal end of the ring gear 59.
have. The bearing cap 51 has a first hydraulic pressure supply hole 51a and a second hydraulic pressure supply hole 51b. The first camshaft 23 has a first
A first hydraulic supply path 62 that connects the hydraulic supply hole 51a to the first hydraulic chamber 60 and a second hydraulic supply path 63 that connects the second hydraulic supply hole 51b to the second hydraulic chamber 61 are formed. .

The lubricating oil sucked up from the oil pan 65 by the hydraulic pump 64 is supplied to each of the hydraulic pressure supply holes 51a and 51b through the oil filter 66 at a predetermined pressure. In addition, each hydraulic supply path 60, 6
In order to selectively supply the hydraulic pressure to each of the hydraulic chambers 60 and 61 through the respective hydraulic pressure supply holes 51 a and 51 b, an OCV 8 is provided.
0 is connected.

The OCV 80 is a four-port directional control valve that switches the lubricating oil flow direction by reciprocating a spool 84 in an axial direction by a plunger 83 driven by an electromagnetic actuator 81 and a coil spring 82. Then, the electromagnetic actuator 81
However, the duty is controlled so that the opening degree is adjusted, and the magnitude of the hydraulic pressure supplied to each of the hydraulic chambers 60 and 61 is adjusted.

The casing 85 of the OCV 80 has a tank port 85t, an A port 85a, a B port 85b, and a reservoir port 85r. The tank port 85t is connected to the oil pan 65 via the hydraulic pump 64, and the A port 85a is connected to the first hydraulic supply hole 5
1a and the B port 85b are connected to the second hydraulic pressure supply hole 51b. The reservoir port 85r is connected to the oil pan 65.

The spool 84 is a cylindrical valve body,
It has four lands 84a for sealing the flow of the lubricating oil between the two ports, a passage 84b communicating between the two ports and allowing the flow of the lubricating oil, and two passages 84c.

In the VVT 50 having these configurations, OVT
When the drive of the CV 80 is controlled and the spool 84 is moved to the left in the drawing, the passage 84b
t and the A port 85a, and the first hydraulic pressure supply hole 51a
Is supplied with lubricating oil. Then, the first hydraulic pressure supply hole 51a
Is supplied to the first hydraulic chamber 60 via the first hydraulic pressure supply path 62, and the hydraulic pressure is applied to the distal end side of the ring gear 59.

At the same time, the passage 84c communicates the B port 85b with the reservoir port 85r, and the lubricating oil in the second hydraulic chamber 61 is supplied to the second hydraulic supply passage 63, the second hydraulic supply hole 51b, and the OCV 80. Is discharged to the oil pan 65 through the B port 85b and the reservoir port 85r.

Accordingly, the ring gear 59 is moved while rotating to the base end side (right side in the drawing) by the hydraulic pressure applied to the front end side, and twist is given to the intake side camshaft 23 via the inner cap 52. . As a result, the rotation phase of the intake side camshaft 23 with respect to the intake side timing pulley 27 (crankshaft 14) is changed, and the intake side camshaft 23 rotates from the most retarded position to the most advanced position, and the intake valve 21 Is advanced.

The intake valve 21 whose valve opening timing is advanced in this way is opened while the exhaust valve 31 is open, and the valve over which the intake valve 21 and the exhaust valve 31 are simultaneously opened. The lap period is extended. The movement of the ring gear 59 to the proximal end side is restricted by the ring gear 59 abutting on the intake-side timing pulley 27. When the ring gear 59 abuts on the intake-side timing pulley 27 and stops, the intake valve 21 is stopped. The valve opening timing is the earliest.

On the other hand, when the drive of the OCV 80 is controlled and the spool 84 is moved rightward in the drawing, the passage 84
b communicates between the tank port 85t and the B port 85b,
Lubricating oil is supplied to the second hydraulic pressure supply hole 51b. And
The lubricating oil supplied to the second hydraulic pressure supply hole 51b is supplied to the second hydraulic pressure chamber 61 via the second hydraulic pressure supply passage 63, and the hydraulic pressure is applied to the base end side of the ring gear 59.

At the same time, the passage 84c communicates between the A port 85a and the reservoir port 85r, and the lubricating oil in the first hydraulic chamber 60 is supplied to the first hydraulic supply passage 62, the first hydraulic supply hole 51a, and the OCV 80. Is discharged to the oil pan 65 through the A port 85a and the reservoir port 85r.

Accordingly, the ring gear 59 is moved while rotating to the distal end side (left side in the drawing) by the hydraulic pressure applied to the proximal end side, and the intake side camshaft 23 is twisted in the opposite direction via the inner cap 52. Granted. As a result,
Intake side timing pulley 27 (crankshaft 14)
, The rotational phase of the intake-side camshaft 23 is changed, the intake-side camshaft 23 rotates from the most advanced position to the most retarded position, and the valve opening timing of the intake valve 21 is retarded.

In this way, the valve opening period of the intake valve 21 is retarded, so that the valve overlap period during which the intake valve 21 and the exhaust valve 31 are simultaneously opened is reduced or eliminated. The movement of the ring gear 59 toward the distal end is regulated by the contact of the ring gear 59 with the housing 56. When the ring gear 59 contacts the housing 56 and stops, the valve opening timing of the intake valve 21 becomes the latest. .

The valve timing of the intake valve 21 changed by the VVT 50 is calculated based on a cam angle signal output from the cam angle sensor 44 and a crank angle signal output from the crank angle sensor 40.

That is, for example, the time required from the input of the cam angle signal to the ECU 70 until the input of the BTDC 30 ° crank angle signal (reference timing signal) is measured using the engine speed NE. The actual displacement angle VTB of the intake-side camshaft 23 with respect to the crankshaft 14 is calculated by converting the time into a displacement angle using the relationship between the known time and the crank angle.

Next, a control system of the abnormality detection device VC of the valve timing control device according to the present embodiment will be described with reference to a control block diagram shown in FIG. The control system of the abnormality detection device VC of the valve timing control device according to the present embodiment is an electronic control unit 70 (hereinafter, referred to as “ECU”).
The core is configured. The target valve timing determining means, valve timing control means, abnormality determining means, normal return determining means, first and second
A determination prohibition unit, a determination time extension unit, and the like are realized.

The ECU 70 has a ROM 71 which stores an abnormality determination and normal return determination processing program for determining abnormality and normal return in the VVT 50 executed as a main routine, and a map for changing valve timing corresponding to various conditions. are doing. The ECU 70
Has various control programs such as a fail determination processing program, a normal return determination processing program, and a start condition determination processing program that are executed as subroutines.

Further, the ECU 70 executes an arithmetic processing based on a control program stored in the ROM 71.
The PU 72 has a RAM 73 for temporarily storing the calculation results of the CPU 72, data input from each sensor and the like, and a backup RAM 74 for holding various data stored in the RAM 73 when power supply is stopped.

Then, the CPU 72, the ROM 71, and the RAM
73 and a backup RAM 74 include a bidirectional bus 75
And the input interface 76 and the output interface 77.

The input interface 76 includes a crank angle sensor 40, an engine speed sensor 41, a cylinder discrimination sensor 42, a water temperature sensor 43, a cam angle sensor 44, a throttle sensor 45, an intake pressure sensor 46, and an oxygen sensor 47.
Etc. are connected. When the signal output from each sensor is an analog signal, an A / D (not shown)
After being converted into a digital signal by the converter, it is output to the bidirectional bus 75.

The output interface 77 is connected to external circuits such as the injector 17, the igniter 19, and the OCV 80. These external circuits are connected to the CPU 72.
The operation is controlled based on the result of the calculation of the control program executed in.

Next, a description will be given, with reference to the flowcharts shown in FIGS. 5 to 10, of an abnormality determination and normal return determination program in the abnormality detection device VC of the valve timing control device according to the first embodiment having the above-described configuration.

Here, the abnormality determination and normal return determination program includes a failure determination processing program for determining whether or not a failure (abnormality) has occurred in the VVT 50;
The main subroutine includes a normal return determination program for determining whether or not the failed VVT 50 has returned to a normal state. The abnormality determination and normality return determination program is executed, for example, every 240 ° CA when the engine 10 is operating.

Hereinafter, each determination processing program in the subroutine will be described according to the main routine of the abnormality determination and normal return determination program shown in FIG. In addition, "S" in the flowchart of each program
Indicates each step.

When the main routine starts, a start condition determination processing program is executed in a subroutine (S10). The start condition determination processing program is a program that determines whether the current operation state is a state suitable for the failure determination of the VVT 50 or the normal return determination. Then, the current driving state is determined as fail,
If it is determined that the state is not suitable for normal return determination,
This is a program that executes determination prohibition, extension of the determination time, and the like, and prevents erroneous determination of failure and erroneous determination of normal return.

The start condition determination processing program will be described with reference to the flowchart shown in FIG. First, it is determined whether or not the engine speed NE detected by the engine speed sensor 41 is less than 500 rpm (S100). And the engine speed NE is 5
If it is determined that the rotation speed is less than 00 rpm (S10
0: YES), the shift to the next step is prohibited until the engine speed NE becomes 500 rpm or more.

On the other hand, when the engine speed NE is 500 rpm
If it is determined that the above is true (S100: NO),
It is determined whether the engine speed NE is equal to or greater than 4000 rpm (S110). And the engine speed N
If it is determined that E is equal to or greater than 4000 rpm (S110: YES), the process returns to S100. On the other hand, the engine speed NE is 4000 rpm
m (S110: N
O), the step moves to S120.

Here, the engine speed NE is within a predetermined range (500 rpm <engine speed NE ≦ 4000 rpm).
The reason for performing the fail detection in the VVT 50 only in the case of m) will be described.

First, when the engine speed NE is low, the cam angle signal detected by the cam angle sensor 44 varies, and it is erroneously detected that the intake camshaft 23 is being displaced even if the displacement is stopped. , Intake side camshaft 2
This is because, even when the displacement of No. 3 is changing, it may be erroneously detected as stopped.

That is, in a region where the engine speed NE is low, a sufficient moment of inertia cannot be obtained, so that the rotation of the crankshaft 14 varies, and the intake cam driven by the crankshaft 14 via the timing belt 35 The rotation of the shaft 23 also varies.

Also, when the engine speed NE is high, the detection accuracy of the cam angle by the cam angle sensor 44 is reduced, and there is a risk of erroneous detection. That is, the detection accuracy of the magnetic pickup functioning as the cam angle sensor 44 decreases as the rotation speed of the magnetic rotor, which is the detection target, increases.

At S120, it is determined whether or not the engine coolant temperature THW detected by the coolant temperature sensor 43 is lower than 80 ° C. And the engine water temperature THW is 8
If it is determined that the temperature is lower than 0 ° C. (S120: Y
ES), the step moves to S100. On the other hand, if it is determined that the engine coolant temperature THW is equal to or higher than 80 ° C. (S120: NO), the process proceeds to S130,
It is determined whether or not engine water temperature THW is equal to or higher than 110 ° C.

Then, the engine coolant temperature THW is 110 ° C.
If it is determined that this is the case (S130: YE
S), the step moves to S100, and the engine coolant temperature TH
If it is determined that W is less than 110 ° C. (S1
30: NO), the step moves to S140.

Here, the reason why the failure detection in the VVT 50 is executed only when the engine coolant temperature THW is within a predetermined range (80 ° C ≦ engine coolant temperature THW <110 ° C) will be described.

As described above, the VVT 50 in this embodiment has a structure driven hydraulically by lubricating oil. Generally, lubricating oil has a high viscosity in a low temperature environment and has a high viscosity in a high temperature environment. It has the property of low viscosity. Therefore, before the engine 10 is sufficiently warmed up, for example, when the engine coolant temperature THW is less than 80 ° C., the lubricating oil has a high viscosity and a low fluidity.

As a result, the flow resistance and the like inside the VVT 50 become higher and the operation of the VVT 50 becomes unstable, as compared with the case of being driven by the lubricating oil after warm-up, so that the actual displacement angle VTB becomes smaller than the target displacement angle VTT. It takes a long time to converge to the above, and there is a possibility that a false state is erroneously detected.

On the other hand, when the engine 10 is placed in a high temperature environment, for example, when the engine water temperature THW is 110 ° C. or higher, the lubricating oil has a low viscosity and a high fluidity. Therefore, OCV80 and VVT50
Oil leaks easily at the connection part of the VVT5
0 cannot supply a predetermined oil pressure, and VVT
This is because the operation of 50 may become unstable.

When the conditions in all the steps from S100 to S130 are not satisfied, it is determined that the operation state is such that a failure determination or a normal return determination can be performed, and the steps shift from the subroutine to the main routine.

Subsequently, in S20, it is determined whether or not a failure has occurred in the VVT 50 and whether or not the failure is being determined.
That is, it is determined whether or not either the advance fail flag XVTFA = 1 or the retard fail flag XVTFR = 1 is established. If both the advance fail flag XVTFA and the retard fail flag XVTFR are 0 (S20: NO), it is determined that the failure determination is not underway, and the process proceeds to S30.

In S30, a subroutine, a clear condition determination processing program for a continuous time counter CVTER for counting a time when the absolute value of the difference between the target displacement angle VTT and the calibration displacement angle VT is larger than the first predetermined value b, is executed. Be executed. Such a duration counter CVTER clear condition determination processing program will be described with reference to the flowchart shown in FIG.

Here, the actual displacement angle VTB is the actual displacement angle of the intake side camshaft 23 with respect to the crankshaft 14, and based on the reference crank angle signal (reference timing signal) and the cam angle signal, It is calculated as follows.

First, the signal interval (pulse interval) from when the cam angle signal detected by the cam angle sensor 44 is input to the ECU 70 to when the reference timing signal detected by the crank angle sensor 40 is input to the ECU 70 is shown. , Using the engine speed NE. Next, by using the relationship between the known crank angle and time (engine speed NE), the measured time is used as the actual displacement angle V as a cam angle with respect to the crank angle.
It is converted to TB.

The target displacement angle VTT is determined based on the engine speed NE detected by the engine speed sensor 41 and the intake pressure PM detected by the intake pressure sensor 46.

The calibration displacement angle VT is obtained by subtracting the most retarded learning value GVTFR from the actual displacement angle VTB. Further, the most retarded learning value GVTFR is a learned value obtained by learning the most retarded displacement of the intake camshaft 23 with respect to the crankshaft 14 as the reference displacement angle of the VVT 50.

First, in step S300, the calibration actual displacement angle VT
Is determined by using the most advanced displacement angle obtained by subtracting the nearest value a from the most advanced displacement angle VTMAX, to determine whether the calibration actual displacement angle VT is the displacement angle near the most advanced angle. Further, it is determined whether or not the absolute value of the difference between the calibration actual displacement angle VT and the target displacement angle VTT is equal to or smaller than a first predetermined value b set to a value larger than a normal first predetermined value c described later. Is done.

Then, the calibration actual displacement angle VT is equal to or more than the most advanced displacement angle (VTMAX-a) and the absolute value of the difference between the calibration actual displacement angle VT and the target displacement angle VTT is the second absolute value.
If it is determined that the difference is equal to or smaller than the predetermined value b (S300:
YES), the step moves to S340, and the duration counter CVTER is reset to "0".

On the other hand, the calibration actual displacement angle VT is smaller than the most advanced displacement angle (VTMAX-a), or the absolute value of the difference between the calibration actual displacement angle VT and the target displacement angle VTT is larger than the second predetermined value b. Is determined to be satisfied at least one of the determination conditions (S300: N
O), move on to the next step.

The reason why a value larger than the normal first predetermined value c is used as the first predetermined value b will be described. That is, since the component parts of the VVT 50 have component tolerances, the maximum displacement angles realized in the respective VVTs 50 vary, and the realized maximum displacement angle does not always coincide with the most advanced target displacement angle VTT. do not do.

Therefore, when the most advanced angle of displacement VTMAX realized by the VVT 50 is smaller than the most advanced angle of the desired displacement angle VTT, mechanically, the VVT 50 becomes:
Even when the most advanced displacement angle is realized, the target displacement angle VT
The absolute value of the difference between T and the calibration actual displacement angle VT is not reduced,
There is a risk that a failure is erroneously detected as having occurred.

Therefore, when the calibration actual displacement angle VT is a displacement angle near the maximum displacement angle, the calibration actual displacement angle VT is compared with the case where the calibration actual displacement angle VT takes another displacement angle.
It is necessary to relax the criterion for determining whether T has converged to the target displacement angle VTT.

Here, the most retarded angle VTMIN realized by the VVT 50 is the most retarded target displacement angle VT.
If it is larger than T, the absolute value of the difference between the target displacement angle VTT and the calibration actual displacement angle VT is not reduced even if the VVT 50 mechanically realizes the most retarded displacement angle, and a failure occurs. It may be erroneously detected as having occurred.

In step S310, the calibration actual displacement angle VT is calculated by using the most retarded near displacement angle obtained by adding the nearest value a to the most retarded displacement angle VTMIN. It is determined whether the angle is
It is determined whether the absolute value of the difference between the calibration actual displacement angle VT and the target displacement angle VTT is equal to or less than the relaxed first predetermined value b.

That is, the calibration actual displacement angle VT is equal to or less than the most retarded displacement angle (VTMIN + a), and the absolute value of the difference between the calibration actual displacement angle VT and the target displacement angle VTT is equal to or less than the first predetermined value b. Is determined (S31
0: YES), the step moves to S340, and the duration counter CVTER is reset to "0".

On the other hand, the calibration actual displacement angle VT is larger than the most retarded vicinity displacement angle (VTMIN + a), or the absolute value of the difference between the calibration actual displacement angle VT and the target displacement angle VTT is larger than the first predetermined value b. If it is determined that at least one of the determination conditions is satisfied (S31
0: NO), proceed to the next step.

At S320, when the actual calibration angle VT is other than the most advanced angle and the most retarded angle, the actual actual angle VT and the target angle V
It is determined whether or not the absolute value of the difference from TT is equal to or less than a normal first predetermined value c.

That is, the calibration actual displacement angle VT is larger than the most retarded angle near displacement angle (VTMIN + a), less than the most advanced angle near displacement angle (VTMAX-a), and the calibration actual displacement angle VT and the target displacement angle VTT are If it is determined that the absolute value of the difference is equal to or smaller than the normal first predetermined value c (S3
20: YES), the step moves to S340, and the duration counter CVTER is reset to "0".

On the other hand, the calibration actual displacement angle VT is less than or equal to the most retarded displacement angle (VTMIN + a) or greater than the most advanced displacement angle (VTMAX-a). When it is determined that at least one of the determination conditions that the absolute value of the difference from the target displacement angle VTT is larger than the normal first predetermined value c is satisfied (S320: NO), the next step is performed. Some S3
Move to 30.

At S330, that is, at S30
If none of the conditions from 0 to S320 is satisfied, the duration counter CVTER, which is one of the conditions for starting the failure detection in the main routine, is incremented by one. Thus, S330 and S34
When each processing of 0 is completed, the step shifts from the subroutine to the main routine.

In the main routine, the step moves to S40, and in a subroutine, a stop time counter CVT for counting the time during which the actual displacement angle VTB is stopped.
The STP clear condition determination processing program is executed.
The stop time counter CVTSTP clear condition determination processing program will be described with reference to the flowchart shown in FIG.

First, in S400, the absolute value of the displacement angle change amount of the intake side camshaft 23 with respect to the crankshaft 14, that is, the difference between the currently detected calibration actual displacement angle VT and the previously detected calibration actual displacement angle VTO is calculated. It is determined whether the absolute value of the difference is equal to or less than a second predetermined value d.

Then, the actually detected calibration actual displacement angle V
If the absolute value of the difference between T and the previously detected calibration actual displacement angle VTO is equal to or smaller than the second predetermined value d (S400: YE
S), it is determined that the displacement angle of the intake side camshaft 23 is not displaced, and the process proceeds to S410. In S410 receiving this, the stop time counter CVT which is one of the conditions for starting the failure detection in the main routine is set.
STP is incremented by one.

On the other hand, when the absolute value of the difference between the currently detected calibration actual displacement angle VT and the previously detected calibration actual displacement angle VTO is larger than the second predetermined value d, the intake camshaft It is determined that the displacement angle of 23 is under displacement (S400: NO), and the step moves to S420.
Then, in S420, the stop time counter CVTSTP
Is reset to “0”, and the calibration actual displacement angle VT detected this time is stored as the calibration actual displacement angle VTO.

When the processes of S410 and S420 are completed, the steps shift from the subroutine to the main routine. Then, in the main routine, the step moves to S50, and a fail determination processing program as a subroutine is executed. This fail determination processing program will be described with reference to the flowchart shown in FIG.

In this fail determination processing program,
Based on the result of the determination processing executed in S30 and S40, it is determined whether or not the VVT 50 has failed. If a failure has occurred, it is determined whether the failure that has occurred is an advance failure or a retard failure.

First, in S500, it is determined whether the duration time counter CVTER is equal to or longer than 5 seconds and the stop time counter CVTSTP is equal to or longer than 5 seconds. That is, if the absolute value of the difference between the target displacement angle VTT and the calibration actual displacement angle VT is larger than the first predetermined values b and c, it is determined five times or more, and the change in the calibration actual displacement angle VT is determined by the second predetermined value d. It is determined whether or not the following is determined five times or more.

Then, the duration counter CVTER is set to 5
sec and the stop time counter CVTST
If it is determined that P is 5 seconds or more (S50
0: YES), the step moves to S510.

On the other hand, the duration time counter CVTE
R is 5 seconds or more, or stop time counter CVT
If it is determined that the STP is not satisfied for any one of 5 seconds or more (S500: NO), VVT5
It is determined that 0 has not failed. Neither the advance fail flag XVTFA nor the retard fail flag XVTFR is set.

In step S510, the current calibration actual displacement angle VT
Is determined to be equal to or greater than 30 ° CA, and if it is determined that the calibration actual displacement angle VT is equal to or greater than 30 ° CA (S510: YES), the advance fail flag XVTFA is determined.
Is set (S520). That is, since the calibration actual displacement angle VT is equal to or greater than 30 ° CA, it is determined that a failure has occurred in the VVT 50 in the advanced angle state.

On the other hand, in S510, when it is determined that the current calibration actual displacement angle VT is less than 30 ° CA (S510: NO), feedback control for converging the calibration actual displacement angle VT to the target displacement angle VTT. It is determined whether 5 seconds have elapsed since the processing was executed (S5).
30). Then, the calibration actual displacement angle VT is changed to the target displacement angle V
If it is determined that 5 seconds have elapsed since the feedback control process for converging to TT is performed (S53
0: YES), a retard fail flag XVTFR is set (S540).

That is, the calibration actual displacement angle VT is 30 ° C.
A, which is less than 5 after feedback control is executed.
Since the displacement of the calibration actual displacement angle VT is not detected even after the lapse of sec, it is determined that a failure has occurred in the VVT 50 in the retarded state.

On the other hand, if it is determined that 5 seconds have not elapsed since the execution of the feedback control (S530: NO), it is determined that the VVT 50 has not failed, and the advance fail flag XVTFA is determined. ,
Neither of the retard fail flags XVTFR is set. Then, the steps shift from the subroutine to the main routine.

Next, the normal return determination processing program will be described with reference to the flowchart shown in FIG. This normal return determination processing program is a subroutine program for determining whether or not a failure has been resolved in the VVT 50 in which it has been determined that a failure has occurred and the VVT 50 has returned to normal. Therefore, at S20 in the main routine, the advance fail flag XVTFA
= 1 or the retard fail flag XVTFR = 1 is determined (S20: YE
S) Executed.

In the determination of the normal return, it is determined whether or not the absolute value of the difference between the currently detected calibration actual displacement angle VT and the previously detected calibration actual displacement angle VTO is equal to or less than a third predetermined value e. It is determined (S600). Note that a hysteresis is provided between the third predetermined value e and the second predetermined value d in order to prevent frequent chattering due to the normal return determination and the failure determination, and the third predetermined value e is equal to the second predetermined value. It is set to a value larger than the value d.

Then, the calibration actual displacement angle V detected this time is
If the absolute value of the difference between T and the previously detected calibration actual displacement angle VTO is equal to or smaller than the third predetermined value e (S600: YE
S), the displacement angle of the intake side camshaft 23 is VVT5
It is determined that it has not been displaced by an amount sufficient to determine the normal return of 0, and the determination of the normal return is not made.

On the other hand, the calibration actual displacement angle VT detected this time
If the absolute value of the difference between the detected actual displacement angle VTO and the previously detected calibration actual displacement angle VTO is larger than the third predetermined value e (S600: N
O), the displacement angle of the intake side camshaft 23 is VVT5
It is determined that it has been displaced by an amount sufficient to determine the normal return of 0, and the determination of the normal return is made. Then, the following S610
In step S20, one of the advance fail flag XVTFA and the retard fail flag XVTFR, which is determined to be set in S20, is lowered.

As a result, the advance fail flag XVTF
A, or the fail handling process in various controls based on the retard fail flag XVTFR is canceled, and normal various controls are executed.

Next, an abnormality detection device VC of the valve timing control device according to the second embodiment will be described with reference to the drawings. The configuration of the abnormality detection device VC of the valve timing control device according to the second embodiment is the same as the configuration of the abnormality detection device VC of the valve timing control device according to the second embodiment. Omitted.

The abnormality detecting device VC of the valve timing control device according to the second embodiment, when the VVT 50 is in an unstable operation state, fails instead of prohibiting the execution of the fail determination process or the normal return determination process. It is characterized in that erroneous determination is suppressed by extending the determination time for normal return. Hereinafter, description will be made with reference to FIG. 11 and FIG.

In FIG. 11, the determination in each of steps S100 to S130 is performed as described in the first embodiment. However, in each step, “Y
When the determination of "ES" is made, the process proceeds to S150 without returning to S100, and sets an unstable operation flag F1 indicating that the VVT 50 is in an unstable operation state. Meanwhile, 1
If the determination in S30 is "NO", S140
To lower the operation unstable flag F1.

Therefore, when the operation instability flag F1 is set, it is determined that the VVT 50 is in an operation instability state, and various controls corresponding to this are executed.

An example will be described with reference to the flowchart shown in FIG. S shown in this flowchart
Steps 730 to S770 correspond to S30 shown in the flowchart shown in FIG. 7 used in the first embodiment.
The steps correspond to steps 0 to S340, respectively, and a description thereof will be omitted.

In S700, it is determined whether or not the unstable operation flag F1 is set (F1 = 1). If it is determined that the unstable operation flag F1 is not set (S700: NO), T ₀ is stored as a determination time T for determining whether or not the absolute value of the difference is equal to or less than a predetermined value.
For the determination time T, for example, the absolute value of the difference between the calibration actual displacement angle VT and the target displacement angle VTT in S730 is the first value.
This is a time for determining whether or not the difference is equal to or less than a predetermined value b. It is determined that the absolute value of the difference detected within this time is the absolute value of the difference between the current actual displacement angle VT and the target displacement angle VTT. Is done.

[0148] On the other hand, when the operation instability flag F1 is determined to be erected (S700: YES), stores the T ₁ as the determination time T. At this time, T ₁ stored is longer than T ₀ . That is, by extending the determination time, erroneous determination due to, for example, low fluidity of the lubricating oil and unstable operation of the VVT 50 is suppressed.

As described above in detail based on each embodiment, the abnormality detection device VC of the valve timing control device according to the above embodiment has the absolute value of the difference between the target displacement angle VTT and the calibrated actual displacement angle VT that is the first value. When the absolute value of the difference between the calibration actual displacement angle VT and the previous calibration actual displacement angle VTO is larger than the predetermined values b and c and is equal to or smaller than the second predetermined value d, VVT5
A configuration is provided for determining that a failure has occurred at 0.

Therefore, in the initial stage where the absolute value of the difference between the target displacement angle VTT and the calibration actual displacement angle VT is large, a failure occurs in the VVT 50 despite the displacement of the calibration actual displacement angle VT. Erroneous determination can be avoided.

If the target displacement angle VTT is a displacement angle near the maximum displacement, the target displacement angle VTT is used as a threshold value for determining the absolute value of the difference between the target displacement angle VTT and the calibration actual displacement angle VT. Is a first predetermined value b set to be larger than the first predetermined value c used when is a displacement angle other than the vicinity of the maximum displacement.

Therefore, VV may vary due to the tolerance of the components.
Even if the operable range of T50 varies and the actual displacement angle VT does not match the target displacement angle VTT of the maximum displacement, it is regarded that the actual calibration angle VT has reached the target displacement angle VTT of the maximum displacement. be able to.

As a result, although the actual displacement angle VTB of the intake camshaft 23 with respect to the crankshaft 14 is the most displaced, the calibration actual displacement angle VT is the target displacement angle VTT with the largest displacement. There is no erroneous determination that a failure has occurred simply because they do not match.

Further, the abnormality detecting device VC of the valve timing control device determines whether or not the absolute value of the difference between the calibrated actual displacement angle VT and the previously calibrated actual displacement angle VTO is larger than a third predetermined value e. A normal return determination processing program for determining whether or not a normal return from a failure is provided is provided as a configuration.

Therefore, the target displacement angle VTT and the calibration actual displacement angle V
Unlike the case where the normal return is determined based on the absolute value of the difference from T, the determination of the normal return is not made even though the device is normally in the fail state.

Further, the third predetermined value e (threshold value) for determining the absolute value of the difference between the calibration actual displacement angle VT and the previous calibration actual displacement angle VTO is larger than the second predetermined value used for fail determination. Large values are used.

Therefore, the frequent execution of the normal return determination and the failure determination processing is suppressed, and the chattering associated therewith is also prevented. As a result, it is possible to avoid a frequent change in the control amount depending on the determination result of the normal return determination or the failure determination.

Further, when the VVT 50 is in an unstable operation state, the configuration is such that the fail determination processing program and the normal return determination processing program are not executed. Therefore, when the VVT 50 is in an unstable operation state, for example, the operation resistance is large because the oil viscosity is low, and the calibration actual displacement angle VT converges to the target displacement angle VTT as compared with the case of normal oil viscosity. If it takes time, the fail determination and the normal return determination processing are not executed.

As a result, although the calibration actual displacement angle VT is being displaced toward the target displacement angle VTT, V
It is possible to avoid erroneous determination that the VT 50 is determined to be in the fail state.

When the operation of the VVT 50 is unstable, the failure determination processing program or
A configuration is provided for extending the determination time T in the normal return determination processing program.

Therefore, for example, when the oil viscosity is low and the operating resistance is large, and it takes a longer time for the calibration actual displacement angle VT to converge on the target displacement angle VTT than in the case of normal oil viscosity, The determination time T is extended.

As a result, although the calibration actual displacement angle VT is being displaced toward the target displacement angle VTT, V
The erroneous determination that the VT 50 is determined to be in the fail state can be suppressed.

In the present invention, various modifications and improvements can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, a mechanism that changes the rotation phase of the intake side camshaft 23 with respect to the crankshaft 14 by hydraulic pressure and changes the valve timing of the intake valve 21 is used as the VVT 50. However, the rotational phase of the intake camshaft 23 with respect to the crankshaft 14 may be changed by another driving means such as a step motor.

That is, if the rotation phase of the intake camshaft 23 with respect to the crankshaft 14 can be changed, the valve timing of the intake valve 21 can be changed. Then, there is a possibility that a failure occurs due to foreign matter biting or the like.

Further, in the above-described embodiment, there is provided a structure in which the valve overlap period is changed by variably controlling the valve timing of the intake valve 21. However, the valve overlap period may be changed by variably controlling the valve timing of the exhaust valve 31 or variably controlling the valve timing of the intake valve 21 and the exhaust valve 31.

In any case, the valve overlap period is changed, and the method may be adopted so that desired engine characteristics can be obtained. Further, in the above embodiment, the failure determination of the VVT 50 is determined by the actual displacement angle VTB detected by the cam angle sensor 44.
Is based on the absolute value of the difference between the calibration actual displacement angle VT calibrated by the most retarded learning value GVTFR and the target displacement angle VTT.

However, as long as the displacement angle of the intake camshaft 23 with respect to the crankshaft 14 can be detected, it may be detected by another method. Also,
Although the actual displacement angle VTB detected by the cam angle sensor 44 is calibrated by the most retarded angle learning value GVTFR, the actual displacement angle VT in the VVT 50 in which the most retarded angle learning is not performed.
This may be performed based on the absolute value of the difference between B and the target displacement angle VTT. In such a case, the failure determination error caused by not executing the most retarded angle learning is eliminated.

Further, in the above embodiment, the VV is calculated based on the engine coolant temperature THW and the engine speed NE.
Although it is determined whether or not T50 is in an unstable operation state, the determination may be made using other determination factors.

[0169]

As described above, according to the abnormality detecting device for the valve timing control device according to the first aspect of the present invention, the variable valve timing is determined only by the fact that the absolute value of the difference between the target valve timing and the actual valve timing is large. It is possible to avoid a situation where the mechanism is erroneously determined to have an abnormality.

As a result, especially in the initial stage of control,
It is possible to prevent the variable valve timing mechanism from being determined to be abnormal even though the actual valve timing is in the process of converging toward the target valve timing.

According to the abnormality detecting device for the valve timing control device according to the second aspect of the present invention, the absolute value of the difference between the target valve timing and the actual valve timing does not decrease due to the physical restriction in the variable valve timing mechanism. Even in this case, it can be determined that the actual valve timing has converged to the target valve timing.

As a result, even though the actual valve timing is displaced to the most displaced valve timing, it is erroneously determined that an abnormality has occurred in the variable valve timing mechanism due to physical restrictions in the variable valve timing mechanism. Can be prevented.

Further, according to the abnormality detecting device for the valve timing control device according to the third aspect of the present invention, the target valve timing and the actual valve timing are transiently irrespective of the occurrence of an abnormality in the variable valve timing mechanism. When the absolute value of the timing difference is equal to or greater than the first predetermined value,
It is possible to prevent erroneous determination that the normal state has been restored.

Further, in the abnormality detecting device for the valve timing control device according to the fourth aspect of the present invention, the third predetermined value is set to a value larger than the second predetermined value.
Immediately after the normal return determination is made by the normal return determining means, it is possible to avoid a situation in which an abnormality is determined. As a result, it is possible to prevent chattering in various controls affected by the abnormality determination of the variable valve timing mechanism.

Furthermore, according to the abnormality detecting device for a valve timing control device according to the fifth aspect of the present invention, it is determined whether the variable valve timing mechanism has an abnormality or a normal return under the condition that the operation of the variable valve timing mechanism is unstable. Is not executed, and each erroneous determination due to unstable operation can be reliably prevented.

Further, in the abnormality detecting device for the valve timing control device according to the present invention, the determination time for performing the abnormality determination and the normal return determination under the condition that the operation of the variable valve timing mechanism is unstable is determined. Will be extended. Accordingly, it is possible to avoid erroneous determination of abnormality and determination of normal return even though the variable valve timing mechanism is actually operating.

Further, according to the abnormality detecting device of the valve timing control device according to the seventh aspect of the present invention, it is possible to detect the oil temperature via the water temperature, and a separate detecting means for detecting the oil temperature is required. No need to prepare.

Further, according to the abnormality detecting device for the valve timing control device according to the present invention, it is possible to prevent the erroneous determination due to the variation of the engine speed and the variation of the valve timing detected by the valve timing detecting means. be able to.

[Brief description of the drawings]

FIG. 1 is a conceptual configuration diagram showing a basic conceptual configuration of an abnormality detection device of a valve timing control device according to the present invention.

FIG. 2 is a system configuration diagram showing a schematic configuration of a gasoline engine system to which the present invention is applied.

FIG. 3 is a schematic configuration diagram of a variable valve timing mechanism system.

FIG. 4 is a control block diagram of an abnormality detection device of the valve timing control device.

FIG. 5 is a flowchart showing a main routine of an abnormality determination and normal return determination program.

FIG. 6 is a flowchart of a start condition determination processing program executed as a subroutine in the first embodiment.

FIG. 7 is a flowchart of a duration time counter CVTER clear condition determination processing program executed as a subroutine in the first embodiment.

FIG. 8 is a flowchart of a stop time counter CVTSTP clear condition determination processing program executed as a subroutine.

FIG. 9 is a flowchart of a fail determination processing program executed as a subroutine.

FIG. 10 is a flowchart of a normal return determination processing program executed as a subroutine.

FIG. 11 is a flowchart of a start condition determination processing program executed as a subroutine in the second embodiment.

FIG. 12 is a flowchart of a duration time counter CVTER clear condition determination processing program executed as a subroutine in the second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Engine, 14 ... Crankshaft, 15 ... Combustion chamber, 20 ... Intake passage, 21 ... Intake valve, 22 ... Intake port, 23 ... Intake side camshaft, 26 ... Throttle valve, 30 ... Exhaust passage, 40 ... Crank angle Sensor, 44
... Cam angle sensor, 45 ... Throttle sensor, 46 ... Intake pressure sensor, 50 ... VVT, 70 ... ECU, 71 ... RO
M, 73: RAM, M10: Variable valve timing mechanism, M11: Valve timing detection means, M12: Valve timing control means, M13: Abnormality determination means, M14
... Normal return determination means, M16 ... First determination prohibition means, M1
7: determination time extension means, M19: second determination prohibition means, V
C: An abnormality detection device of the valve timing control device.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-323115 (JP, A) JP-A-6-317118 (JP, A) JP-A-4-112908 (JP, A) JP-A-4-112 91330 (JP, A) JP-A-7-293287 (JP, A) JP-A-6-317117 (JP, A) JP-A-7-233742 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02D 13/02 F01L 1/34

Claims (8)

(57) [Claims] An intake valve and an exhaust valve that are driven at a predetermined timing in synchronization with the rotation of a crankshaft of an internal combustion engine to open and close an intake passage and an exhaust passage that communicate with a combustion chamber, respectively. Operating state detecting means for detecting; target valve timing determining means for determining a target valve timing according to the operating state of the internal combustion engine detected by the operating state detecting means; A variable valve timing mechanism for changing at least one of the valve timings, valve timing detection means for detecting the actual valve timing of the valve on the side where the variable valve timing mechanism is provided, and the valve timing detection The actual valve timing detected by the means, Valve timing control means for controlling the variable valve timing mechanism to converge on the target valve timing determined by the target valve timing determination means; target valve timing determined by the target valve timing determination means; The absolute value of the difference from the actual valve timing detected by the timing detecting means is equal to or greater than a first predetermined value, and the absolute value of the change amount of the actual valve timing detected by the valve timing detecting means is a second predetermined value An abnormality detection device for a valve timing control device, comprising: abnormality determination means for determining that an abnormality has occurred in the variable valve timing mechanism in the following cases. 2. The abnormality detection device for a valve timing control device according to claim 1, wherein the first predetermined value is a valve timing near an actual valve timing detected by the valve timing detection means. In this case, the actual valve timing detected by the valve timing detecting means is set to a larger value than when the actual valve timing is a valve timing other than the vicinity of the most displaced valve timing. Abnormality detection device for control device. 3. The abnormality detection device for a valve timing control device according to claim 1, wherein the valve timing is determined after the abnormality determination means determines that an abnormality has occurred in the variable valve timing mechanism. When the amount of change in the actual valve timing detected by the detecting means is equal to or greater than a third predetermined value, the variable valve timing mechanism includes normal return determining means for determining that the variable valve timing mechanism has returned to a normal state. Characteristic abnormality detection device for valve timing control device. 4. The valve timing control apparatus according to claim 3, wherein the third predetermined value is set to be larger than the second predetermined value. Abnormality detection device for control device. 5. The abnormality detection device for a valve timing control device according to claim 1, wherein the variable valve timing mechanism is a variable valve timing mechanism driven by hydraulic pressure. The operating state detecting means includes oil temperature detecting means for detecting the temperature of the oil that drives the variable valve timing mechanism, and when it is determined that the oil temperature detected by the oil temperature detecting means is not in a predetermined region. The abnormality determination in the variable valve timing mechanism by the abnormality determination means, or,
An abnormality detection device for a valve timing control device, comprising: first determination prohibition means for prohibiting at least one of normality determination in the variable valve timing mechanism by the normality return determination means. 6. The abnormality detection device for a valve timing control device according to claim 1, wherein the variable valve timing mechanism is a variable valve timing mechanism driven by hydraulic pressure. The operating state detecting means includes oil temperature detecting means for detecting the temperature of the oil that drives the variable valve timing mechanism, and when it is determined that the oil temperature detected by the oil temperature detecting means is not in a predetermined region. A determination time extension unit that extends at least one of a determination of an abnormality in the variable valve timing mechanism by the abnormality determination unit and a determination of a normal return in the variable valve timing mechanism by the normal return determination unit. An abnormality detection device for a valve timing control device, characterized in that: 7. The abnormality detection device for a valve timing control device according to claim 5, wherein the oil temperature detection means detects the oil temperature via a water temperature. Abnormality detection device. 8. The abnormality detection device for a valve timing control device according to claim 1, wherein the operation state detection means detects a rotation speed of the internal combustion engine. An engine speed detecting means, wherein when the engine speed detected by the engine speed detecting means is not in a predetermined range, an abnormality judgment in the variable valve timing mechanism by the abnormality judging means;
An abnormality detection device for a valve timing control device, further comprising second determination prohibition means for prohibiting at least one of normality determination in the variable valve timing mechanism by the normality return determination means.