JPH08246820A - Abnormality detection device for internal combustion engine having variable valve timing mechanism - Google Patents

Abstract

PURPOSE: To suppress erroneous detection in an internal combustion engine having a variable valve timing mechanism in detecting abnormality of displacement angle of a cam shaft in respect to a crank shaft. CONSTITUTION: An abnormality detection device VC for an internal combustion engine having a variable valve timing mechanism detects abnormality occurrence in a displacement angle of an intake side cam shaft 23 in respect to a crank shaft 14 due to erroneous streaching of a timing belt 35 on an intake side timing pulley 27. For detecting abnormality, a determination displacement angle A is calculated by subtracting a displacement angle between the slowest displacement angle of the intake side cam shaft 23 and a structure actual displacement angle VT, from the structure actual displacement angle VT. When deviation between the determination displacement angle A and a displacement angle 30 CA in structure of a VVT 50 is a first specified value (e) or more, valve timing fail of a displacement angle of the intake side cam shaft 23 is detected in respect to the crank shaft 14.

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 an internal combustion engine having a variable valve timing mechanism for changing valve timing by displacing a displacement angle of a camshaft with respect to a crankshaft in accordance with an operating condition. Relates to an abnormality detecting device for an internal combustion engine having a variable valve timing mechanism for detecting an abnormality in a displacement angle of a camshaft with respect to a crankshaft.

[0002]

2. Description of the Related Art Generally, various control timings in an engine are determined on the basis of a rotation angle (crank angle) of a crankshaft, and opening / closing timings of intake valves and exhaust valves are also defined by the crank angle. Here, many intake valves and exhaust valves are driven by a camshaft so as to achieve a predetermined opening / closing timing, and the camshaft is driven by a crankshaft via a transmission member such as a timing belt or a timing chain. It is driven to rotate.

Therefore, when the displacement angle of the camshaft with respect to the crankshaft deviates from the predetermined displacement angle due to the tooth flapping of the timing belt or the like, or the timing belt or the like being misplaced, the intake valve and the exhaust valve have predetermined displacements. The engine output characteristics are deteriorated because the engine is not opened / closed at the opening / closing timing.

Therefore, based on the crank angle detected by the crank angle sensor and the cam angle detected by the cam angle sensor, the deviation of the angle (timing) of the camshaft with respect to the crankshaft, that is, the displacement angle is within a predetermined range. There has been proposed a timing abnormality detection device that constantly determines whether or not it exists. According to this timing abnormality detection device, the displacement angle of the camshaft with respect to the crankshaft is always detected, and the timing abnormality is detected when the displacement angle is out of the predetermined range.

By the way, in recent years, an engine having a variable valve timing mechanism for changing the valve timing of at least one of an intake valve and an exhaust valve according to the operating state of the engine has been put into practical use. And
As a variable valve timing mechanism, for example, a variable valve timing mechanism that continuously displaces a rotational phase (displacement angle) of a camshaft with respect to a crankshaft is known.

In an engine having such a variable valve timing mechanism, an actual rotational phase (actual displacement angle) is detected by using a phase difference detecting device as disclosed in Japanese Patent Laid-Open No. 59-105911. Feedback control is performed to converge the actual displacement angle to the target rotation phase (target displacement angle) determined based on the operating state of the engine.

Even in an engine having such a variable valve timing mechanism, the displacement angle of the camshaft with respect to the crankshaft is inevitably deviated due to misalignment of the timing belt or the like. As a result, even if the variable valve timing mechanism changes the valve timing by displacing the displacement angle, the predetermined valve timing may not be realized and desired engine characteristics may not be obtained.

Therefore, it becomes necessary to detect an abnormality in the timing due to the crossing of the timing belt or the like.
In such a case, the displacement angle of the camshaft with respect to the crankshaft is constantly detected in the same manner as a normal engine,
It seems that it is enough to detect the timing abnormality due to the crossing of the timing belt or the like.

[0009]

However, in an engine having a variable valve timing mechanism, the optimum valve timing for the engine condition at each time is realized by displacing the displacement angle of the camshaft with respect to the crankshaft.

Therefore, while the camshaft is displacing toward the target displacement angle, the displacement angle of the camshaft with respect to the crankshaft changes continuously, and the displacement angle does not take a constant value. Absent. As a result,
As in the case of a normal engine, if a fixed threshold value is used and an abnormality is determined based on whether or not the displacement angle is within the threshold value, there is a problem of erroneous detection.

Further, even when the camshaft detects an abnormality after reaching the target displacement angle, the camshaft can take various target displacement angles, and therefore the displacement angle abnormality is detected by a threshold value of 1. I couldn't do it.

In that case, it seems that the timing abnormality should be judged by changing the predetermined value as the judgment threshold value for each target displacement angle. However, when the camshaft is displaced toward the target displacement angle, there is a displacement response delay, and the target displacement angle and the actual displacement angle do not necessarily match.

Therefore, if the predetermined value serving as the threshold value for determination is simply changed for each target displacement angle and it is successively determined whether or not the displacement angle is within the predetermined value, the displacement angle becomes abnormal. Although it has not occurred, there is a problem that it is easy to erroneously detect that an abnormality has occurred.

The present invention has been made to solve the above-mentioned conventional problems. In an internal combustion engine having a variable valve timing mechanism, an erroneous detection is made in detecting an abnormality in the displacement angle of the camshaft with respect to the crankshaft. The purpose is to suppress.

[0015]

In order to achieve the above object, an abnormality detecting device for an internal combustion engine having a variable valve timing mechanism according to the invention of claim 1 comprises a crankshaft M2 of an internal combustion engine M1 which rotates, A rotary motion transmitting means M3 for transmitting the rotary motion of the crankshaft M2, and an intake side camshaft M4 and an exhaust side rotationally driven in synchronization with the rotation of the crankshaft M2 via the rotary motion transmitting means M3. A camshaft M5, and an intake valve M9 and an exhaust valve M10 that are driven at a predetermined timing in synchronization with the rotations of the camshafts M4 and M5 to open and close an intake passage M7 and an exhaust passage M8 leading to the combustion chamber M6, respectively. An operating state detecting means M11 for detecting an operating state of the internal combustion engine M1 and a rotation of the crankshaft M2. A With a reference timing signal generating means M12 for generating a reference timing signal at a predetermined crank angle, the intake-side cam shaft M4 or the exhaust camshaft relative to the crankshaft M2 M
By displacing at least one of the five displacement angles from the reference displacement angle to the target displacement angle, the valve timing of at least one of the intake valve M9 and the exhaust valve M10 is changed from the reference valve timing to the target valve timing. The target displacement angles of the camshafts M4 and M5 on the side where the variable valve timing mechanism M13 is arranged are set according to the operating states of the variable valve timing mechanism M13 and the internal combustion engine M1 detected by the operating state detecting means M11. Target displacement angle determining means M14 for determining and the camshafts M4, M5 on the side where the variable valve timing mechanism M13 is disposed.
Displacement timing signal generating means M1 for generating a displacement timing signal corresponding to the actual displacement angle with the rotation of
5, the reference timing signal generated by the reference timing signal generating means M12, and the displacement timing signal generated by the displacement timing signal generating means M15, the variable valve timing mechanism M13 arrangement for the crankshaft M2. Displacement angle calculation means M16 for calculating the actual displacement angle of the camshafts M4, M5 on the installation side, and the displacement angle calculation means M
The variable valve timing so that the actual displacement angle of the camshafts M4, M5 on the side where the variable valve timing mechanism M13 is disposed calculated by 16 is converged to the target displacement angle determined by the target displacement angle determination means M14. The variable valve timing mechanism control means M17 for controlling the mechanism M13, the actual displacement angle calculated by the displacement angle calculation means M16, and the displacement angle based on the reference displacement angle of the variable valve timing mechanism M13. The displacement amount calculation means M18 for calculating the displacement amount and the displacement angles of the camshafts M4, M5 on the side where the variable valve timing mechanism M13 is arranged are controlled to be maintained at a predetermined target displacement angle by the variable valve timing mechanism control means M17. To determine whether or not A holding control determination unit M19, by the holding control determination unit M19, the cam shaft in the variable valve timing mechanism M13 disposed side M4,
It is determined that M5 is held and controlled at a predetermined target displacement angle, and the displacement amount of the displacement angle calculated by the displacement amount calculation means M18 is calculated from the actual displacement angle calculated by the displacement angle calculation means M16. When the excluded displacement angle is equal to or larger than the first predetermined value, the abnormality determining means M20 for determining that the internal combustion engine M1 is abnormal.
And are provided as components.

An abnormality detecting device for an internal combustion engine having a variable valve timing mechanism according to a second aspect of the present invention is the abnormality detecting device for an internal combustion engine having a variable valve timing mechanism according to the first aspect. The determination means M19 is configured to calculate the target displacement angle determined by the target displacement angle determination means M14 and the displacement angle calculation means M16.
When the deviation from the actual displacement angle calculated by is less than the second predetermined value and the displacement amount of the displacement angle calculated by the displacement amount calculating means M18 is less than the third predetermined value, the variable The variable valve timing mechanism control means M17 determines that the displacement angles of the camshafts M4 and M5 on the side where the valve timing mechanism M13 is disposed are controlled to be maintained at a predetermined target displacement angle.

Furthermore, an abnormality detecting device for an internal combustion engine having a variable valve timing mechanism according to a third aspect of the present invention is the abnormality detecting device for an internal combustion engine having a variable valve timing mechanism according to claim 1 or 2. The predetermined target displacement angle determined by the holding control determination means M19 is a displacement angle of the maximum displacement in the variable valve timing mechanism M13.

[0018]

In the abnormality detecting device for an internal combustion engine having the variable valve timing mechanism according to the invention described in claim 1, the crankshaft M2 starts rotating motion when the internal combustion engine M1 starts. Then, the rotational movement of the crankshaft M2 is transmitted to the intake side camshaft M4 and the exhaust side camshaft M5 via the rotational movement transmitting means M3. As a result, both camshafts M4 and M5 are rotationally driven in synchronization with the rotation of the crankshaft M2.

Intake valve M9 and exhaust valve M10
Is driven at a predetermined timing in synchronization with the rotations of both camshafts M4 and M5, and leads to an intake passage M leading to the combustion chamber M6.
7 and the exhaust passage M8 are opened and closed.

The operating state detecting means M12 detects the operating state of the internal combustion engine M1 and determines the target displacement angle determining means M1.
Reference numeral 4 denotes the camshaft M on the side where the variable valve timing mechanism M13 is arranged according to the operating state of the internal combustion engine M1 detected by the operating state detecting means M12.
4. Determine the target displacement angle of M5. Further, the reference timing signal generating means M12 generates a reference timing signal at a predetermined crank angle as the crankshaft M2 rotates.

The variable valve timing mechanism M13 displaces at least one of the intake side camshaft M4 and the exhaust side camshaft M5 relative to the crankshaft M2 from the reference displacement angle to the target displacement angle. As a result, the valve timing of at least one of the intake valve M9 and the exhaust valve M10 is changed from the reference valve timing to the target valve timing.

The displacement timing signal generating means M15 generates a displacement timing signal corresponding to the actual displacement angle as the camshafts M4 and M5 rotate on the side where the variable valve timing mechanism M13 is arranged. Then, the displacement angle calculating means M16 calculates the actual displacement angle of the camshafts M4, M5 on the side where the variable valve timing mechanism M13 is arranged, based on the reference timing signal and the displacement timing signal. Further, the displacement amount calculation means M18 calculates the displacement amount of the displacement angle based on the actual displacement angle calculated by the displacement angle calculation means M16 and the reference displacement angle of the variable valve timing mechanism M13.

Variable valve timing mechanism control means M17
Controls the variable valve timing mechanism M13 so that the actual displacement angle calculated by the displacement angle calculation means M16 converges to the target displacement angle determined by the target displacement angle determination means M14. Further, the holding control determination means M
19 is the displacement angle of the camshafts M4 and M5 on the side where the variable valve timing mechanism M13 is arranged,
It is determined whether the variable valve timing mechanism control means M17 holds and controls the predetermined target displacement angle.

Then, the abnormality determining means M20 is controlled by the holding control determining means M19 so as to control the variable valve timing mechanism M1.
It is determined that the displacement angles of the camshafts M4 and M5 on the side where the three are disposed are controlled to be maintained at a predetermined target displacement angle,
Further, when the displacement angle obtained by subtracting the displacement amount of the displacement angle calculated by the displacement amount calculation unit M18 from the actual displacement angle calculated by the displacement angle calculation unit M16 is equal to or greater than the first predetermined value, the internal combustion engine is abnormal. Is determined to have occurred.

Therefore, the variable valve timing mechanism M
The abnormality determination in the internal combustion engine M1 is performed based on the displacement angle excluding the displacement angle displacement amount of the camshafts M4 and M5 displaced from the reference displacement angle by 13. As a result, the variable valve timing mechanism M13
In the internal combustion engine M1 having the following, the rotational motion transmitting means M3 is generated by changing the generation timing of the displacement timing signal.
It is possible to prevent erroneous detection of an abnormal occurrence of the internal combustion engine M1 due to the above problem.

Further, in the abnormality detecting apparatus for an internal combustion engine having the variable valve timing mechanism according to the invention as defined in claim 2, the holding control judging means M19 has the target displacement angle determined by the target displacement angle determining means M14, The deviation from the actual displacement angle calculated by the displacement angle calculating means M16 is equal to or less than the second predetermined value, and the displacement amount calculating means M1.
When the displacement amount of the displacement angle calculated by 8 is less than or equal to the third predetermined value, the displacement angles of the camshafts M4 and M5 on the side where the variable valve timing mechanism M13 is disposed are controlled to be maintained at a predetermined target displacement angle. To judge.

Therefore, the variable valve timing mechanism M
When 13 reaches the target displacement angle, it is determined that the holding control is performed in a substantially stopped state. As a result, the abnormality determination of the internal combustion engine M1 is performed in a stable state, and erroneous detection is suppressed.

Further, in the abnormality detecting apparatus for the internal combustion engine having the variable valve timing mechanism according to the third aspect of the present invention, the predetermined target displacement angle judged by the holding control judging means M19 is the maximum in the variable valve timing mechanism M13. Displacement Displacement angle is adopted.

Therefore, the variable valve timing mechanism M
The abnormality determination of the internal combustion engine M1 is executed at the most stable displacement angle among the displacement angles taken by 13, and erroneous detection is further suppressed.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in an engine abnormality detecting device having a variable valve timing mechanism will be described below with reference to the drawings.

First, the construction of an engine abnormality detecting device VC having a variable valve timing mechanism according to this embodiment will be described with reference to FIGS. FIG. 2 is a schematic configuration diagram showing a gasoline engine system having a variable valve timing mechanism.

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

Further, a crank angle sensor 40 is disposed 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). Here, equiangular teeth are formed on the outer circumference of the rotor, and a pulse-shaped crank angle signal is generated and detected every time the equiangular teeth of the rotor pass in front of the electromagnetic pickup.

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 the air-fuel mixture, and the top of the cylinder head 12 is formed. A spark plug 16 for igniting the air-fuel mixture is provided in the combustion chamber 15 so as to project into the combustion chamber 15.

A distributor 18 is arranged near the exhaust side camshaft 33 of the cylinder head 12. The distributor 18 is connected to the exhaust side camshaft 33, and an engine speed sensor 41 for detecting the speed of the crankshaft 14 and a cylinder discrimination sensor 42 for detecting a reference position signal generated at a predetermined rate. 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 engine speed NE (the rotation speed of the crankshaft 14) is detected by measuring the number of generated pulse signals.

Further, each spark 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 by the distributor 18 with each crank angle. It is distributed to the spark plugs 16.

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
The reference numeral 2 has an intake port 22 and an exhaust port 32. The intake port 20 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
An intake valve 21 is provided, and an exhaust valve 31 is provided at the exhaust port 32.

Above the intake valve 21, the intake-side camshaft 2 for opening and closing the intake valve 21 is opened.
3 is disposed, and an exhaust side cam shaft 33 for driving the exhaust valve 31 to open and close is disposed above the exhaust valve 31. An intake side timing pulley 27 and an exhaust side timing pulley 34 are attached to one end of each camshaft 23, 33.
7, 34 are connected to the crankshaft 14 via a timing belt 35.

Therefore, when the engine 10 is operating, the camshaft 2 is driven from the crankshaft 14 via the timing belt 35 and the timing pulleys 27 and 34.
The rotation driving force is transmitted to the camshafts 3 and 33, and each camshaft 2
The intake valve 21 and the exhaust valve 31 are opened / closed by rotating 3, 33. Each of these valves 21,
31 is the rotation of the crankshaft 14 and the piston 13
In synchronism with the vertical movement of the intake stroke, that is, the intake stroke, the compression stroke,
The engine 10 is driven at a predetermined opening / closing timing in synchronization with a series of four strokes in 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 arranged near the intake side camshaft 23. The cam angle sensor 44 is attached to the intake side camshaft 23. It is composed of a magnetic rotor (not shown) and an electromagnetic pickup (not shown) connected to each other. A plurality of teeth are formed on the outer circumference of the magnetic rotor at equal angles.
A pulsed cam angle signal (displacement timing signal) accompanying the rotation of the intake camshaft 23 is detected between BTDC 90 ° and 30 ° before the compression TDC of a predetermined cylinder.

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

A throttle sensor 4 for detecting the throttle opening TA is provided near the throttle valve 26.
5 are provided. Further, a surge tank 2 for suppressing intake pulsation is provided downstream of the throttle valve 26.
5 is formed. And, in the surge tank 25,
An intake pressure sensor 46 that detects the intake pressure in the surge tank 25 is provided. An injector 17 for supplying fuel to the combustion chamber 15 is arranged 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 that is pressure-fed 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 at the same time as the intake of the air, fuel is injected from each injector 17 toward the intake port 22. As a result, the air-fuel mixture is generated in 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 in the intake stroke.

A catalytic converter 36 containing a three-way catalyst for purifying exhaust gas is arranged in the exhaust passage 30. An oxygen sensor 47 for detecting the oxygen concentration in the exhaust gas is arranged in the exhaust passage 30.

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 opening / closing timing of the intake valve 21 to change the valve overlap amount.
"T". ) Are arranged. This VVT50 is
Crankshaft 14 (intake side timing pulley 27)
Is a mechanism for continuously changing the valve timing of the intake valve 21 by changing the displacement angle of the intake side camshaft 23 with respect to the rotation of.

The system configuration of the VVT 50 will be described with reference to FIG. Here, FIG. 2 shows VVT5.
4 is an explanatory view showing a cross section near the intake side camshaft 23 in which 0 is arranged, and the entire control system of the VVT 50. FIG.

The control system of VVT50 is VVT5.
0, an oil control valve 80 (hereinafter referred to as “OCV”) that applies a driving force to the VVT 50, a cam angle sensor 44 that detects a cam angle signal, and a cam angle sensor 44.
An ECU 70 that drives and controls the OCV 80 based on input signals from various sensors such as

The VVT 50 is disposed between the intake camshaft 23 and the intake 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 rotatably mounted near the front end of the intake side camshaft 23, and an inner cap 52 has a hollow bolt 53 and a pin 54 at the front end of the intake side camshaft 23. It is attached so that it can rotate integrally.

A housing 56 having a cap 55 is attached to the intake side timing pulley 27 by means of a bolt 57 and a pin 58 so as to be integrally rotatable. With this housing 56, the tip of the intake side camshaft 23 and the inner side. The entire cap 52 is covered. Further, on the outer circumference of the intake side timing pulley 27, a large number of external teeth 27a for hanging the timing belt 35 are formed.

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

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

Due to these meshing, 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. 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.

In the space S, in order to move the ring gear 59 in the axial direction, a first hydraulic chamber 60 is provided at the tip end side of the ring gear 59, and a second hydraulic chamber 61 is provided at the base end side 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. In addition, inside the intake side camshaft 23, the first
A first hydraulic pressure supply passage 62 that communicates the hydraulic pressure supply hole 51a and the first hydraulic pressure chamber 60, and a second hydraulic pressure supply passage 63 that communicates the second hydraulic pressure supply hole 51b and the second hydraulic pressure chamber 61 are formed. .

Lubricating oil sucked up from the oil pan 65 by the hydraulic pump 64 is supplied to the respective hydraulic pressure supply holes 51a and 51b through the oil filter 66 with a predetermined pressure. In addition, each hydraulic pressure supply path 60, 6
In order to selectively supply the hydraulic pressure to the hydraulic pressure chambers 60 and 61 via the OCV 1, the OCV 8 is provided in the hydraulic pressure supply holes 51a and 51b.
0 is connected.

The OCV 80 is a 4-port directional control valve in which the plunger 83 driven by the electromagnetic actuator 81 and the coil spring 82 reciprocates the spool 84 in the axial direction to switch the flow direction of the lubricating oil. Then, the electromagnetic actuator 81
However, the opening degree is adjusted by the duty control, and the magnitude of the hydraulic pressure supplied to each hydraulic chamber 60, 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 pressure supply hole 5.
1a and B port 85b are connected to the second hydraulic pressure supply hole 51b. Further, the reservoir port 85r communicates with the oil pan 65.

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

In the VVT 50 having these structures, O
When the CV 80 is drive-controlled and the spool 84 is moved to the left in the drawing, the passage 84b is in the tank port 85.
t and the A port 85a are communicated with each other, and the first hydraulic pressure supply hole 51a
Is supplied with lubricating oil. Then, the first hydraulic pressure supply hole 51a
The lubricating oil supplied to is supplied to the first hydraulic chamber 60 via the first hydraulic supply passage 62, and hydraulic pressure is applied to the tip 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 with the second hydraulic pressure supply passage 63, the second hydraulic pressure supply hole 51b, and the OCV 80. The oil is discharged to the oil pan 65 via the B port 85b and the reservoir port 85r.

Therefore, the ring gear 59 is moved while being rotated to the base end side (right side in the drawing) by the hydraulic pressure applied to the tip end side, and the intake side cam shaft 23 is twisted via the inner cap 52. . As a result, the rotational phase (displacement angle) of the intake-side camshaft 23 relative to the intake-side timing pulley 27 (crankshaft 14) is changed (displaced), and the intake-side camshaft 23 changes from the most retarded angle displacement angle to the most advanced angle displacement angle. The intake valve 21
The valve opening timing of is advanced.

The intake valve 21 whose valve opening timing is advanced in this way is opened while the exhaust valve 31 is open, so that the intake valve 21 and the exhaust valve 31 are simultaneously opened. The lap period is extended. The movement of the ring gear 59 toward the base end side is restricted by the ring gear 59 contacting the intake side timing pulley 27, and when the ring gear 59 stops contacting the intake side timing pulley 27, the intake valve 21 moves. The valve opening timing is the earliest.

On the other hand, when the OCV 80 is drive-controlled and the spool 84 is moved to the right in the drawing, the passage 84
b connects 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 hydraulic pressure is applied to the base end side of the ring gear 59.

At the same time, the passage 84c connects the A port 85a and the reservoir port 85r, and the lubricating oil in the first hydraulic chamber 60 is supplied with the first hydraulic pressure supply passage 62, the first hydraulic pressure supply hole 51a, and the OCV 80. The oil is discharged to the oil pan 65 via the A port 85a and the reservoir port 85r.

Therefore, the ring gear 59 is moved while being rotated to the front end side (the left side in the drawing) by the hydraulic pressure applied to the base end side, and the intake 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 (displacement angle) of the intake-side camshaft 23 relative to is changed (displaced), the intake-side camshaft 23 is displaced from the most advanced displacement angle toward the most retarded displacement angle, and the opening timing of the intake valve 21 is changed. Is delayed.

By retarding the valve opening timing of the intake valve 21 in this manner, the valve overlap period in 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 tip side is restricted by the ring gear 59 coming into contact with the housing 56, and when the ring gear 59 comes into contact with the housing 56 and stops, the 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 the cam angle signal output from the cam angle sensor 44 and the crank angle signal output from the crank angle sensor 40.

That is, for example, after the cam angle signal (displacement timing signal) is input to the ECU 70, the BTD
Measuring the time required until a C30 ° crank angle signal (reference timing signal) is input using the engine speed NE, and converting the time into a displacement angle using the known relationship between the crank angle and the crank angle. Thus, the actual displacement angle VTB of the intake camshaft 23 with respect to the crankshaft 14 is calculated.

Next, the control system of the abnormality detecting device VC for the internal combustion engine having the variable valve timing mechanism according to this embodiment will be described with reference to the control block diagram shown in FIG. A control system of the abnormality detection device VC for an internal combustion engine having a variable valve timing mechanism is configured with an electronic control unit 70 (hereinafter referred to as “ECU”) as a core. The ECU 70 implements variable valve timing mechanism control means, abnormality determination means, holding control determination means, displacement angle calculation means, target displacement angle determination means, displacement amount calculation means, and the like.

The ECU 70 stores an abnormality determination processing program executed as a main routine for determining an abnormality in the engine 10, and a map for displacing the displacement angle of the intake camshaft 23 in accordance with various conditions.
It has M71. Further, the ECU 70 has various control programs such as a fail determination processing program executed as a subroutine, a continuation time counter CVTER clear condition determination processing program, and a stop time counter CVTSTP clear condition determination processing program.

Further, the ECU 70 executes a calculation process based on a control program stored in the ROM 71.
It has a RAM 72 for temporarily storing the PU 72, a calculation result in 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.

The CPU 72, ROM 71, RAM
73 and the backup RAM 74 are the bidirectional bus 75.
And an input interface 76 and an 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.

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

Next, an abnormality determination program in the abnormality detection apparatus VC of the internal combustion engine having the variable valve timing mechanism according to the present embodiment having the above-mentioned configuration will be described with reference to FIGS.
This will be described with reference to the flowchart shown in FIG.

Here, the abnormality determining program has a fail determining processing program as a main subroutine for determining whether or not a failure (abnormality) has occurred between the timing belt 35 and the intake side timing pulley 27. are doing. Then, the abnormality determination program is, for example,
It is executed every 240 ° CA while the engine 10 is operating.

Each judgment processing program in the subroutine will be described below according to the main routine of the abnormality judgment program shown in FIG. In addition, "S" in the flow chart of each program indicates each step.

When the main routine starts, the stop time counter CVTSTP clear condition determination processing program is executed in a subroutine (S10). The stop time counter CVTSTP clear condition determination processing program is a program for counting the time when the deviation between the target displacement angle VTT and the calibration displacement angle VT is larger than the second predetermined value b. The 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 is calculated as follows based on the reference crank angle signal (reference timing signal) and the cam angle signal.

First, after the displacement timing signal detected by the cam angle sensor 44 is input to the ECU 70,
The signal interval (pulse interval) until the reference timing signal detected by the crank angle sensor 40 is input to the ECU 70 is measured as time using the engine speed NE. Next, the measured time is converted into an actual displacement angle VTB as a cam angle with respect to the crank angle by using a known relationship between the crank angle and the time (engine speed NE).

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

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

First, in S100, the calibration actual displacement angle VT
Is used to determine whether or not the calibration actual displacement angle VT is a displacement angle in the vicinity of the most advanced angle by using the most advanced angle in the vicinity of the most advanced angle VTMAX. Further, it is determined whether the deviation between the calibration actual displacement angle VT and the target displacement angle VTT is less than or equal to a “second predetermined value b” set to a value larger than a “normal second predetermined value c” described later. To be done.

Then, the calibration actual displacement angle VT is equal to or more than the most advanced angle displacement angle (VTMAX-a), and the deviation between the calibration actual displacement angle VT and the target displacement angle VTT is "second predetermined value b" or less. If it is determined that there is (S100: Y
ES), the step proceeds to S140, and the duration counter CVTER is reset to "0".

On the other hand, the calibration actual displacement angle VT is less than the most advanced angle displacement angle (VTMAX-a), or the deviation between the calibration actual displacement angle VT and the target displacement angle VTT is larger than the "second predetermined value b". If it is determined that at least one of the determination conditions is satisfied (S100: N
O), move to the next step.

The reason why a value larger than the "normal second predetermined value c" is used as the "second predetermined value b" will be described. That is, since the component parts of the VVT 50 have component tolerances, the maximum displacement angle realized in each VVT 50 varies, and the realized maximum displacement angle and the target advance angle VTT are not always the same. Because not.

Therefore, when the most advanced angle displacement angle VTMAX realized by the VVT 50 is smaller than the most advanced target displacement angle VTT, even if the VVT 50 realizes the most advanced angle displacement angle due to the mechanism. , The deviation is not reduced,
There is a risk of false detection that a failure has occurred inside the VVT 50.

Therefore, when the calibration actual displacement angle VT is a displacement angle in the vicinity of the maximum displacement angle, the calibration actual displacement angle V is compared to when the calibration actual displacement angle VT takes another displacement angle.
It is necessary to relax the threshold value (second predetermined value) for determining whether or not convergence has occurred based on the deviation between T and the target displacement angle VTT.

Here, the most retarded displacement angle VTMIN realized by the VVT 50 is the most retarded target displacement angle VT.
If it is larger than T, the deviation is not reduced and VV50 is reduced due to the mechanism even if the VVT 50 realizes the most retarded displacement angle.
There is a risk of false detection that a failure has occurred inside T50.

Therefore, in the subsequent S110, the calibration actual displacement angle VT uses the displacement angle near the most retarded angle obtained by adding the neighborhood value a to the most retarded displacement angle VTMIN. It is judged whether it is an angle,
It is determined whether the deviation between the calibrated actual displacement angle VT and the target displacement angle VTT is less than or equal to the relaxed “second predetermined value b”.

That is, if the calibration actual displacement angle VT is equal to or less than the most retarded angle displacement angle (VTMIN + a) and the deviation between the calibration actual displacement angle VT and the target displacement angle VTT is less than or equal to the "second predetermined value b". If determined (S110:
(YES), the step proceeds to S140, and the duration counter CVTER is reset to "0".

On the other hand, the calibration actual displacement angle VT is larger than the displacement angle (VTMIN + a) near the most retarded angle, or the deviation between the calibration actual displacement angle VT and the target displacement angle VTT is larger than the "second predetermined value b". If it is determined that at least one of the determination conditions is satisfied (S11
0: NO), move to next step.

At the subsequent S120, when the calibration actual displacement angle VT is other than the most advanced angle near displacement angle and the most retarded angle near displacement angle, the calibration actual displacement angle VT and the target displacement angle V
It is determined whether the deviation from TT is less than or equal to the “normal second predetermined value c”.

That is, the calibration actual displacement angle VT is larger than the most retarded angle displacement angle (VTMIN + a) and less than the most advanced angle displacement angle (VTMAX-a), and the calibration actual displacement angle VT and the target displacement angle VTT are equal to each other. When it is determined that the deviation is less than or equal to the “normal second predetermined value c” (S12
0: YES), the step proceeds to S140, and the duration time counter CVTER is reset to "0".

On the other hand, the calibration actual displacement angle VT is equal to or less than the most retarded angle near the displacement angle (VTMIN + a) or is equal to or more than the most advanced angle near the displacement angle (VTMAX-a), or the calibration actual displacement angle VT. When it is determined that at least one of the determination conditions that the deviation from the target displacement angle VTT is larger than the “normal second predetermined value c” is satisfied (S120: NO), the next step is performed. S13
Move to 0.

Then, in S130, that is, S10
When none of the judgment conditions from 0 to S120 is satisfied, the duration time counter CVTER, which is one of the fail detection start conditions in the main routine, is incremented by one. Thus, S130 and S140
When each processing of (3) is finished, the step shifts from the subroutine to the main routine.

In the main routine, the step proceeds to S20, and in the subroutine, the 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.
This stop time counter CVTSTP clear condition determination processing program will be described with reference to the flowchart shown in FIG.

First, in S200, the displacement angle change amount of the intake camshaft 23 with respect to the crankshaft 14, that is, the deviation between the calibration actual displacement angle VT detected this time and the calibration actual displacement angle VTO detected previously is determined by 3 It is determined whether or not it is equal to or less than the predetermined value d.

Then, the calibration actual displacement angle V detected this time
If the deviation between T and the previously detected calibration actual displacement angle VTO is less than or equal to the third predetermined value d (S200: YES), it is determined that the displacement angle of the intake side camshaft 23 is not displaced, and the step Moves to S210. S that received this
In 210, the stop time counter CVTSTP, which is one of the fail detection start conditions in the main routine, is set to 1
Is incremented by one.

On the other hand, when the deviation between the calibration actual displacement angle VT detected this time and the calibration actual displacement angle VTO detected previously is larger than the third predetermined value d, the intake side camshaft 23 is displaced. It is determined to be in progress (S200: N
O), the step moves to S220. And S22
At 0, 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 S210 and S220 are completed in this way, the step shifts from the subroutine to the main routine. Then, in the main routine, the step proceeds to S30, and the fail determination processing program which is the subroutine is executed. This fail determination processing program will be described with reference to the flowchart shown in FIG.

In such a fail judgment processing program,
Based on the result of the determination process executed in S10 and S20, it is determined whether or not a failure has occurred between the timing belt 35 and the intake side timing pulley 27. That is, it is determined whether or not the desired displacement angle of the intake side camshaft 23 with respect to the crankshaft 14 is deviated due to misapplication of the timing belt 35, tooth jumping, or the like.

First, in S300, it is determined whether or not the intake side camshaft 23 is displaced to the most retarded displacement angle. That is, the fail determination processing program has a configuration for performing the fail determination when the intake camshaft 23 is held at the predetermined target displacement angle VTT in order to perform the accurate fail determination. Here, in the present embodiment, the predetermined target displacement angle VTT
As the above, the displacement angle of the most retarded angle at which the ring gear 59 contacts the housing 56 and the operation of the ring gear 59 (the intake side camshaft 23) is physically restricted is used.

If it is determined that the intake camshaft 23 has been displaced to the most retarded displacement angle (S300: YES), the step proceeds to S310. On the other hand, when it is determined that the intake camshaft 23 is not displaced to the most retarded displacement angle (S30
0: NO), the step shifts from the subroutine to the main routine.

At the subsequent S310, it is determined whether 5 seconds have passed since the feedback control process for converging the calibrated actual displacement angle VT to the most retarded target displacement angle VTT was executed. That is, the accuracy of fail determination is improved by stabilizing the behavior of the intake camshaft 23 by waiting for 5 seconds after displacing the intake camshaft 23 to the most retarded displacement angle.

If it is determined that 5 seconds have passed since the feedback control process for converging the calibrated actual displacement angle VT to the target displacement angle VTT was executed (S3
10: YES), and the step moves to S320. On the other hand, 5 seconds after feedback control is executed
If it is determined that c has not elapsed (S310: N
O), the step shifts from the subroutine to the main routine.

In the following S320, the stop time counter CV
It is determined whether TSTP is 5 seconds or more. That is, it is determined whether or not it has been determined five times or more that the change in the calibration actual displacement angle VT is less than or equal to the third predetermined value d. And the stop time counter CVTSTP is 5 sec.
If it is determined that the above is the case (S320: YE
S), since the intake camshaft 23 is held at the most retarded displacement angle and is in a very stable state, the step is advanced toward the determination of valve timing failure.

On the other hand, the stop time counter CVTSTP is 5
If it is determined to be less than sec (S320: N
O), since the intake camshaft 23 is not in the state of being held at the most retarded displacement angle and is not suitable for the determination of valve timing failure, the step shifts from the subroutine to the main routine.

Next, in S330, the duration time counter C
It is determined whether VTER is 5 seconds or less. That is, it is determined whether the number of times that the deviation between the target displacement angle VTT and the calibration actual displacement angle VT is larger than the second predetermined values b and c is 5 times or less.

Then, the duration counter CVTER becomes 5
If it is determined that the time is equal to or less than sec, (S330: YE
S), the intake side camshaft 23 is set at the target displacement angle VTT
Since it means that it has converged to (the most retarded displacement angle), the step is advanced toward the determination of the valve timing failure.

On the other hand, the duration counter CVTE
When it is determined that R is larger than 5 sec (S33
0: NO), the intake side camshaft 23 has not yet converged to the target displacement angle VTT, and is in a failed state due to foreign matter being caught inside the VVT 50. Therefore, the subsequent steps in this subroutine are not executed, and the step shifts to the main routine.

In S340, first, the calibrated actual displacement angle VT of the intake side camshaft 23 displaced by the VVT 50 to the target displacement angle VTT and the intake side camshaft 2
The displacement amount of the displacement angle of the intake side camshaft 23 is calculated from the maximum retardation displacement angle as the reference displacement angle of 3. Then, the determination displacement angle A is calculated by further excluding the displacement angle displacement amount obtained from the calibration actual displacement angle VT.
In this embodiment, the VVT 50 having the displacement angle of the intake side camshaft 23 with respect to the crankshaft 14 in the VVT 50 structure, that is, the most retarded displacement angle (reference displacement angle) of 30 ° CA is used.

In the following S350, the judgment displacement angle A and VV
T50 configuration displacement angle 30 ° CA (reference displacement angle)
It is determined whether or not the deviation between and is greater than or equal to the first predetermined value e. That is, the determination displacement angle A calculated in S340 described above is constant even if the component tolerance and the like are taken into consideration, as long as a failure such as a cross-over has not occurred between the timing belt 35 and the intake side timing pulley 27. Should indicate a displacement angle close to the structural displacement angle of 30 ° CA.
Therefore, the determination displacement angle A and the structural displacement angle 30 ° CA
By determining whether or not the deviation between and is greater than or equal to the first predetermined value e, it is possible to determine the failure that has occurred between the timing belt 35 and the intake side timing pulley 27.

In the present embodiment, when the displacement angle of the intake camshaft 23 is the most retarded displacement angle,
Since the fail judgment is executed, the deviation between the judgment displacement angle A and the structural displacement angle 30 ° CA does not become so large. Therefore, a small value can be used as the first predetermined value e.

On the other hand, if the fail judgment is executed when the intake side camshaft 23 has another predetermined target displacement angle, the judgment displacement angle A and the structural displacement angle 30 ° C.
The deviation from A is larger than that in the former case. Therefore, it is necessary to use, for example, a value of about 11 ° CA as the first predetermined value e.

If it is determined that the deviation between the determined displacement angle A and the structural displacement angle 30 ° CA is equal to or greater than the first predetermined value e (S350: YES), the timing belt 35 and the intake side timing are determined. It is determined that a failure such as a tooth jump has occurred due to a crossing with the pulley 27.
In response to this determination, in the next step S360, the valve timing fail flag XVTF is set, and the step shifts from the subroutine to the main routine.

Then, the valve timing fail XVT
The control amount affected by F is changed to a predetermined control amount. Further, for example, an abnormality warning lamp in the meter panel is turned on.

On the other hand, when it is determined that the deviation between the determined displacement angle A and the structural displacement angle 30 ° CA is less than the first predetermined value e (S350: NO), the timing belt 3
5 and the intake side timing pulley 27 are crossed with each other, and it is determined that a failure such as tooth flapping has not occurred. Therefore, the valve timing fail flag XVTF is not set and the step shifts from the subroutine to the main routine.

As described above in detail with reference to each embodiment, the engine abnormality detecting device VC having the variable valve timing mechanism according to the above-described embodiment is used as the reference displacement angle (the most retarded displacement angle) of the intake camshaft 23. To the target displacement angle VTT, the determination displacement angle A is calculated by removing the displacement angle amount from the calibration actual displacement angle VT.

When the deviation between the judgment displacement angle A and the structural displacement angle 30 ° CA is equal to or larger than the first predetermined value e,
Intake side camshaft 23 with respect to the crankshaft 14
Is provided with a configuration for detecting an abnormal displacement angle (valve timing failure). Here, the valve timing failure is caused by, for example, a crossing error generated between the timing belt 35 and the intake side timing pulley 27, a tooth jump, or the like.

Therefore, in the case where the intake side camshaft 23 is displaced by the VVT 50 to a displacement angle different from the reference displacement angle, and the generation timing of the cam angle signal (displacement timing signal) with respect to the crank angle signal (reference timing signal) changes. Even if there is, the valve timing failure can be detected without being affected by the displacement of the intake side camshaft 23.

Further, there is provided a structure for detecting a valve timing failure when the intake camshaft 23 is held and controlled at a predetermined target displacement angle VTT. Therefore, while the valve timing fail is being detected, the generation timing of the displacement timing signal with respect to the reference timing signal does not change sequentially, and the valve timing fail can be accurately detected.

Further, a predetermined target displacement angle VT for judging whether or not the intake side camshaft 23 is being held and controlled.
The most retarded displacement angle is adopted as T. Where VV
When T50 achieves the most retarded displacement angle, the ring gear 59 comes into contact with the housing 56 and the operation of the ring gear 59 is physically restricted, so that the intake camshaft 23 is stably held. is there.

Therefore, in calculating the calibration actual displacement angle VT, the determination displacement angle A, etc., the calculation error is suppressed, and the valve timing failure is detected.
The detection accuracy can be further improved.

The present invention can be modified and improved in various ways without departing from the spirit thereof. For example, in the above embodiment, the engine 10 including the cam angle sensor 44 and the cylinder discrimination sensor 42 independently is used, but the cam angle sensor 44 is replaced with the cylinder discrimination sensor 42 in order to reduce the number of components.
You may use the engine shared as.

In such a case, not only the displacement timing signal but also the timing failure of the cylinder discrimination signal can be detected. Further, as the VVT 50, a mechanism is used which changes the valve timing of the intake valve 21 by displacing the displacement angle of the intake side camshaft 23 with respect to the crankshaft 14 by hydraulic pressure. However, the displacement angle of the intake side camshaft 23 with respect to the crankshaft 14 may be displaced by other driving means such as a step motor.

That is, in the case of the VVT 50 configured to displace the displacement angle of the intake side camshaft 23 with respect to the crankshaft 14, the generation timing of the displacement timing signal with respect to the reference timing signal changes, so that the generation timing of the displacement timing signal This is because it is necessary to detect the valve timing failure without being affected by the change.

In the above embodiment, the valve timing of the intake valve 21 is variably controlled to change the valve overlap period. However, the valve overlap period may be changed by variably controlling the valve timing of the exhaust valve 31 or by variably controlling the valve timing of the intake valve 21 and the exhaust valve 31.

In any case, the valve overlap period may be changed so that the desired engine characteristics can be obtained without change. Further, in the above-described embodiment, the actual displacement angle VTB detected by the cam angle sensor 44 for the fail determination of the VVT 50 is detected.
Is calibrated with the most retarded learning value GVTFR to calculate the calibration actual displacement angle VT. However,
Intake side camshaft 23 with respect to the crankshaft 14
Other methods may be used as long as the displacement angle can be detected.

Further, the actual displacement angle VTB detected by the cam angle sensor 44 is calibrated by the most retarded angle learning value GVTFR, but the calibrated actual displacement angle VT is used. The displacement angle VTB may be used. Even in such a case, the valve timing failure may occur, and therefore the valve timing failure can be accurately detected by applying the present invention.

[0130]

As described above, claim 1 and claim 2 are provided.
According to the abnormality detection device for the internal combustion engine having the variable valve timing mechanism according to the invention described in (1), there is a case where the generation timing of the displacement timing signal changes due to the displacement of the camshaft on the variable valve timing mechanism installation side. Also,
It is possible to avoid a situation in which an abnormal displacement angle of the camshaft with respect to the crankshaft is erroneously detected.

Further, since an abnormality in the displacement angle of the camshaft with respect to the crankshaft is detected while the camshaft on which the variable valve timing mechanism is disposed is held at the predetermined target displacement angle, the abnormality can be detected more reliably. It can be done more accurately.

As a result, even in the internal combustion engine having the variable valve timing mechanism, the abnormality in the displacement angle of the camshaft with respect to the crankshaft can be detected in the same manner as a normal internal combustion engine.

According to the abnormality detecting device for the internal combustion engine having the variable valve timing mechanism according to the third aspect of the present invention, when the displacement angle of the camshaft on which the variable valve timing mechanism is disposed is the maximum displacement angle. It is provided with a configuration for performing abnormality detection.

Therefore, the camshaft on which the variable valve timing mechanism is arranged is in a very stable state, and erroneous detection is further suppressed when detecting an abnormality, as compared with the case where another displacement angle is set.

[Brief description of drawings]

FIG. 1 is a conceptual configuration diagram showing a basic conceptual configuration of an abnormality detection device for an internal combustion engine having a variable valve timing mechanism 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 engine abnormality detection device having a variable valve timing mechanism.

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

FIG. 6 is a flowchart of a duration counter CVTER clear condition determination processing program executed as a subroutine.

FIG. 7 is a flowchart of a stop time counter CVTSTP clear condition determination processing program executed as a subroutine.

FIG. 8 is a flowchart of a fail determination processing program executed as a subroutine.

[Explanation of symbols]

10 ... Engine, 14 ... Crank shaft, 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, 46 ... Intake pressure sensor, 50 ... VV
T, 70 ... ECU, 71 ... ROM, 73 ... RAM, M2
... crankshaft, M3 ... rotary motion transmission means, M4 ...
Intake side camshaft, M5 ... Exhaust side camshaft, M1
2 ... Reference timing signal generation means, M13 ... Variable valve timing mechanism, M15 ... Displacement timing signal generation means, M17 ... Variable valve timing mechanism control means, M1
9 ... Holding control judging means, M20 ... Abnormality judging means, VC ...
An abnormality detection device for an internal combustion engine having a variable valve timing mechanism.

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location G01M 15/00 G01M 15/00 Z

Claims (3)

[Claims] 1. A crankshaft of an internal combustion engine which rotates, a rotary motion transmitting means for transmitting the rotary motion of the crankshaft, and a rotary shaft which is synchronized with the rotation of the crankshaft via the rotary motion transmitting means. An intake-side camshaft and an exhaust-side camshaft that are driven, and an intake valve and an exhaust valve that are driven at predetermined timings in synchronization with the rotation of the camshafts and that open and close an intake passage and an exhaust passage that communicate with the combustion chamber, respectively. An operating state detecting means for detecting an operating state of the internal combustion engine; a reference timing signal generating means for generating a reference timing signal at a predetermined crank angle with rotation of the crankshaft; and an intake side with respect to the crankshaft. Displacement angle of at least one of the camshaft or the exhaust-side camshaft Variable valve timing mechanism for changing the valve timing of at least one of the intake valve and the exhaust valve from the reference valve timing to the target valve timing by displacing the degree from the reference displacement angle to the target displacement angle, and the operating state. Target displacement angle determining means for determining a target displacement angle of the camshaft on the side where the variable valve timing mechanism is disposed according to the operating state of the internal combustion engine detected by the detecting means; and the variable valve timing mechanism. Displacement timing signal generating means for generating a displacement timing signal corresponding to an actual displacement angle with the rotation of the camshaft on the mounting side, a reference timing signal generated by the reference timing signal generating means, and the displacement timing signal Generated by generating means Displacement angle calculation means for calculating an actual displacement angle of the camshaft on the side of the variable valve timing mechanism with respect to the crankshaft, the displacement angle calculation means calculating the displacement angle calculation means. A variable valve timing for controlling the variable valve timing mechanism so that the actual displacement angle of the camshaft on the side where the variable valve timing mechanism is disposed converges to the target displacement angle determined by the target displacement angle determination means. Mechanism control means, an actual displacement angle calculated by the displacement angle calculation means, and a displacement amount calculation means for calculating the displacement amount of the displacement angle based on the reference displacement angle of the variable valve timing mechanism, The cam shuff on the side where the variable valve timing mechanism is installed Holding control determining means for determining whether the variable valve timing mechanism controlling means holds and controls the variable valve timing mechanism to a predetermined target displacement angle, and the holding control determining means causes the variable valve timing mechanism to be installed. The displacement of the displacement angle calculated by the displacement amount calculating means from the actual displacement angle calculated by the displacement angle calculating means is determined to be held and controlled by the camshaft at the predetermined target displacement angle. A variable valve timing mechanism comprising: abnormality determining means for determining that an abnormality has occurred in the internal combustion engine when the displacement angle excluding the amount is equal to or greater than a first predetermined value. An abnormality detecting device for an internal combustion engine having the same. 2. The abnormality detection device for an internal combustion engine having the variable valve timing mechanism according to claim 1, wherein the holding control determination means determines the target displacement angle determined by the target displacement angle determination means and the displacement angle calculation. If the deviation from the actual displacement angle calculated by the means is less than or equal to a second predetermined value and the displacement amount of the displacement angle calculated by the displacement amount calculation means is less than or equal to a third predetermined value, then the variable An internal combustion engine having a variable valve timing mechanism, characterized in that it is determined that the displacement angle of the camshaft on the side where the valve timing mechanism is disposed is controlled to be maintained at a predetermined target displacement angle by the variable valve timing mechanism control means. Anomaly detection device. 3. The abnormality detection device for an internal combustion engine having the variable valve timing mechanism according to claim 1, wherein the predetermined target displacement angle determined by the holding control determination means is in the variable valve timing mechanism. An abnormality detection device for an internal combustion engine having a variable valve timing mechanism, wherein the displacement angle is the maximum displacement.