KR20090003170A - Variable valve timing apparatus - Google Patents

Abstract

link mechanisms (A) and (B) connected to an intake camshaft and operated to change a phase of an intake valve; and a control pin (A) (2034) sliding on a guide plate (2040) along a guide groove (A) (2041) to allow the link mechanism (A) to operate; a control pin (B) (2134) sliding on the guide plate (2040) along a guide groove (B) (2042) to allow the link mechanism (B) to operate. The control pin (B) (2134) is detached from an end of the guide groove (B) (2042) when the control pins (A) (2034) and (B) (2134) are moved in a direction allowing the phase to be retarded until the control pin (A) (2034) abuts against an end of the guide groove (A) (2041).

Description

Variable Valve Timing Device {VARIABLE VALVE TIMING APPARATUS}

The present invention relates to a variable valve timing device. In particular, it is related with the variable valve timing apparatus which changes the timing which a valve opens and closes with the change amount according to the operation amount of an operation part (link mechanism).

Conventionally, VVT (Variable Valve Timing) is known which changes the phase (crank angle) at which the intake valve and the exhaust valve open and close in response to an operating state. In general, VVT changes the phase by relatively rotating the cam shaft for opening and closing the intake valve and exhaust valve with respect to the sprocket or the like. The cam shaft is rotated by a hydraulic pressure or an electric motor. When rotating a camshaft with an electric motor, compared with the case of rotating by hydraulic pressure, the torque which rotates a camshaft is hard to be obtained. Therefore, when the cam shaft is rotated by the electric motor, the torque of the electric motor is transmitted to the cam shaft via the link mechanism or the like to rotate the cam shaft.

Japanese Laid-Open Patent Publication No. 2005-48706 discloses a valve timing adjusting device that transmits torque to a driven shaft (cam shaft) by a link (link mechanism) to adjust the opening and closing timing of the valve. The valve timing adjusting device described in this patent document is formed in a transmission system that transmits a drive torque of a drive shaft to a driven shaft for driving and opening and closing at least one valve of an intake valve and an exhaust valve in an internal combustion engine, and opening and closing timing of at least one valve. Adjust it. The valve timing adjusting device generally includes a guide member that forms a guide path having a constant width, and a movable member that is coupled to both sides of the guide path in the width direction thereof so that the guide member can slide relative to the guide member in the stretching direction of the guide path. And a plurality of links configured to form a confined link together with the guide member and the movable body when the movable body is coupled to the corresponding link, respectively, with respect to the drive shaft in accordance with the relative sliding of the movable body relative to the guide member. It includes a phase change mechanism for changing the rotational phase of the driven shaft, and a torque transmission portion for transmitting the control torque to the guide member. The guide member, when viewed in the radial direction, extends inclined with respect to the radial axis and forms a guide path that varies in distance with respect to the center of rotation, and rotates relative to the corresponding link by transmission of control torque.

The valve timing adjusting device described in this publication includes a guide member extending inclined with respect to the radial axis when viewed in the radial direction and forming a guide path in which the radial distance from the center of rotation changes. It couples to a movable body from both sides of the width direction. Thereby, the control torque can be transmitted from the torque transmission part to the guide member and rotated relative to the link corresponding to the guide member. Therefore, the movable body can be made to slide relative to the guide member so that the rotational phase of the driven shaft can be changed, and as a result, the timing of at least one valve of the intake valve and the exhaust valve can be adjusted.

However, when the valve timing adjusting device described in the Japanese Laid Open Patent Application is made to change the opening / closing timing of the valve using a plurality of link mechanisms, it is difficult to detect the failure (failure) of the link mechanism. Even when any one of the plurality of link mechanisms is damaged, it is possible to change the opening and closing timing of the valve by another link mechanism, and the valve is opened and closed under control.

The present invention relates to a variable valve timing apparatus capable of detecting a failure.

A first aspect of the present invention is to provide a variable valve timing device for changing the opening and closing timing of at least one of the intake valve and the exhaust valve. The variable valve timing device includes a first operating portion configured to change the opening and closing timing of at least one of the intake valve and the exhaust valve by an amount of change in accordance with an operation amount, and the intake valve and the exhaust valve controlled by the first mechanism. A second operating portion configured to change the opening / closing timing of the same valve as at least one of the change amount according to the operating amount, and the first operating portion so that the operating range of the first operating portion is smaller than the operable range of the second operating portion; It includes a restriction limiting the operation.

According to the present invention, the opening and closing timing of at least one of the intake valve and the exhaust valve is based on the operating amount of the first operating portion (for example, the first link mechanism) and the second operating portion (for example, the second link mechanism). It is changed by the amount of change. Thereby, even when any one operation part is damaged and cannot operate normally, the other operation part can change the opening / closing timing of at least one of the intake valve and the exhaust valve. The operable range of the first actuating part is limited by the limiting part so as to be smaller than the operable range of the second actuating part and can operate within that range. If the first operating portion is operating normally without suffering damage or the like, it is possible to change the opening and closing timing of at least one of the intake valve and the exhaust valve until the operation of the first operating portion is limited by the restricting portion. On the contrary, in the case where the first actuating part is damaged and cannot operate normally, the operation of the first actuating part is not limited by the limiting part and exceeds the operable range of the first actuating part, so that at least one of the intake valve and the exhaust valve The opening and closing timing can be further changed. Therefore, by detecting the opening / closing timing of at least one of the intake valve and the exhaust valve, it is possible to determine whether or not a failure has occurred in the first operating part. As a result, a variable valve timing apparatus capable of detecting a failure can be provided.

Preferably the strength of the first actuating part is lower than that of the second actuating part.

According to the present invention, the first operating portion is formed to have a lower strength than the second operating portion. In this way, the failure can be generated before the second operation part in the first operation part capable of detecting the failure. Therefore, when the first operating portion operates normally and a failure cannot be detected, no failure occurs in the second operating portion.

In addition the valve is preferably driven by a camshaft. The first actuating portion and the second actuating portion are link mechanisms connected to the cam shaft to be operated by the actuator to rotate the cam shaft. When the cam shaft is rotated by the actuator through the link mechanism, the opening and closing timing of at least one of the intake valve and the exhaust valve is changed.

According to the present invention, it is possible to detect a failure occurring in a link mechanism operated by an actuator which causes the cam shaft to rotate to change the opening timing of either of the intake valve and the exhaust valve.

A second aspect of the present invention is to provide a variable valve timing device for changing the opening and closing timing of at least one of an intake valve and an exhaust valve. The variable valve timing device includes a first operating portion configured to change the opening and closing timing of at least one of the intake valve and the exhaust valve by an amount of change in accordance with an operation amount, and the intake valve and the exhaust valve controlled by the first mechanism. A second operating portion configured to change the opening / closing timing of the same valve as at least one of the operation amount to a change amount according to the operating amount, and the first operating portion in a direction in which opening / closing timing of at least one of the intake valve and the exhaust valve is perceived. In the direction in which the opening and closing timing of at least one of the intake valve and the exhaust valve is advanced, the first limiting portion restricting the operation of the first operating portion so that the operable range is smaller than the operable range of the second operating portion. Such that the operable range of the second actuating part is smaller than the operable range of the first actuating part And a second limiting portion for limiting the operation of the second actuating portion.

According to the invention, the opening and closing timing of at least one of the intake valve and the exhaust valve is controlled by the operation of the first actuating part (e.g., the first link mechanism) and the second actuating part (e.g., the second link mechanism). The amount is changed according to the quantity. Thereby, even when any one operation part is damaged and cannot operate normally, the opening / closing timing of at least one of an intake valve and an exhaust valve can be changed by another operation part. The first actuating portion is operable by the first actuating portion of the second actuating portion in a direction in which opening and closing timing of at least one of the intake valve and the exhaust valve is perceived by the first limiting portion restricting its actuation. Operate in a range smaller than the possible range. The second actuating portion is operable by the second actuating portion in the direction in which opening and closing timing of at least one of the intake valve and the exhaust valve is advanced by the second limiting portion restricting its operation. Operate in a range smaller than the possible range. If the first operating portion is operating normally without suffering damage or the like, the opening and closing timing of at least one of the intake valve and the exhaust valve may be delayed until the operation of the first operating portion is limited by the first restricting portion. On the contrary, in the case where the first operating portion is damaged and cannot be operated normally, the operation of the first operating portion is not limited by the limiting portion and exceeds the operable range of the first operating portion so that at least one of the intake valve and the exhaust valve The opening and closing timing can be further delayed. Similarly, if the second operating portion is operating normally without suffering damage or the like, the opening and closing timing of at least one of the intake valve and the exhaust valve can be advanced until the operation of the second operating portion is limited by the second limiting portion. have. On the contrary, if the second operating portion is damaged and cannot operate normally, the operation of the second operating portion is not limited by the second limiting portion and exceeds the operable range of the second operating portion so that at least one of the intake valve and the exhaust valve The timing of opening and closing the valve can be further advanced. Therefore, by detecting the opening / closing timing of at least one of the intake valve and the exhaust valve, it is possible to determine whether or not a failure has occurred in the first operating portion or the second operating portion. As a result, a variable valve timing device capable of detecting a failure can be provided.

The valve is preferably driven by a camshaft. The first actuating portion and the second actuating portion are link mechanisms connected to the cam shaft to be operated by the actuator to rotate the cam shaft. When the cam shaft is rotated by the actuator through the link mechanism, the opening and closing timing of at least one of the intake valve and the exhaust valve is changed.

According to the present invention, it is possible to detect a failure occurring in a link mechanism operated by an actuator which causes the cam shaft to rotate to change the opening timing of either of the intake valve and the exhaust valve.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram which shows the engine of the vehicle in which the variable valve timing apparatus of this invention of 1st Embodiment is mounted.

2 is a map defining the phase of the intake cam axis.

3 is a cross-sectional view showing the intake VVT mechanism.

4 is a cross-sectional view taken along the line A-A of FIG.

5 is a (first) cross-sectional view taken along the line B-B in FIG.

FIG. 6 is a (second) cross sectional view taken along the line B-B in FIG.

FIG. 7 is a cross-sectional view taken along the line C-C of FIG. 3.

FIG. 8 is a cross-sectional view taken along the line D-D of FIG. 3.

Fig. 9 is a flowchart showing the structure of a control program executed by an ECU controlling the intake VVT mechanism of the variable valve timing apparatus of the present invention in the first embodiment.

FIG. 10 is a (second) cross sectional view taken along the line C-C in FIG.

FIG. 11 is a (third) cross sectional view taken along the line C-C in FIG.

12 is a (first) cross-sectional view of a link mechanism of the variable valve timing apparatus of the present invention in the second embodiment.

It is (2nd) sectional drawing of the link mechanism of the variable valve timing apparatus of this invention of 2nd Embodiment.

It is (1st) sectional drawing of the guide plate of the variable valve timing apparatus of this invention of 3rd Embodiment.

Fig. 15 is a flowchart showing the structure of a control program executed by an ECU controlling the intake VVT mechanism of the variable valve timing apparatus of the present invention in the third embodiment.

It is (2nd) sectional drawing of the guide plate of the variable valve timing apparatus of this invention of 3rd Embodiment.

It is (third) sectional drawing of the guide plate of the variable valve timing apparatus of this invention of 3rd Embodiment.

18 is a cross-sectional view of a limiting pin that defines a range within which the link mechanism can operate in the variable valve timing apparatus of the present invention in another embodiment.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described, referring drawings. In the following description, the same code | symbol is attached | subjected to the same component. The names and functions of the parts are the same. Therefore, detailed description thereof will not be repeated.

<1st embodiment>

With reference to FIG. 1, the engine of the vehicle equipped with the variable valve timing apparatus which concerns on 1st Embodiment of this invention is demonstrated.

The engine 1000 is a V-type eight cylinder engine with an "A" bank 1010 and a "B" bank 1012 each containing four cylinders (cylinders). Moreover, you may use the engine of a type other than a V-type 8 cylinder.

The engine 1000 intakes air from the air cleaner 1020. The intake air amount is regulated by the throttle valve 1030. The throttle valve 1030 is an electromagnetic throttle valve driven by a motor.

Air is introduced into the cylinder 1040 through the intake manifold 1032. Air is mixed with fuel in the cylinder (combustion chamber) 1040. The cylinder 1040 is directly injected with fuel from the injector 1050. That is, the injection hole of the injector 1050 is formed in the cylinder 1040.

Fuel is injected at the intake stroke. In addition, the timing at which fuel is injected is not limited to the intake stroke. In addition, in this embodiment, the engine 1000 is demonstrated as a direct injection engine in which the injection hole of the injector 1050 was formed in the cylinder 1040. As shown in FIG. However, in addition to the direct injection injector (in cylinder) 1050, a port injection injector may be provided. In addition, only the port injection injector may be formed.

The air-fuel mixer in the cylinder 1040 is ignited by the spark plug 1060 and thus burns. After combustion, the air-fuel mixer, ie, the exhaust gas, is purified by the three-way catalyst 1070 and then discharged out of the vehicle. The air-fuel mixture may be burned down to lower the piston l080, which causes the crankshaft 1090 to rotate.

Intake valve 1100 and exhaust valve 1110 are formed at the top of cylinder 1040. Intake valve 1100 is driven by intake camshaft 1120. The exhaust valve 1110 is driven by the exhaust cam shaft 1130. The intake camshaft 1120 and the exhaust camshaft 1130 are connected by a chain, a gear, etc., and rotate at the same rotational speed.

The intake valve 110 is controlled in phase (opening / closing timing) by the intake VVT mechanism 2000 formed on the intake camshaft 1120. The phase (opening / closing timing) of the exhaust valve 1110 is controlled by the exhaust VVT mechanism 3000 formed on the exhaust cam shaft 1130.

In this embodiment, each phase of the intake valve 1100 and the exhaust valve 1110 is controlled by rotating the intake cam shaft 1120 and the exhaust cam shaft 1130 by the VVT mechanism. In addition, the method of controlling a phase is not limited to this.

The intake VVT mechanism 2000 is operated by the electric motor 2060 (not shown in FIG. 1). The electric motor 2060 is controlled by the ECU 4000. The current and voltage of the electric motor 2060 are detected by an ammeter (not shown) and a voltmeter (not shown) and input to the ECU 4000.

The exhaust VVT mechanism 3000 is operated by hydraulic pressure. In addition, the intake VVT mechanism 2000 may be operated by hydraulic pressure, and the exhaust VVT mechanism 3000 may be operated by an electric motor.

The ECU 4000 receives a signal indicating the rotational speed and the crank angle of the crank shaft 1090 from the crank angle sensor 5000. In addition, a signal indicating the respective phases (position of the cam shaft in the rotational direction) of the intake cam shaft 1120 and the exhaust cam shaft 1130 is input to the ECU 4000 from the cam position sensor 5010.

In addition, the ECU 4000 has a signal indicating the water temperature (temperature of the coolant) of the engine 1000 from the coolant temperature sensor 5020 and the intake air amount of the engine 1000 from the air flow meter 5030 (the amount of air taken into the engine 1000). ) Is input.

The ECU 4000 is based on signals input from these sensors and maps and programs stored in a memory (not shown), for example, such that the throttle angle, ignition timing, fuel injection timing, The fuel injection amount, the phase of the intake valve 1100, the phase of the exhaust valve 1110, and the like are controlled.

In the present embodiment, the ECU 4000 determines the phase of the intake valve 1100 based on a map using the engine rotational speed NE and the intake air amount KL as parameters, as shown in FIG. 2. A plurality of maps for determining the phase of the intake valve 1100 are stored for each cooling water temperature.

Hereinafter, the intake VVT mechanism 2000 will be further described. As shown in FIG. 3, the intake VVT mechanism 2000 includes a sprocket 2010, a cam plate 2020, a link mechanism (A) 2030, a link mechanism (B) 2130, a guide plate 2040, and a cycloid. A speed reducer 2050 and an electric motor 2060.

The sprocket 2010 is connected to the crank shaft 1090 through a chain or the like. The speed of rotation of the sprocket 2010 is one-half of the speed of rotation of the crankshaft 1090. The intake camshaft 1120 is formed to be rotatable relative to the sprocket 2010 concentrically with the axis of rotation of the sprocket 2010.

The cam plate 2020 is connected to the intake camshaft 1120 by pins 1070. The cam plate 2020 rotates together with the intake camshaft 1120 in the sprocket 2010. In addition, the cam plate 2020 and the intake camshaft 1120 can be integrally formed.

The link mechanism (A) 2030 is composed of arms (A1) 2031 (not shown in FIG. 3) and arms (A2) 2032 (not shown in FIG. 3). The link mechanism (B) 2130 is composed of an arm (Bl) 213l and an arm (B2) 2132.

As shown in FIG. 4, which is the AA cross-section of FIG. 3, the sprocket 2010 on the arms A1 2031 and B1 2131 such that the arms are point-symmetrical with respect to the axis of rotation of the intake cam shaft 1120. ) Is formed inside. Arm (203) and arm (B1) 2131 are connected to sprocket 2010 such that these arms can rock around pin (2) 2082.

As shown in FIG. 5 which is the BB cross section of FIG. 3, and as shown in FIG. 6 which shows the state which advanced the phase of the intake valve 1100 with respect to the state of FIG. 5, the arm (Al) 2031 and a cam plate are shown. 2020 is connected by an arm A2 2032. Arm B1 2131 and cam plate 2020 are connected by arms B2 2132.

Arm (A2) 2032 is supported so as to be swingable about pin (3) 2074 and against arm (Al) 2031. Similarly, arm B2 2132 is supported so as to be swingable about pin 3, 2074 and against arm B1 2131. The arms A2 2032 and B2 2132 are supported so as to be pivotable about the pins 4 and 2076 and with respect to the cam plate 2020.

The link mechanism (A) 2030 and the link mechanism (B) 2130 cause the intake cam shaft 1120 to rotate relative to the sprocket 2010, thereby changing the phase of the intake valve 1100.

In this embodiment, a pair of link mechanism (A) 2030 and link mechanism (B) 2130 are formed. At this time, even if any one of the link mechanism (A) 2030 and the link mechanism (B) 2130 is damaged or broken, it is preferable to change the phase of the intake valve 1100 by the other link mechanism. It is possible.

Returning to FIG. 3, the control pin (A) 2034 is provided in the surface by the side of the guide plate 2040 of the link mechanism (A) 2030 (arm A2 2032). Similarly, a control pin (B) 2134 is provided on the side of the guide plate 2040 side of the link mechanism (B) 2130 (arm B2) 2132.

The control pin (A) 2034 and the control pin (B) 2134 are provided concentrically with the pins 3 and 2074. The control pin (A) 2034 slides in the guide groove (A) 2041 formed in the guide plate 2040. The control pin (B) 2134 slides in the guide groove (B) 2042 formed in the guide plate 2040.

The control pin (A) 2034 and the control pin (B) 2134 slide radially in the guide grooves (A) 2041 and the guide grooves (B) 2042 of the guide plate 2040 to move radially. . The control pin (A) 2034 and control pin (B) 2134 sliding radially can cause the intake cam shaft 1120 to rotate relative to the sprocket 2010.

As shown in FIG. 7, which is the cross-sectional view of FIG. 3, the guide groove (A) 2041 and the guide groove (B) 2042 are controlled by the control pin (A) 2034 and the control by the rotation of the guide plate 2040. The fin (B) 2134 is formed to be inclined at a predetermined angle with respect to the radial direction so that the pin (B) 2134 can be moved in the radial direction. In addition, the shape of the guide groove (A) 2041 and the guide groove (B) 2042 is not limited to this.

If the control pin (A) 2034 and the control pin (B) 201 move further radially from the center of the axis of the guide plate 2040, the phase of the intake valve 1100 becomes more perceptual. That is, the amount of change in phase is determined by the link mechanism (A) 2030 and the link mechanism (B) 2130 as the positions of the control pin (A) 2034 and the control pin (B) 2134 move in the radial direction. It has a value corresponding to the working amount of.

Further, if the control pins (A) 2034 and the control pins (B) 2134 are further moved in the radial direction from the center of the axis of the guide plate 2040, the phase of the intake valve 1100 can be more advanced.

Guide groove (A) 2041 is shorter than guide groove (B) 2042. Guide grooves (A) 2041 and guide grooves (B) 2042 differ only in length. In addition, these guide grooves are formed to be point symmetrical about the axis center of the guide plate 2040.

As shown in FIG. 7, the control pins (A) 2034 and the control pins (A) in the direction in which the phases are perceived until the control pins (A) 2034 abut the ends of the guide grooves (A) 2041. When the B) 2134 is moved, the control pin (B) 2134 is separated from the end of the guide groove (B) 2042.

Move the control pin (A) 2034 and the control pin (B) 2134 in the direction in which the phase is advanced until the control pin (A) 2034 abuts against the end of the guide groove (A) 2041. In this case, the control pin (B) 2134 may be separated from the end of the guide groove (B) 2042.

When the control pin (A) 2034 abuts on the end of the guide groove (A) 2041, the operation of the link mechanism (A) 2030 is limited in the direction in which the phase is perceived. Thus, when the link mechanism (A) 2030 operates normally, the phase at which the control pin (A) 2034 abuts on the end of the guide groove (A) 2041 is the maximum perceived angle (maximum angle). do.

In addition, when the control pin (A) 2034 and the control pin (B) 2134 are moved in the direction in which the phase is to be advanced, the control pin (A) 2034 is an end of the guide groove (A) 2041. Is in phase with the control pin (B) 2134 and with the end of the guide groove (B) 2042 being the most advanced angle (the most advanced angle).

Returning to FIG. 3, the guide plate 2040 is formed with a plurality of recesses 2044 for connecting the guide plate 2040 and the cycloid reducer 2050 to each other on the surface of the cycloid reducer 2050 side.

The cycloid reducer 2050 is composed of a ring gear 2052 and a planetary gear 2054. The ring gear 2052 is fixed relative to the sprocket 2010 so that it can rotate with the sprocket 2010.

The planetary gear 2054 is formed with a plurality of convex portions 2056 accommodated in the concave portion 2044 of the guide plate 2040. The planetary gear 2054 is rotatably supported about the eccentric axis 2066 of the coupling 2062 formed eccentrically with respect to the axis center 2064 of the output shaft of the electric motor 2060.

8 is a cross-sectional view taken along the line D-D of FIG. 3. The number of teeth of the planetary gear 2054 is one less than the number of teeth of the ring gear 2052. The planetary gear 2054 is formed such that some of its teeth engage with the ring gear 2052.

By the electric motor 2060, when the coupling 2062 is rotated about the axis center 2064 and relative to the ring gear 2052, the entire planetary gear 2054 is centered on the axis center 2064. At the same time, the planetary gear 2054 rotates about the eccentric shaft 2066. By the rotational movement of the planetary gear 2054, the guide plate 2040 can rotate relative to the sprocket 2010 so that the phase of the intake valve 1100 is changed.

When the output shaft rotational speed of the electric motor 2060 is the same as the rotational speed of the sprocket 2010, the coupling 2062 and the planetary gear 2054 rotate at the same rotational speed as the ring gear 2052 (sprocket 2010). . In this case, the guide plate 2040 rotates at the same rotational speed as the sprocket 2010 so that the phase of the intake valve 1100 is maintained.

With reference to FIG. 9, the control structure of the program executed by the ECU 4000 which controls the intake VVT mechanism 2000 to determine whether the intake VVT mechanism 2000 has failed is demonstrated. The program described below is executed at a predetermined time such as when the engine 1000 is started with the ignition switch (not shown) turned on or when it is in the idling state.

In S100, the ECU 4000 controls the intake VVT mechanism 2000 such that the phase (or opening / closing timing of the valve) of the intake valve 1100 is perceived to the maximum. For example, the electric motor 2060 is operated in a direction in which the phase is to be perceived until the drive current of the electric motor 2060 increases sharply (or until a lock current is detected).

In S110, the ECU 4000 detects the phase of the intake valve 1100 (phase of the intake camshaft 1120) based on the signals transmitted from the crank angle sensor 5000 and the cam position sensor 5010.

In S120, the ECU 4000 determines whether a phase perceived more than the phase at which the control pin (A) 2034 abuts the end of the guide groove (A) 2041 is detected. If the control pin (A) 2034 detects a phase that is more perceptible than the phase abutting the end of the guide groove (A) 2041 (YES in S120), the control process shifts to S130. If not (NO in S120), the control shifts to S140.

In S130, the ECU 4000 determines that a failure has occurred in the intake VVT mechanism 2000. At this time, it is determined that the link mechanism (A) 2030 has failed. In S140, the ECU 4000 determines that the link mechanism (A) 2030 of the intake VVT mechanism 2000 operates normally.

The operation of the ECU 4000 for controlling the variable valve timing device of the present embodiment will be described based on the structure and flowchart as described above.

At a predetermined time, the intake VVT mechanism 2000 is controlled so that the phase of the intake valve 1100 is perceived to the maximum (S100) and the current phase is detected (S110).

If the link mechanism (A) 2030 of the intake VVT mechanism 2000 is intact and can be operated normally, as shown in FIG. 10, the control pin (A) 2034 is a guide groove (A) ( Abutting the end of 2041, the control pin (B) 2134 is in a state separated from the end of the guide groove (B) 2042.

In this state, the phase is no longer perceived. Therefore, the detected phase coincides with the phase where the control pin (A) 2034 abuts against the end of the guide groove (A) 2041 (NO in S120).

In this case, it can be said that the link mechanism (A) 2030 is operating normally. Therefore, it is determined that the link mechanism (A) 2030 of the intake VVT mechanism 2000 operates normally (S140).

When a failure occurs, such as when the link mechanism (A) 2030 of the intake VVT mechanism 2000 is damaged and broken, the control pin (A) 2034 is formed in the guide groove (A) 2041. Although abutting on the end, the operation of the link mechanism (A) 2030 is not limited. Therefore, the rotation of the intake cam shaft 1120 with respect to the sprocket 2010 is not limited.

In this case, as shown in FIG. 11, the link mechanism (B) 2130 operates until the control pin (B) 2134 abuts against the end of the guide groove (B) 2042, and the intake cam shaft 1120 is operated. ) Is rotated relative to the sprocket 2010.

The phase detected in this state becomes a phase perceived more than the phase where the control pin (A) 2034 abuts on the end of the guide groove (A) 2041. Thus, if a phase perceived more than the phase at which the control pin (A) 2034 abuts the end of the guide groove (A) 2041 (YES in S120), the intake VVT mechanism 2000 is connected to the link mechanism A. In step 2030, it is determined that a failure has occurred (S130). Therefore, the failure which occurred in the link mechanism (A) 2030 of the intake VVT mechanism 2000 can be detected.

Therefore, this embodiment provides the variable valve timing apparatus performed by the intake VVT mechanism, and the guide groove A in which the control pin A of the link mechanism A slides makes the direction perceiving the phase of an intake valve. WHEREIN: The control pin B of the link mechanism B is formed shorter than the guide groove B which slides. Thereby, if the link mechanism A is operating normally without suffering damage or the like, the phase can be perceived until the control pin A of the link mechanism A abuts against the end of the guide groove A. FIG. When the link mechanism A is damaged and broken, the phase can be further perceived until the control pin B of the link mechanism B abuts against the end of the guide groove B. Therefore, it is possible to determine whether or not a failure has occurred in the link mechanism A from the phase detected when the intake VVT mechanism is controlled so that the phase is perceived to the maximum. As a result, the failure which occurred in the intake VVT mechanism can be detected.

<2nd embodiment>

EMBODIMENT OF THE INVENTION Hereinafter, 2nd Embodiment of this invention is described. This embodiment differs from the first embodiment in that the link mechanism A is formed so that the strength of the link mechanism A is lower than that of the link mechanism B.

The remaining hardware structure and control structure are the same as in the above-described first embodiment. The function is also the same. Therefore, this is not described in detail again.

As shown in FIG. 12, holes 2036 are formed in the arms A2 and 2032 of the link mechanism A 2030 so as to have a lower strength than the arms B2 2 l32 of the link mechanism B 2130. It is.

In addition to or instead of the hole 2036, the notch 2038 is formed on the side surface of the arm A2 2032 of the link mechanism A 2030 to form the arm A2. The strength of 2032 may be lowered.

In addition, instead of or in addition to the arm A2 2032, the arm Al 1203 is provided with a hole or a notch, so that the strength of the arm Al 1203 is greater than that of the arm B1 2131. It may be low.

In addition, the strengths of the pins (2) 2072, the pins (3) 2074 and the pins (4) 2076 of the link mechanism (A) 2030 are determined by the pins (2) of the link mechanism (B) 2130. You may make it lower than the intensity | strength of (2072), the pin (3) 2074, and the pin (4) 2076.

This causes damage or similar failures to occur before the link mechanism (B) 2130 in the link mechanism (A) 2030 that can detect that a failure has occurred. Therefore, when the link mechanism (A) 2030 operates normally and a failure cannot be detected, the link mechanism (B) 2130 does not generate a failure.

Third Embodiment

EMBODIMENT OF THE INVENTION Hereinafter, 3rd Embodiment of this invention is described. In this embodiment, when the control pin A and the control pin B are moved in the direction in which the phase is advanced until the control pin B abuts against the end of the guide groove B, the control pin A The separation from the end of the guide groove A is different from the first embodiment described above.

Other hardware structures are the same as in the above-described first or second embodiment. Their function is the same. Therefore, detailed description thereof will not be repeated here.

As shown in FIG. 14, in the same manner as in the first embodiment described above in this embodiment, the direction in which the phase is to be perceived until the control pins (A) 2034 abuts against the ends of the guide grooves (A) 2141. When the control pin (A) 2034 and the control pin (B) 2134 are moved, the control pin (B) 2134 is separated from the end of the guide groove (B) 2142.

In the present embodiment, unlike the first embodiment described above, the guide groove (B) 2142 in which the control pins (B) 2134 of the link mechanism (B) 2130 slides changes the phase of the intake valve 1100. In the advancing direction, the control pins (A) 2034 of the link mechanism (A) 2030 are formed shorter than the guide grooves (A) 2141 that slide.

Thus, the control pins (A) 2034 and the control pins (B) 2134 in the direction in which the phase is to be advanced until the control pins (B) 2134 abut the ends of the guide grooves (B) 2142. Control pin (A) 2034 is separated from the end of the guide groove (A) 2141.

When the control pins (B) 2134 abut the ends of the guide grooves (B) 2142, the operation of the link mechanism (B) 2130 is restricted in the direction of phase advancement. Therefore, when the link mechanism (B) 2130 operates normally, the phase where the control pin (B) 2134 abuts on the end of the guide groove (B) 2142 becomes the most advanced phase.

Referring to Fig. 15, a description will be given of a control structure of a program executed by the ECU 4000 for controlling the intake VVT mechanism 2000 to determine whether a failure has occurred in the intake VVT mechanism 2000. . In addition, the program described below is executed before or after execution of the program of 1st Embodiment mentioned above.

In S200, the ECU 4000 controls the intake VVT mechanism 2000 so that the phase (opening and closing timing) of the intake valve 1100 is most advanced. For example, the electric motor 2060 is operated in a direction in which the phase will be advanced until the drive current of the electric motor 2060 suddenly increases (until the lock current is detected).

In S210, the ECU 4000 detects the phase of the intake valve 1100 (phase of the intake camshaft 1120) based on the signals transmitted from the crank angle sensor 5000 and the cam position sensor 5010.

In S220, the ECU 4000 determines whether or not an advanced phase has been detected than the phase in which the control pin (B) 2134 abuts the end of the guide groove (B) 2142. If the control pin (B) 2134 is detected with a phase more advanced than the phase abutting the end of the guide groove (B) 2142 (YES in S220), the control process shifts to S230. If not (NO in S220), the control proceeds to S240.

In S230, the ECU 4000 determines that a failure has occurred in the intake VVT mechanism 2000. At this time, it is determined that a failure has occurred in the link mechanism (B) 2130. In S240, ECU 4000 determines that link mechanism (B) 2130 of intake VVT mechanism 2000 operates normally. The operation of the ECU 4000 for controlling the variable valve timing apparatus according to the present embodiment will be described based on the above structure and flowchart.

The intake VVT mechanism 2000 is controlled so that the phase of the intake valve 1100 is fully advanced (S200) and the current phase is detected (S210).

If the link mechanism (B) 2130 of the intake VVT mechanism 2000 is able to operate normally without being damaged or the like, as shown in FIG. 16, the control pins (B) 2134 are guide grooves (B). (2142), and the control pin (A) 2034 is separated from the end of the guide groove (A) (2141).

In this state, the phase is not advanced further. Therefore, the detected phase coincides with the phase in which the control pins (B) 2134 abut the ends of the guide grooves (B) 2142 (NO in S220).

In this case, it can be said that the link mechanism (B) 2130 is operating normally. Therefore, it is determined that the link mechanism (B) 2130 of the intake VVT mechanism 2000 is normal (S240).

When a failure occurs, such as when the link mechanism (B) 2130 of the intake VVT mechanism 2000 is damaged and broken, the control pin (B) 2134 ends at the end of the guide groove (B) 2142. Even if it is in contact with, the operation of the link mechanism (B) 230 is not limited. Therefore, the relative rotation of the intake cam shaft 1120 with respect to the sprocket 2010 is not limited.

In this case, as shown in FIG. 17, the link mechanism (A) 2030 is operated until the control pin (A) 2034 abuts against the end of the guide groove (A) 2141, and the intake cam shaft 1120 is operated. It is rotated relative to this sprocket 2010.

The phase detected in the above state becomes a phase more advanced than the phase in which the control pins (B) 2134 abut the ends of the guide grooves (B) 2142. Thus, if a phase more advanced than the phase in which the control pin (B) 2134 abuts the end of the guide groove (B) 2142 is detected (YES in S220), the link mechanism B of the intake VVT mechanism 2000 is detected. In operation 2130, it is determined that a failure has occurred (S230).

Thereby, the failure which occurred in the link mechanism (A) 2030 of the intake VVT mechanism 2000 can be detected similarly to 1st Embodiment mentioned above, and thereby, the failure which occurred in the link mechanism (B) 2130 is detected. can do.

Therefore, this embodiment provides the variable valve timing apparatus implemented by the intake VVT mechanism, and the guide groove A in which the control pin A of the link mechanism A slides is in the direction which perceives the phase of the intake valve. Therefore, the control pin B of the link mechanism B is formed shorter than the guide groove B that slides, and the guide groove B in which the control pin B of the link mechanism B slides is in phase with the intake valve. In the direction of advancing, the control pin A of the link mechanism A is formed shorter than the guide groove A that slides. Thereby, the link mechanism A operates normally without suffering damage or the like, and the phase can be perceived until the control pin A of the link mechanism A abuts against the end of the guide groove A. FIG. When the link mechanism A is damaged and broken, the phase can be further perceived until the control pin B of the link mechanism B abuts against the end of the guide groove B. Similarly, if the link mechanism B is operating normally without suffering damage or the like, the phase can be advanced until the control pin B of the link mechanism B abuts against the end of the guide groove B. FIG. If the link mechanism B is damaged and broken, the phase can be further advanced until the control pin A of the link mechanism A abuts against the end of the guide groove A. FIG. Therefore, from the phase detected when the intake VVT mechanism is controlled so that the phase becomes the most angle or the most advanced angle, it is possible to determine whether the link mechanism A or the link mechanism B has failed. As a result, the failure which occurred in the intake VVT mechanism can be detected.

In the first to third embodiments, although two link mechanisms are formed in the intake VVT mechanism 2000, three or more link mechanisms may be formed.

In addition, two or more link mechanisms may be used in the exhaust VVT mechanism 3000 to change the phase of the exhaust valve 1110 and the failure of the link mechanism may be detected in the exhaust VVT mechanism 3000.

In addition, a mechanism other than or in addition to the link mechanism may be used to change the phase of the intake valve 1100 or the exhaust valve 1110, and failures occurring in the mechanism can be detected.

<Other embodiment>

In addition to the guide grooves (A) 2041 and 2141 and the guide grooves (B) 2042 and 2142 formed in the guide plate 2040, as shown in FIG. 18, the limit pin (1) 2200 or the limit pin (2). ) 2202 can be used to limit the operable range of link mechanism (A) 2030 or link mechanism (B) 2130.

In Fig. 18, the limiting pin (1) 2200 has a link mechanism (A) such that the operable range of the link mechanism (A) 2030 is smaller than the operable range of the link mechanism (B) 2130 in the perceptual direction. Limit the operation of 2030).

The limiting pins (2) 2202 are formed of the link mechanism (B) 2130 such that the operable range of the link mechanism (B) 2130 in the advancing direction is smaller than the operable range of the link mechanism (A) 2030. Restrict operation.

The disclosed embodiments are to be considered in all respects only as illustrative and not restrictive. It is intended that the scope of the invention only be limited by the appended claims.

Claims (5)

A variable valve timing device for changing the opening and closing timing of at least one of the intake valve and the exhaust valve, A first operating portion configured to change the opening and closing timing of at least one of the intake valve and the exhaust valve by an amount of change in accordance with an operation amount; A second operating portion configured to change the opening and closing timing of the same valve as at least one of the intake valve and the exhaust valve controlled by the first mechanism to an amount of change in accordance with an operation amount; And a restricting portion for limiting the operation of the first operating portion such that the operable range of the first operating portion is smaller than the operable range of the second operating portion. 2. The variable valve timing device of claim 1 wherein the strength of the first actuating portion is lower than the strength of the second actuating portion. The valve of claim 1, wherein the valve is driven by a camshaft, The actuating part is a link mechanism connected to the cam shaft to rotate the cam shaft and operated by an actuator, And the open / close timing of at least one of the intake valve and the exhaust valve is changed when the cam shaft is rotated by the actuator through the link mechanism. A variable valve timing device for changing the opening and closing timing of at least one of the intake valve and the exhaust valve, A first operating portion configured to change the opening and closing timing of at least one of the intake valve and the exhaust valve by an amount of change in accordance with an operation amount; A second operating portion configured to change the opening and closing timing of the same valve as at least one of the intake valve and the exhaust valve controlled by the first mechanism to an amount of change in accordance with an operation amount; A first limiting operation of the first operating portion such that an operable range of the first operating portion is smaller than an operable range of the second operating portion in a direction in which opening and closing timing of at least one of the intake valve and the exhaust valve is perceived; With 1 limit, A second limiting operation of the second operating portion such that an operable range of the second operating portion is smaller than an operable range of the first operating portion in a direction in which opening and closing timing of at least one of the intake valve and the exhaust valve is advanced; A variable valve timing device comprising two restriction portions. The valve of claim 4, wherein the valve is driven by a camshaft, The actuating portion is a link mechanism connected to the cam shaft so as to rotate the cam shaft and operated by an actuator, The opening and closing timing of at least one of the intake valve and the exhaust valve is changed when the cam shaft is rotated by the actuator through the link mechanism.

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