VALVE OPENING/CLOSING TIMING CONTROL APPARATUS

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 U.S.C. §119 to Japanese Patent Application 2016-083684 and Japanese Patent Application 2017-015688, filed on Apr. 19, 2016 and Jan. 31, 2017, respectively, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

This disclosure relates to a valve opening/closing timing control apparatus that includes a driving side rotating body that rotates synchronously with a crankshaft of an internal combustion engine, a driven side rotating body that rotates integrally with a camshaft for the opening or closing of a valve of the internal combustion engine, and a lock mechanism that restrains the rotating bodies in a predetermined relative rotation phase.

BACKGROUND DISCUSSION

As a valve opening/closing timing control apparatus including a lock mechanism as described above, JP 2013-160095A (Reference 1) discloses a technology that includes a driving side rotating body (outer rotor) and a driven side rotating body (inner rotor), and also includes a lock mechanism (an advance/retardation mechanism) having a lock pin and a fitting recess so as to regulate such relative rotation phase.

In this reference 1, a lock spring is provided to apply pressure to the lock pin in a protruding direction. The lock pin includes a first pressure receiving surface that is formed on an end of the lock pin to cause hydraulic pressure to act on the lock pin in a retracting direction, a second pressure receiving surface that is formed in an annular shape on an intermediate portion of the lock pin to cause hydraulic pressure to act on the lock pin in the retracting direction, and a biasing pressure receiving surface that causes hydraulic pressure to act on the lock pin in the protruding direction.

In this configuration, at the time of unlocking, the lock pin is extracted from the fitting recess by causing the hydraulic pressure of hydraulic oil in an independent unlocking flow path, which is branched from an advance angle flow path, to act on the first pressure receiving surface and the second pressure receiving surface. On the contrary, when switching the lock pin to a locked state, the lock pin is fitted into the fitting recess by causing the hydraulic pressure of the hydraulic oil in a locking flow path, which is branched from a retardation angle flow path, to independently act on the biasing pressure receiving surfaces.

In addition, JP 2013-019278A (Reference 2) discloses a technology that includes a driving side rotating body (outer rotor), a driven side rotating body (inner rotor), and a lock mechanism having a lock member and a lock recess to maintain these rotating bodies in a locking phase, and also includes a regulation mechanism having a regulation member and a regulation recess so as to determine the range of displacement of the relative rotation phase between the driving side rotating body and the driven side rotating body.

In this reference 2, the lock member includes a first end configured to be fitted into the lock recess by the biasing force of a spring and a second end having a larger diameter than that of the first end, and a first pressure receiving surface is formed at the boundary position of the first and second ends. From this configuration, when unlocking the lock member, a hydraulic fluid is supplied to the first pressure receiving surface. In addition, the regulation member includes a first end configured to be fitted into the regulation recess by the biasing force of a spring and a fourth end having a larger diameter than that of the first end, and a first pressure receiving surface is formed at the position that is successive to the fourth end. When releasing the regulation from this configuration, the hydraulic fluid is supplied to the first pressure receiving surface.

As described in Reference 1 or Reference 2, a configuration, which includes a fitting end configured to be fitted into a lock recess (the fitting recess in Reference 1), and a pressure receiving surface having a larger diameter than that of the fitting end such that unlocking is performed by supplying the hydraulic oil to the pressure receiving surface is employed. In the case of shifting to a locked state, the pressure of hydraulic fluid acting on the pressure receiving surface is released so that the shifting to the locked state is implemented by the biasing force of a spring.

Specifically, the pressure in a flow path, which communicates with the pressure receiving surface, is reduced to a drain pressure by operating a control valve. However, for example, considering the configuration of Reference 1, even when the pressure in flow paths, which respectively communicate with the first pressure receiving surface and the second pressure receiving surface, is reduced, it is considered that time is required until the pressure in the flow path communicating with the second pressure receiving surface (the independent unlocking flow path in Reference 1) is reduced, and slight time retardation is caused until the lock member starts to operate. In addition, even when the lock member starts to operate, it is considered that, since the hydraulic fluid is discharged from the flow path communicating with the second pressure receiving surface, the operating speed of the lock member is reduced from the pressure acting upon discharge.

These problems are caused by the flow path resistance in the flow path communicating with the second pressure receiving surface, and there is room for improvement in consideration of rapid shifting to the locked state.

Thus, a need exists for a valve opening/closing timing control apparatus which is not susceptible to the drawback mentioned above.

SUMMARY

A feature of an aspect of this disclosure resides in that a valve opening/closing timing control apparatus includes: a driving side rotating body configured to rotate synchronously with a crankshaft of an internal combustion engine; a driven side rotating body included in the driving side rotating body and configured to rotate integrally with a camshaft for opening or closing of a valve of the internal combustion engine on a same axis as a rotation axis of the driving side rotating body; a hydraulic fluid control mechanism configured to displace a relative rotation phase between the driving side rotating body and the driven side rotating body by supplying a hydraulic fluid to one of an advance angle chamber and a retardation angle chamber, which are defined between the driving side rotating body and the driven side rotating body; and a lock mechanism including a lock member slidably inserted into a guide hole formed in one of the driving side rotating body and the driven side rotating body, a biasing member configured to bias the lock member in a direction where an engaging portion on one end side of the lock member protrudes, and a lock recess formed in a remaining one of the driving side rotating body and the driven side rotating body so as to allow the engaging portion to be fitted thereinto. The lock member includes the engaging portion, a main body portion having a larger diameter than that of the engaging portion, and a first pressure receiving surface formed in an annular shape on an end surface of the main body portion at an intermediate position between the engaging portion and the main body portion. The valve opening/closing timing control apparatus further includes: a first unlocking flow path configured to communicate with the first pressure receiving surface when the engaging portion is moved from a locking position where the engaging portion is fitted into the lock recess to a position at which the engaging portion is farther spaced apart from the lock recess than at a locking boundary position where the engaging portion is separated from the lock recess; and a second unlocking flow path configured to communicate with the first pressure receiving surface when the engaging portion is at an unlocking position at which the engaging portion is farther spaced apart from the lock recess than at the locking boundary position, and to be in non-communication state with the first pressure receiving surface as a flow path is closed by the main body portion when the engaging portion is at the locking boundary position.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and additional features and characteristics of this disclosure will become more apparent from the following detailed description considered with the reference to the accompanying drawings, wherein:

FIG. 1 is a cross-sectional view of a valve opening/closing timing control apparatus;

FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1;

FIG. 3 is a block circuit diagram of a control system;

FIG. 4 is an operational image diagram of a main lock mechanism;

FIG. 5 is an operational image diagram of a lock unit in a predetermined phase;

FIG. 6 is an operational image diagram of the lock unit, which is displaced from the predetermined phase in a retardation angle direction;

FIG. 7 is an operational image diagram of the lock unit, which is further displaced from the predetermined phase in the retardation angle direction;

FIG. 8 is an operational image diagram of the lock unit, which reaches a first stop phase;

FIG. 9 is an operational image diagram of the lock unit, which is displaced from the first stop phase in an advance angle direction;

FIG. 10 is an operational image diagram of the lock unit, which reaches a second stop phase;

FIG. 11 is an operational image diagram of the lock unit, which reaches an intermediate locking phase;

FIG. 12 is a timing chart illustrating a phase displacement in a lock shifting control;

FIG. 13 is a flowchart of a lock shifting control;

FIG. 14 is a flowchart of a retry control routine;

FIG. 15 is an Image diagram of a main lock mechanism, which is in the second stop phase;

FIG. 16 is a chart illustrating variation in the area of a flow path, such as, for example, a drain flow path or a communication portion;

FIG. 17 is an image diagram of the main lock mechanism, which is in a first comparative phase Qf;

FIG. 18 is an image diagram of the main lock mechanism, which is in a second comparative phase Qn;

FIG. 19 is a flowchart of a lock shifting control according to an additional embodiment (a);

FIG. 20 is a timing chart illustrating a phase displacement according to the additional embodiment (a);

FIG. 21 is an image diagram of the main lock mechanism, which is in the intermediate locking phase, according to an additional embodiment (b);

FIG. 22 is a timing chart illustrating a phase displacement according to the additional embodiment (b); and

FIG. 23 is a flowchart of a lock shifting control according to the additional embodiment (b).

DETAILED DESCRIPTION

Hereinafter, the embodiment of the present invention will be described with reference to the drawings.

[Basic Configuration]

As illustrated in FIGS. 1 and 2, a valve opening/closing timing control apparatus A includes an outer rotor 20 as a driving side rotating body, an inner rotor 30 as a driven side rotating body, and an electromagnetic control valve 40 as a hydraulic fluid control mechanism that controls hydraulic oil as a hydraulic fluid.

The valve opening/closing timing control apparatus A is disposed coaxially with the rotation axis X of an intake camshaft 5 of an engine E as an internal combustion engine, and is provided with an advance angle chamber Ca and a retardation angle chamber Cb between the outer rotor 20 (driving side rotating body) and the inner rotor 30 (driven side rotating body). By supplying the hydraulic oil (hydraulic fluid) to one of the advance angle chamber Ca and the retardation angle chamber Cb under the control of the electromagnetic control valve 40, the relative rotation phase between the outer rotor 20 and the inner rotor 30 about the rotation axis X (hereinafter, referred to as a “relative rotation phase”) is displaced, so that a change in the opening/closing timing of an intake valve 5V is implemented.

The valve opening/closing timing control apparatus A includes a lock unit LU that maintains the relative rotation phase in an intermediate locking phase M illustrated in FIG. 2. The lock unit LU includes a main lock mechanism Lm and an auxiliary lock mechanism Ls. When these mechanisms simultaneously reach a locked state, the relative rotation phase is maintained in the intermediate locking phase M.

In particular, the intermediate locking phase M is to set the intake valve 5V to the opening/closing timing that is suitable for starting the engine E. Therefore, when an artificial operation is performed to stop the engine E, prior to stopping the engine E, a control unit 90 illustrated in FIG. 3 performs a control to displace the relative rotation phase to the intermediate locking phase M and to set the lock unit LU to the locked state.

[Engine]

The engine E (an example of an internal combustion engine) of FIG. 1 is illustrated as being provided in a vehicle such as a passenger car, and includes a crankshaft 1 in the lower portion of the engine E. In addition, pistons 3 are accommodated inside cylinder bores of a cylinder block 2, which is provided at the upper position of the engine E, and the pistons 3 are connected to the crankshaft 1 by connecting rods 4, respectively. In the upper portion of the engine E, the intake camshaft 5 configured to open or close the intake valves 5V and an exhaust camshaft (not illustrated) are provided.

In an engine constituent member 10 that rotatably supports the intake camshaft 5, a supply flow path 8 is formed to be supplied with the hydraulic oil from a hydraulic pump P driven by the engine E. The hydraulic pump P supplies lubricating oil as the hydraulic oil, which is stored in an oil pan of the engine E, to the electromagnetic control valve 40 via the supply flow path 8.

A timing chain 7 is wound around an output sprocket 6, which is formed on the crankshaft 1 of the engine E, and a timing sprocket 22S of the outer rotor 20. In addition, a sprocket is provided on the front end of an exhaust camshaft on the exhaust side, and the timing chain 7 is also wound around the sprocket.

[Valve Opening/Closing Timing Control Apparatus]

As illustrated in FIGS. 1 and 2, the valve opening/closing timing control apparatus A rotates synchronously with the crankshaft 1 because the timing chain 7 is wound around the timing sprocket 22S of the outer rotor 20. In addition, the inner rotor 30 rotates integrally with the intake camshaft 5 because the inner rotor 30 is connected to the intake camshaft 5 by a connecting bolt 50.

In the valve opening/closing timing control apparatus A, as illustrated in FIG. 2, the entire apparatus rotates in a driving rotation direction S. The direction in which the inner rotor 30 rotates relative to the outer rotor 20 in the same direction as the driving rotation direction S is referred to as an advance angle direction Sa, and the opposite direction is referred to as a retardation angle direction Sb. In addition, the opening/closing timing of the intake valve 5V becomes faster by displacement in the advance angle direction Sa, and the opening/closing timing of the intake valve 5V becomes slower by displacement in the retardation angle direction Sb.

In addition, although this embodiment illustrates the valve opening/closing timing control apparatus A provided on the intake camshaft 5, the valve opening/closing timing control apparatus A may be provided on the exhaust camshaft, or may be provided on both the intake camshaft 5 and the exhaust camshaft.

The outer rotor 20 includes an outer rotor main body 21, a front plate 22, and a rear plate 23, which are fastened to each other by plural fastening bolts 24. The above-described timing sprocket 22S is formed on the outer circumference of the front plate 22. Plurality of (three) protrusions 21T are integrally formed on the inner circumference of the outer rotor main body 21 to protrude inward in a diametric direction.

The inner rotor 30 includes an inner rotor main body 31, which has a cylindrical shape and is in close contact with the protrusions 21T of the outer rotor main body 21, and plural (three) vane portions 32, which protrudes outward in the diametric direction from the outer circumference of the inner rotor main body 31 to come into contact with the inner circumferential surface of the outer rotor main body 21.

An intermediate member 9 is disposed on the inner circumference of the front plate 22. When a bolt head portion 52 of the connecting bolt 50 is pressed against the intermediate member 9, the intermediate member 9, the inner rotor main body 31, and the intake camshaft 5 are integrated to each other.

In this way, because the inner rotor 30 is included in the outer rotor 20, plural (three) fluid pressure chambers C are formed on the outer circumferential side of the inner rotor main body 31 at the intermediate positions between the adjacent protrusions 21T in a rotational direction. Each of the fluid pressure chambers C is divided into an advance angle chamber Ca and a retardation angle chamber Cb by a vane portion 32. The inner rotor 30 is provided with plural (three) advance angle flow paths 33, each of which communicates with an advance angle chamber Ca, and plural (three) retardation angle flow paths 34, each of which communicates with a retardation angle chamber Cb.

As illustrated in FIG. 1, a torsion spring 28 is provided over the outer rotor 20 and the intermediate member 9 so as to assist the displacement of the relative rotation phase in the advance angle direction Sa by applying a biasing force in the advance angle direction Sa from the maximum retardation angle phase.

[Valve Opening/Closing Timing Control Apparatus: Connecting Bolt]

As illustrated in FIG. 1, the connecting bolt 50 includes a bolt main body 51, a portion of which has a cylindrical shape, a bolt head portion 52 on the outer end thereof, and a male screw portion 53 on the inner end thereof.

Inside the intake camshaft 5, a shaft inner space 5T in which a portion of the connecting bolt 50 is closely fitted is formed, and a female screw portion to which the male screw portion 53 of the connecting bolt 50 is screwed is formed. The shaft inner space 5T communicates with the above-described supply flow path 8, and the hydraulic oil from the hydraulic pump P is supplied into the shaft inner space 5T.

Inside the bolt main body 51, a spool chamber having a cylinder inner surface shape is coaxially formed with the rotation axis X from the bolt head portion 52 toward the male screw portion 53, and a spool 41 is accommodated in the spool chamber to be movable in the direction along the rotation axis X. The outer end side (in the direction of the bolt head portion 52) of the spool 41 is configured to protrude outward by the biasing force of a spool spring. In addition, a land portion is formed on the outer circumference of the spool 41 to control the flow of the hydraulic oil, and a drain hole 41 D is formed in the protruding side end to discharge the hydraulic oil.

The bolt main body 51 is provided with a flow path, through which the hydraulic oil is supplied from the shaft inner space 5T to the spool 41, and a flow path, through which the hydraulic oil is supplied to or discharged from the advance angle flow path 33 and the retardation angle flow path 34 according to the operation of the spool 41.

[Electromagnetic Control Valve]

As described above, the electromagnetic control valve 40 includes a spool 41 and an electromagnetic solenoid 44. The electromagnetic solenoid 44 includes a plunger 44a, the protruding amount of which is controlled by electric power supplied thereto.

The spool 41 is provided, on the outer end side, with an abutment surface, on which the plunger 44a is abutted. By controlling the protruding amount of the plunger 44a, the spool 41 is set to an advance angle position illustrated in FIG. 1, a neutral position at which the spool 41 is more press-fitted by a predetermined amount than at the advance angle position, and a retardation angle position at which the spool 41 is more press-fitted than at the neutral position.

In addition, when the spool 41 is set to the neutral position, the advance angle flow path 33 and the retardation angle flow path 34 are closed. As a result, no hydraulic fluid is supplied to or discharged from the advance angle chamber Ca and the retardation angle chamber Cb, and the relative rotation phase is maintained.

In addition, when the spool 41 is set to the advance angle position, the hydraulic oil is supplied to the advance angle flow path 33, and at the same time, the hydraulic oil is discharged from the retardation angle flow path 34 through the drain hole 41D in the spool 41. Thereby, the relative rotation phase is displaced in the advance angle direction Sa.

In addition, when the spool 41 is set to the retardation angle position, the hydraulic oil is supplied to the retardation angle flow path 34, and at the same time, the hydraulic oil is discharged from the advance angle flow path 33 through the drain hole 41D in the spool 41. Thereby, the relative rotation phase is displaced in the retardation angle direction Sb.

[Valve Opening/Closing Timing Control Apparatus: Main Lock Mechanism]

As illustrated in FIGS. 1, 2, and 4 to 11, the main lock mechanism Lm includes a lock member 71 slidably inserted into a guide hole 70, which is formed in one of the vane portions 32 in the attitude parallel with the rotation axis X, a main lock recess 72 formed in the rear plate 23 so as to allow an engaging portion 71b of the lock member 71 to be engaged therein, and a main lock spring 73 as a biasing member that obtains the biasing force required to cause the engaging portion 71b to be engaged in the main lock recess 72. The guide hole 70 includes a large-diameter guide hole portion 70a and a small-diameter guide hole portion 70b having a smaller diameter than that of the large-diameter guide hole portion 70a.

Although the entire lock member 71 has a cylindrical shape, the lock member 71 includes a main body portion 71a that is slidably accommodated in the large-diameter guide hole portion 70a of the guide hole 70, the engaging portion 71b that has a smaller diameter than that of the main body portion 71a and is slidably accommodated in the small-diameter guide hole portion 70b, and a shaft-shaped portion 71c that is provided at the intermediate position therebetween and has a smaller diameter than that of the engaging portion 71b.

The lock member 71 includes a first pressure receiving surface U1 formed on the end surface of the main body portion 71a at the intermediate position between the main body portion 71a and the engaging portion 71b, and a second pressure receiving surface U2 formed on the protruding side end of the engaging portion 71b.

The main lock recess 72 is formed in a groove shape to extend along the displacement direction of the relative rotation phase. Specifically, the main lock recess 72 is formed in an arc-shaped region about the rotation axis X and has a slightly greater width than the diameter of the engaging portion 71b. Thereby, the engaging portion 71b enables the displacement of the relative rotation phase within the range of a fittable region along the direction in which the main lock recess 72 is formed, in a state of being fitted into the main lock recess 72.

The main lock spring 73 is configured in the form of a compression coil spring, which is disposed between the end surface of the main body portion 71a on the opposite side of the engaging portion 71b and the front plate 22.

The vane portion 32 having the guide hole 70 formed therein is provided with a first unlocking flow path 75 that communicates with the small-diameter guide hole portion 70b and a second unlocking flow path 76 that communicates with the large-diameter guide hole portion 70a.

The first unlocking flow path 75 communicates with the first pressure receiving surface U1 when the engaging portion 71b is moved from a locking position J1 at which the engaging portion 71b is completely fitted into the main lock recess 72 as illustrated in FIGS. 5, 10, and 11 to the position at which the engaging portion 71b is farther spaced apart from the main lock recess 72 than at a locking boundary position J2, which corresponds to the position immediately after the engaging portion 71b is extracted from the main lock recess 72 as illustrated in FIG. 9.

In particular, when the engaging portion 71b is in a region extending from the locking position J1 to the locking boundary position J2, the second unlocking flow path 76 is closed by the main body portion 71a and is in non-communication with the first pressure receiving surface U1.

In addition, when the engaging portion 71b is farther spaced apart from the main lock recess 72 than at the locking boundary position J2 to thereby be at an unlocking position J3 illustrated in FIGS. 7 and 8, the first unlocking flow path 75 communicates with the second pressure receiving surface U2.

In addition, when the engaging portion 71b is farther spaced apart from the main lock recess 72 than at the locking boundary position J2 to thereby be at the unlocking position J3 illustrated in FIGS. 7 and 8, the second unlocking flow path 76 communicates with the first pressure receiving surface U1.

The first unlocking flow path 75 communicates with a first control port 75a, which is open toward the inner surface of the rear plate 23, and also communicates with a first retardation angle port 75b at the position spaced apart from the guide hole 70. In addition, when the relative rotation phase is displaced from the intermediate locking phase M illustrated in FIGS. 2 and 11 to the region that is included in a sequence region G (see FIG. 12) illustrated in FIGS. 9 and 10, the first control port 75a communicates with a drain flow path 23D, which is drilled in the rear plate 23. Although the first control port 75a and the first retardation angle port 75b are formed in the positional relationship illustrated in FIG. 2, for easy understanding, a detailed configuration is not illustrated in FIGS. 4 to 11.

In addition, as illustrated in FIGS. 5 and 6, when the relative rotation phase is in an unlocking phase in which the relative rotation phase is farther displaced than the sequence region G (see FIG. 12) in the advance angle direction Sa, the first retardation angle port 75b communicates with a first retardation angle side groove 23R, which is formed in the rear plate 23.

The drain flow path 23D communicates with an external space of the rear plate 23 and the first unlocking flow path 75 so that the hydraulic oil is discharged, which greatly reduces the pressure acting on the first pressure receiving surface U1. In addition, the first retardation angle side groove 23R communicates with the retardation angle chamber Cb and the first retardation angle port 75b so that the hydraulic oil is supplied from the retardation angle chamber Cb to the first pressure receiving surface U1.

The second unlocking flow path 76 is configured such that, when the hydraulic oil is supplied to the retardation angle flow path 34, the hydraulic oil having the same pressure as in the retardation angle flow path 34 is supplied to the second unlocking flow path 76. From this configuration, only when the lock member 71 is at the unlocking position J3 illustrated in FIG. 7, the hydraulic oil is supplied from the second unlocking flow path 76 to the first pressure receiving surface U1.

In addition, as a configuration that supplies the hydraulic oil to the second unlocking flow path 76, a flow path configuration that makes the second unlocking flow path 76 communicate with the retardation angle flow path 34 or makes the second unlocking flow path 76 communicate with the retardation angle chamber Cb may be adopted.

As illustrated in FIG. 8, a locking assist flow path 22A is formed in a groove shape in the inner surface of the front plate 22 so as to communicate with an opening portion of the large-diameter guide hole portion 70a when the relative rotation phase is displaced closer to the retardation angle side than the intermediate locking phase M. Although the locking assist flow path 22A, as illustrated in FIG. 2, communicates with an assist groove 32a formed in the vane portion 32 so that some of the hydraulic oil is supplied to the large-diameter guide hole portion 70a, for easy understanding, for example, FIGS. 4 to 11 illustrate the locking assist flow path 22A as directly communicating with the large-diameter guide hole portion 70a, and do not illustrate the assist groove 32a.

Through the formation of the locking assist flow path 22A, when the relative rotation phase is displaced from the phase illustrated in FIG. 8 in the advance angle direction Sa, some of the hydraulic oil supplied to the advance angle chamber Ca is supplied to the large-diameter guide hole portion 70a to assist the operation of the lock member 71 into the main lock recess 72.

In addition, as illustrated in FIGS. 4 to 7, a communication portion 25 is formed in the front plate 22 to make the opening portion of the large-diameter guide hole portion 70a communicate with the external space when the relative rotation phase is displaced in the advance angle direction from the intermediate locking phase M. Although the communication portion 25, as illustrated in FIG. 2, is configured as an opening that penetrates the front plate 22 and communicates with the large-diameter guide hole portion 70a through a communication groove 32b formed in the vane portion 32, for example, FIGS. 4 to 11 illustrate the communication portion 25 as having a groove shape, and do not illustrate the communication groove 32b for easy understanding.

Through the formation of the communication portion 25, outside air is suctioned into the large-diameter guide hole portion 70a when the engaging portion 71b of the lock member 71 is engaged with the main lock recess 72, which reduces the influence of a negative pressure, thereby allowing the operation of the lock member 71 to be easily performed.

[Valve Opening/Closing Timing Control Apparatus: Auxiliary Lock Mechanism]

As illustrated in FIG. 2, the auxiliary lock mechanism Ls includes a lock body 81 slidably inserted into a support hole 80, which is formed in one of the protrusions 21T of the outer rotor main body 21 in the attitude along the radial direction about the rotation axis X, an auxiliary lock recess 82 formed in the outer circumference of the inner rotor main body 31 so as to allow a regulation end 81a of the lock body 81 to be fitted thereinto, and an auxiliary lock spring 83 as a biasing body that obtains the biasing force required to cause the lock body 81 to be engaged with the auxiliary lock recess 82. An auxiliary unlocking flow path 35 communicates with the auxiliary lock recess 82, and is supplied with the hydraulic oil from the advance angle flow path 33.

The lock body 81 has a plate shape, and the protruding side thereof is referred to as a regulation end 81a. In addition, the lock body 81 may be configured to have a rod shape. The auxiliary lock spring 83 is configured as a compression coil spring, which is disposed between the end surface of the lock body 81 on the opposite side of the regulation end 81a and the rear plate 23 to exert the biasing force required to cause the regulation end 81a to be engaged with the auxiliary lock recess 82.

The auxiliary lock recess 82 is formed in a concave shape to extend along the displacement direction of the relative rotation phase. Thereby, in a state where the regulation end 81a is fitted into the auxiliary lock recess 82, the relative rotation phase may be displaced in a predetermined region along the direction in which the auxiliary lock recess 82 is formed.

As illustrated in FIG. 2, when the relative rotation phase is in the intermediate locking phase M, the lock body 81 of the auxiliary lock mechanism Ls is abutted on the end of the auxiliary lock recess 82 in the retardation angle direction Sb, and the lock member 71 of the main lock mechanism Lm is abutted on the end of the main lock recess 72 in the advance angle direction Sa. Thereby, the relative rotation phase is maintained in the intermediate locking phase M.

In the valve opening/closing timing control apparatus A, as described above, the displacement of the relative rotation phase is implemented by the control of the hydraulic oil by the electromagnetic control valve 40, and the shifting of the main lock mechanism Lm and the auxiliary lock mechanism Ls to the locked state is implemented by the control of the hydraulic oil by the electromagnetic control valve 40.

[Control Configuration]

As illustrated in FIG. 3, the valve opening/closing timing control apparatus A includes a control unit 90 that outputs a control signal to the electromagnetic solenoid 44 of the electromagnetic control valve 40. Detected signals from a phase sensor N, which detects the relative rotation phase, and a temperature sensor T, which detects the temperature of the engine E (basically, the temperature of cooling water), are input to the control unit 90.

In addition, although it is assumed that the phase sensor N acquires the rotation angle of the crankshaft 1 and the rotation angle of the inner rotor 30 at short intervals and detects the relative rotation phase by calculation, the relative rotation phase may be detected from the phase difference between the outer rotor 20 and the inner rotor 30.

The control unit 90 functions as an ECU that controls the engine E. For example, at the time of performing a control to stop the engine, the control unit 90 performs a control to shift the relative rotation phase to the intermediate locking phase M, and performs a control to stop the engine E after the lock unit LU reaches the locked state. In particular, the control unit 90 includes a lock shifting controller 91 that implements the shifting of the lock unit LU to the locked state, an unlocking controller 92 that implements the unlocking of the lock unit LU, and a phase controller 93 that implements the displacement of the relative rotation phase.

In addition, although the lock shifting controller 91, the unlocking controller 92, and the phase controller 93 are configured by software, but may be configured by hardware such as, for example, logic, or may be partially configured by hardware.

In addition, in the following description, a control to supply the hydraulic oil in a flow path system that displaces the relative rotation phase in the advance angle direction Sa (e.g., the advance angle flow path 33 or the advance angle chamber Ca) is referred to as an “advance angle operation.” On the contrary, a control to supply the hydraulic oil to a flow path system that displaces the relative rotation phase in the retardation angle direction Sb (e.g., the retardation angle flow path 34 or the retardation angle chamber Cb) is referred to as a “retardation angle operation.”

[Shifting of Main Lock Mechanism to Locked State]

A lock shifting control will be described in which the lock shifting controller 91 shifts the relative rotation phase to the intermediate locking phase M, starting from a state where the relative rotation phase is in a predetermined phase K (see FIGS. 5 and 12) in which the relative rotation phase is displaced from the fittable region in the advance angle direction Sa.

As illustrated in the timing chart of FIG. 12 and the flowchart of FIG. 13, in the lock shifting control, a first phase control is started to displace the relative rotation phase toward the intermediate locking phase M by the retardation angle operation. By this first phase control, the displacement is stopped at the time when the phase sensor N detects that the relative rotation phase exceeds the intermediate locking phase M from the predetermined phase K illustrated in FIG. 5 and reaches a first stop phase Q1 (steps #101 to #103). In addition, the specific example of the first phase control includes steps #101 to #103.

Since the hydraulic oil is supplied to the retardation angle flow path 34 when the retardation angle operation is started in a state where the relative rotation phase is in the predetermined phase K (the timing V in FIG. 12), the lock member 71 reaches the unlocking position J3 as illustrated in FIG. 7 after the lock member 71 starts to operate in an unlocking direction as illustrated in FIG. 6 by the pressure of the hydraulic oil acting on the first pressure receiving surface U1 from the first unlocking flow path 75.

When the relative rotation phase is displaced as illustrated in FIGS. 5 to 7, the sequential timings vary in the order of V, VI, and VII in FIG. 12. In addition, in a situation where the relative rotation phase varies as described above, the lock body 81 is in an unlocked state. Then, when the lock member 71 reaches the unlocking position J3, since the second unlocking flow path 76 communicates with the first pressure receiving surface U1, the first unlocking flow path 75 communicates with the second pressure receiving surface U2, and the pressure of the hydraulic oil acts thereon, the lock member 71 is maintained at the unlocking position J3.

By continuing the retardation angle operation, the relative rotation phase reaches the first stop phase Q1 illustrated in FIG. 8 in a state where the lock member 71 is maintained at the unlocking position J3 (the timing VIII in FIG. 12). The lock body 81 is fitted into the auxiliary lock recess 82 when the relative rotation phase reaches the first stop phase Q1.

When the relative rotation phase, which is closer to the retardation angle side than the first stop phase Q1 and the intermediate locking phase M, passes the intermediate locking phase M in the course of reaching the first stop phase Q1, the first control port 75a communicates with the drain flow path 23D. However, since the lock member 71 is maintained at the unlocking position J3 by the pressure of the hydraulic oil from the second unlocking flow path 76, the engaging portion 71b of the lock member 71 is not fitted into the main lock recess 72.

Thereafter, a second phase control is started to displace the relative rotation phase in the direction opposite to the first phase control by the advance angle operation. Since, in the first stop phase Q1, the locking assist flow path 22A communicates with the opening portion of the large-diameter guide hole portion 70a as illustrated in FIG. 8, the operation of the lock member 71 to the main lock recess 72 is assisted by the pressure of the hydraulic oil along with the displacement of the relative rotation phase in the advance angle direction Sa.

After the relative rotation phase passes the phase illustrated in FIG. 9 by this advance angle operation, as illustrated in FIG. 10, the relative rotation phase reaches a second stop phase Q2 that is included in the sequence region G. At the time when the phase sensor N detects that the relative rotation phase reaches the second stop phase Q2, the displacement is stopped and the relative rotation phase waits (stops to operate and stands by) for a first set time T1 (steps #104 to #106). In addition, the steps #104 to #106 correspond to a specific example of the second phase control.

The phases of FIGS. 9 and 10 appear at the timings IX and X in FIG. 12. In addition. FIG. 12 illustrates a state where the relative rotation phase waits for the first set time T1 after reaching the second stop phase Q2. In addition, since the hydraulic oil is supplied to the auxiliary unlocking flow path 35, the lock body 81 is extracted from the auxiliary lock recess 82.

The first set time T1 is set to be longer as the temperature detected by the temperature sensor T is lower. When waiting as described above, the pressure in the retardation angle flow path 34 and the retardation angle chamber Cb is greatly reduced. In addition, in the second stop phase Q2, as illustrated in FIGS. 10 and 15, a state where the opening portion of the large-diameter guide hole portion 70a of the guide hole 70 communicates with the drain flow path 230 through the first unlocking flow path 75 and a state where the communication portion 25 causes the opening portion of the large-diameter guide hole portion 70a of the guide hole 70 to communicate with the external space are continuously maintained. Therefore, the pressure acting on the first pressure receiving surface U1 and the second pressure receiving surface U2 is reduced, and an operation of fitting the engaging portion 71b of the lock member 71 into the main lock recess 72 by the biasing force of the main lock spring 73 is performed.

In particular, in this second stop phase Q2, since the second unlocking flow path 76 is closed by the main body portion 71a of the lock member 71, no hydraulic oil flows to the second unlocking flow path 76, and there is no problem of reducing the operation speed of the lock member 71 due to the flow path resistance acting on the hydraulic oil in the second unlocking flow path 76.

Thereafter, a third phase control is performed to displace the relative rotation phase toward the intermediate locking phase M by the retardation angle operation. The control terminates when the relative rotation phase detected by the phase sensor N is stopped at the intermediate locking phase M illustrated in FIG. 11 by the retardation angle operation (steps #107 and #108).

The phase change at the time when the relative rotation phase reaches the intermediate locking phase M as described above is illustrated as the timing XI in FIG. 12. In the case where the relative rotation phase detected by the phase sensor N is stopped at the intermediate locking phase M by the above-described control, the engaging portion 71b of the lock member 71 is fitted into the main lock recess 72 prior to the stop, as illustrated in FIG. 10. In this state, when the relative rotation phase is displaced in the retardation angle direction Sb, the engaging portion 71b is abutted on the end of the main lock recess 72 so that the relative rotation is stopped.

At the timing when the relative rotation is stopped as described above, the regulation end 81a of the lock body 81 of the auxiliary lock mechanism Ls is shifted to a state where it is fitted into the auxiliary lock recess 82. As a result, the relative rotation phase of the valve opening/closing timing control apparatus A is maintained at the intermediate locking phase M.

In particular, after the third phase control, when the phase sensor N detects that the relative rotation phase detected by the phase sensor N exceeds the intermediate locking phase M and is displaced to the retardation angle side, a retry control (step #200) is executed.

This retry control (step #200) is automatically executed when it is determined that the relative rotation phase detected by the phase sensor N exceeds the intermediate locking phase M and is displaced to the retardation angle side. The retry control is set as a sub-routine. That is, as illustrated in the timing chart of FIG. 12 (the area indicated by the two-dot chain line) and the flowchart of FIG. 14, fourth phase control is performed to stop the displacement at the time when the phase sensor N detects that the relative rotation phase reaches the first stop phase Q1 (steps #201 and #202).

In the fourth phase control, the advance angle operation is performed so as to displace the relative rotation phase in the same direction as the second phase control. The displacement by the fourth phase control is stopped at the time when the phase sensor N detects that the relative rotation phase reaches the second stop phase Q2 that is included in the sequence region G and the relative rotation phase waits for a second set time T2, which is longer than the first set time T1 (steps #203 to #205).

When the stop state continues for a long time in the second stop phase Q2 as described above, a state where the small-diameter guide hole portion 70b communicates with the drain flow path 23D via the first unlocking flow path 75 is maintained for a long time. Therefore, the pressure in the small-diameter guide hole portion 70b is reduced so that it becomes possible to make an operation by which the engaging portion 71b of the lock member 71 is fitted into the main lock recess portion 72 by the biasing force of the main lock spring 73.

Thereafter, the fifth phase control displaces the relative rotation phase toward the intermediate locking phase M by performing the retardation angle operation, and when the relative rotation phase detected by the phase sensor N is stopped at the intermediate locking phase M, the fifth phase control is terminated (step #206).

In the retry control (step #200), when the stop of the relative rotation phase is not performed at the intermediate locking phase M, the steps #108 and #200 are repeatedly performed. However, for example, when the number of repetition times reaches a set number of times, a control form is conceivable in which the lock shifting control is forcibly terminated, or error information is output to terminate the control.

In particular, when the retry control (step #200) is repeatedly performed, a control form may be set to extend the waiting time to correspond to the number of repetition times.

In addition, in a situation where the relative rotation phase is opposite to the predetermined phase K with the intermediate locking phase M being interposed therebetween, a control to start from the step #104 in the flowchart of FIG. 13 is performed when the lock shifting control is executed.

[Setting of Second Stop Phase]

FIG. 15 illustrates, in an enlarged scale, a state of the main lock mechanism Lm in the second stop phase Q2 set by the control of the lock shifting controller 91. In the second stop phase Q2, it is required to cause the engaging portion 71b of the lock member 71 to be engaged with the main lock recess 72 as soon as possible by the biasing force of the main lock spring 73. In order to enable such an engagement, the second stop phase Q2 is set such that the hydraulic oil is rapidly discharged from the drain flow path 23D and outside air is rapidly suctioned from the communicating portion 25.

In the chart of FIG. 16, on the basis of the intermediate locking phase M indicated by “O” on the horizontal axis, in the region on the retardation angle side (the left side in FIG. 16) and in the sequence region G on the advance angle side (the right side in FIG. 16), the equivalent diameters of respective flow paths through which the hydraulic oil is supplied or discharged are illustrated in graphs.

As illustrated in FIG. 16, in a situation where the relative rotation phase is closer to the retardation angle side (the left side in FIG. 16) than the intermediate locking phase M, the flow path area (communication diameter) in the communication region between the locking assist flow path 22A and the advance angle chamber Ca is illustrated as advance angle chamber communication Da in a graph. The flow path area is increased to a predetermined value while the relative rotation phase approaches the intermediate locking phase M, but becomes zero (completely closed) before the relative rotation phase reaches the intermediate locking phase M.

Likewise, in a situation where the relative rotation phase is closer to the retardation angle side (the left side in FIG. 16) than the intermediate locking phase M, the flow path area (communication diameter) of the communication region between the retardation angle chamber Cb and the main lock recess 72 is illustrated as retardation angle chamber communication Db in a graph. The flow path area is reduced while the relative rotation phase approaches the intermediate locking phase M, and becomes zero (completely closed) before the relative rotation phase reaches intermediate locking phase M.

In addition, in a situation where the relative rotation phase is closer to the sequence region G on the advance angle side (the right side in FIG. 16) than the intermediate locking phase M, the flow path area (communication diameter) of the communication region between the external space and the communicating portion 25 is illustrated as atmosphere communication Dc in the graph. The flow path area is zero (completely closed) in the intermediate locking phase M, and is enlarged as gets farther away from the intermediate locking phase M toward the advance angle side.

In addition, the flow path area (communication diameter) of the communication region between the first unlocking flow path 75 and the drain flow path 23D is illustrated as drain communication Dd in a graph. The flow path area becomes the largest when the relative rotation phase is near the intermediate locking phase M and is reduced as gets farther away from the intermediate locking phase M at the advance angle side and the retardation angle side.

Here, as illustrated in FIGS. 16 and 17, considering a situation where the relative rotation phase is in a first comparative phase Qf, which is far from the intermediate locking phase M, in the sequence region G, as illustrated in FIG. 16, the flow path area of the atmosphere communication Dc is close to the maximum value, whereas the flow path area of the drain communication Dd is close to the minimum value.

On the other hand, as illustrated in FIGS. 16 and 18, considering a situation where the relative rotation phase is in a second comparative phase Qn, which is close to the intermediate locking phase M, in the sequence region G as illustrated in FIG. 16, the flow path area of the atmospheric communication Dc of the communicating portion 25 is close to the minimum value, whereas the flow path area of the drain communication Dd between the first unlocking flow path 75 and the drain flow path 23D is close to the maximum value.

In addition, in FIG. 16, in a case where the graph of the atmospheric communication Dc and the graph of the drain communication Dd intersect each other in the central region of the sequence region G, and the relative rotation phase is present near the central region, approximately the same amount of hydraulic oil flows to the communicating portion 25 and the drain flow path 23D0.

In the central region, both the flow path area of the atmosphere communication Dc and the flow path area of the drain communication Dd exceed 20% of the maximum value thereof. In addition, in a situation where approximately the same amount of hydraulic oil flows to the communicating portion 25 and the drain flow path 23D, when the lock member 71 is engaged with the main lock recess 72, outside air is suctioned from the communicating portion 25, and at the same time, the hydraulic oil is discharged from the drain flow path 230, which enables the rapid operation of the lock member 71.

For this reason, the region of the sequence region G, in which both the flow path area of the atmosphere communication Dc and the flow path area of the drain communication Dd exceed 20% of the maximum value thereof, is set to the second stop phase Q2, so that the engaging portion 71b of the lock member 71 is engaged with the main lock recess 72 as soon as possible by the biasing force of the main lock spring 73.

[Unlocking: Displacement in Advance Angle Direction]

In addition, as illustrated in FIG. 11, when the relative rotation phase is displaced in the advance angle direction Sa starting from a state where the relative rotation phase is maintained in the intermediate locking phase M, the unlocking controller 92 executes the advance angle operation. By this control, some of the hydraulic oil supplied to the advance angle flow path 33 is supplied to the auxiliary unlocking flow path 35.

In addition to this supply, the pressure in the auxiliary lock recess 82 of the auxiliary lock mechanism Ls is increased, and as illustrated in FIG. 5, the regulation end 81a of the lock body 81 is spaced apart from the auxiliary lock recess 82 to realize unlocking. Thereafter, when the relative rotation phase is displaced in the advance angle direction Sa, the phase controller 93 maintains the control of supplying the hydraulic oil to the advance chamber Ca. As a result, as illustrated in FIG. 5, the main lock mechanism Lm performs the displacement of the relative rotation phase in a state where the engaging portion 71b is engaged with the main lock recess 72 (within the range of the fittable region), and the relative rotation phase may be set to an arbitrary phase. [Unlocking: Displacement in Retardation Angle Direction]

On the contrary, as illustrated in FIG. 11, when the relative rotation phase is displaced in the retardation angle direction Sb starting from a state where the relative rotation phase is maintained in the intermediate locking phase M, a control is performed in the order in which the unlocking controller 92 displaces the relative rotation phase in the advance angle direction Sa, and thereafter the phase controller 93 operates in the retardation angle direction Sb.

That is, the auxiliary lock mechanism Ls is unlocked when the unlocking controller 92 firstly executes the advance angle operation, and the displacement is stopped when the relative rotation phase exceeds the sequence region G and reaches the unlocking phase illustrated in FIG. 5. In this phase, the first retardation angle port 75b of the first unlocking flow path 75 communicates with the first retardation angle side groove 23R.

In this state, when the phase controller 93 performs a control to supply the hydraulic oil to the retardation angle chamber Cb, the lock member 71 starts to operate in the unlocking direction as illustrated in FIG. 6, and then reaches the unlocking position J3 as illustrated in FIG. 7. By continuing the control to supply the hydraulic oil to the retardation angle chamber Cb, the relative rotation phase exceeds the intermediate locking phase M in a state where the lock member 71 is maintained at the unlocking position J3, and the lock body 81 is fitted into the auxiliary lock recess 82.

The displacement in the retardation angle direction Sb is performed within a range in which the lock body 81 is displaceable while being fitted into the auxiliary lock recess 82. In the same manner as the above description, the first control port 75a communicates with the drain flow path 23D in the course of reaching the relative rotation phase, which is closer to the retardation angle side than the intermediate locking phase M. However, since the lock member 71 is maintained at the unlocking position J3 by the pressure of the hydraulic oil from the second unlocking flow path 76, the engaging portion 71b of the lock member 71 is not be fitted into the main lock recess 72.

[Acting Effect of Embodiment]

In this embodiment, when the relative rotation phase is set to the intermediate locking phase M, the main lock mechanism Lm and the auxiliary lock mechanism Ls of the lock unit LU simultaneously reach the locked state, thereby maintaining the intermediate locking phase M. In addition, the displacement of the relative rotation phase in the advance angle direction Sa is implemented by supplying the hydraulic oil to the advance angle flow path 33 and the auxiliary unlocking flow path 35. In addition, when the displacement of the relative rotation phase in the retardation angle direction Sb is performed, the displacement is implemented by firstly displacing the relative rotation phase in the advance angle direction Sa, and then displacing the relative rotation phase in the retardation angle direction Sb. Accordingly, there is provided a configuration that does not require a dedicated control valve for unlocking.

In order to implement such a control, the main lock recess 72 of the main lock mechanism Lm is formed in a groove shape to extend in the peripheral direction, and the auxiliary lock recess 82 of the auxiliary lock mechanism Ls is also formed in a groove shape to extend in the peripheral direction.

Accordingly, when the relative rotation phase is maintained in the sequence region G, the hydraulic oil is discharged from the first unlocking flow path 75 to the drain flow path 23D, thereby enabling the shifting of the main lock mechanism Lm to the locked state.

In particular, when the first unlocking flow path 75 and the second unlocking flow path 76 are provided in order to control the operation of the lock member 71 of the main lock mechanism Lm, and the engaging portion 71b of the lock member 71 is located at the locking position J1 or the locking boundary position J2, the operation of the lock member 71 toward the locking position J1 can be rapidly performed so as to enable reliable locking by limiting the supply and discharge of the hydraulic oil in the second unlocking flow path 76.

Additional Embodiment

This disclosure may be configured in the following manner, in addition to the above-described embodiment (elements having the same functions as those in the above-described embodiment will be designated by the same reference numerals and symbols as those in the above-described embodiment).

(a) The lock shifting control illustrated in FIGS. 19 and 20 is basically the same as the lock shifting control described in the above-described embodiment, and has a difference in that, after the relative rotation phase reaches the first stop phase Q1 by first phase control, the displacement speed is reduced until the relative rotation phase shifts to the second stop phase Q2 by second phase control.

That is, the first phase control to displace the relative rotation phase from the predetermined phase K toward the intermediate locking phase M is started, and the displacement is stopped at the time when the phase sensor N detects that the relative rotation phase exceeds the intermediate locking phase M and reaches the first stop phase Q1 (steps #301 to #303). Next, the second phase control to displace the relative rotation phase in the direction opposite to the first phase control is performed, and the displacement is stopped at the time when the phase sensor N detects that the relative rotation phase reaches the second stop phase Q2 of the sequence region G (steps #304 to #307).

In particular, by setting the absolute value of the displacement speed in the second phase control to a value that is smaller than the absolute value of the displacement speed in the first phase control, the displacement speed in the sequence region G is reduced. As a result, the time during which the relative rotation phase exists in the sequence region G is increased, and the discharge of the hydraulic oil from the drain flow path 23D is sufficiently performed, so that the engaging portion 71b is reliably fitted into the main lock recess 72.

Thereafter, when a third operation of displacing the relative rotation phase toward the intermediate locking phase M is executed by performing the retardation angle operation and the control is terminated (step #308).

(b) As illustrated in FIG. 21, when the phase sensor N detects that the relative rotation phase reaches the intermediate locking phase M by a third phase control of the lock shifting control, a dither control is performed to alternately and repeatedly supply the hydraulic oil to the retardation angle chamber Cb and the advance angle chamber Ca for a set time Td, so that an operation of fitting the lock member 71 into the main lock recess 72 is reliably performed.

That is, in this additional embodiment (b), a control to displace the relative rotation phase as illustrated in the timing chart of FIG. 22 is performed by a lock shifting control illustrated in the flowchart of FIG. 23. Since the timing chart of FIG. 22 and the flowchart illustrated in FIG. 23 add the dither control of the present embodiment (b) disclosed here to the above-described embodiment, others excluding the dither control are common with the description of the above embodiment.

That is, the first phase control is started to displace the relative rotation phase toward the intermediate locking phase M by the retardation angle operation. By this first phase control, the displacement is stopped at the time when the phase sensor N detects that the relative rotation phase exceeds the intermediate locking phase M from the predetermined phase K illustrated in FIG. 5 and reaches the first stop phase Q1 (steps #401 to #403). In addition, the steps #401 to #403 correspond to a specific example of the first phase control.

Thereafter, the second phase control is started to displace the relative rotation phase in the direction opposite to the first phase control by the advance angle operation. In the first stop phase Q1, since the locking assist flow path 22A communicates with the opening portion of the large-diameter guide hole portion 70a (see FIG. 8), an operation of the lock member 71 to the main lock recess 72 is assisted by the pressure of the hydraulic oil together with the displacement of the relative rotation phase in the advance angle direction Sa.

The relative rotation phase reaches the second stop phase Q2 included in the sequence region G by the advance angle operation (see FIG. 10). The displacement is stopped at the time when the phase sensor N detects that the relative rotation phase reaches the second stop phase Q2 (steps #404 to #406), and the relative rotation phase waits (stops to operate and stands by) for the first set time T1. In addition, the steps #404 to #406 correspond to a specific example of the second phase control.

In this way, when waiting, the pressure in the retardation angle flow path 34 and the retardation angle chamber Cb is in a greatly reduced state. In addition, in the second stop phase Q2, a state where the opening portion of the large-diameter guide hole portion 70a of the guide hole 70 communicates with the drain flow path 23D via the first unlocking flow path 75 and a state where the communication portion 25 causes the external space to communicate with the opening portion of the large-diameter guide hole portion 70a of the guide hole 70 are continuously maintained. As a result, the pressure acting on the first pressure receiving surface U1 and the second pressure receiving surface U2 is reduced such that an operation of fitting the engaging portion 71b of the lock member 71 into the main lock recess 72 is performed by the biasing force of the main lock spring 73.

Thereafter, the third phase control is performed to displace the relative rotation phase in the direction of the intermediate locking phase M by the retardation angle operation. When it is determined that the relative rotation phase detected by the phase sensor N reaches the intermediate locking phase M illustrated in FIG. 21 by the retardation angle operation, the dither control is performed (steps #407 to #409).

In the dither control of the step #409, a control signal is output to the electromagnetic control valve 40 so that the hydraulic oil is alternately and repeatedly supplied to the advance angle chamber Ca and the retardation angle chamber Cb for the set time Td. By performing the dither control, when the relative rotation phase reaches the intermediate locking phase M and the engaging portion 71b of the lock member 71 of the main lock mechanism Lm is already engaged with the main lock recess 72 as illustrated in FIG. 21, the relative rotation phase is slightly displaced in the advance angle direction Sa as illustrated in FIG. 22, but is not displaced in the retardation angle direction Sb.

In addition, by executing this dither control, even if the side surface of the engaging portion 71b of the lock member 71 and the side surface of the main lock recess 72 are pressed to come into contact with each other, a slight gap is intermittently formed to reduce frictional resistance so that the movement of the lock member 71 in the engagement direction can be assisted by the biasing force of the main lock spring 73. As a result, the engaging portion 71b is reliably shifted to a sufficient depth with respect to the main lock recess 72.

In this dither control, since the engaging portion 71b may be shifted to a sufficient depth into the main lock recess 72 by a slight displacement of the relative rotation phase, even in a state where the relative rotation phase is in the intermediate locking phase M and the regulation end 81a of the lock body 81 of the auxiliary lock mechanism Ls is engaged with the auxiliary lock recess 82, the relative rotation phase is displaced in the advance angle direction Sa and the retardation angle direction Sb according to a slight gap between the regulation end 81a and the auxiliary lock recess 82, so that the shifting of the main lock mechanism Lm to the locked state can be implemented.

In addition, the timing to start the dither control may be either immediately after the relative rotation phase reaches the intermediate locking phase M or the time when a slight time has elapsed. In addition, the number of times of supplying the hydraulic oil alternately to the advance angle chamber Ca and the retardation angle chamber Cb, or the interval when the hydraulic oil is alternately supplied may be arbitrarily set.

After the dither control is executed as described above, when the relative rotation phase is shifted to the locked state in the intermediate locking phase M by performing the control to perform the retardation angle operation, the relative rotation phase is not displaced, and when the relative rotation phase is not shifted to the locked state and when the phase sensor N detects that the relative rotation phase exceeds the intermediate locking phase M and is displaced to the retardation angle side, the retry control (step #200) is executed. The retry control is common with the description of the above-described exemplary embodiment, and thus a control form is the same as that illustrated in FIG. 14.

(c) In the control of the embodiment (a), the dither control is executed. That is, after the step #308 of the flowchart of FIG. 19, the dither control (step #409) described in the embodiment (b) is executed so that the operation of shifting the engaging portion 71b of the lock member 71 to a sufficient depth into the main lock recess 72 is reliably performed.

(d) After the retry control (see FIG. 14), a control mode is set to perform the dither control when the relative rotation phase reaches the intermediate locking phase M (step #108 of the flowchart of FIG. 13). By setting the control mode in this manner, the movement of the lock member 71 in the engaging direction is assisted by the biasing force of the main lock spring 73, and the engaging portion 71b is reliably shifted to a sufficient depth into the main lock recess 72.

In particular, when executing the dither control in the retry control, it is considered that, when the set time Td during which the dither control is executed is longer than the set time Td of the dither control in the lock shifting control, the number of times of displacement of the relative rotation phase in the advance angle direction Sa and the retardation angle direction Sb is increased.

(e) In the lock shifting control, the time during which the relative rotation phase waits after reaching the sequential region G may be changed according to the hydraulic pressure and the rotational speed of the engine E.

As a specific control form, by extending the waiting time as the hydraulic pressure is increased, it is considered that, after the pressure of the hydraulic oil acting on the lock member 71 is removed, the pressure of the hydraulic oil continuously acting on the lock member 71 is reliably removed. In addition, by extending the waiting time as the rotational speed is increased, it is considered that an operation is performed under the influence of frictional force acting on the lock member 71 due to centrifugal force.

Similarly to this, the degree by which the displacement speed of the relative rotation phase is reduced may be changed according to the hydraulic pressure and the rotational speed of the engine E by the lock shifting control described in the exemplary embodiment (a).

(f) In the case where the retry control is performed in the lock shifting control, the waiting time at the time of performing the shifting to the locked state is stored to be associated with the temperature of the engine E, the hydraulic pressure, or the rotational speed of the engine E. Then, when performing the lock shifting control, a control form may be set to set the waiting time that is suitable for a stored condition.

By setting the waiting time based on the stored information as described above, reliable shifting to the locked state is enabled. The control based on the stored information may also be applied to the speed limitation of the above-described embodiment (a).

(g) As a hydraulic fluid control mechanism, an electromagnetic valve may be provided outside the valve opening/closing timing control device A. In this configuration, a flow path configuration may be simplified compared to a case where an electromagnetic valve is provided inside the valve opening/closing timing control device A.

(h) As a modification of the configuration in which the main lock mechanism Lm is provided in the vane portion 32, the lock member 71 may be configured to protrude outward in the radial direction. In addition, as the auxiliary lock mechanism Ls, the lock body 81 may be configured to move inward or outward along an axis that is parallel to the rotation axis X.

(i) The electromagnetic control valve 40 may be configured such that the advance angle position and the retardation angle position are disposed in the reverse order.

This disclosure may be applied to a valve opening/closing timing control device, which includes a driving side rotating body, a driven side rotating body, and a lock mechanism to restrain these rotating bodies in a predetermined relative rotation phase.

According to this configuration, in a locked state where the engaging portion of the lock member is fitted into the lock recess, when the hydraulic fluid is supplied to the first unlocking flow path, the pressure of the hydraulic fluid is applied to the first pressure receiving surface so as to extract the engaging portion from the lock recess, thereby implementing shifting to an unlocked state. In addition, when the engaging portion of the lock member reaches the unlocking position after shifting to the unlocked state, it is also possible to cause the pressure of the hydraulic fluid to act on the first pressure receiving surface so that the unlocked state can be maintained by supplying the hydraulic fluid to the second unlocking flow path.

In addition, in a state in which the engaging portion of the lock member is closer to the locking direction than the locking boundary position, the second unlocking flow path is closed by the main body portion of the lock member. Therefore, a phenomenon in which the hydraulic fluid flows into/flows out from the second unlocking flow path is not caused when the engaging portion of the lock member moves toward the lock recess by the biasing force of the biasing member, and the operating speed of the lock member is not suppressed. For example, in a configuration in which the hydraulic fluid flows into the second unlocking flow path when the lock member shifts to the locked state, the operating speed of the lock member is reduced since the flow of the hydraulic fluid is suppressed by the resistance in the second unlocking flow path. However, the configuration of the present invention solves this problem.

Accordingly, the valve opening/closing timing control apparatus in which the lock member can be rapidly fitted into the lock recess is configured.

In the aspect of this disclosure, the lock recess may include a fittable region that extends in a displacement direction to enable displacement of the relative rotation phase in a state where the engaging portion is fitted into the lock recess, and a phase in which the engaging portion is fitted into one side end of the fittable region of the lock recess in the displacement direction may be set to a locking phase. A range of the fittable region under influence of the set locking phase may be set to a sequence region, and in the sequence region, a drain flow path configured to discharge the hydraulic fluid may communicate with the first unlocking flow path. An unlocking phase may be set to be opposite to the locking phase on the basis of the sequence region in the fittable region, and in the unlocking phase, the first unlocking flow path and the drain flow path are in non-communication state with each other in a state where the engaging portion is fitted into the lock recess, and supply of the hydraulic fluid to the first unlocking flow path and the second unlocking flow path is enabled.

According to this configuration, by setting the relative rotation phase to the sequence region, the hydraulic fluid that applies pressure to the first pressure receiving surface may be discharged from the first unlocking flow path to the drain flow path so that the pressure acting on the first pressure receiving surface can be reduced, and an operation of fitting the engaging portion of the lock member into the lock recess can be performed.

In addition, when the state of setting the relative rotation phase to the sequence region is maintained, shifting to the locked state can be reliably implemented.

Further, by setting the relative rotation phase to an unlocking phase, no hydraulic fluid is discharged from the drain flow path and the hydraulic fluid is supplied from the first unlocking flow path and the second unlocking flow path so that shifting to the unlocked state can be rapidly performed.

In the aspect of this disclosure, the valve opening/closing timing control apparatus may further include: a phase sensor configured to detect the relative rotation phase; and a lock shifting control unit configured to: start a first phase control so as to displace the relative rotation phase from a predetermined phase, which is opposite to the locking phase on the basis of the sequence region, to the locking phase; stop the displacement by the first phase control at a time when the phase sensor detects that the relative rotation phase exceeds the locking phase from the predetermined phase; start a second phase control so as to displace the relative rotation phase in a direction opposite to that in the first phase control; stop the displacement by the second phase control at a time when the phase sensor detects that the relative rotation phase reaches a predetermined phase in the sequence region; and start a third phase control so as to displace the relative rotation phase toward the locking phase.

According to this configuration, when the lock shifting control unit performs the first phase control, the displacement is stopped when the relative rotation phase exceeds the sequence region and the locking phase. Subsequently, when the lock shifting control unit performs the second phase control, the displacement is stopped when the relative rotation phase exceeds the locking phase and reaches a phase included in the sequence region. In the sequence region, since the engaging portion of the lock member is fittable into the lock recess and the hydraulic fluid is discharged from the first unlocking flow path to the drain flow path, an operation of fitting the engaging portion into the lock recess can be performed by the biasing force of the biasing member. Thereafter, when the lock shifting control unit performs the third phase control to displace the relative rotation phase toward the locking phase, the engaging portion may be abutted on the end surface of the inner end of the lock recess, which becomes a locking position so that the shifting to the locking phase can be performed.

In the aspect of this disclosure, in the second phase control, when the relative rotation phase reaches the sequence region and the displacement is stopped, the stop may be continued for a set time.

According to this configuration, for example, as in a case where the hydraulic fluid has high viscosity due to the low temperature thereof, even if the hydraulic fluid is not smoothly discharged from the drain flow path and the reduction in the pressure of the first unlocking flow path requires an extra time, it is possible to cause the hydraulic fluid to be sufficiently discharged and to cause the engaging portion to be reliably fitted into the lock recess by continuing the stop for the set time in the sequence region.

In the aspect of this disclosure, a control form of the lock shifting control unit may be set: to start a fourth phase control to stop the displacement when the phase sensor detects that the relative rotation phase exceeds the locking phase and is displaced to a predetermined phase after the third phase control, and thereafter displace the relative rotation phase in the same direction as the second phase control; to stop the fourth phase control at a time when the phase sensor detects that the relative rotation phase reaches a predetermined phase in the sequence region; to maintain the stopped state for a longer time than the set time; and then to perform a fifth phase control to displace the relative rotation phase toward the locking phase.

When the relative rotation phase is displaced beyond the locking phase after the third phase control, the engaging portion of the lock member is not fitted into the lock recess. Thus, the displacement by the third phase control is continuously stopped to the second phase control start position. Thereafter, the relative rotation phase is shifted to the sequence region and then stopped by performing the fourth phase control, and by maintaining the stop time to be longer than the previous set time, it becomes possible to perform an operation in which the engaging portion is fitted into the lock recess by the biasing force of the biasing member. In addition, by subsequently performing the fifth phase control, shifting to the locking phase can be reliably performed.

In the aspect of this disclosure, an absolute value of a displacement speed in the second phase control may be set to be smaller than an absolute value of a displacement speed in the first phase control.

According to this configuration, even if the hydraulic fluid is not smoothly discharged from the drain flow path and the reduction in the pressure of the first unlocking flow path requires an extra time as in a case where the hydraulic fluid has high viscosity due to, for example, a low temperature thereof, it is possible to allow the fitting of the engaging portion into the lock recess to be reliably performed by reducing the displacement speed of the relative rotation phase in the second phase control to be lower than the displacement speed in the first phase control so that the drain time can be extended and the hydraulic fluid can be sufficiently discharged.

In the aspect of this disclosure, in the second phase control, the displacement speed in the sequence region may be reduced with respect to the displacement speed before reaching the sequence region.

In the aspect of this disclosure, the lock shifting control unit may perform a dither control to alternately and repeatedly supply the fluid into the advance angle chamber and the retardation angle chamber within a set time when the phase sensor detects that the relative rotation phase reaches the locking phase by the third phase control.

According to this configuration, when the relative rotation phase is displaced toward the locking phase in the lock shifting control to reach the locking phase, the operation of causing the engaging portion of the lock member to be engaged with the lock recess is performed by the biasing force of the biasing member. However, it is also conceivable that when the engaging portion is pressed to come into contact with the inner circumferential wall of the lock recess so that the frictional resistance is increased, a problem may be caused in that the engaging portion is not inserted to a sufficient depth. In connection with this, by performing the dither control when the relative rotation phase reaches the locking phase, the frictional resistance may be reduced by releasing the pressure contact state in the press contact portion between the engaging portion and the lock recess, so that the engaging portion can be inserted into the lock recess to a sufficient depth.

In the aspect of this disclosure, a locking assist flow path may be formed to apply a pressure of the hydraulic fluid to the lock member in an engagement direction when the relative rotation phase is opposite to the sequence region on the basis of the locking phase.

According to this configuration, for example, when the relative rotation phase is displaced from the phase, which is opposite to the locking phase on the basis of the sequence region, toward the locking phase, the pressure of the hydraulic fluid acts on the lock member in the engagement direction from the locking assist flow path. This also enables the operating speed of the engaging portion of the lock member toward the lock recess to be increased.

In the aspect of this disclosure, the valve opening/closing timing control apparatus may further include: an auxiliary lock mechanism including a lock body slidably inserted into a support hole portion formed in one of the driving side rotating body and the driven side rotating body, a biasing body configured to bias a regulation end on one end side of the lock body so that the regulation end protrudes, and an auxiliary lock recess formed in a remaining one of the driving side rotating body and the driven side rotating body so that the regulation end of the lock body is fitted into the auxiliary lock recess by biasing force of the biasing body. The auxiliary lock recess may be formed in a region extending along the displacement direction of the relative rotation phase so that the displacement of the relative rotation phase is enabled in a state where the regulation end is fitted into the auxiliary lock recess. In a state where the relative rotation phase is in the locking phase, the lock body may be disposed at a position at which the lock body inhibits the displacement of the relative rotation phase between both ends of the auxiliary lock recess in the displacement direction.

According to this configuration, when the relative rotation phase is in the locking phase, the lock body is fitted into the auxiliary lock recess and the lock member is fitted into the lock recess. Thus, in this state, the relative rotation phase may not be displaced in any one of an advance angle direction and a retardation angle direction, and may be maintained at an intermediate phase between the maximum advance angle phase and the maximum retardation angle phase.

In the aspect of this disclosure, one of the driving side rotating body and the driven side rotating body may be configured as an inner rotor having the guide hole formed therein, and a remaining one of the driving side rotating body and the driven side rotating body may be configured as an outer rotor having a pair of plates for fitting of the inner rotor therebetween, the lock recess being formed in one of the plates, and a communication portion being formed in a remaining one of the plates so as to enable communication between the guide hole and an external space. As the relative rotation phase approaches the locking phase in the sequence region, a flow path area of the communication portion communicating with the external space may be reduced and a flow path area of the drain flow path communicating with the first unlocking flow path may be increased, and in the second phase control, when the flow path area of the communication portion and the flow path area of the drain flow path reach 20% or more of that in a completely opened state, the displacement by the second phase control may stop.

According to this configuration, when the displacement of the relative rotation phase by the third phase control causes each of the flow path area of the communication portion and the flow path area of the drain flow path reaches 20% or more of that in the completely opened state, a control to stop the third phase control is performed. With this stop, a resistance acting on air suctioned from the communication portion to the space of the guide hole in which the biasing member is located is reduced, and a resistance acting on the fluid discharged from the first unlocking flow path to the drain flow path is reduced. As a result, the displacement speed of the lock member is increased so that shifting to the locked state can be rapidly performed.

In the aspect of this disclosure, the set time of the dither control performed after the fifth control may be set to be longer than the set time of the dither control performed after the third control.

In the aspect of this disclosure, in the lock shifting control, a duration in which the relative rotation phase reaches the sequence region and the displacement is stopped may be changed according to a hydraulic pressure and a number of revolutions of the internal combustion engine.

The principles, preferred embodiment and mode of operation of the present invention have been described in the foregoing specification. However, the invention which is intended to be protected is not to be construed as limited to the particular embodiments disclosed. Further, the embodiments described herein are to be regarded as illustrative rather than restrictive. Variations and changes may be made by others, and equivalents employed, without departing from the spirit of the present invention. Accordingly it is expressly intended that all such variations, changes and equivalents which fall within the spirit and scope of the present invention as defined in the claims, be embraced thereby.

Number	Date	Country	Kind
2016-083684	Apr 2016	JP	national
2017-015688	Jan 2017	JP	national

VALVE OPENING/CLOSING TIMING CONTROL APPARATUS

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