VALVE OPENING-CLOSING TIMING CONTROL APPARATUS

Abstract

A valve opening-closing timing control apparatus includes an intermediate phase retaining mechanism retaining the relative rotational phase of a driven-side rotational member relative to the driving-side rotational member at an intermediate phase that is a phase between most retarded angle phase and most advanced angle phase. The driving-side rotational member synchronously rotates with a crankshaft of an internal combustion engine. The driven-side rotational member integrally rotates with a camshaft of the internal combustion engine and makes relative rotations relative to the driving-side rotational member. The valve opening-closing timing control apparatus further includes a state variable acquisition portion acquiring a state variable relating to the internal combustion engine and a phase controller displacing the relative rotational phase to the intermediate phase on condition that the relative rotational phase is at a retarded angle phase at a time at which the internal combustion engine stops and the state variable satisfies a predetermined condition.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 U.S.C. §119 to Japanese Patent Application 2012-196471, filed on Sep. 6, 2012, the entire content of which is incorporated herein by reference.

TECHNICAL FIELD

This disclosure generally relates to a valve opening-closing timing control apparatus.

BACKGROUND DISCUSSION

A valve opening-closing timing control apparatus, which controls an opening timing and a closing timing of either an intake valve or an exhaust valve of an internal combustion engine or each one of the intake valve and the exhaust valve of the internal combustion engine, is conventionally used in order to improve fuel efficiency of the internal combustion engine. This kind of valve opening-closing timing control apparatus changes a relative rotational phase between a driving-side rotational member that synchronously rotates with a crankshaft and a driven-side rotational member that integrally rotates with a camshaft to control the opening timing and the closing timing of the intake valve and/or the exhaust valve.

At the same time, in recent years, an internal combustion engine that compresses a fuel-air mixture taken into the internal combustion engine with a higher pressure is also considered in order to respond to a demand for further improving fuel efficiency. In this type of internal combustion engine, a compression ratio becomes high in a state where a timing that closes an intake valve and a timing at which a piston reaches near a bottom dead center coincide. At this time, in a state where temperature of the fuel-air mixture is high, pre-ignition may occur. Pre-ignition is an event in which the fuel-air mixture self-ignites before ignition by a spark plug. Such a pre-ignition event raises wall temperature of a cylinder rapidly, which becomes a cause for lowering an output of the internal combustion engine and for an unstable rotation of the internal combustion engine. Accordingly, a technology to restrain pre-ignition to occur has been considered, for example as in JP4687964B, hereinafter referred to as Reference 1.

A valve opening-closing timing control apparatus described in Reference 1 includes an intermediate phase retaining structure to retain a relative rotational phase at an intermediate phase, which is a phase between most retarded angle phase and most advanced angle phase. Note that the relative rotational phase refers to the relative rotational phase between a driving-side rotational member and a driven-side rotational member. In the valve opening-closing timing control apparatus according to Reference 1, at a time at which an internal combustion engine is made to stop and on condition that a state variable relating to the internal combustion engine satisfies a predetermined condition, the relative rotational phase is controlled to be at a phase in a direction of a retarded angle phase relative to the intermediate phase before the internal combustion engine stops. Furthermore, at the time at which the internal combustion engine is made to stop and on condition that the state variable relating to the internal combustion engine does not satisfy the predetermined condition, the relative rotational phase is controlled to be at the intermediate phase before the internal combustion engine stops. Moreover, in a case where the state variable relating to the internal combustion engine changes to a condition that does not satisfy the predetermined condition after the internal-combustion engine is made to stop, the relative rotational phase is controlled to be at the intermediate phase.

A valve opening-closing timing control apparatus described in Reference 1 controls the relative rotational phase in a case where an internal combustion engine is suspended in a stop condition for a short time, for example, in an idle stop condition. A valve opening-closing timing control apparatus described in Reference 1 does not take into an account of a control, for example, in a state where the internal combustion engine is stopped by an operation of an ignition key instead of by an idle stop function. Accordingly, in the valve opening-closing timing control apparatus described in Reference 1, pre-ignition is not fully restrained from occurring and the pre-ignition may occur in a state where the internal combustion engine is made to re-start before temperature falls after the internal combustion engine has stopped in a high temperature state.

A need thus exists for a seat slide apparatus for a vehicle, which is not susceptible to the drawback mentioned above.

SUMMARY

A valve opening-closing timing control apparatus includes a driving-side rotational member configured to synchronously rotate with a crankshaft of an internal combustion engine, a driven-side rotational member configured to integrally rotate with a camshaft of the internal combustion engine and makes relative rotations relative to the driving-side rotational member, a fluid pressure chamber formed by the driving-side rotational member and the driven-side rotational member, a vane arranged in the fluid pressure chamber to partition the fluid pressure chamber into a retarded angle chamber and an advanced angle chamber, the retarded angle chamber configured to move relative rotational phase of the driven-side rotational member relative to the driving-side rotational member in a retarded angle direction that is one direction of the relative rotations and the advanced angle chamber configured to move the relative rotational phase in an advanced angle direction that is another direction of the relative rotations, an intermediate phase retaining mechanism retaining the relative rotational phase at an intermediate phase that is a phase between most retarded angle phase and most advanced angle phase, a state variable acquisition portion acquiring a state variable relating to the internal combustion engine, and a phase controller displacing the relative rotational phase to the intermediate phase on condition that the relative rotational phase is at a retarded angle phase relative to the intermediate phase at a time at which the internal combustion engine stops and the state variable satisfies a predetermined condition.

A valve opening-closing timing control apparatus includes a driving-side rotational member configured to synchronously rotate with a crankshaft of an internal combustion engine, a driven-side rotational member configured to integrally rotate with a camshaft of the internal combustion engine and makes relative rotations relative to the driving-side rotational member, a fluid pressure chamber formed by the driving-side rotational member and the driven-side rotational member, a vane arranged in the fluid pressure chamber to partition the fluid pressure chamber into a retarded angle chamber and an advanced angle chamber, the retarded angle chamber within which a volume increases in a case where a relative rotational phase of the driven-side rotational member relative to the driving-side rotational member moves in a retarded angle direction that is one direction of the relative rotations, the advanced angle chamber within which a volume increases in a case where the relative rotational phase moves in an advanced angle direction that is a different direction from the retarded angle direction, an intermediate phase retaining mechanism retaining the relative rotational phase at an intermediate phase that is a phase between most retarded angle phase and most advanced angle phase where the most retarded angle phase is a phase at which the volume within the retarded angle chamber is at maximum and the most advanced angle phase is a phase at which the volume within the advanced angle chamber is at maximum, a state variable acquisition portion acquiring a state variable relating to the internal combustion engine, and a phase controller displacing the relative rotational phase to the intermediate phase on condition that the relative rotational phase at a time at which the internal combustion engine stops is at a position closer to the most retarded angle phase relative to the intermediate phase and the state variable acquired by the state variable acquisition portion satisfies a predetermined condition.

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 drawing illustrating a configuration of a valve opening-closing timing control apparatus as a whole viewed from a side;

FIG. 2 is a cross-sectional view drawing taken along line II-II in FIG. 1 illustrating the valve opening-closing timing control apparatus according to an embodiment in an intermediate phase lock state;

FIG. 3 is a cross-sectional view drawing taken along line III-III in FIG. 1 illustrating the valve opening-closing timing control apparatus according to the embodiment in a state in which the valve opening-closing timing control apparatus is released from the intermediate phase lock state;

FIG. 4 is a cross-sectional view drawing taken along line IV-IV in FIG. 1 illustrating the valve opening-closing timing control apparatus according to the embodiment in a most retarded angle phase state;

FIG. 5 is a flow chart describing a control by a phase controller; and

FIG. 6 is a cross-sectional view drawing illustrating the valve opening-closing timing control apparatus according to an alternative embodiment.

DETAILED DESCRIPTION

An embodiment of a valve opening-closing timing control apparatus 1 will be described in detail. FIG. 1 is a cross-sectional view drawing illustrating a configuration of a valve opening-closing timing control apparatus 1 as a whole viewed from a side. FIGS. 2 to 4 are cross-sectional view drawings taken along line II-II, III-III, and IV-IV respectively in FIG. 1 illustrating the valve opening-closing timing control apparatus according to the embodiment in different states. The valve opening-closing timing control apparatus 1 is applicable, for example, to a vehicle provided with an internal combustion engine E as a drive source and to a hybrid vehicle provided with an internal combustion engine E and an electric motor as drive sources. The valve opening-closing timing control apparatus 1 controls valve opening and closing timing of the internal combustion engine E. Accordingly, the valve opening-closing timing control apparatus 1 controls valve opening and closing timing of the internal combustion engine E of the drive source having the internal combustion engine E and the electric motor. Such valve opening-closing timing control apparatus 1 will be described below referring to drawings. Note that the internal combustion engine is provided with a reference alphabet E.

The valve opening-closing timing control apparatus 1 includes an outer rotor 12, which serves as a driving-side rotational member, and an inner rotor 2, which serves as a driven-side rotational member. The outer rotor 12 synchronously rotates with a crankshaft 110 of the internal combustion engine E. The inner rotor 2 integrally rotates with a camshaft 101 of the internal combustion engine E. Furthermore, the inner rotor 2 and the outer rotor 12 are coaxially arranged. The inner rotor 2 is arranged such that the inner rotor 2 may rotate relative to the outer rotor 12. The valve opening-closing timing control apparatus 1 according to the embodiment controls an opening timing and an closing timing of an intake valve 115 by defining a relative rotational phase, or a relative rotational angle, between the outer rotor 12 and the inner rotor 2, each of which rotates with a rotational axis X as center.

The inner rotor 2 is integrally assembled on an end portion of the camshaft 101. More specifically, the inner rotor 2 is fastened and retained to the end portion of the camshaft 101 by a fastening bolt 20.

The valve opening-closing timing control apparatus 1 includes a front plate 11, the outer rotor 12, and a rear plate 13. The front plate 11 is arranged at a position in a direction opposite to where the camshaft 101 connects. The outer rotor 12 is integrally arranged with a timing sprocket 15. The rear plate 13 is arranged at a position in a direction in which the camshaft 101 connects with. The outer rotor 12 is arranged outward of the inner rotor 2 and then sandwiched between the front plate 11 and the rear plate 13 from each direction in an axial direction. The fastening bolt 20 fastens and retains the front plate 11, the outer rotor 12, and the rear plate 13 in the aforementioned state to the end portion of the camshaft 101.

In a state where the crankshaft 110 rotates, a rotational driving power is transmitted to the timing sprocket 15 via a power transmission member 102 so that the outer rotor 12 is driven to rotate in a rotational direction S, which is illustrated in FIG. 2. In accordance with the rotational driving of the outer rotor 12, the inner rotor 2 is driven to rotate in the rotational direction S so that the camshaft 101 rotates. A cam 116 arranged on the camshaft 101 pushes down the intake valve 115 of the internal combustion engine E so that the intake valve is opened.

As FIG. 2 illustrates, a multiple number of protruding portions 14 are formed on the outer rotor 12. Each of the protruding portions 14 protrudes inwardly in a radial direction. The protruding portions 14 are formed at intervals in a direction conforming to the rotational direction S. Accordingly, fluid pressure chambers 4 are formed between the outer rotor 12 and the inner rotor 2. The protruding portions 14 act as shoes for an outer peripheral surface 2a of the inner rotor 2. In the valve opening-closing timing control apparatus 1 according to the embodiment, four fluid pressure chambers 4 are provided, however, number of the fluid pressure chambers 4 is not limited to four and may be provided with a different number of the fluid pressure chambers 4.

On portions of the outer peripheral surface 2a facing the fluid pressure chambers 4, vane grooves 21 recessing in a radial direction of the inner rotor 2 are formed. A portion of each vane 22 is inserted into the vane groove 21. Accordingly each vane 22 is arranged to extend outwardly in a radial direction of the outer peripheral surface 2a. Accordingly, the vanes 22 are arranged in the fluid pressure chambers 4.

Each of the fluid pressure chambers 4 is partitioned into an advanced angle chamber 41 and a retarded angle chamber 42 by the vane 22 in the rotational direction S. In a state where oil is supplied into the retarded angle chamber 42, the relative rotational phase of the inner rotor 2 relative to the outer rotor 12 moves, or shifts, in a retarded angle direction S2, which is one direction of the relative rotations of the inner rotor 2 relative to the outer rotor 12. The retarded angle direction S2 is a direction that makes the volume of the retarded angle chamber 42 to increase, which is the direction indicated as S2 in FIG. 2. In a state where oil is supplied into the advanced angle chamber 41, the relative rotational phase moves, or shifts, in an advanced angle direction S1, which is the other direction of the relative rotations of the inner rotor 2 relative to the outer rotor 12. The advanced angle direction S1 is a direction that makes the volume of the advanced angle chamber 41 increase by the vane 22 making a rotational displacement relative to the outer rotor 12. Note that the advanced angle direction S1 is the direction indicated as S1 in FIG. 2. A spring 23 is arranged between each of the vane grooves 21 and each of the vanes 22 to bias the vane 22 outwardly in the radial direction. Accordingly, the advanced angle chamber 41 and the retarded angle chamber 42 are restrained from oil leakage therebetween.

As FIGS. 1 and 2 illustrate, advanced angle passages 43 are formed on the inner rotor 2 and the camshaft 101 to communicate with the advanced angle chambers 41. Furthermore, retarded angle passages 44 are formed on the inner rotor 2 and the camshaft 101 to communicate with the retarded angle chambers 42. The advanced angle passages 43 and the retarded angle passages 44 connect to a predetermined port of a first control valve 174, which will be described in detail later.

By controlling the first control valve 174, oil is supplied into or discharged out of the advanced angle chambers 41 and the retarded angle chambers 42 to apply fluid pressure of the oil on the vanes 22. Furthermore, the first control valve 174 may hold an amount of supply or discharge of oil at a constant rate. Accordingly, the relative rotational phase is controlled to shift in the advanced angle direction S1 or in the retarded angle direction S2, or the relative rotational phase is held at a selected phase.

As FIG. 1 illustrates, the valve opening-closing timing control apparatus 1 according to the embodiment is provided with a torsion spring 3 spanning the inner rotor 2 and the front plate 11. The torsion spring 3 biases the inner rotor 2 in the advanced angle direction S1, which is the direction against an average displacement force in the retarded angle direction S2 in accordance with a torque fluctuation of the camshaft 101. Accordingly, the relative rotational phase may smoothly and swiftly shift in the advanced angle direction S1.

Upon the arrangement described herewith, a position of the inner rotor 2 may be smoothly displaced relative to the outer rotor 12 within a predetermined range with the rotational axis X as the center of rotation. The predetermined range in which the inner rotor 2 may make relative rotational displacement relative to the outer rotor 12 corresponds to the range in which the vane 22 may shift within the fluid pressure chamber 4. Furthermore, the predetermined range corresponds to a phase difference between the most advanced angle phase and the most retarded angle phase. The most retarded angle phase is the phase at which the volume of the retarded angle chamber 42 is at maximum. The most advanced angle phase is the phase at which the volume of the advanced angle chamber 41 is at maximum.

An intermediate phase retaining mechanism 6 retains the relative rotational phase between the outer rotor 12 and the inner rotor 2 at an intermediate phase by retaining the outer rotor 12 and the inner rotor 2 at a predetermined relative position in a situation where fluid pressure of oil is unstable at a time immediately after a start of the internal combustion engine E. Note that the intermediate phase is a phase between the most retarded angle phase and the most advanced angle phase. By retaining the relative rotational phase of the inner rotor 2 relative to the outer rotor 12 at the intermediate phase, a rotational phase of the camshaft 101 relative to a rotational phase of the crankshaft 110 is maintained at an appropriate phase so that the internal combustion engine E is provided with a stable rotation. Note that, in the valve opening-closing timing control apparatus 1 according to the embodiment, the intermediate phase is defined as the phase at which the valve opening timing of the intake valve 115 and the valve opening timing of an exhaust valve are made to partially overlap or the phase at which the valve closing timing of the exhaust valve is made nearly equal to, or made to zerolap with, the valve opening timing of the intake valve 115. At the phase at which the valve opening timing of the intake valve 115 and the exhaust valve are made to partially overlap, a low emission internal combustion engine E with a reduced hydrocarbon (HC) at the start of the internal combustion engine E may be provided. At the phase at which the valve closing timing of the exhaust valve is made nearly equal to the valve opening timing of the intake valve 115, an internal combustion engine E having a reliable start up quality in a cold region and having good idling stability may be provided.

The intermediate phase retaining mechanism 6, as FIGS. 1 and 2 illustrate, includes an intermediate phase lock passage 61, two intermediate phase lock grooves 62, two housing portions 63, two intermediate phase lock members 64, and two springs 65. Each of the intermediate phase lock members 64 is formed in a plate form.

The intermediate phase lock passage 61 is formed on the inner rotor 2 and the camshaft 101. The intermediate phase lock passage 61 connects the intermediate phase lock grooves 62 and a second control valve 175, which will be described in detail later. The second control valve 175 independently controls oil supply/discharge states to switch between the two states, which are a state of supplying oil to the intermediate phase lock grooves 62 and a state of discharging oil from the intermediate phase lock grooves 62. The intermediate phase lock grooves 62 are formed on the outer peripheral surface 2a of the inner rotor 2. Each of the intermediate phase lock grooves 62 is provided with a predetermined width in the directions of the relative rotations. The housing portions 63 are formed on the outer rotor 12 at two locations. The intermediate phase lock members 64 are arranged in the housing portions 63 in a state such that each of the intermediate phase lock members 64 may protrude from or retreat into the housing portion 63 in the radial direction. The springs 65 are arranged in the housing portions 63. Each of the springs 65 biases the intermediate phase lock member 64 inwardly in the radial direction, which is in the direction toward the intermediate phase lock groove 62.

In a state where oil is discharged from the intermediate phase lock groove 62, each of the intermediate phase lock member 64 protrudes into the intermediate phase lock groove 62. As FIG. 2 illustrates, in a state where each of the intermediate phase lock members 64 makes entry into the intermediate phase lock groove 62, the intermediate phase lock members 64 are in a state where the intermediate phase lock members 64 are simultaneously engaged to respective ends of the intermediate phase lock grooves 62, the end in a circumferential direction. As a result, a relative rotational displacement of the inner rotor 2 relative to the outer rotor 12 is restrained so that the relative rotational phase is retained at the intermediate phase. In a state where oil is supplied into the intermediate phase lock grooves 62 by controlling the second control valve 175, the intermediate phase lock members 64 retreat into the housing portions 63 from the intermediate phase lock grooves 62, as FIG. 3 illustrates. Accordingly, the inner rotor 2 is released from a state where the inner rotor 2 is restrained at a selected relative rotational phase. In other words, the inner rotor 2 is made to freely make a relative rotational displacement. Hereinafter, a state where the intermediate phase retaining mechanism 6 is restraining the relative rotational phase at the intermediate phase is referred to as an intermediate phase lock state. Furthermore, a state where the intermediate phase retaining mechanism 6 is not restraining the relative rotational phase at the intermediate phase is referred to as an intermediate phase lock release state.

Note that a form of the intermediate phase lock member 64 is not limited to a plate form as described in the description for the valve opening-closing timing control apparatus 1 according to the embodiment. The form of the intermediate phase lock member 64 may be appropriately altered to a pin form or other forms.

The intermediate phase lock groove 62 arranged at a position in the retarded angle direction S2, which is one of the two intermediate phase lock grooves 62, is provided with a ratchet form. The ratchet form of the intermediate phase lock groove 62 arranged at the position in the retarded angle direction S2 is formed in a step form recessing in the radial direction where the recess for each step of the step form gradually becomes deeper in the radial direction towards the retarded angle direction S2. Note that the intermediate phase lock groove 62 arranged at a position in the retarded angle direction S2 is the groove that restrains the relative rotational phase of the inner rotor 2 relative to the outer rotor 12 from a displacement in the advanced angle direction S1. The ratchet structure gradually restrains the intermediate phase lock member 64 by guiding easier entry of the intermediate phase lock member 64 into the intermediate phase lock groove 62. Furthermore, the intermediate phase lock passage 61 branches in two passages in a middle in the inner rotor 2 and the two passages connects to the intermediate phase lock groove 62 respectively.

A most retarded angle lock mechanism 7 restrains the relative rotational phase of the inner rotor 2 relative to the outer rotor 12 at the most retarded angle phase by retaining the outer rotor 12 and the inner rotor 2 at a predetermined relative position in a state where the internal combustion engine E is operating at a low rotational speed, for example, at a time at which the internal combustion engine E is in an idling state. Accordingly, the inner rotor 2 does not make a relative rotational displacement regardless of displacement forces in the retarded angle direction S1 and in the advanced angle direction S2 in accordance with the torque fluctuation of the camshaft 101. As a result, a stable idling state is provided. Note that, in the valve opening-closing timing control apparatus 1 according to the embodiment, the most retarded angle phase is a phase at which the intake valve 115 opens at a timing later than a timing at which the exhaust valve closes. The most retarded angle phase is the phase at which the internal combustion engine E is provided with a reliable start up quality while avoiding pre-ignition to occur while the internal combustion engine E is in a warm temperature range.

The most retarded angle lock mechanism 7 includes a most retarded angle lock passage 71, a most retarded angle lock groove 72, a housing portion 73, a most retarded angle lock member 74, and a spring 75, as FIG. 2 illustrates. The most retarded angle lock member 74 is formed in a plate form. The most retarded angle lock passage 71 is a passage that branches from the advanced angle passage 43. The most retarded angle lock member 74 is the same member as the intermediate phase lock member 64 arranged at a position in the advanced angle direction S1, which is one of the two intermediate phase lock members 64. The intermediate phase lock member 64 arranged at the position in the advanced angle direction S1 is the member that restrains the relative rotational phase of the inner rotor 2 relative to the outer rotor 12 from a displacement in the retarded angle direction S2. Similarly, the housing portion 73 is as same as the housing portion 63 arranged at a position in the advanced angle direction S1, which is one of the two housing portions 63. Furthermore, the spring 75 is as same as the spring 65 arranged in the housing portion 63 arranged at a position in the advanced angle direction S1.

Upon the arrangement described herewith, in a state where oil is discharged from the most retarded angle lock groove 72, the most retarded angle lock member 74 protrudes into the most retarded angle lock groove 72. As FIG. 4 illustrates, in a state where the most retarded angle lock member 74 makes an entry into the most retarded angle lock groove 72, the most retarded angle lock member 74 is in a state where the most retarded angle lock member 74 is engaged to the most retarded angle lock groove 72. Accordingly, the relative rotational displacement of the inner rotor 2 relative to the outer rotor 12 is restrained and the relative rotational phase is retained at the most retarded angle phase. In a state where the first control valve 174 is controlled to shift the relative rotational phase in the advanced angle direction S1, oil is supplied into the most retarded angle lock groove 72 so that the most retarded angle lock member 74 retreats into the housing portion 73 from the most retarded angle lock groove 72. Accordingly, the relative rotational phase is released from a restrained state. Hereinafter, a state where the most retarded angle lock mechanism 7 is restraining the relative rotational phase at the most retarded angle phase is referred to as a most retarded angle lock state. Furthermore, a state where the most retarded angle lock mechanism 7 is not restraining the relative rotational phase at the most retarded angle phase is referred to as a most retarded angle lock release state.

In a state where the relative rotational phase is at a phase other than at the most retarded angle phase, the most retarded angle lock member 74 and the most retarded angle lock groove 72 are out of positions. While the most retarded angle lock member 74 and the most retarded angle lock groove 72 are out of positions, the most retarded angle lock member 74 makes contact with and slides on the outer peripheral surface 2a of the inner rotor 2. Note that the form of the most retarded angle lock member 74 may be appropriately altered from the aforementioned plate form. The most retarded angle lock member 74 may be formed in a pin form or other forms.

Upon the arrangement described herewith, in a state where an electricity supply to the second control valve 175 is cut off while the valve opening-closing timing control apparatus 1 according to the embodiment is in the intermediate phase lock state, which is illustrated in FIG. 2, the state of the valve opening-closing timing control apparatus 1 according to the embodiment shifts to the intermediate phase lock release state. As long as the electricity supply to the second control valve 175 is cut off, oil supply into the intermediate phase lock groove 62 continues so that the intermediate phase lock member 64 is restrained from making entry into the intermediate phase lock groove 62.

As FIG. 4 illustrates, in a state where the relative rotational phase is shifted to the most retarded angle phase and the most retarded angle lock member 74 faces the most retarded angle lock groove 72, the most retarded angle lock member 74, which is the intermediate phase lock member 64, makes an entry into the most retarded angle lock groove 72, which brings the valve opening-closing timing control apparatus 1 according to the embodiment to the most retarded angle lock state.

Accordingly, the valve opening-closing timing control apparatus 1 according to the embodiment provides a simplified arrangement of the valve opening-closing timing control apparatus 1. The simplified arrangement of the valve opening-closing timing control apparatus 1 may reduce number of components for the valve opening-closing timing control apparatus 1 and may reduce manufacturing cost. By making the intermediate phase lock member 64 and the most retarded angle lock member 74 common, the outer rotor 12 is provided with more space in the circumferential direction. Accordingly, as FIG. 2 illustrates, the valve opening-closing timing control apparatus 1 may be provided with the fluid pressure chambers 4 at four locations. As a result, a force to shift the relative rotational phase may be increased, so that a swift phase shift may be provided. Furthermore, length of each of the fluid pressure chambers 4 in the circumferential direction may be increased so that a wider range for shifting the relative rotational phase may be provided.

A hydraulic circuit for the valve opening-closing timing control apparatus 1 according to the embodiment will be described next. As FIG. 1 illustrates, the hydraulic circuit includes a first pump 171, a second pump 172, and an oil retention portion 173. The first pump 171 is driven by the internal combustion engine E to supply oil. The second pump 172 is positioned on a downstream side of the first pump 171. The second pump 172 is driven by a power source different from the internal combustion engine E to supply oil. The oil retention portion 173 is arranged between the first pump 171 and the second pump 172 such that the oil retention portion 173 may retain oil. The hydraulic circuit furthermore includes the first control valve 174 and the second control valve 175. The first control valve 174 controls oil supply to the fluid pressure chambers 4 and the intermediate phase retaining mechanism 6. The second control valve 175 controls oil supply to the intermediate phase retaining mechanism 6.

A phase controller 180 controls operations of the second pump 172, the first control valve 174, and the second control valve 175 to control the relative rotational phase of the inner rotor 2 relative to the outer rotor 12. The phase controller 180 utilizes an arithmetic processing unit. The phase controller 180 may be a single controlling unit or may be a multiple number of controlling units combined that may serve as the phase controller 180.

An example of a command receiving portion 181 includes an ignition key and a system ready switch installed on a vehicle. The command receiving portion 181 is configured to receive commands from an operator similar to a drive permission command and a drive stop command, which are operated by turning on or turning off an ignition key or by switching on or switching off a system ready switch. The phase controller 180 controls driving operation based on the drive permission command and the drive stop command received at the command receiving portion 181. In a state where the phase controller 180 receives a drive permission command, the phase controller 180 allows operations of the internal combustion engine E and the electric motor. In a state where the internal combustion engine E and the electric motor are operational, and a vehicle is furthermore provided with a driving operation similar to an operation of an accelerator, the phase controller 180 controls functions of the vehicle in accordance with the driving operation. In a state where the phase controller 180 receives a drive stop command, the phase controller 180 brings the internal combustion engine E and the electric motor to inoperable states.

A state variable acquisition portion 182 acquires state variables relating to operations of the internal combustion engine E. Examples of the state variables relating to the operations of the internal combustion engine E include temperature of oil in lubrication system 178 that flows within the internal combustion engine E, temperature of a cooling medium for cooling the internal combustion engine E, and temperature of air taken into the internal combustion engine E. Examples of the oil that flows within the internal combustion engine E include engine oil, which is oil lubricating the internal combustion engine E, and oil for operating the valve opening-closing timing control apparatus 1. The cooling medium, in general, refers to a coolant. The air taken into the internal combustion engine E refers to air that is taken in, or introduced, from an intake opening for use in generating an air-fuel mixture. In the valve opening-closing timing control apparatus 1 according to the embodiment, the state variable acquisition portion 182 acquires at least one of the aforementioned temperatures relating to the internal combustion engine E as the state variable. A thermometer may serve as the state variable acquisition portion 182.

In the valve opening-closing timing control apparatus 1 according to the embodiment, the first pump 171 is a mechanical hydraulic pump driven by a rotational force transmitted from the crankshaft 110 of the internal combustion engine E. The first pump 171 sucks in oil retained in an oil pan 176 from an intake port and discharges the oil from a discharge port to a downstream side. The discharge port of the first pump 171 communicates with the lubrication system 178 of the internal combustion engine E and the oil retention portion 173 of the internal combustion engine E via a filter 177. The lubrication system 178 includes each one of portions in the internal combustion engine E and peripheral portions that require oil supply.

The second pump 172 is driven by a power source different from the internal combustion engine E. An example of the second pump 172 is an electric pump driven by an electric motor. Accordingly, the second pump 172 may be operated by an operational signal from the phase controller 180 regardless of an operating state of the internal combustion engine E. The second pump 172 sucks in oil retained in the oil retention portion 173 from an intake port and discharges the oil from a discharge port to a downstream side. The discharge port of the second pump 172 communicates with the first control valve 174 and the second control valve 175. More specifically, the second pump 172 may supply oil to or may discharge oil from the retarded angle chambers 42 and the advanced angle chambers 41. Accordingly, the relative rotational phase of the inner rotor 2 relative to the outer rotor 12 may be controlled. Furthermore, a bypass passage 179 is provided at a position parallel to the position of the second pump 172. The bypass passage 179 is provided for communicating between a passage in an upstream side of the second pump 172 and a passage in the downstream side of the second pump 172. The bypass passage 179 is provided with a check valve 179A.

The oil retention portion 173 is arranged between the first pump 171 and the second pump 172. The oil retention portion 173 includes a retention chamber 173A configured to retain a predetermined amount of oil. Furthermore, the oil retention portion 173 includes a first communication opening 173B, a second communication opening 173C, and a lubrication system communication opening 173D. The first communication opening 173B is provided for communicating between the retention chamber 173A and a passage in the downstream side of the first pump 171. The second communication opening 173C is arranged at a position lower than the first communication opening 173B. The second communication opening 173C is provided for communicating between the retention chamber 173A and the passage in the upstream side of the second pump 172. The lubrication system communication opening 173D is arranged at a position higher than the first communication opening 1738. The lubrication system communication opening 173D is provided for communicating between the retention chamber 173A and the lubrication system 178. An amount of oil in the retention chamber 173A of the oil retention portion 173, which is the amount of oil having a level that is higher than a level of the second communication opening 173C and lower than a level of the first communication opening 173B, is defined as the amount that is more than an amount of oil supply required by the second pump 172 in a state where the first pump 171 is at a stop.

In the valve opening-closing timing control apparatus 1 according to the embodiment, in a state where the internal combustion engine E is at a stop, which is in a state where the first pump 171 is at a stop, the second pump 172 operates to supply oil to the fluid pressure chambers 4 and the intermediate phase retaining mechanism 6. Accordingly, an amount of oil in the retention chamber 173A of the oil retention portion 173 is defined as the amount that is more than a sum of oil that fills the fluid pressure chambers 4, oil that fills the most retarded angle lock passage 71 of the intermediate phase retaining mechanism 6, and oil that fills piping and other related members arranged between the retention chamber 173A and the second pump 172. As a result, even in a state where the first pump 171 is at a stop, operating the second pump 172 alone may shift the relative rotational phase of the inner rotor 2 relative to the outer rotor 12 to a selected phase.

Portions of the lubrication system 178 at which the lubrication system communication opening 173D of the oil retention portion 173 communicates with is provided with a predetermined flow path resistance with respect to the flow of oil. The flow path resistance by the lubrication system 178 is considered favorable in a state where the oil discharged from the first pump 171 fills the oil retention chamber 173A and furthermore supplies an appropriately pressured oil to the fluid pressure chambers 4 and other related portions via the bypass passage 179 while the first pump 171 is in operation and the second pump 172 is at a stop. Note that examples of the portions of the lubrication system 178 refer to main gallery portions, chain tensioner portions, and piston jet portions of the internal combustion engine E.

The amount of oil in the oil retention portion 173 changes in accordance with a state of the internal combustion engine E. In a state where the internal combustion engine E is at a stop, supply of oil from the first pump 171 is not provided. Meanwhile, the lubrication system 178 and the first pump 171 communicate with outside air. Accordingly, oil flows out of the lubrication system communication opening 173D and the first communication opening 173B while air flows into the retention chamber 173A. On the other hand, each of the second pump 172 and the check valve 179A is provided with a sealed structure so that the oil in a region lower than the first communication opening 173B does not flow out. Accordingly, an effective amount of oil in the oil retention portion 173 while the internal combustion engine E is at a stop is defined as the amount where a level of oil is lower than the first communication opening 173B and higher than the second communication opening 173C.

At a time immediately after the internal combustion engine E is stopped or started, the first pump 171 is in a stop state or is in an insufficiently operating state. In a state where the second pump 172 is operated to supply oil to the fluid pressure chambers 4 while the first pump 171 is in the aforementioned state, the oil in the retention chamber 173A of the oil retention portion 173 is sucked into the second pump 172 so that an amount of oil in the retention chamber 173A reduces. Meanwhile, the portions of the lubrication system 178 that communicate with the lubrication system communication opening 173D communicate with outside air so that air may flow in from the lubrication system communication opening 173D via the lubrication system 178. Accordingly oil intake resistance by the second pump 172 becomes small. As a result, the second pump 172 may operate even in a state, for example, where temperature of oil is low and viscosity of oil is high.

Furthermore, after the internal combustion engine E is operated to start, the first pump 171 discharges an appropriate amount of oil so that oil fills the retention chamber 173A of the oil retention portion 173. Meanwhile, the portions of the lubrication system 178 that communicate with the lubrication system communication opening 173D communicate with outside air. Accordingly, the air in the retention chamber 173A is forced out form the lubrication system communication opening 173D via the lubrication system 178. Furthermore, the lubrication system 178 is provided with the flow path resistance with respect to the flow of oil. Accordingly, after oil fills the retention chamber 173A, the oil in the retention chamber 173A is retained at a predetermined range of pressure by the flow path resistance of the lubrication system 178. As a result, even in a state where an operation of the second pump 172 is stopped, the fluid pressure chambers 4 and the intermediate phase retaining mechanism 6 and similar members are supplied with appropriately pressured oil via the bypass passage 179. Note that in a state where the rotational speed of the internal combustion engine E becomes low, which is a state where the first pump 171 may not supply an appropriately pressured oil, the second pump 172 may be operated to supply oil accordingly. In a state where the internal combustion engine E is stopped and the second pump 172 is furthermore stopped, oil in the retention chamber 173A returns to a state similar to the state where the internal combustion engine E is stopped.

An example of the first control valve 174 is a variable electromagnetic spool valve. The variable electromagnetic spool valve displaces a spool, which is slidably arranged within a sleeve, against a spring in a state where electricity is supplied from the phase controller 180 to a solenoid. The first control valve 174 includes an advanced angle port communicating with the advanced angle passage 43, a retarded angle port communicating with the retarded angle passage 44, a supply port communicating with the passage in the downstream side of the second pump 172, and a drain port communicating with the oil pan 176.

The first control valve 174 is provided with a three positions control valve. The three positions control valve provides three controls, which are an advanced angle control, a retarded angle control, and a hold control. By operating the advanced angle control, the advanced angle port communicates with the supply port and the retarded angle port communicates with the drain port. By operating the retarded angle control, the retarded angle port communicates with the supply port and the advanced angle port communicates with the drain port. By operating the hold control, the advanced angle port and the retarded angle port are closed. By operating the advanced angle control, the vanes 22 make relative rotational displacement in the advanced angle direction S1 relative to the outer rotor 12 so that the relative rotational phase shifts toward the advanced angle. By operating the retarded angle control, the vanes 22 make relative rotational displacement in the retarded angle direction S2 relative to the outer rotor 12 so that the relative rotational phase shifts toward the retarded angle. By operating the hold control, the vanes 22 do not make relative rotational displacement so that the relative rotational phase may be retained at a selected phase.

By operating the advanced angle control, oil is supplied to the advanced angle passage 43 and the most retarded angle lock passage 71. In a state where the most retarded angle lock mechanism 7 is in the most retarded angle lock state, the most retarded angle lock passage 71 is closed by the most retarded angle lock member 74. The advanced angle control makes the most retarded angle lock member 74 retreat from the most retarded angle lock groove 72 to bring the most retarded angle lock mechanism 7 to the most retarded angle lock release state. Accordingly, oil is supplied to the advanced angle chamber 41 via the advanced angle passage 43 so that the inner rotor 2 makes a relative rotational displacement toward the advanced angle.

Furthermore, the first control valve 174 operates controlled by the phase controller 180. The operation of the first control valve 174 controls oil supply to or oil discharge from the advanced angle chambers 41 and the most retarded angle lock passage 71. Furthermore, the operation of the first control valve 174 controls oil supply to or oil discharge from the retarded angle chamber 42. Accordingly, the first control valve 174 controls the intermediate phase retaining mechanism 6 to switch between the intermediate phase lock state and the intermediate phase release state. Furthermore, accordingly, the first control valve 174 controls relative rotational phase of the inner rotor 2 relative to the outer rotor 12. The valve opening-closing timing control apparatus 1 according to the embodiment is set up to be in a state where the retarded angle control may be operated while the first control valve 174 is supplied with electricity. Furthermore, the valve opening-closing timing control apparatus 1 according to the embodiment is set up to be in a state where the advanced angle control may be operated while the electricity supply to the first control valve 174 is cut off. Moreover, an opening degree of the first control valve 174 is controlled by adjusting duty ratio of the electric power supplied to the electromagnetic solenoid. Accordingly, an amount of oil supplied or an amount of oil discharged may be adjusted with subtlety.

The second control valve 175 is a variable electromagnetic spool valve similarly to the first control valve 174. The second control valve 175 includes a restraining port communicating with the intermediate phase lock passage 61, a supply port communicating with the passage in the downstream side of the second pump 172, and a drain port communicating with the oil pan 176. Furthermore, the second control valve 175 is provided with a two positions control valve. The two positions control valve provides two controls, which are a release control and a restraining control. By operating the release control, the restraining port communicates with the supply port. By operating the restraining control, the restraining port communicates with the drain port. The second control valve 175 operates controlled by the phase controller 180. The operation of the second control valve 175 controls oil supply to or oil discharge from the intermediate phase lock groove 62 of the intermediate phase retaining mechanism 6. Accordingly, the second control valve 175 controls the intermediate phase retaining mechanism 6 to switch between a restrained state and a released state.

Switching between a state where oil is supplied to the intermediate phase lock groove 62 and a state where oil is discharged from the intermediate phase lock groove 62 is controlled by the second control valve 175. Note that, the valve opening-closing timing control apparatus 1 according to the embodiment is set up to be in a state where oil may be discharged from the intermediate phase lock groove 62 while the second control valve 175 is supplied with electricity. Furthermore, the valve opening-closing timing control apparatus 1 according to the embodiment is set up to be in a state where oil may be supplied to the intermediate phase lock groove 62 while the electricity supply to the second control valve 175 is cut off.

Furthermore, a crank angle sensor detecting a rotational angle of the crankshaft 110 is arranged at a position close to the crankshaft 110 of the internal combustion engine E. A camshaft angle sensor detecting a rotational angle of the camshaft 101 is arranged at a position close to the camshaft 101. The phase controller 180 detects the relative rotational phase from detected results from the crank angle sensor and the camshaft angle sensor to determine the phase of the relative rotational phase. Furthermore, the phase controller 180 receives information related to the ignition key being turned on or off, information indicating temperature acquired by the state variable acquisition portion 182 at each portion, and other information. In a memory unit of the phase controller 180, information related to appropriately controlling the relative rotational phase in accordance with an operating state of the internal combustion engine E is stored. Accordingly, the phase controller 180 controls the relative rotational phase in accordance with the operating state of the internal combustion engine E.

In the valve opening-closing timing control apparatus 1 according to the embodiment, the phase controller 180 displaces the relative rotational phase to the intermediate phase on condition that the relative rotational phase at the time the internal combustion engine E has stopped is at a phase toward the retarded angle phase relative to the intermediate phase and the state variable satisfies the predetermined condition. The relative rotational phase refers to the rotational phase between the outer rotor 12 and the inner rotor 2. The intermediate phase refers to the phase at which the valve opening-closing timing control apparatus 1 is in the intermediate phase lock state in the valve opening-closing timing control apparatus 1 according to the embodiment. The relative rotational phase may be determined from the detected results from the crank angle sensor and the camshaft angle sensor. In the valve opening-closing timing control apparatus 1 according to the embodiment, the state variable is at least one of temperature of oil, temperature of the cooling medium, and temperature of air.

In the valve opening-closing timing control apparatus 1 according to the embodiment, the predetermined condition refers to each condition where temperature of oil, of the cooling medium, and of air is equal to or less than a predetermined temperature setting. The phase controller 180 drives the second pump 172 on condition where at least one of the temperature of oil, the temperature of the cooling medium, or the temperature of air is equal to or less than the predetermined temperature defined for each of the oil, the cooling medium and the air. Furthermore, the phase controller 180 displaces the relative rotational phase between the outer rotor 12 and the inner rotor 2 to the intermediate phase by using the first control valve 174 and the second control valve 175. Accordingly, in a situation after the internal combustion engine E is stopped and even in a situation where the internal combustion engine E is cooled down to a cool state, pre-ignition is reliably restrained from occurring.

Note that the control by the phase controller 180, which refers to the control that displaces the relative rotational phase to the intermediate phase, is operated in a state where the internal combustion engine E is at a stop, which is while the internal combustion engine E is stopped. Accordingly, the second pump 172, the first control valve 174, and the second control valve 175 are controlled by using an electric energy from a battery. The second pump 172, especially, is an electric pump.

Procedures that the phase controller 180 follows will be described next using the flow chart in FIG. 5. In a state where the operation of the internal combustion engine E is stopped, the procedure proceeds in a direction that is indicated as Yes in a step S01 and then the phase controller 180 judges whether or not the relative rotational phase between the outer rotor 12 and the inner rotor 2 is at a phase toward the retarded angle relative to the intermediate phase. The judgment is based on the detected results from the crank angle sensor and the camshaft angle sensor. In a state where the relative rotational phase is at a phase toward the retarded angle relative to the intermediate phase, the procedure proceeds in a direction that is indicated as Yes in a step S02 and the phase controller 180 judges whether or not a predetermined condition satisfies.

In a state where the predetermined condition satisfies, the procedure proceeds in a direction that is indicated as Yes in a step S03 and the phase controller 180 displaces the relative rotational phase to the intermediate phase, which is the procedure of a step S04. Then the procedure ends. On the other hand, in a state where the predetermined condition does not satisfy, the procedure proceeds in a direction that is indicated as No in the step S03 and the phase controller 180 maintains the current relative rotational phase, which is the procedure of a step S05. Then the procedure ends.

In the step S02, in a state where the relative rotational phase is not at a phase toward the retarded angle relative to the intermediate phase, the procedure proceeds in a direction that is indicated as No in the step S02, and then the procedure ends as is. Accordingly, the phase controller 180 controls the relative rotational phase of the outer rotor 12 and the inner rotor 2 after the operation of the internal combustion engine E is stopped.

The valve opening-closing timing control apparatus 1 according to other embodiments will be described next. In the valve opening-closing timing control apparatus 1 according to the embodiment, the state variables are defined as at least one of temperature of oil that flows in the internal combustion engine E, temperature of the cooling medium that cools the internal combustion engine E, and air that is taken into the internal combustion engine E. Nevertheless, the state variables are not limited to the above-mentioned state variables. The state variable may be an elapsed time relative to the point in time at which the internal engine E is stopped. In such a case, the state variable acquisition portion 182 may measure the elapsed time to acquire the state variable. The state variable acquisition portion 182 may acquire information of the elapsed time as a result of a measurement by a counter that is provided separately from the state variable acquisition portion 182, instead.

In a state where the elapsed time relative to the point in time at which the internal combustion engine E is stopped is used as the state variable, the phase controller 180 may displace the relative rotational phase to the intermediate phase on condition that the elapsed time becomes equal to or greater than the predetermined elapsed time. Even with the arrangement described herewith, in a situation after the internal combustion engine E is stopped and even in a situation where the internal combustion engine E is cooled down to the cool state, pre-ignition is reliably restrained from occurring.

In the valve opening-closing timing control apparatus 1 according to the embodiment, the phase controller 180 displaces the relative rotational phase to the intermediate phase on condition that the relative rotational phase at the time the internal combustion engine E is stopped is at a phase toward the retarded angle phase relative to the intermediate phase and a state variable furthermore satisfies the predetermined condition. More specifically, the outer rotor 12 and the inner rotor 2 are controlled to be in the intermediate phase lock state. Nevertheless, such characteristic of the valve opening-closing timing control apparatus 1 according to the embodiment may be altered. The phase controller 180 may be arranged to displace the relative rotational phase to a phase between the intermediate phase and the most retarded angle phase on condition that the relative rotational phase at the time the internal combustion engine E is stopped is at a phase toward the retarded angle phase relative to the intermediate phase and a state variable furthermore satisfies the predetermined condition.

In such a case, as FIG. 6 illustrates, the most retarded angle lock groove 72 of the valve opening-closing timing control apparatus 1 according to the embodiment is favorably altered to a start position lock groove 92. Similarly, the most retarded angle lock member 74 is favorably altered to a start position lock member 94 and the start position lock groove 92 is favorably arranged to communicate with the intermediate phase lock passage 61. Upon such arrangement, the valve opening-closing timing control apparatus 1 may control the relative rotational phase at each of the most retarded angle phase, the most advanced angle phase, and the intermediate phase. Furthermore, by receiving the start position lock member 94 in the start position lock groove 92 a start position may be appropriately defined. Accordingly, in a situation after the internal combustion engine E is stopped and even in a situation where the internal combustion engine E is cooled down to the cool state, pre-ignition is reliably restrained from occurring.

The valve opening-closing timing control apparatus 1 according to this disclosure is applicable to a valve opening-closing timing control apparatus 1 that controls the relative rotational phase of the driven-side rotational member integrally rotating with the camshaft 101 of the internal combustion engine E relative to the driving-side rotational member synchronously rotating with the crankshaft 110 of the internal combustion engine E.

According to an aspect of this disclosure, a valve opening-closing timing control apparatus 1 includes a driving-side rotational member (an outer rotor 12) configured to synchronously rotate with a crankshaft 110 of an internal combustion engine E, a driven-side rotational member (an inner rotor 2) configured to integrally rotate with a camshaft 101 of the internal combustion engine E and makes relative rotations relative to the driving-side rotational member (the outer rotor 12), a fluid pressure chamber 4 formed by the driving-side rotational member (the outer rotor 12) and the driven-side rotational member (the inner rotor 2), a vane 22 arranged in the fluid pressure chamber 4 to partition the fluid pressure chamber 4 into a retarded angle chamber 42 and an advanced angle chamber 41, the retarded angle chamber 42 configured to move relative rotational phase of the driven-side rotational member (the inner rotor 2) relative to the driving-side rotational member (the outer rotor 12) in a retarded angle direction S2 that is one direction of the relative rotations and the advanced angle chamber 41 configured to move the relative rotational phase in an advanced angle direction S1 that is another direction of the relative rotations, an intermediate phase retaining mechanism 6 retaining the relative rotational phase at an intermediate phase that is a phase between most retarded angle phase and most advanced angle phase, a state variable acquisition portion 182 acquiring a state variable relating to the internal combustion engine E, and a phase controller 180 displacing the relative rotational phase to the intermediate phase on condition that the relative rotational phase is at a retarded angle phase relative to the intermediate phase at a time at which the internal combustion engine E stops and the state variable satisfies a predetermined condition.

Upon the arrangement described herewith, the relative rotational phase may be displaced to the intermediate phase on condition that the intermediate phase is considered appropriate as the relative rotational phase between the driving-side rotational member (the outer rotor 12) and the driven-side rotational member (the inner rotor 2) at a time of starting the internal combustion engine E. Accordingly, the internal combustion engine E may be smoothly re-started. On the other hand, in a situation where pre-ignition may occur at the time of re-starting the internal combustion engine E, the relative rotational phase is restrained from displaced to the intermediate phase. As a result, pre-ignition is reliably restrained from occurring.

According to another aspect of this disclosure, the state variable acquisition portion 182 of the valve opening-closing timing control apparatus 1 acquires at least one of temperature of oil flowing in the internal combustion engine E, temperature of a cooling medium for cooling the internal combustion engine E, and temperature of air taken into the internal combustion engine E as the state variable. The phase controller 180 displaces the relative rotational phase to the intermediate phase on condition that temperature acquired as the state variable is equal to or less than a predetermined temperature for each of the state variables.

Upon the arrangement described herewith, the internal combustion engine E may be re-started with the relative rotational phase at the retarded angle phase in a case similar to a case where the internal combustion engine E is stopped by the idle stop function and re-starting the internal combustion engine E in a warm state where the state of the internal combustion engine E is not cooled down and in a case similar to a case where the internal combustion engine E has stopped operation and re-starting the internal combustion engine E after a short period while the internal combustion engine E is still in a warm state. Accordingly, pre-ignition is reliably restrained from occurring. On the other hand, in a state where the internal combustion engine E is in a cool state, the internal combustion engine E may be started with the relative rotational phase at the intermediate phase, which is appropriate for the internal combustion engine E in the cool state.

According to further aspect of this disclosure, the state variable acquisition portion 182 of the valve opening-closing timing control apparatus 1 acquires an elapsed time relative to a point in time at which the internal combustion engine E is stopped as the state variable. The phase controller 180 displaces the relative rotational phase to the intermediate phase on condition that the elapsed time acquired as the state variable by the state variable acquisition portion 182 becomes equal to or greater than a predetermined elapsed time.

Upon the arrangement described herewith, the internal combustion engine E may be started with the relative rotational phase between the driving-side rotational member (the outer rotor 12) and the driven-side rotational member (the inner rotor 2) at a retarded angle phase in a case where the internal combustion engine E is operated to start after the internal combustion engine E is stopped and is in a cooled state after a predetermined time has elapsed relative to the point in time where the internal engine E is stopped. Accordingly, pre-ignition is reliably restrained from occurring. On the other hand, in a state where the internal combustion engine E is in a cool state, the internal combustion engine E may be started with the relative rotational phase at the intermediate phase, which is appropriate for the internal combustion engine E in the cool state.

According to another aspect of this disclosure, the phase controller 180 of the valve opening-closing timing control apparatus 1 displaces the relative rotational phase to the intermediate phase while the internal combustion engine E is at a stop.

Upon the arrangement described herewith, the relative rotational phase may be altered in advance while the internal combustion engine E is at a stop. Accordingly at the time the internal combustion engine E is operated to start in the next time, the internal combustion engine E may start operation in a state where a setting of the relative rotational phase to the intermediate phase has completed so that the internal combustion engine E may be smoothly started.

According to further aspect of this disclosure, a valve opening-closing timing control apparatus 1 includes a driving-side rotational member (an outer rotor 12) configured to synchronously rotate with a crankshaft 110 of an internal combustion engine E, a driven-side rotational member (an inner rotor 2) configured to integrally rotate with a camshaft 101 of the internal combustion engine E and makes relative rotations relative to the driving-side rotational member (the outer rotor 12), a fluid pressure chamber 4 formed by the driving-side rotational member (the outer rotor 12) and the driven-side rotational member (the inner rotor 2), a vane 22 arranged in the fluid pressure chamber 4 to partition the fluid pressure chamber 4 into a retarded angle chamber 42 and an advanced angle chamber 41, the retarded angle chamber 42 within which a volume increases in a case where a relative rotational phase of the driven-side rotational member (the inner rotor 2) relative to the driving-side rotational member (the outer rotor 12) moves in a retarded angle direction S2 that is one direction of the relative rotations, the advanced angle chamber 41 within which a volume increases in a case where the relative rotational phase moves in an advanced angle direction S1 that is a different direction from the retarded angle direction S2, an intermediate phase retaining mechanism 6 retaining the relative rotational phase at an intermediate phase that is a phase between most retarded angle phase and most advanced angle phase where the most retarded angle phase is a phase at which the volume within the retarded angle chamber 42 is at maximum and the most advanced angle phase is a phase at which the volume within the advanced angle chamber 41 is at maximum, a state variable acquisition portion 182 acquiring a state variable relating to the internal combustion engine E, and a phase controller 180 displacing the relative rotational phase to the intermediate phase on condition that the relative rotational phase at a time at which the internal combustion engine E stops is at a position closer to the most retarded angle phase relative to the intermediate phase and the state variable acquired by the state variable acquisition portion 182 satisfies a predetermined condition.

Upon the arrangement described herewith, the relative rotational phase may be displaced to the intermediate phase on condition that the intermediate phase is considered appropriate as the relative rotational phase between the driving-side rotational member (the outer rotor 12) and the driven-side rotational member (the inner rotor 2) at a time of starting the internal combustion engine E. Accordingly, the internal combustion engine E may be smoothly re-started. On the other hand, in a situation where pre-ignition may occur at the time of re-starting the internal combustion engine E, the relative rotational phase is restrained from displaced to the intermediate phase. As a result, pre-ignition is reliably restrained from occurring.

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.

Claims

1. A valve opening-closing timing control apparatus, comprising:

a driving-side rotational member configured to synchronously rotate with a crankshaft of an internal combustion engine;

a driven-side rotational member configured to integrally rotate with a camshaft of the internal combustion engine and makes relative rotations relative to the driving-side rotational member;

a fluid pressure chamber formed by the driving-side rotational member and the driven-side rotational member;

a vane arranged in the fluid pressure chamber to partition the fluid pressure chamber into a retarded angle chamber and an advanced angle chamber, the retarded angle chamber configured to move relative rotational phase of the driven-side rotational member relative to the driving-side rotational member in a retarded angle direction that is one direction of the relative rotations and the advanced angle chamber configured to move the relative rotational phase in an advanced angle direction that is another direction of the relative rotations;

an intermediate phase retaining mechanism retaining the relative rotational phase at an intermediate phase that is a phase between most retarded angle phase and most advanced angle phase;

a state variable acquisition portion acquiring a state variable relating to the internal combustion engine; and

a phase controller displacing the relative rotational phase to the intermediate phase on condition that the relative rotational phase is at a retarded angle phase relative to the intermediate phase at a time at which the internal combustion engine stops and the state variable satisfies a predetermined condition.

2. The valve opening-closing timing control apparatus according to claim 1, wherein

the state variable acquisition portion acquires at least one of temperature of oil flowing in the internal combustion engine, temperature of a cooling medium for cooling the internal combustion engine, and temperature of air taken into the internal combustion engine as the state variable, and wherein

the phase controller displaces the relative rotational phase to the intermediate phase on condition that temperature acquired as the state variable is equal to or less than a predetermined temperature for each of the state variables.

3. The valve opening-closing timing control apparatus according to claim 1, wherein

the state variable acquisition portion acquires an elapsed time relative to a point in time at which the internal combustion engine is stopped as the state variable and wherein

the phase controller displaces the relative rotational phase to the intermediate phase on condition that the elapsed time acquired as the state variable by the state variable acquisition portion becomes equal to or greater than a predetermined elapsed time.

4. The valve opening-closing timing control apparatus according to claim 1, wherein

the phase controller displaces the relative rotational phase to the intermediate phase while the internal combustion engine is at a stop.

5. A valve opening-closing timing control apparatus, comprising:

a driving-side rotational member configured to synchronously rotate with a crankshaft of an internal combustion engine;

a driven-side rotational member configured to integrally rotate with a camshaft of the internal combustion engine and makes relative rotations relative to the driving-side rotational member;

a fluid pressure chamber formed by the driving-side rotational member and the driven-side rotational member;

a vane arranged in the fluid pressure chamber to partition the fluid pressure chamber into a retarded angle chamber and an advanced angle chamber;

the retarded angle chamber within which a volume increases in a case where a relative rotational phase of the driven-side rotational member relative to the driving-side rotational member moves in a retarded angle direction that is one direction of the relative rotations;

the advanced angle chamber within which a volume increases in a case where the relative rotational phase moves in an advanced angle direction that is a different direction from the retarded angle direction;

an intermediate phase retaining mechanism retaining the relative rotational phase at an intermediate phase that is a phase between most retarded angle phase and most advanced angle phase where the most retarded angle phase is a phase at which the volume within the retarded angle chamber is at maximum and the most advanced angle phase is a phase at which the volume within the advanced angle chamber is at maximum;

a state variable acquisition portion acquiring a state variable relating to the internal combustion engine; and

a phase controller displacing the relative rotational phase to the intermediate phase on condition that the relative rotational phase at a time at which the internal combustion engine stops is at a position closer to the most retarded angle phase relative to the intermediate phase and the state variable acquired by the state variable acquisition portion satisfies a predetermined condition.