Variable valve actuating apparatus for internal combustion engine

A variable valve actuating apparatus includes: a first lock recessed portion; a first lock member; a second lock recessed portion formed in the second rotary member's side; a second lock member; a first lock passage arranged to supply the hydraulic fluid, and thereby to move the first lock member out of the first lock recessed portion; and a second lock passage arranged to supply the hydraulic fluid, and thereby to move the second lock member out of the second lock recessed portion, at least a part of the first lock recessed portion and at least a part of the second lock recessed portion being disposed at a position to be projected in an axial direction when the first lock member and the second lock member are in the lock state.

BACKGROUND OF THE INVENTION

This invention relates to a variable valve actuating apparatus for an internal combustion engine which is configured to variably control an operation characteristic of an engine valve which is an intake valve and/or an exhaust valve of the internal combustion engine.

U.S. Patent Application Publication No. 2010/212617 A1 (corresponding to Japanese Patent Application Publication No. 2010-196486) discloses a conventional variable valve actuating apparatus.

The above-described variable valve actuating apparatus includes two intake valves in each cylinder; an inner cam shaft integrally provided with an inner cam provided on an outer circumference of the inner cam shaft, and arranged to drive one of the intake valves; and an outer cam shaft disposed on an outer circumference of the inner cam shaft to be relatively rotated (relative to the inner cam shaft), and integrally provided with an outer cam provided on an outer circumference of the outer cam shaft, and arranged to drive the other of the intake valves. At an end portion of the inner cam shaft and an end portion of the outer cam shaft, there are integrally provided, respectively, two vane-type hydraulic actuators which are arranged in series (with each other) in an axial direction.

The two hydraulic actuators are arranged to relatively rotate the inner cam shaft and the outer cam shaft by the supplied hydraulic pressure, and thereby to control the operation angle of the intake valve. Moreover, the two hydraulic pressure actuators are arranged to relatively rotate the inner cam shaft and the outer cam shaft relative to (with respect to) the crank shaft, and thereby to control opening/closing timing of each intake valve.

SUMMARY OF THE INVENTION

However, in the conventional variable valve actuating apparatus, the two hydraulic actuators are integrally provided at the end portions of the inner cam shaft and the outer cam shaft, and arranged in series (with each other) in the axial direction. Accordingly, an axial length of the apparatus becomes long, so that a size of the apparatus becomes larger.

It is, therefore, an object of the present invention to provide a variable valve actuating apparatus which is arranged to control a relative rotational phase of an inner cam shaft and an outer cam shaft, and to control relative rotational phases of both cam shafts with respect to the cranks shaft, and whose size is decreased.

According to one aspect of the present invention, a variable valve actuating apparatus for an internal combustion engine, the variable valve actuating apparatus comprises: an inner cam shaft including an inner cam formed on an outer circumference thereof; an outer cam shaft which is provided on the outer circumference of the inner cam shaft, which includes an outer cam provided radially outside the outer cam shaft, the outer cam shaft and the inner cam shaft being arranged to be relatively rotated so as to vary a relative rotational phase of the outer cam with respect to the inner cam; a drive rotary member to which a rotational force is transmitted from a crank shaft, and which includes an operation chamber formed within the drive rotary member; a first rotary member which includes a rotor fixed to one of the inner cam shaft and the outer cam shaft, vanes separating the operation chamber to an advance angle operation chamber and a retard angle operation chamber, and a receiving chamber formed within the first rotary member, and which is arranged to be rotated in an advance angle direction or in a retard angle direction relative to the drive rotary member by a hydraulic pressure selectively supplied to or drained from the advance angle operation chamber and the retard angle operation chamber; and a second rotary member fixed to the other of the inner cam shaft and the outer cam shaft, rotatably received within the receiving chamber of the first rotary member, and arranged to be rotated relative to the first rotary member and the drive rotary member within a predetermined angle range; a first lock recessed portion formed on a sliding surface of the drive rotary member on which an axial end surface of the second rotary member is slid; a first lock member which is arranged to be moved in a direction of a rotation axis of the second rotary member, and which is arranged to be moved into and engaged with the first lock recessed portion, and thereby to lock the relative rotation between the drive rotary member and the second rotary member, and which is arranged to be moved out of the first lock recessed portion, and thereby to release the lock between the drive rotary member and the second rotary member; a second lock recessed portion formed in the second rotary member's side; a second lock member provided to the first rotary member to be moved in an axial direction, and arranged to be moved into and engaged with the second lock recessed portion to lock the relative rotation between the first rotary member and the second rotary member, and to be moved out of the second recessed portion to release the lock between the first rotary member and the second rotary member; a first lock passage arranged to supply the hydraulic fluid, and thereby to move the first lock member out of the first lock recessed portion; and a second lock passage arranged to supply the hydraulic fluid, and thereby to move the second lock member out of the second lock recessed portion, at least a part of the first lock recessed portion and at least a part of the second lock recessed portion being disposed at a position to be projected in an axial direction when the first lock member and the second lock member are in the lock state.

According to another aspect of the invention, a variable valve actuating apparatus for an internal combustion engine, the variable valve actuating apparatus comprises: an inner cam shaft including an inner cam formed on an outer circumference thereof; an outer cam shaft which is provided on the outer circumference of the inner cam shaft, which includes an outer cam provided radially outside the outer cam shaft, the outer cam shaft and the inner cam shaft being arranged to be relatively rotated so as to vary a relative rotational phase of the outer cam with respect to the inner cam; a drive rotary member to which a rotational force is transmitted from a crank shaft; a first rotary member which is fixed to one of the inner cam shaft and the outer cam shaft, which is arranged to be rotated in an advance angle direction or in a retard angle direction relative to the drive rotary member by a hydraulic pressure, and which includes a receiving chamber formed within the first rotary member; a second rotary member fixed to the other of the inner cam shaft and the outer cam shaft, rotatably received within the receiving chamber of the first rotary member, and arranged to be rotated relative to the first rotary member and the drive rotary member within a predetermined angle range; a first lock recessed portion formed on a sliding surface of the drive rotary member on which an axial end surface of the second rotary member is slid; a first lock member which is arranged to be moved in a direction of a rotation axis of the second rotary member, and which is arranged to be moved into and engaged with the first lock recessed portion, and thereby to lock the relative rotation between the drive rotary member and the second rotary member, and which is arranged to be moved out of the first lock recessed portion, and thereby to release the lock between the drive rotary member and the second rotary member; a second lock recessed portion formed in the second rotary member's side; a second lock member provided to the first rotary member to be moved in an axial direction, and arranged to be moved into and engaged with the second lock recessed portion to lock the relative rotation between the first rotary member and the second rotary member, and to be moved out of the second recessed portion to release the lock between the first rotary member and the second rotary member; a first lock passage arranged to supply the hydraulic fluid, and thereby to move the first lock member out of the first lock recessed portion; and a second lock passage arranged to supply the hydraulic fluid, and thereby to move the second lock member out of the second lock recessed portion, at least a part of the first lock recessed portion and at least a part of the second lock recessed portion being disposed at a position to be projected in an axial direction when the first lock member and the second lock member are in the lock state.

According to still another aspect of the invention, a variable valve actuating apparatus for an internal combustion engine, the variable valve actuating apparatus comprises: an inner cam shaft including an inner cam formed on an outer circumference thereof; an outer cam shaft which is provided on the outer circumference of the inner cam shaft, which includes an outer cam provided radially outside the outer cam shaft, the outer cam shaft and the inner cam shaft being arranged to be relatively rotated so as to vary a relative rotational phase of the outer cam with respect to the inner cam; a drive rotary member to which a rotational force is transmitted from a crank shaft, and which includes an operation chamber formed within the drive rotary member; a first rotary member which includes a rotor fixed to one of the inner cam shaft and the outer cam shaft, vanes separating the operation chamber to an advance angle operation chamber and a retard angle operation chamber, and a receiving chamber formed within the first rotary member, and which is arranged to be rotated in an advance angle direction or in a retard angle direction relative to the drive rotary member by a hydraulic pressure selectively supplied to or drained from the advance angle operation chamber and the retard angle operation chamber; and a second rotary member fixed to the other of the inner cam shaft and the outer cam shaft, rotatably received within the receiving chamber of the first rotary member, and arranged to be rotated relative to the first rotary member and the drive rotary member within a predetermined angle range; a first lock mechanism provided to the first rotary member, and arranged to lock a relative rotation between the first rotary member and the second rotary member, and to release the lock of the relative rotation between the first rotary member and the second rotary member; and a second lock mechanism provided to the second rotary member, and arranged to lock a relative rotation between the drive rotary member and the second rotary member in accordance with a request, and to release the lock of the relative rotation between the drive rotary member and the second rotary member in accordance with the request.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, variable valve actuating apparatuses for an internal combustion engine according to embodiments of the present invention are illustrated with reference to the drawings. In these embodiments, the variable valve actuating apparatus is applied to an exhaust valve side of, for example, a four cylinder gasoline internal combustion engine.

First Embodiment

The internal combustion engine includes two exhaust valves at each one cylinder. The variable valve actuating apparatus is arranged to variably control an opening and closing timing and an operation angle (opening angle) of both exhaust valves in accordance with a driving state of the engine.

That is, as shown inFIG. 1-FIG.5, the variable valve actuating apparatus includes a sprocket1arranged to be driven and rotated through a timing chain by a crank shaft (not shown) of the engine; a cam shaft2on the exhaust side which is provided to be rotated relative to sprocket1; a phase varying mechanism3disposed between sprocket1and cam shaft2, and arranged to shift a relative rotational phase of sprocket1and cam shaft2; and a hydraulic pressure circuit4which is arranged to actuate phase varying mechanism3.

The two exhaust valves of each cylinder includes an umbrella (bonnet) portion arranged to open and close an opening end of each of the two exhaust portions on the cylinder's side. Each of the two exhaust valves is arranged to be urged in a closing direction by a spring force of a valve spring through a valve lifter disposed at an upper end portion of each exhaust valve.

As shown inFIG. 1andFIG. 2, cam shaft2includes an outer cam shaft5having a hollow inside portion; and an inner cam shaft6which has a solid inside portion, and which is provided within outer cam shaft5to be rotated relative to outer cam shaft5. Inner cam shaft6is rotatably supported on an inner circumference surface of outer cam shaft. On the other hand, outer cam shaft5is rotatably supported by a cylinder head (not shown) through a cam bearing.

Outer cam shaft5is integrally provided with a first drive cam5aon an outer circumference surface of outer cam shaft5at a predetermined position by the press fit. First drive cam5ais arranged to open one of the exhaust valve of each cylinder through the valve lifter.

Inner cam shaft6includes an internal screw hole6cformed within a tip end portion6bof inner cam shaft6in the axial direction, and into which an external screw of the outer circumference of a shaft portion9cof a cam bolt9is screwed. Moreover, a second drive cam6ais fixed at a predetermined position of inner cam shaft6in the axial direction. Second drive cam6ais arranged to open the one of the exhaust valves through the same valve lifer while sliding on the outer circumference of outer cam shaft5.

Inner cam shaft6includes a through hole6dwhich is formed to extend in the diameter direction. A connection shaft7penetrates through through hole6dof inner cam shaft6, and fixed to through hole6dof inner cam shaft6. Moreover, both end portions7aand7bof connection shaft7are fixed in the inside portions of second drive cam6aby the press fit. With this, second drive cam6ais fixed to inner cam shaft6. Moreover, connection shaft7penetrates through a pair of insertion holes5cand5dformed in outer cam shaft5to penetrate through outer cam shaft5fin the diameter direction. Each of insertion holes5cand5dis formed into a slit shape extending in a circumferential direction, so as to allow inner cam shaft6to rotate relative to outer cam shaft5within a predetermined angle range, through connection shaft7.

As shown inFIG. 1andFIGS. 2A and 2B, first drive cam5aand second drive cam6aare disposed adjacent to each other through a minute gap between first drive cam5aand second drive cam6a. Moreover, first drive cam5aand second drive cam6ainclude outer circumference surfaces5band6bhaving the same oval cam profile. First drive cam5aand second drive cam6aare arranged to independently open and close the one of the exhaust valves of the one cylinder.

As shown inFIG. 1, andFIG. 3-FIG.5, phase varying mechanism3includes a housing8which is disposed at one end portion of cam shaft2, and which is integrally formed with sprocket1; and a first vane rotor10which is a first rotary member that is fixed at the one end portion of outer cam shaft5by cam bolt9from the axial direction, and that is rotatably received within housing8; three first to third shoes11a-11cprotruding from an inner circumference surface of housing8; three retard fluid pressure chambers12which are retard angle operation chambers that are separated by three shoes11a-11cand three first to third vanes20-22of first vane rotor10described later; and advance fluid pressure chambers13which are advance angle operation chambers that are separated by three first to third shoes11a-11cand three first to third vanes20-22.

Housing8includes a cylindrical housing main body14which has openings at both axial ends, and which is used together with sprocket1; and a front plate15and a rear plate16which closes the front and rear axial openings of housing main body14. Front plate15and rear plate16are integrally connected together with housing main body14by screwing together from the axial direction by three bolts17.

Housing main body14is formed from a sintered metal into a cylindrical integral body. Housing main body14includes a toothed portion is which is integrally formed on an outer circumference of a front end of housing main body14, and around which a chain is wound; and three first to third shoes11a-11cwhich are integrally formed on an inner circumference, and which protrude in the inward direction.

Each of shoes11a-11chas a substantially trapezoid shape as viewed in the side direction. Two of the shoes11a-11c(shoes11band11c) are disposed at an interval of 180 degrees in the circumferential direction of housing main body14. One of shoes11a-11c(shoe11a) is disposed between the two of shoes11a-11c. Each of shoes11a-11cincludes a seal groove formed at a tip end portion of the each of shoes11a-11cin the axial direction. A seal member18which is substantially U-shape is mounted and fixed in each of the seal grooves of shoes11a-11c.

Moreover, each of shoes11a-11cincludes a bolt insertion hole11dwhich is formed at a radially outer side portion (outer circumference portion) of each of shoes11a-11c, and which penetrates through the each of shoes11a-11c. Each of bolts17is inserted into one of the bolt insertion holes11d.

First shoe11aincludes a flat first raised surface11awhich is formed on one circumferential side surface in the circumferential direction. On the other hand, second shoe11bincludes a flat second raised surface11fwhich is formed on one circumferential side surface confronting the one circumferential side surface of first shoes11ain the circumferential direction. When first vane rotor20described later is rotated in a clockwise direction and in a counterclockwise direction as shown inFIG. 5andFIG. 6, the corresponding surfaces of first vane20(which confront raised surfaces11eand11f) are abutted on these raised surfaces11eand11fso as to restrict first vane rotor10at a most retard position and most advance angle position.

Front plate15is formed by press-forming a metal sheet, into a circular disc plate having a relatively small thickness. Front plate15includes a large diameter hole15awhich is formed at a central portion of front plate15, and in which a flange-shaped seat portion9bof a head portion9aof cam bolt9is disposed and received; and three bolt insertion holes15bwhich are formed on an outer circumference side at a regular interval in the circumferential direction, which penetrate through front plate15, and each of which one of bolts17is inserted through. Moreover, this front plate15includes two breath holes15cand15deach of which has a small diameter, each of which penetrates through front plate15, which are formed on an inner circumference portion of front plate15.

These breath holes15cand15dare arranged to connect the outside air and a second sliding hole42of a second lock mechanism41described later when first vane rotor10is positioned at the relative rotational positions on the most advance angle side and on the most retard angle side, so as to ensure the good slidability of a second lock pin43.

Rear plate16is formed from the sintered alloy into a circular disc shape having a thickness larger than the thickness of front plate15. Rear plate16includes a support hole16awhich is formed at a central portion of rear plate16, which penetrates through rear plate16, into which a cylindrical rear end portion of a first rotor19(described later) of a first vane rotor10is inserted, and which rotatably supports the cylindrical rear end portion of first rotor19of first vane rotor10. Moreover, rear plate16includes three internal screw holes16bformed on the outer circumference side of rear plate16at a regular interval in the circumferential direction, and into which the external screws of the tip end portions of bolts17are respectively screwed.

Rear plate16includes first lock holes31aand31bwhich are two first lock recessed portions of first lock mechanism28described later, and which are formed on the outer circumference portion of rear plate16at predetermined positions. These first lock holes31aand31bare formed at a predetermined interval on the same arc locus so that a first lock pin30which is the first lock member of first lock mechanism28is engaged with first lock holes31aand31bat relative rotational positions of the most advance angle position and the most retard angle position of first vane rotor10, as described later.

Rear plate16includes a positioning pin16cwhich is located on the outer circumference portion of rear plate16at a predetermined position, which protrudes, and which is inserted in and engaged with a positioning hole14aformed in second shoe11bof housing main body14so as to position rear plate16with respect to housing main body14.

First vane rotor10is integrally formed from, for example, the sintered metal. As shown inFIG. 1,FIG. 3, andFIG. 5, first vane rotor10includes a first rotor19on a central side; and three first to third vanes20-22which protrude from the outer circumference of first rotor19in the radial directions.

First rotor19has an overall shape which is formed into a substantially cylindrical hollow shape. First rotor19has a stepped shape having a large diameter portion19aand a small diameter portion19bwhich are arranged in the circumferential direction. Large diameter portion19aof first rotor19has a large outside diameter.

Small diameter portion19bof first rotor19has a small outside diameter smaller than the outside diameter of large diameter portion19aof first rotor19. First rotor19includes large diameter portion19abetween first vane20and second vane21; and small diameter portion19bbetween first vane20and third vane22.

This first rotor19includes an insertion hole19dwhich is formed at a central portion of a disc wall19cformed at the front end portion of first rotor19, into which shaft portion9cof cam bolt9is inserted, and which penetrates through first rotor19in the axial direction; and first and second mounting holes19eand19fwhich are formed into stepped shapes. A tip end portion5dof outer cam shaft5is mounted in first mounting hole19eof first rotor19. A tip end portion6cof inner cam shaft6is mounted in second mounting hole19fof first rotor19. Moreover, this first rotor19is fixed at tip end portion6cof inner cam shaft6by being tightened by cam bolt9through disc wall19cfrom the axial direction.

In this first rotor19, tip end portion5dof outer cam shaft5is mounted in first mounting hole19e. However, first rotor19is not connected with outer cam shaft5so as to allow the free rotation between outer cam shaft5and first rotor19.

Moreover, first rotor19includes a receiving chamber26which is formed in an inside of first rotor19on a rear side of first mounting hole19ein which outer cam shaft5is mounted, and which receives second vane rotor23to be relatively rotated. As shown inFIG. 5, this receiving chamber26includes a circular rotor receiving portion26aformed at a central portion of first rotor19; and a sectorial vane receiving portion26bwhich is formed into a sectorial shape within large diameter portion19a, and which is connected to rotor receiving portion26a.

Large diameter portion19aincludes a second sliding hole42formed at a substantially central position in the circumferential direction, which penetrates in the axial direction, and in which second lock pin43that is a second lock member of second lock mechanism41is slid.

As shown inFIG. 5, first to third vanes20to22have a substantially same circumferential width. Each of first to third vanes20to22includes a mounting groove formed at a tip end portion of the each of first to third vanes20to22. Seal members27are mounted and fixed, respectively, in the mounting grooves of first to third vanes20to22. Seal members27are slidably abutted on an inner circumference surface of housing main body14so as to seal retard fluid pressure chambers and advance fluid pressure chambers12and13.

Moreover, one circumferential side surface of first vane20on a counterclockwise side in the drawing (the advance fluid pressure chamber13's side) is abutted on first raised surface11eso as to restrict the maximum relative rotation when first vane20is relatively rotated on the retard angle side. Furthermore, the other circumferential side surface of first vane20on a clockwise side in the drawing (the retard fluid pressure chamber12's side) is abutted on second raised surface11fso as to restrict the maximum relative rotation when first vane20is relatively rotated on the advance angle side.

As shown inFIG. 1,FIG. 3, andFIG. 5, second vane rotor23received within receiving chamber26includes an annular second rotor24received and held within rotor receiving portion26aof first rotor19to be relatively rotated; and a fourth vane25which is integrally formed on the outer circumference surface of second rotor24, which protrudes from the outer circumference surface of second rotor24, and which is pivotally received within vane receiving chamber26b.

Second rotor24has an outside diameter slightly smaller than an inside diameter of rotor receiving portion26a. Between the outer circumference surface of second rotor24and an inner circumference surface of rotor receiving portion26a, there is formed a minute cylindrical clearance to ensure the free rotation of second rotor24. Moreover, second rotor24has an axial length substantially identical to an axial length of rotor receiving portion26a.

Moreover, as shown inFIG. 1, this second rotor24includes a circular fix hole24awhich is formed at a central portion of second rotor24, and which penetrates in the axial direction. Tip end portion5dof outer cam shaft5is fixed in this fix hole24aof second rotor24by the press fit.

Fourth vane25has a sectorial shape corresponding to vane receiving portion26b. Fourth vane25is received within vane receiving portion26bto be relatively rotated. Moreover, between an outer circumference surface25bof fourth vane25and an inner circumference surface of vane receiving portion26b, there is formed a clearance.

Moreover, fourth vane25includes a first sliding hole29which is a second lock recessed hole, which is formed in fourth vane25on a counterclockwise side of the circumferential direction, that is, on the retard angle side, and which penetrates through fourth vane25in the axial direction. First lock pin30of first lock mechanism28is slid within this first sliding hole29.

Hydraulic pressure circuit4is arranged to supply the hydraulic pressure selectively to retard fluid pressure chambers12and advance fluid pressure chambers13, and to drain (discharge) the hydraulic pressure selectively from retard fluid pressure chambers12and advance fluid pressure chambers13. As shown inFIG. 1andFIG. 4, hydraulic pressure circuit4includes a retard side passage36connected with retard fluid pressure chambers12; an advance side passage37connected with advance fluid pressure chambers13; an oil pump39arranged to supply the hydraulic pressure selectively to retard side passage36and advance side passage37thorough an electromagnetic switching valve (solenoid valve)38; and a drain passage40connected selectively to retard side passage36and advance side passage37through electromagnetic switching valve38.

As shown inFIG. 4, retard side passage36includes a groove36aformed on an outer circumference surface of outer cam shaft5; a radial hole and an axial hole36bwhich are continuously formed within inner cam shaft6, and which are connected with groove36a; a radial hole36cformed on the tip end side of axial hole36a; an annular groove36dformed on the inner circumference surface of second mounting hole19fof first rotor19, and connected with radial hole36a; and three retard side oil holes36ewhich is formed within first rotor19in the radial directions, and which connects annular groove36dand retard fluid pressure chambers12.

Similarly, as shown inFIG. 4, advance side passage37includes a groove37aformed on the outer circumference surface of outer cam shaft5; a radial hole and an axial hole37bwhich are continuously formed within inner cam shaft6, and which are connected with groove37a; and a radial hole37cformed on the tip end side of axial hole37b; a connection hole37dformed at the tip end portion of outer cam shaft5in the radial direction, and connected with radial hole37c; an annular groove37eformed on the inner circumference surface of first mounting hole19eof first rotor19, and connected with connection hole37d; and three advance side holes37fwhich are formed within first rotor19in the radial directions, and which connect annular groove37eand advance fluid pressure chambers13.

In electromagnetic switching valve38, a spool valve within electromagnetic switching valve38is moved in an axial direction by an output and a shut-off of a control current from a control unit (ECU) (not shown) to an electromagnetic coil. With this, electromagnetic switching valve38is arranged to control to switch selectively discharge passage39aof oil pump39and drain passage40with respect to retard side passage36and advance side passage37. That is, when the control unit outputs the control current, electromagnetic switching valve38connects discharge passage39aand retard side passage36, and concurrently connects drain passage40and advance side passage37. On the other hand, when the control unit shuts off the control current, electromagnetic switching valve38connects discharge passage39aand advance side passage37, and concurrently connects drain passage40and retard side passage36.

An internal computer of the control unit senses a current driving state of the engine by receiving information signals from various sensors such as a crank angle sensor, an air flow meter, a water temperature sensor, and a throttle valve opening degree sensor (not shown). The control unit outputs the control current to the electromagnetic coil of electromagnetic switching valve38in accordance with this driving state of the engine.

As shown inFIG. 1,FIG. 3, andFIG. 8, first lock mechanism28includes a sliding hole29formed in fourth vane25of second vane rotor23; first lock pin30slidably received within sliding hole29, and arranged to be moved toward and away from (into and out of) rear plate16(in the forward direction and in the rearward direction with respect to rear plate16); and two first lock holes31aand31bwhich are formed in rear plate16, and with which a tip end portion30aof first lock pin30is engaged to lock second vane rotor23; and a first engagement/release mechanism arranged to engage tip end portion30aof first lock pin30with lock holes31aand31bin accordance with the driving state of the engine, and to release the engagement of tip end portion30aof first lock pin30with lock holes31aand31bin accordance with the driving state of the engine.

First sliding hole29has a uniform inside diameter which is relatively large. First sliding hole29penetrates through second vane rotor23(fourth vane25) in the axial direction.

First lock pin30includes a rear end portion having an outer circumference surface having a substantially uniform outside diameter to correspond to first sliding hole29; and a tip end portion30ahaving a small diameter slightly smaller than an inside diameter of first lock holes31aand31b. Moreover, first lock pin30includes a stepped pressure receiving surface30bwhich has a stepped shape, and which is formed between the rear end portion and tip end portion30a. Furthermore, there is formed an annular first pressure receiving chamber32between pressure receiving surface30band a first oil groove25aformed by cutting an edge of a tip end of first sliding hole29.

Each of first lock holes31aand31bhas a bottomed cylindrical shape. As described above, first lock holes31aand31bare formed on the inside surface of rear plate16on the inner circumference side at a predetermined interval in the circumferential direction.

One lock hole31ais formed at a position at which first lock pin30is engaged with lock hole31afrom the axial direction when second vane rotor23is relatively rotated on the most advance angle side. The other lock hole31bis formed at a position at which first lock pin30is engaged with lock hole31bfrom the axial direction when second vane rotor23is relatively rotated on the most retard angle side.

Accordingly, when first lock pin30is engaged with the one first lock hole31a, the relative rotational angle between housing8and second vane rotor23becomes a shift conversion angle (phase) of the most advance angle which is optimal for the start of the engine. When first lock pin30is engaged with the other first lock hole31b, the relative rotational angle between housing8and second vane rotor23becomes a shift angle (phase) of the most retard angle.

First lock pin30has an outside diameter larger than an inside diameter of second sliding hole42described later. Accordingly, when first lock pin30is moved in the rearward direction (the leftward direction inFIG. 8), a rear end outer circumference edge30bof first lock pin30is abutted on the edge of second sliding hole42, so that the maximum rearward movement of first lock pin30is restricted. At this time, tip end portion30aof first lock pin30is fully moved out of first lock holes31aand31b.

The first engagement and release mechanism shares a part of an engagement and release mechanism of second lock mechanism41. The first engagement and release mechanism includes a coil spring33elastically mounted (disposed) between a rear end portion of second lock pin43described later and the inner end surface of front plate15, and arranged to urge first lock pin30through second lock pin43in the forward direction (in the direction toward first lock hole31aand31b); and a first release hydraulic pressure circuit34arranged to supply the hydraulic pressure to first pressure receiving surface30band first lock holes31aand31bthrough first pressure receiving chamber32, and thereby to move first lock pin30out of first lock holes31aand31bto release the lock.

As shown inFIG. 1,FIG. 4, andFIG. 8, first release hydraulic pressure circuit34is constituted independently of hydraulic pressure circuit4. First release hydraulic pressure circuit34includes a first release passage35which is a first lock passage connected with first lock holes31aand31b; and a first electromagnetic switching valve (first solenoid valve)46arranged to connect selectively discharge passage39aof oil pump39and drain passage40to release passage35.

First release passage35includes a first end portion arranged to be connected with oil pump39and drain passage40through first electromagnetic switching valve46; and a second end portion. The second end portion of first release passage35includes a groove35aand a radial hole which are formed in an outer circumference surface of outer cam shaft5; an axial hole35bwhich is formed within inner cam shaft6in the axial direction, and which is connected with the radial hole; and a connection hole35cwhich is formed at the tip end portion of outer cam shaft5, which penetrates through outer cam shaft5in the radial direction, and which is arranged to connect axial hole35band first pressure receiving chamber32(first lock holes31aand31b).

First electromagnetic switching valve46is controlled by an ON-OFF control signal from the control unit configured to control electromagnetic switching valve38. First electromagnetic switching valve46is arranged to control to switch discharge passage39aand drain passage40to first release passage35.

As shown inFIG. 1,FIG. 4, andFIG. 8, second lock mechanism41includes second sliding hole42formed in first rotor19of first vane rotor10in the axial direction; second lock pin43slidably received in second sliding hole42, and which is moved toward and away from (into and out of) first lock pin30; a second lock hole44which is formed in the rear end portion of first lock pin30, and with which a tip end portion43aof second lock pin43is engaged to connect first vane rotor10and second vane rotor23; and a second engagement and release mechanism arranged to engage tip end portion43aof second lock pin43with second lock hole44in accordance with the driving state of the engine, and to release the engagement of tip end portion43aof second lock pin43and second lock hole41in accordance with the driving state of the engine.

Second sliding hole42is arranged in series with (aligned with) first sliding hole29when first vane rotor10and second vane rotor23are in a predetermined relative rotational position. Second sliding hole42has a uniform inside diameter which is slightly smaller than an inside diameter of first sliding hole29. Second sliding hole42penetrates through first rotor19in the axial direction.

Second lock pin43includes a rear end portion having an outer circumference surface having a substantially uniform outside diameter which corresponds to second sliding hole42, and which is smaller than the outside diameter of first lock pin30. Moreover, second lock pin43includes tip end portion43awhich has a small diameter slightly smaller than the inside diameter of second lock hole44. Furthermore, second lock pin43includes a stepped second pressure receiving surface43bwhich has a stepped shape, and which is located between the rear end portion and tip end portion43aof second lock pin43. In this way, first lock pin30and second lock pin43, and first lock holes31aand31band second lock hole44are disposed in series in the axial direction, so that a project area (projected area) of first lock pin30and second lock pin43, and first lock holes31aand31band second lock hole44are overlapped.

Moreover, a second oil groove45is formed by cutting the edge of the rear end portion of first sliding hole29. Furthermore, a second pressure receiving chamber50is formed between second oil groove45and second pressure receiving surface43b. Second oil groove45is connected with a second release passage48described later.

Second lock hole44is formed into a bottomed cylindrical shape. When tip end portion43aof second lock pin43is engaged (locked) with second lock hole44, first lock pin30and second lock pin43are disposed in series with each other, so that first vane rotor10and second vane rotor23are connected with each other.

As described above, the second engagement and release mechanism includes coil spring33which is an elastic member that is elastically disposed between the rear end portion of second lock pin43and the inner end surface of front plate15, and that is arranged to urge second lock pin43in the forward direction (in the direction toward second lock hole44); and a second release hydraulic pressure circuit47arranged to supply the hydraulic pressure through second pressure receiving chamber50to second pressure receiving surface43band second lock hole44, and thereby to move second lock pin43away from (out of) second lock hole44to release the lock.

As shown inFIG. 1,FIG. 4, andFIG. 8, second release hydraulic pressure circuit47is constituted independently of hydraulic pressure circuit4and first release hydraulic pressure circuit34. Second hydraulic pressure circuit47includes second release passage48which is a second lock passage connected through second to oil groove45to second pressure receiving chamber50; and a second electromagnetic switching valve (solenoid valve)49arranged to connect selectively discharge passage39aof oil pump39and drain passage40to second release passage48.

Second release passage48includes a first end portion arranged to be connected through second electromagnetic switching valve49to discharge passage39aand drain passage40; and a second end portion. The second end portion of second release passage48includes a groove48aand a radial hole which are formed in the outer circumference surface of outer cam shaft5; an axial hole48bformed within inner cam shaft6in the axial direction, and connected to the radial hole; and a connection hole48cwhich is formed at the tip end portion of outer cam shaft5, which penetrates through outer cam shaft5in the radial direction, and which is arranged to connect axial hole48band second pressure receiving chamber50(second lock hole44).

Second electromagnetic switching valve49is controlled by an ON-OFF control signal from the control unit. Second electromagnetic switching valve49is arranged to switch discharge passage39aand drain passage40with respect to second release passage48.

[Function of First Embodiment]

First, at the start of the engine, as shown inFIG. 5andFIG. 8, tip end portion30aof first lock pin30is previously engaged with first lock hole31aon the advance angle side by the spring force of coil spring33, and tip end portion43aof second lock pin43is engaged with second lock hole44. With this, first lock pin30and second lock pin43are connected with each other in series state. Accordingly, first vane rotor10and second vane rotor23are locked at the relative rotational position on the advance angle side which is optimal for the start of the engine, relative to sprocket1.

Accordingly, as shown inFIG. 2A, two drive cams5aand6abecome the same rotational phase through outer cam shaft5and inner cam shaft6. The opening and closing timing characteristic of one of the exhaust valves is held to the phase on the advance angle side at the initial stage (at the beginning), as shown by a bold solid line ofFIG. 12.

Accordingly, when the engine is started by switching the ignition switch to the ON state from this state, it is possible to obtain the good start performance (the good startability) by the smooth cranking.

Then, in a predetermined driving region after the start of the engine, the control unit outputs the control current to electromagnetic switching valve38and first electromagnetic switching valve46. First, discharge passage39aand first release passage35are connected with each other. The hydraulic fluid discharged from oil pump39is supplied through first release passage35into first pressure receiving chamber32, so that first pressure receiving chamber32becomes the high pressure. With this, first lock pin30and also second lock pin43are moved in the rearward direction (leftward direction inFIG. 10) by the high hydraulic pressure acted to first pressure receiving surface30b, against the spring force of coil spring33. First lock pin30is moved out of the one first lock hole31a, so that the lock between rear plate16(housing8) and second vane rotor23is released. At this time, second vane rotor23and first vane rotor10are maintained in the connection state (the lock state). Accordingly, the lock between housing8, and the unit of second vane rotor23and first vane rotor10are released (second vane rotor23and first vane rotor10are released together from the lock with housing8), so as to ensure the free relative rotation.

At the same time, discharge passage39aand retard side passage36are connected with each other, and moreover advance side passage37and drain passage40are connected with each other. Accordingly, the hydraulic pressure discharged from oil pump39is supplied through retard side passage36into retard fluid pressure chambers12, so that retard fluid pressure chambers12become the high pressure. On the other hand, the hydraulic pressure within advance fluid pressure chambers13is drained (discharged) to the oil pan, so that advance fluid pressure chambers13become the low pressure.

Accordingly, as shown inFIG. 6, first vane rotor10and second vane rotor23are rotated on the retard angle side relative to housing8in accordance with the pressure increase of retard fluid pressure chambers12. With this, outer cam shaft5and also inner cam shaft6are synchronously rotated on the retard angle side in the counterclockwise direction. First drive cam5aand second drive cam6abecome the same rotational phase. The opening and closing timing of one of the exhaust valves is controlled to the retard angle side, so that the opening and closing timing characteristic of the one of the exhaust valves is shifted to the phase on the most retard angle side, as shown by a bold solid line inFIG. 13.

At this time, the control unit does not output the control current to second electromagnetic switching valve49. Accordingly, second release passage48and drain passage40are connected with each other. Consequently, as shown inFIG. 9, the lock state between first vane rotor10and second vane rotor23is continued since second lock pin43is continued to be engaged with second lock hole44.

When the driving state of the engine is further varied, the control current from the control unit to electromagnetic switching valve38and first electromagnetic switching valve46is shut off. Moreover, the control current is outputted to second electromagnetic switching valve49. Accordingly, drain passage40and first release passage35are connected with each other, so that first pressure receiving chamber32(the other first lock hole31b) becomes the low pressure. On the other hand, discharge passage39aand second release passage48are connected with each other. With this, the hydraulic pressure discharged from oil pump39is supplied through second release passage48to second pressure receiving chamber50(second lock hole44), so that second pressure receiving chamber50becomes the high pressure.

Accordingly, as shown inFIG. 10, first lock pin30is moved in the forward direction (the rightward direction inFIG. 10) in accordance with the pressure increase of second lock hole44, and engaged with the other first lock hole31b. Concurrently, second lock pin43is moved in the rearward direction (the leftward direction inFIG. 10) against the spring force of coil spring33, and moved out of second lock hole44, so that the lock (the connection) between first vane rotor10and second vane rotor23is released. With this, second vane rotor23is locked with rear plate16(housing8), and held at the relative rotational position on the retard angle side. On the other hand, the free relative rotation of first vane rotor10is allowed.

At this time, discharge passage39aand advance side passage37are connected with each other, and retard side passage36and drain passage40are connected with each other. Accordingly, the discharge hydraulic pressure of oil pump39is supplied to advance fluid pressure chambers13, so that advance fluid pressure chambers13become the high pressure. On the other hand, the hydraulic fluid within retard fluid pressure chambers12are drained (discharged) through drain passage40to the oil pan, so that retard fluid pressure chambers12become the high pressure.

Accordingly, as shown inFIG. 7andFIG. 11, the only first vane rotor10is rotated on the advance angle side relative to housing8. The relative rotation of second vane rotor23on the advance angle side is restricted, and second vane rotor23is held at the relative rotational position on the most retard angle side.

Consequently, first drive cam5aof outer cam shaft5is held at the rotational position on the retard angle side. As shown inFIG. 2B, second drive cam6aof inner cam shaft6controls the opening and closing timing of one of the exhaust valves to the rotational position on the advance angle side, similarly to a case of the start of the engine. Therefore, first drive cam5aof outer cam shaft5becomes an open angle state in which first drive cam5aof outer cam shaft5is opened with respect to second drive cam6aof inner cam shaft6.

Accordingly, as shown inFIG. 14, in the opening and closing timing characteristic of the one of the exhaust valves, two drive cams5aand6apress the valve lifter during a time period longer than the time period during which drive cams5aand6apress the valve lifter at the initial phase. That is, a time period during which the one of the exhaust valves is opened becomes longer, the scavenging time period of the combustion gas is continuously increased.

The control unit performs the energization control to electromagnetic switching valve38and first and second electromagnetic switching valves46and49in accordance with the various variation of the driving state of the engine, and stop of the engine. With this, it is possible to arbitrarily shift the relative rotational positions of first vane rotor10and second vane rotor23.

With this, it is possible to arbitrarily rotate outer cam shaft5and inner cam shaft6relatively. Consequently, it is possible to shift first drive cam5aand second drive cam6ato the same phase on the advance angle side and the retard angle side, and moreover to arbitrarily perform the open angle control by the phase deviation.

As described above, in this embodiment, it is possible to shift the relative rotational phase of cam shafts5and6relative to housing8(the crank shaft) by independently or synchronously controlling the relative rotational phases of outer cam shaft5and inner cam shaft6by using hydraulic pressure circuits4,34, and47, and thereby to perform the opening and closing timing control of the exhaust valve with the high accuracy.

Moreover, second vane rotor23is received within first rotor19of first vane rotor10. Vane rotors10and23are arranged in parallel to each other. Accordingly, it is possible to sufficiently decrease the axial length of the apparatus, relative to a case in which vane rotors are arranged in series with each other. Consequently, it is possible to improve the mountability to the engine.

Moreover, first rotor19of first vane rotor10is constituted by large diameter portion19aand small diameter portion19bwithout increasing the overall shape of first rotor19of first vane rotor10. Accordingly, it is possible to suppress the decrease of the volumes of retard fluid pressure chambers12and advance fluid pressure chambers13due to small diameter portion19b, and thereby to increase the pressure receiving areas of vanes20-22. Consequently, it is possible to ensure the rapid response of the relative rotation of first vane rotor10on the retard angle side or the advance angle side by the hydraulic fluid supplied to fluid pressure chambers12and13.

Moreover, in this embodiment, first lock pin30and second lock pin43are arranged in series with each other. Furthermore, second lock hole44is formed in the rear end portion of first lock pin30. The lock between first vane rotor10and second vane rotor23, and the release of the lock between first vane rotor10and second vane rotor23are performed by the hydraulic pressure supplied to and drained from the second lock hole44. Therefore, it is possible to simplify the overall structure of the apparatus, and to effectively use the space.

That is, in a case where first lock holes31and second lock hole44are formed in different members such as rear plate16and front plate15, and lock pins30and43are moved in the opposite directions of the forward and rearward directions, the overall structure of the apparatus is complicated, and the installation (arrangement) of the hydraulic pressure circuits are complicated. However, in this embodiment, second lock hole44is formed by using first lock pin30. Accordingly, it is possible to simplify the overall structure of the apparatus, and to effectively use the space. Consequently, it is possible to facilitate the manufacturing operation and the assembling operation, and to decrease the manufacturing cost and the assembling operation cost.

Second Embodiment

FIG. 15toFIG. 21show a variable valve actuating apparatus according to a second embodiment of the present invention. This variable valve actuating apparatus is similarly applied to one of two exhaust valves of one cylinder. The variable valve actuating apparatus according to the second embodiment is substantially identical to the apparatus according to the first embodiment in most aspects as shown by the use of the same reference numerals. Unlike the first embodiment, the other first lock hole31bis omitted. Moreover, an arrangement (direction) of second vane rotor23with respect to first vane rotor10is opposite to the arrangement of second vane rotor23with respect to first vane rotor10in the variable valve actuating apparatus according to the first embodiment. However, the initial relative rotational phases of vane rotors10and23are the same.

That is, at the start of the engine, as shown inFIG. 15andFIG. 18, tip end portion30aof first lock pin30is previously engaged with first lock hole31aon the advance angle side by the spring force of coil spring33. Moreover, tip end portion43aof second lock pin43is engaged with second lock hole44. With this, first lock pin30and second lock pin43are connected in series with each other. Accordingly, first vane rotor10and second vane rotor23are locked at the relative rotational position on the advance angle side which is optimal for the start of the engine, with respect to sprocket1.

Accordingly, as shown inFIG. 2A, two drive cams5aand6abecome the same rotational phase through outer cam shaft5and inner cam shaft6. Therefore, the opening and closing timing characteristic of the one of the exhaust valves is held to the phase on the retard angle side at the initial stage, as shown by a bold solid line ofFIG. 22.

Accordingly, when the engine is started from this state by switching the ignition switch to the ON state, it is possible to obtain the good start performance by the smooth cranking.

In the predetermined driving region after the start of the engine, the control unit outputs the control current to electromagnetic switching valve38and first electromagnetic switching valve46. With this, discharge passage39aand first release passage35are connected with each other. The hydraulic fluid discharged from oil pump39is supplied through first release passage35to first pressure receiving chamber32, so that first pressure receiving chamber32becomes the high pressure. With this, first lock pin30and also second lock pin43are moved in the rearward direction (leftward direction inFIG. 18) by the high hydraulic pressure acted to first pressure receiving surface30bagainst the spring force of coil spring33, so that first lock pin30is moved out of the one of first lock holes31a. With this, the lock between rear plate16(housing8) and second vane rotor23is released. At this time, second vane rotor23and first vane rotor10are maintained in the connection state (the lock state). Accordingly, the lock between housing8, and one unit of first vane rotor10and second vane rotor23are released, so as to ensure the free relative rotation between housing8, and one unit of first vane rotor10and second vane rotor23.

Concurrently, electromagnetic switching valve38connects discharge passage39aand retard side passage36, and connects advance side passage37and drain passage40. Accordingly, the hydraulic pressure discharged from oil pump39is supplied through retard side passage36to retard fluid pressure chambers12, so that retard fluid pressure chambers12become the high pressure. On the other hand, the hydraulic pressure within advance fluid pressure chambers13is drained (discharged) to the oil pan, so that advance fluid pressure chambers13become the low pressure.

Accordingly, as shown inFIG. 16, first vane rotor10and second vane rotor23are rotated on the retard angle side relative to housing8in accordance with the pressure increase of retard fluid pressure chambers13. With this, outer cam shaft5and inner cam shaft6are synchronously rotated together on the retard angle side in the counterclockwise direction, so that first drive cam5aand second drive cam6abecome the same rotational phase. The opening and closing timing of one of the exhaust valves is controlled to the retard angle side. The opening and closing timing characteristic of the one of the exhaust valves is shifted to the phase on the most retard angle side, as shown by a bold solid line inFIG. 23.

At this time, the control unit does not output the control current to second electromagnetic switching valve49, so that second release passage48and drain passage40are connected with each other. Accordingly, as shown inFIG. 19, first vane rotor10is continued to be in the lock state with second vane rotor23since second lock pin43is continued to be engaged with second lock hole44.

When the driving state of the engine is further varied, the control current from the control unit to first electromagnetic switching valve46is shut off. Moreover, the control current is outputted to electromagnetic switching valve38and second electromagnetic switching valve49.

Accordingly, drain passage40and first release passage35are connected with each other, so that first pressure receiving chamber32(first lock hole31a) becomes the low pressure. On the other hand, discharge passage39aand second release passage48are connected with each other. With this, the hydraulic fluid discharged from oil pump39is supplied through second release passage48to second pressure receiving chamber50(second lock hole44), so that second pressure receiving chamber50becomes the high pressure.

Accordingly, as shown inFIG. 20, first lock pin30is moved in the forward direction (the rightward direction inFIG. 20) in accordance with the pressure increase of second lock hole44, and engaged with first lock hole31a. Concurrently, second lock pin43is moved in the rearward direction (the leftward direction) against the spring force of coil spring33, and moved out of second lock hole44. Consequently, the lock (the connection) between first vane rotor10and second vane rotor23is released. With this, second vane rotor23is locked with rear plate16(housing8), and held at the relative rotational position on the advance angle side. On the other hand, the free relative rotation of first vane rotor10is allowed.

At this time, discharge passage39aand retard side passage36are connected with each other, and moreover advance side passage37and drain passage40are connected with each other. Accordingly, the discharge hydraulic pressure of oil pump39is supplied to retard fluid pressure chambers12, so that retard fluid pressure chambers12become the high pressure. On the other hand, the hydraulic fluid within advance fluid pressure chambers13is drained (discharged) through drain passage40to the oil pan, so that the advance fluid pressure chambers13are maintained in the low pressure state.

Accordingly, as shown inFIG. 17andFIG. 21, the only first vane rotor10is rotated on the retard angle side relative to housing8. The relative rotation of second vane rotor23on the retard angle side is restricted, and second vane rotor23is held at the relative rotational position on the most advance angle side.

Consequently, second drive cam6aof inner cam shaft6is held at the rotational position on the advance angle side. On the other hand, first drive cam5aof outer cam shaft5controls the opening and closing timing of the one of the exhaust valves to the rotational position on the retard angle side. First drive cam5aof outer cam shaft becomes the open state in which the first drive cam5ais opened with respect to second drive cam6a.

Accordingly, in the opening and closing timing characteristic of one of the exhaust valves, as shown inFIG. 24, two drive cams5aand6apress the valve lifter during a time period longer than a time period during which two drive cams5aand6apress the valve lifter at the initial phase. That is, a time period during which the one of the exhaust valves is opened is increased. Accordingly, the scavenging time period of the combustion gas is continuously increased.

The control unit performs the energization control to electromagnetic switching valve38, and first and second switching valves46and49in accordance with the various variations of the driving state of the engine, and the stop of the engine. With this, it is possible to arbitrarily shift the relative rotational positions of first vane rotor10and second vane rotor23. Accordingly, it is possible to arbitrarily rotate outer cam shaft5and inner cam shaft6relatively. Moreover, it is possible to shift first drive cam5aand second drive cam6ato the same phase on the advance angle side and the retard angle side, and to arbitrarily perform the open angle control by the phase deviation.

As described above, in this embodiment, it is possible to shift the relative rotational phases of inner cam shaft5and outer cam shaft6relative to (with respect to) housing8(the crank shaft) by independently or synchronously controlling the relative rotational phases of outer cam shaft5and inner cam shaft6by using hydraulic pressure circuits4,34, and47, like the first embodiment, and thereby to perform the opening and closing timing control of the exhaust valve with the high accuracy.

Moreover, second vane rotor23is received within first rotor19of first vane rotor10. With this, first vane rotor10and second vane rotor23are arranged in parallel (to each other). Accordingly, it is possible to sufficiently decrease the axial length of the apparatus, relative to the conventional art in which vane rotors are arranged in series with each other. Consequently, it is possible to improve the mountability to the vehicle.

The other functions and the other operations are identical to those of the first embodiment.

The present invention is not limited to the above-described embodiments. It is possible to concurrently or independently control the lock between first vane rotor10and second vane rotor23, and the release of the lock between first vane rotor10and second vane rotor23arbitrarily, in accordance with the driving state of the engine.

Moreover, in the embodiments, two drive cams5aand6aare used with respect to one of the exhaust valves. However, drive cam5aand drive cam6amay independently open and close, respectively, two exhaust valves of one cylinder, and moreover control to the open angle state. Moreover, the variable valve actuating apparatus according to the present invention is applicable to an intake valve, in addition to the exhaust valve.

Moreover, in the present invention, the first rotary member and the second rotary member are not limited to the vane rotor. For example, a plurality of gears may be used in place of the vane rotors.

Moreover, the lock release of the first rotary member with respect to the drive rotary member, and the lock release between the first rotary member and the second rotary member may be performed by an electric means such as an electric motor, in place of the hydraulic pressure.

[a1] In the variable valve actuating apparatus according to the embodiments of the present invention, at least one of the first lock recessed portions and the first lock member are engaged and locked with each other when the first rotary member is positioned at a relative rotational position on one of a most advance angle and a most retard angle (side) with respect to the drive rotary member, and the second rotary member is positioned at a relative rotational position on the other of the most advance angle (side) and the most retard angle with respect to the first rotary member.

[b1] In the variable valve actuating apparatus according to the embodiments of the present invention, the second rotary member constantly receives a rotational torque in the retard angle direction relative to the first rotary member at least while the drive rotary member is rotated; and at least one of the first lock recessed portions and the first lock member are locked with each other when the first rotary member is positioned at the relative rotational position on the most advance angle relative to the drive rotary member, and the second rotary member is positioned at the relative rotational position on the most retard angle relative to the first rotary member.
[c1] In the variable valve actuating apparatus according to the embodiments of the present invention, the first lock member is moved into and engaged with the other of the first lock recessed portions so as to lock the relative rotation between the drive rotary member and the second rotary member, when the first rotary member is positioned at the relative rotational position on the most advance angle relative to the drive rotary member, and the second rotary member is positioned at the relative rotational position on the most advance angle relative to the first rotary member.
[d1] In the variable valve actuating apparatus according to the embodiments of the present invention, the second lock recessed portion and the second lock member are engaged and locked with each other at a position at which the second rotary member is positioned at a relative rotational position on the most advance angle relative to the first rotary member.
[e1] In the variable valve actuating apparatus according to the embodiments of the present invention, the second lock recessed portion and the second lock member are engaged and locked with each other when the second rotary member is a relative rotational position on the most retard angle relative to the first rotary member.
[f1] In the variable valve actuating apparatus according to the embodiments of the present invention, the receiving chamber is opened on one axial side surface of the first rotary member.
[g1] In the variable valve actuating apparatus according to the embodiments of the present invention, the rotor of the first rotary member includes a large diameter portion larger than a diameter of a portion other than the large diameter portion of the rotor of the first rotary member.
[h1] In the variable valve actuating apparatus according to the embodiments of the present invention, when the internal combustion engine is stopped, the first lock member is engaged with the first lock recessed portion, and the second lock member is engaged with the second lock recessed portion.
[i1] In the variable valve actuating apparatus according to the embodiments of the present invention, the first rotary member is arranged to be rotated relative to the drive rotary member in a state where the first lock member is moved out of the first lock recessed portion to release the lock, and the second lock member is engaged with the second lock recessed portion.
[j1] In the variable valve actuating apparatus according to the embodiments of the present invention, the first rotary member is arranged to be rotated relative to the drive rotary member when the first lock member is engaged with the first lock recessed portion and the second lock member is moved out of the second recessed portion to release the lock.
[k1] In the variable valve actuating apparatus according to the embodiments of the present invention, the first lock recessed portion(s) is formed at a portion of the drive rotary member on the outer cam shaft's side and the inner cam shaft's side in the axial direction.
[l1] In the variable valve actuating apparatus according to the embodiments of the present invention, the first lock passage and the second lock passage receive a hydraulic pressure from a hydraulic pressure circuit independently from the advance angle operation chambers and the retard angle operation chambers.
[m1] In the variable valve actuating apparatus according to the embodiments of the present invention, the second lock recessed portion is formed at an end portion of the first lock member on a side opposite to the first lock recessed portion.
[n1] In the variable valve actuating apparatus according to the embodiments of the present invention, the first lock member is restricted from being moved into the second rotary member.
[o1] In the variable valve actuating apparatus according to the embodiments of the present invention, the first lock member has an outside diameter larger than an outside diameter of the second lock member.

A variable valve actuating apparatus for an internal combustion engine according to the embodiments of the present invention, the variable valve actuating apparatus includes: an inner cam shaft including an inner cam formed on an outer circumference thereof; an outer cam shaft which is provided on the outer circumference of the inner cam shaft, which includes an outer cam provided radially outside the outer cam shaft, the outer cam shaft and the inner cam shaft being arranged to be relatively rotated so as to vary a relative rotational phase of the outer cam with respect to the inner cam; a drive rotary member to which a rotational force (torque) of a crank shaft is transmitted, and which includes an operation chamber formed within the drive rotary member; a first rotary member which includes a rotor fixed to one of the inner cam shaft and the outer cam shaft, vanes separating the operation chamber into an advance angle operation chamber and a retard angle operation chamber, and a receiving chamber formed within (inside) the first rotary member, and which is arranged to be rotated toward an advance angle side or a retard angle side with respect to the drive rotary member by the hydraulic pressure selectively supplied to the advance angle operation chamber and the retard angle operation chamber; a second rotary member which is fixed to the other of the inner cam shaft and the outer cam shaft, which is rotatably received within the receiving chamber, and which is arranged to rotated within a predetermined angle range with respect to (relative to) the drive rotary member and the first rotary member; a first lock recessed portion formed on a sliding surface of the drive rotary member on which an axial end surface of the second rotary member is slid; a first lock member which is arranged to be moved in a direction of a rotational axis of the second rotary member, and which is arranged to be moved into and engaged with the first recessed portion, and thereby to lock the relative rotation between the drive rotary member and the second rotary member, and which is arranged to be moved out of the first lock recessed portion, and thereby to release the lock between the drive rotary member and the second rotary member; a second lock recessed portion formed at an end portion which is located on a side opposite to the first lock recessed portion of the first lock member; a second lock member provided to the first rotary member to be moved in an axial direction, and arranged to be moved into and engaged with the second lock recessed portion to lock the relative rotation between the first rotary member and the second rotary member, and to be moved out of the second recessed portion to release the lock between the first rotary member and the second rotary member; an urging member arranged to urge the second lock member in a direction of the second lock recessed portion (toward the second lock recessed portion); a first lock passage arranged to move the first lock member together with the second lock member engaged with the second lock recessed portion, in the rearward direction against the urging force of the urging member by supplying the hydraulic fluid, and thereby to move the first lock member (and the second lock member) out of the first lock recessed portion; and a second lock passage arranged to move the second lock member in a direction apart from the first lock member by supplying the hydraulic fluid, and to move the second lock member out of the second recessed portion.

A variable valve actuating apparatus for an internal combustion engine according to the embodiments of the present invention, the variable valve actuating apparatus includes: an inner cam shaft including an inner cam formed on an outer circumference thereof; an outer cam shaft which is provided on the outer circumference of the inner cam shaft, which includes an outer cam provided radially outside the outer cam shaft, the outer cam shaft and the inner cam shaft being arranged to be relatively rotated so as to vary a relative rotational phase of the outer cam with respect to the inner cam; a drive rotary member to which a rotational force (torque) of a crank shaft is transmitted; a first rotary member which is fixed to one of the inner cam shaft and the outer cam shaft, which is arranged to be moved toward the advance angle side or the retard angle side with respect to the drive rotary member by the hydraulic pressure, and which includes a receiving chamber formed within the first rotary member; a second rotary member which is fixed to the other of the inner cam shaft and the outer cam shaft, and which is rotatably received within the receiving chamber, and which is arranged to be rotated within a predetermined angle range with respect to (relative to) the drive rotary member and the first rotary member; a first lock recessed portion formed on a sliding surface of the drive rotary member on which an axial end surface of the second rotary member is slid; a first lock member which is arranged to be moved in a direction of a rotational axis of the second rotary member, and which is arranged to be moved into and engaged with the first recessed portion, and thereby to lock the relative rotation between the drive rotary member and the second rotary member, and which is arranged to be moved out of the first lock recessed portion, and thereby to release the lock between the drive rotary member and the second rotary member; a second lock recessed portion formed at an end portion which is located on a side opposite to the first lock recessed portion of the first lock member; a second lock member provided to the first rotary member to be moved in an axial direction, and arranged to be moved into and engaged with the second lock recessed portion to lock the relative rotation between the first rotary member and the second rotary member, and to be moved out of the second recessed portion to release the lock between the first rotary member and the second rotary member; an urging member arranged to urge the second lock member in a direction of the second lock recessed portion (toward the second lock recessed portion); a first lock passage arranged to move the first lock member together with the second lock member engaged with the second lock recessed portion, in the rearward direction against the urging force of the urging member by supplying the hydraulic fluid, and thereby to move the first lock member (and the second lock member) out of the first lock recessed portion; and a second lock passage arranged to move the second lock member in a direction apart from the first lock member by supplying the hydraulic fluid, and to move the second lock member out of the second recessed portion.

A variable valve actuating apparatus for an internal combustion engine, the variable valve actuating apparatus includes: an inner cam shaft including an inner cam formed on an outer circumference thereof; an outer cam shaft which is provided on the outer circumference of the inner cam shaft, which includes an outer cam provided radially outside the outer cam shaft, the outer cam shaft and the inner cam shaft being arranged to be relatively rotated so as to vary a relative rotational phase of the outer cam with respect to the inner cam; a drive rotary member to which a rotational force (torque) of a crank shaft is transmitted; a first rotary member which is fixed to one of the inner cam shaft and the outer cam shaft, which is arranged to be moved toward the advance angle side or the retard angle side with respect to the drive rotary member by the hydraulic pressure, and which includes a receiving chamber formed within the first rotary member; a second rotary member which is fixed to the other of the inner cam shaft and the outer cam shaft, and which is rotatably received within the receiving chamber, and which is arranged to be rotated within a predetermined angle range with respect to (relative to) the drive rotary member and the first rotary member; a first lock mechanism provided to the second rotary member, and arranged to lock a relative rotation between the drive rotary member and the second rotary member in accordance with a request, and to release the lock of the relative rotation between the drive rotary member and the second rotary member in accordance with the request; and a second lock mechanism provided to the first rotary member, and arranged to lock a relative rotation between the first rotary member and the second rotary member, and to release the lock of the relative rotation between the first rotary member and the second rotary member.

[a2] In the variable valve actuating apparatus according to the embodiments of the present invention, at least one of the first lock recessed portions and the first lock member are engaged and locked with each other when the first rotary member is positioned at the relative rotational position on one of the most advance angle side and the most retard angle side relative to the drive rotary member, and the second rotary member is positioned at the relative rotational position opposite to the relative rotational position of the first rotary member.
[b2] In the variable valve actuating apparatus according to the embodiments of the present invention, the second rotary member constantly receives a rotational torque in the retard angle direction relative to the first rotary member at least while the drive rotary member is rotated; and at least one of the first lock recessed portions and the first lock member are locked with each other when the first rotary member is positioned at the relative rotational position on the most advance angle relative to the drive rotary member, and the second rotary member is positioned at the relative rotational position on the most retard angle relative to the first rotary member.
[c2] In the variable valve actuating apparatus according to the embodiments of the present invention, when the first rotary member is positioned at the relative rotational position on the advance angle relative to the drive rotary member, and the second rotary member is positioned at the relative rotational position on the most advance angle relative to the first lock member, the first lock member is moved into and engaged with the other of the first lock recessed portions so that the relative rotation between the drive rotary member and the second rotary member is locked.
[d2] In the variable valve actuating apparatus according to the embodiments of the present invention, the second lock recessed portion and the second lock member are engaged and locked with each other at a position at which the second rotary member is positioned at the relative rotational position on the most advance angle relative to the first rotary member.
[e2] In the variable valve actuating apparatus according to the embodiments of the present invention, the second lock recessed portion and the second lock member are engaged and locked with each other at a position at which the second rotary member is positioned at the relative rotational position on the most retard angle relative to the first rotary member.
[f2] In the variable valve actuating apparatus according to the embodiments of the present invention, the receiving chamber has an opening opened on one axial side surface of the first rotary member.
[g2] In the variable valve actuating apparatus according to the embodiments of the present invention, a portion of the rotor of the first rotary member has a diameter larger than a diameter of other portion other than the portion of the rotor of the first rotary member.
[h2] In the variable valve actuating apparatus according to the embodiments of the present invention, a movement of the first lock member into the first rotary member is restricted.
[i2] In the variable valve actuating apparatus according to the embodiments of the present invention, the first lock member has an outside diameter larger than an inside diameter of the second sliding hole in which the second lock member is slid within the first rotary member.
[j2] In the variable valve actuating apparatus according to the embodiments of the present invention, the first lock member is a hollow cylindrical shape; the second lock member is a hollow cylindrical shape; and the first lock member has an outside diameter larger than an outside diameter of the second lock member.
[k2] In the variable valve actuating apparatus according to the embodiments of the present invention, the first lock member includes a small diameter portion formed at a portion at which the first lock member is engaged with the first lock recessed portion; and the second lock member includes a small diameter portion formed at a portion at which the second lock member is engaged with the second lock recessed portion.
[l2] In the variable valve actuating apparatus according to the embodiments of the present invention, the first rotary member is arranged to be rotated relative to the drive rotary member in a state where the first lock member is engaged with the first lock recessed portion, and the second lock member is not engaged with the second lock recessed portion.
[m2] In the variable valve actuating apparatus according to the embodiments of the present invention, the first rotary member is arranged to be rotated relative to the drive rotary member in a state where the first lock member is moved out of the first lock recessed portion, and the second lock member is engaged with the second lock recessed portion.
[n2] In the variable valve actuating apparatus according to the embodiments of the present invention, the first rotary member is arranged to be rotated relative to the drive rotary member in a state where the first lock member is engaged with the first lock recessed portion, and the second lock member is moved out of the second lock recessed portion.
[o2] In the variable valve actuating apparatus according to the embodiments of the present invention, the first lock recessed portion is formed in an inner end surface of the rear plate which is positioned on the drive cam's side of the outer cam shaft and the inner cam shaft in the axial direction of the drive rotary member.
[p2] In the variable valve actuating apparatus according to the embodiments of the present invention, the variable valve actuating apparatus further includes a hydraulic pressure circuit which is independent from a hydraulic pressure circuit arranged to supply and drain the hydraulic pressure to and from the advance angle operation chambers and the retard angle operation chambers, and which is arranged to supply and drain the hydraulic pressure to and from the first lock passage and the second lock passage.

The entire contents of Japanese Patent Application No. 2012-133344 filed Jun. 13, 2012 and Japanese Patent Application No. 2012-133345 filed Jun. 13, 2012 are incorporated herein by reference.