Valve opening/closing timing control device
09945271 ยท 2018-04-17
Assignee
Inventors
Cpc classification
F01L2001/34476
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01L2001/34466
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01L1/46
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01L2001/34423
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01L2001/34463
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01L1/3442
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01L2001/34473
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01L2001/34459
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F01L1/46
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
Provided is a valve opening/closing timing control device that can speedily achieve a stable operation at the time of starting an engine. The device includes a drive-side rotating body that is rotated in synchronism with a crankshaft and has a plurality of projecting portions, a driven-side rotating body that has a partition portion which forms an advance angle chamber and a retard angle chamber and that is rotated together with a camshaft for valve opening/closing, an intermediate lock mechanism switchable between a locked state and an unlocked state, a pump for supplying fluid to the advance angle chamber, the retard angle chamber or the intermediate lock mechanism, and a communication passage configured to establish communication between the advance angle chamber and the retard angle chamber disposed adjacent in a circumferential direction when the intermediate lock mechanism is under the locked state.
Claims
1. A valve opening/closing timing control device comprising: a drive-side rotating body rotatable in synchronism with a crankshaft of an internal combustion engine, the drive-side rotating body having a plurality of projecting portions that project from a radial outer side to a radial inner side toward a rotational axis; a driven-side rotating body surrounded by the drive-side rotating body and having a partition portion extending toward the radial outer side at a position between adjacent projecting portions of the plurality of projecting portions, thus forming an advance angle chamber and a retard angle chamber between the drive-side rotating body and the drive-side rotating body, the driven-side rotating body being rotatable together with a valve opening/closing camshaft; an intermediate lock mechanism switchable between a locked state in which a relative rotational phase of the driven-side rotating body relative to the drive-side rotating body is restrained to an intermediate lock phase between a most advanced angle phase and a most retarded angle phase and an unlocked state in which the restraint is released; a pump configured to supply fluid to the advance angle chamber, the retard angle chamber or the intermediate lock mechanism; and a communication passage configured to establish communication between the advance angle chamber and the retard angle chamber which are located adjacent each other in a circumferential direction, when the intermediate lock mechanism is under the locked state; wherein the communication passage is formed by cutting out a portion of the driven-side rotating body which portion faces an end portion of one of the plurality of projecting portions.
2. The valve opening/closing timing control device according to claim 1, wherein: at least one projecting portion of the plurality of projecting portions has a length in the circumferential direction set shorter than a length of remaining projecting portions of the plurality of projecting portions in the circumferential direction; and the communication passage is formed in a region facing the at least one projecting portion.
3. The valve opening/closing timing control device according to claim 1, wherein: between the plurality of projecting portions and the driven-side rotating body, there are separately formed a first flow passage communicated to the retard angle chamber and the communication passage, and a second flow passage communicated to the advance angle chamber and the communication passage; when the intermediate lock mechanism is under the locked state, the fluid flows from the second flow passage through the communication passage to the first flow passage; and the first flow passage has a passage cross sectional area greater than a passage cross sectional area of the second flow passage.
4. A valve opening/closing timing control device comprising: a drive-side rotating body rotatable in synchronism with a crankshaft of an internal combustion engine, the drive-side rotating body having a plurality of projecting portions that project from a radial outer side to a radial inner side toward a rotational axis; a driven-side rotating body surrounded by the drive-side rotating body and having a partition portion extending toward the radial outer side at a position between adjacent projecting portions of the plurality of projecting portions, thus forming an advance angle chamber and a retard angle chamber between the drive-side rotating body and the drive-side rotating body, the driven-side rotating body being rotatable together with a valve opening/closing camshaft; an intermediate lock mechanism switchable between a locked state in which a relative rotational phase of the driven-side rotating body relative to the drive-side rotating body is restrained to an intermediate lock phase between a most advanced angle phase and a most retarded angle phase and an unlocked state in which the restraint is released; a pump configured to supply fluid to the advance angle chamber, the retard angle chamber or the intermediate lock mechanism; and a communication passage configured to establish communication between the advance angle chamber and the retard angle chamber which are located adjacent each other in a circumferential direction, when the intermediate lock mechanism is under the locked state; wherein the communication passage is formed by cutting out a portion of the drive-side rotating body which portion faces an outer circumferential end face of the partition portion.
5. A valve opening/closing timing control device comprising: a drive-side rotating body rotatable in synchronism with a crankshaft of an internal combustion engine, the drive-side rotating body having a plurality of projecting portions that project from a radial outer side to a radial inner side toward a rotational axis; a driven-side rotating body surrounded by the drive-side rotating body and having a partition portion extending toward the radial outer side at a position between adjacent projecting portions of the plurality of projecting portions, thus forming an advance angle chamber and a retard angle chamber between the drive-side rotating body and the drive-side rotating body, the driven-side rotating body being rotatable together with a valve opening/closing camshaft; an intermediate lock mechanism switchable between a locked state in which a relative rotational phase of the driven-side rotating body relative to the drive-side rotating body is restrained, at an intermediate lock position, to an intermediate lock phase between a most advanced angle phase and a most retarded angle phase and an unlocked state in which the restraint is released; a pump configured to supply fluid to the advance angle chamber, the retard angle chamber or the intermediate lock mechanism; and a communication passage configured to establish communication between the advance angle chamber and the retard angle chamber which are located adjacent each other in a circumferential direction, when the intermediate lock mechanism is under the locked state; wherein the drive-side rotating body is comprised of an outer circumferential wall portion and front and rear wall portions which are disposed at opposed ends along the rotational axis; and the communication passage is formed on the front wall portion or the rear wall portion at the intermediate lock position.
Description
BRIEF DESCRIPTION OF DRAWINGS
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(8)
DESCRIPTION OF EMBODIMENTS
(9) Next, embodiments of a valve opening/closing timing control device relating to the present disclosure will be explained. It should be understood, however that the present disclosure is not limited to the following embodiments, but various modifications can be made in a range not exceeding its essential spirit.
1. First Embodiment
(10) Next, a first embodiment of the disclosure will be explained with reference to the drawings.
(11) [Basic Configuration]
(12)
(13) The outer rotor 20 includes a cylindrical rotor body 21 (an example of outer circumferential wall portion), a disc-like rear plate 22 (an example of rear wall portion) disposed rearwardly of the rotor body 21 in a direction along a rotational axis X and a disc-like front plate 23 (an example of front wall portion) disposed forwardly of the rotor body 21 in the direction along the rotational axis X. The outer rotor 20 is rotated in synchronism with a crankshaft 1 of an engine E as an internal combustion engine via a power transmission member 2. The inner rotor 30 is coupled to a camshaft 3 that opens/closes an intake value of a combustion chamber of the engine E and is disposed coaxially with the rotational axis X of the outer rotor 20 so as to be rotatable relative to this outer rotor 20. The intermediate lock phase LS, as shown in
(14) [Drive-Side Rotating Body and Driven-Side Rotating Body]
(15) The outer rotor 20 and the inner rotor 30 are bound (sandwiched) between the front plate 23 disposed at a front position and the rear plate 22 disposed on the opposite side (engine E side), and are coupled to each other with connecting bolts 24 as fastening members inserted from the front plate 23 to the outer rotor 20 being threaded with the rear plate 22.
(16) At an outer circumferential position of the rear plate 22, there is integrally formed a sprocket 22S around which the power transmission member 2 such as a timing chain is wound. Between the rear plate 22 and the inner rotor 30, there is provided a torsion spring 27 for urging the inner rotor 30 in an advance angle direction Sa. The outer rotor 20 is rotatably driven by the power transmission member 2 in a direction denoted by a sign S in
(17) As shown in
(18) The inner rotor 30 defines an inner circumferential face 30S which is formed like a cylinder inner face coaxial with the rotational axis X and defines also a cylindrical outer circumferential face centering about the rotational axis X. Into this outer circumferential face, four vane portions 31 (an example of partition portion) formed like plates extending toward the radial outer side of the rotational axis X are fitted. The vane portion 31 is urged by e.g. a spring in a direction away from the rotational axis X. Incidentally, in the above, the vane portion 31 is formed like a plate and the intermediate lock mechanism L is accommodated in the projecting portion 21T. Instead of this, the vane portion 31 can be formed like a block and the intermediate lock mechanism L can be accommodated in the projecting portion 21T along the rotational axis X.
(19) With the above-described arrangement, the plurality of oil chambers C are partitioned from each other by the vane portions 31, so that an advance angle chamber Ca is formed on a counterclockwise side relative to the vane portion 31 and a retard angle chamber Cb is formed on a clockwise side relative thereto. The outer rotor 20 and the inner rotor 30 are rotatable relative to each other by a range of the vane portion 31 movable within the oil chamber C.
(20) At one end portion of the inner rotor 30 in the direction along the rotational axis X, a flange-like portion 32 is formed. And, at a hole portion located at an inner circumferential position of this flange-like portion 32, a connecting bolt 33 is inserted, thus coupling the inner rotor 30 to the camshaft 3. Further, to an inner circumferential face 30S of the inner rotor 30, a passage forming shaft portion 45 is inserted, and this passage forming shaft portion 45 defines an advance angle passage 34, a retard angle passage 35 and a lock passage 36. Further, there are provided a phase control valve 41 (OCV: oil control valve) and a lock control valve 42 (OSV: oil switching valve) coupled to the passage forming shaft portion 45. In an outer circumferential face of the passage forming shaft portion 45, there are formed an annular groove portion communicated to a port of the phase control valve 41 and an annular groove portion communicated to a port of the lock control valve 42. And, in order to separate these groove portions from each other, between the outer circumference of the passage forming shaft portion 45 and the inner circumferential face 30S of the inner rotor 30, there are provided a plurality of seals 46.
(21) [Intermediate Lock Mechanism]
(22) As shown in
(23) The lock recess LD is comprised of a shallow groove and a deep groove continuous with each other in the circumferential direction. As shown in
(24) [Phase Control]
(25) The phase control valve 41 switches over supply, discharge and retention of oil to/from/at the advance angle chamber Ca and the retard angle chamber Cb. In particular, as one of an advance angle passage 34 and a retard angle passage 35 is selected to be supplied with oil and oil is discharged from the other, there is realized an operation of displacing a relative rotational phase of the valve opening/closing timing control device A to the advance angle direction Sa or the retard angle direction Sb.
(26) The lock control valve 42 (OSV: oil switching valve) realizes retention and release of the locked state of the intermediate lock mechanism L of the valve opening/closing timing control device A. In particular, for retaining the locked state, oil discharge is effected from the lock passage 36. For releasing the locked state, oil is supplied to the lock passage 36.
(27) The phase control valve 41 and the lock control valve 42 comprise electromagnetic valves, which respectively include, though not shown, a spool, a spring and an electromagnetic solenoid. Further, in the instant embodiment, there is provided a single pump P which is driven by the engine E and configured to supply oil to the phase control valve 41 and the lock control valve 42 from an oil pan 6. Incidentally, this disclosure is not limited to such single pump. Instead, pumps can be provided individually for the phase control valve 41 and the lock control valve 42.
(28) The phase control valve 41 and the lock control valve 42 are controlled by control signals from an ECU (engine control unit). The ECU is configured to set a target relative rotational phase and to output control signals to the phase control valve 41 and the lock control valve 42 therefor, based on detection signals from a phase sensor (not shown) for detecting a relative rotational phase between the outer rotor 20 and the inner rotor 30, a speed sensor (not shown) for detecting a rotational speed of the engine E, and so on.
(29) Incidentally, instead of providing the phase control valve 41 and the lock control valve 42 separately, there can be provided a single OCV for effecting switchover of supply, discharge, retention of oil to/from/at the advance angle chamber Ca and the retard angle chamber Cb and effecting also switchover of supply and discharge of oil to/from the intermediate lock mechanism L. As an example of oil control in the case of such arrangement, the spool experiences changes in the order of: (1) advance angle chamber Ca supply, retard angle chamber Cb discharge, intermediate lock mechanism L discharge; (2) advance angle chamber Ca supply, retard angle chamber Cb discharge, intermediate lock mechanism L supply; (3) advance angle chamber Ca retention, retard angle chamber Cb retention, intermediate lock mechanism L supply; (4) advance angle chamber Ca discharge, retard angle chamber Cb supply, intermediate lock mechanism L supply; (5) advance angle chamber Ca discharge, retard angle chamber Cb supply, intermediate lock mechanism L discharge.
(30) At the time of stop of the engine E, driving of the pump P is stopped, so that oils present inside the advance angle chamber Ca and the retard angle chamber Cb are discharged into the oil pan 6. In this, oil is discharged from the lock passage 36, thus realizing a locked state. Next, when the engine E is started, a starter motor (not shown) is driven, thus initiating a cranking action. Namely, at the time of starting the engine E, the locked state is maintained, so that the cranking action can proceed under the condition of the relative rotational phase being restrained to a phase suitable for engine start. Subsequently, after oil is supplied to the advance angle chamber Ca, oil is supplied also to the intermediate lock mechanism L, thus releasing the locked state, so that a desired phase control will be executed thereafter.
(31) Incidentally, if the locked state is released when the amount of oil present in the retard angle chamber Cb is small, the camshaft 3 may be rotated repeated in the advance angle direction Sa and the retard angle direction Sb as being exposed to a reaction force from the intake valve, so that fluttering of the relative rotational phase can occur, thus rendering the phase control unstable. Moreover, the vane portion 31 will come into contact with the lateral wall of the retard angle chamber Cb repeatedly, thus inviting noise generation.
(32) [Communication Passage]
(33) Then, in the present embodiment, there is provided a communication passage 5 configured to establish communication between the advance angle chamber Ca and the retard angle chamber Cb which are positioned adjacent each other in the circumferential direction, when the intermediate lock mechanism L is under the locked state. More particularly, as shown in
(34) Further, in the instant embodiment, as shown in
(35) Next, with reference to
(36) Next, upon filling of the oil in the advance angle chamber Ca, as illustrated in
(37) Subsequently, as shown in
(38) The fluid movement mechanisms described above can function effectively even with a single OCV. Especially, with the single OCV, the control will proceed for instance such that at the time of starting the engine E, oil is supplied only to the advance angle chamber Ca and then oil is supplied to the intermediate lock mechanism L for releasing the locked state. At the time of release of the lock, oil is supplied also to the retard angle chamber Cb, so there is realized an operation with stable relative rotational phase. On the other hand, in case the phase control valve 41 and the lock control valve 42 are provided, there is no need to effect switchover of the phase control valve 41 for supplying oil to the advance angle chamber Ca and the retard angle chamber Cb. For this reason, time loss associated with switchover of the phase control valve 41 is eliminated, so that the timing of the lock release can be quickened.
2. Second Embodiment
(39) A second embodiment will now be explained regarding its differences from the first embodiment only, with reference to
(40) In this embodiment, the communication passage 5 is formed by cutting out a portion of the outer rotor 20 which portion comes into opposition to the outer circumferential end face of the vane portion 31 under the locked state. This cutout can be formed at a corner portion or an inner face of the outer rotor 20. In this case, at the time of starting the engine E, with the effect of the centrifugal force associated with rotation of the outer rotor 20, the oil of the advance angle chamber Ca moves toward the outer circumferential side and at the same time it starts moving to the retard angle chamber Cb via the communication passage 5. Namely, the oil supply to the advance angle chamber Ca and the oil supply to the retard angle chamber Cb take place simultaneously. For this reason, even if lock release is effected before the advance angle chamber Ca and the retard angle chamber Cb are filled with oil, the problematic situation of the amount of oil being small in the retard angle chamber Cb only will have already been resolved. So, fluttering of the vane portion 31 can be restricted at earlier stage.
3. Third Embodiment
(41) A third embodiment will now be explained regarding its differences from the first embodiment only, with reference to
(42) In this embodiment, the communication passage 5 is formed by cutting out a portion of one of the rear plate 22 and the front plate 23 to which portion the vane portion 31 under the locked state is projected in the direction of the rotational axis X.
(43) On the near side in the illustration, the advance angle chamber Ca is present and on the far side in the illustration across the vane portion 31, the retard angle chamber Cb is present. Namely, when the intermediate lock mechanism L is under the locked state, the communication passage 5 establishes communication between the advance angle chamber Ca and the retard angle chamber Cb across the vane portion 31.
(44) In this embodiment, the rear plate 22 and the front plate 23 are disc-like members; and the position to which the vane portion 31 is projected in the direction of the rotational axis X is constituted of a plane. For this reason, if the communication passage 5 is formed by cutting out a portion of of the plane of the disc-like member, working using a cutter tool or a mold can be effected easily.
4. Other Embodiments
(45) (1) In the foregoing embodiment, the communication passage 5 is formed by cutting out a portion of the inner rotor 30 which portion faces one projecting portion 21T. Alternatively, it can be formed by cutting out a portion of the inner rotor 30 facing two or more projecting portions 21T. Similarly, the communication passage 5 is not limited to the one formed by cutting out a portion of the outer rotor 20 facing the outer circumferential end face of one vane portion 31, but can be formed by cutting out a portion of the outer rotor 20 facing outer circumferential faces of two or more vane portions 31. Further, this disclosure is not limited to the arrangement of providing the communication passage 5 in either one of the rear plate 22 and the front plate 23; instead, the passage can be provided in both of them or provided at a position corresponding to two or more vane portions 31. If a plurality of communication passages 5 are provided as described above, the charging of oil to the advance angle chamber Ca and the retard angle chamber Cb can be effected even more speedily.
(46) (2) In the foregoing embodiment, the oil supply is started in the advance angle chamber Ca. Instead, the oil supply can be started in the retard angle chamber Cb. In this case too, at the time of starting the engine E, oil charging to the advance angle chamber Ca and the retard angle chamber Cb can be effected speedily via the communication passage 5.
(47) (3) In case the single OCV is provided in the foregoing embodiment, this single OCV can be coupled to the flow passage forming shaft portion 45 formed on the inner side of the inner rotor 30, or the single OCV can be disposed on the inner side of the inner rotor 30 and along the rotational axis X. Further, this disclosure is not limited the arrangement of the foregoing embodiment in which oil is supplied from the front plate 23 side. Instead, the oil can be supplied from the rear plate 22 side to the phase control valve 41 and the lock control valve 42 disposed on the camshaft 3 side or to the single OCV disposed on the inner side of the inner rotor 30 along the rotational axis X.
(48) (4) In the foregoing embodiment, the vane portions 31 are formed in the inner rotor 30 and the projecting portions 21T are formed in the outer rotor 20. Instead, the vane portions 31 (an example of projecting portion) can be formed in the outer rotor 20 and the projecting portions 21T (an example of partition portion) can be formed in the inner rotor 30. In this case, the communication passage 5 will be formed by cutting out a portion of the outer rotor 20 facing the projecting portion 21T or a portion of the inner rotor 30 facing the outer circumferential end face of the vane portion 31.
(49) (5) The valve opening/closing timing control device A of this disclosure can be configured also to control opening/closing timing of not only an intake valve, but also an exhaust valve.
INDUSTRIAL APPLICABILITY
(50) The present disclosure is applicable to a valve opening/closing timing control device for an internal combustion engine of an automobile, etc.
REFERENCE SIGNS LIST
(51) 1: crankshaft
(52) 3: camshaft
(53) 5: communication passage
(54) 20: outer rotor (drive-side rotating body)
(55) 21: rotor body (outer circumferential wall portion)
(56) 21T: projecting portion
(57) 22: rear plate (rear wall portion)
(58) 23: front plate (front wall portion)
(59) 30: inner rotor (driven-side rotating body)
(60) 31: vane portion (partition portion)
(61) 51: first flow passage
(62) 52: second flow passage
(63) C: oil chamber (fluid pressure chamber)
(64) Ca: advance angle chamber
(65) Cb: retard angle chamber
(66) E: engine (internal combustion engine)
(67) L: intermediate lock mechanism
(68) LS: intermediate lock phase
(69) P: pump
(70) X: rotational axis