Variable valve operating control apparatus for internal combustion engine and control method thereof

{
  "publication_number": "US7011055B2",
  "country": "US",
  "kind": "B2",
  "title": "Variable valve operating control apparatus for internal combustion engine and control method thereof",
  "abstract": "A centric phase of an operating angle of an engine valve is detected on the basis of an interval between a reference rotational position of a crankshaft and a reference rotational position of a camshaft, and on the other hand, the centric phase is detected at a period shorter than a period between the reference rotational positions, and one of those detected results is selected on the basis of a predetermined regulation, and an opening characteristic of the engine valve is operated on the basis of the selected centric phase.",
  "claims": [
    "1. A variable valve operating control apparatus for an internal combustion engine comprising: a Variable valve Timing Control mechanism which makes a centric phase of an operating angle of an engine valve variable due to a rotational phase of a camshaft with respect to a crankshaft being varied; a first detecting unit which detects a centric phase of an operating angle of the engine valve on the basis of an interval between a reference rotational position of the crankshaft and a reference rotational position of the camshaft; a second detecting unit which detects a centric phase of an operating angle of the engine valve at a period shorter than that by the first detecting unit; a selecting unit which selects one of the centric phase detected of late by the first detecting unit and the centric phase detected of late by the second detecting unit, on the basis of a predetermined regulation; and an operating unit which operates an opening characteristic of the engine valve on the basis of the centric phase selected by the selecting unit.",
    "2. A variable valve operating control apparatus for an internal combustion engine according to claim 1, wherein the selecting unit selects one in which the opening characteristic of the engine valve is operated so as to be at a safer side between the centric phase detected of late by the first detecting unit and the centric phase detected of late by the second detecting unit.",
    "3. A variable valve operating control apparatus for an internal combustion engine according to claim 1, wherein the operating unit outputs an operate signal to the Variable valve Timing Control mechanism on the basis of the centric phase selected at the selecting unit and a target value for the centric phase.",
    "4. A variable valve operating control apparatus for an internal combustion engine according to claim 3, wherein the Variable valve Timing Control mechanism makes a centric phase of an operating angle of an intake valve variable, and the selecting unit selects one which is further at a retard side, between the centric phase detected of late by the first detecting unit and the centric phase detected of late by the second detecting unit.",
    "5. A variable valve operating control apparatus for an internal combustion engine according to claim 1, further comprising a Variable valve Event and Lift mechanism which makes an operating angle and a lift of the engine valve variable, wherein the operating unit sets a limit value of a operated amount of the Variable valve Event and Lift mechanism on the basis of the centric phase selected at the selecting unit, and operates the Variable valve Event and Lift mechanism within the limit value.",
    "6. A variable valve operating control apparatus for an internal combustion engine according to claim 5, wherein the selecting unit selects one by which a distance between the engine valve and a piston at a piston top dead center is made shorter, between the centric phase detected of late by the first detecting unit and the centric phase detected of late by the second detecting unit.",
    "7. A variable valve operating control apparatus for an internal combustion engine according to claim 1, wherein the first detecting unit comprises a crank angle sensor generating a detection signal at a reference rotational position of the crankshaft, a cam sensor generating a detection signal at a reference rotational position of the camshaft, a measuring unit which measures a interval between a detection signal at a reference rotational position of the crankshaft and a detection signal at a reference rotational position of the camshaft, and a computing unit which computes the centric phase on the basis of the interval.",
    "8. An variable valve operating control apparatus for an internal combustion engine according to claim 1, wherein the second detecting unit comprises a sensor whose output sequentially varies in accordance with a variation in a centric phase of an operating angle of the engine valve.",
    "9. An variable valve operating control apparatus for an internal combustion engine according to claim 1, wherein the second detecting unit is structured such that a permanent magnet is provided at one side of a member which is relatively rotated in accordance with an operating state of the Variable valve Timing Control mechanism, and a yoke is provided at the other side thereof, and a clearance between a center of a magnetic pole of the permanent magnet and the yoke is varied by the relative rotation, and detects a variation in a magnetic flux density due to a variation in the clearance.",
    "10. An variable valve operating control apparatus for an internal combustion engine according to claim 9, wherein the second detecting unit detects a variation in the magnetic flux density by a Hall element.",
    "11. An variable valve operating control apparatus for an internal combustion engine according to claim 1, wherein the second detecting unit comprises a rotator which rotates so as to be integrated with the camshaft, and whose radius sequentially varies in a circumferential direction, a distance sensor which is fixed so as to face onto a peripheral edge of the rotator, and which outputs a detection signal in accordance with a variation in a relative distance with the peripheral edge of the rotator, a crank angle sensor which detects a rotational angle of the crankshaft at every micro-rotational angle, and a computing unit which computes a centric phase of an operating angle of the engine valve on the basis of a rotational angle of the camshaft detected on the basis of an output of the distance sensor and a rotational angle of the crankshaft detected at the crank angle sensor.",
    "12. An variable valve operating control apparatus for an internal combustion engine according to claim 1, wherein the second detecting unit comprises a first rotator which rotates so as to be integrated with the camshaft, and whose radius sequentially varies in a circumferential direction, a first distance sensor which is fixed so as to face onto a peripheral edge of the first rotator, and which outputs a detection signal corresponding to a variation in a relative distance with the peripheral edge of the first rotator, a second rotator which rotates so as to be integrated with the crankshaft, and whose radius sequentially varies in a circumferential direction, a second distance sensor which is fixed so as to face onto a peripheral edge of the second rotator, and which outputs a detection signal corresponding to a variation in a relative distance with the peripheral edge of the second rotator, and a computing unit which computes a centric phase of an operating angle of the engine valve on the basis of a rotational angle of the camshaft detected on the basis of an output of the first distance sensor and a rotational angle of the crankshaft detected on the basis of an output of the second distance sensor.",
    "13. An variable valve operating control apparatus for an internal combustion engine according to claim 1, wherein the Variable valve Timing Control mechanism comprises a driving member to which a turning force is transmitted from the crankshaft, a driven member which is provided so as to be integrated with the camshaft, an intermediate rotator which is provided between the driving member and the driven member, and which accelerates and decelerates a rotation transmitted to the driven member by being relatively rotated with respect to the driving member, and an electromagnetic actuator which makes the intermediate rotator relatively rotate with respect to the driving member.",
    "14. An variable valve operating control apparatus for an internal combustion engine comprising: a Variable valve Timing Control mechanism which makes a centric phase of an operating angle of an engine valve variable due to a rotational phase of a camshaft with respect to a crankshaft being varied; first detecting means for detecting a centric phase of an operating angle of the engine valve on the basis of an interval between a reference rotational position of the crankshaft and a reference rotational position of the camshaft; second detecting means for detecting a centric phase of an operating angle of the engine valve at a period shorter than that by the first detecting means; selecting means for selecting one of the centric phase detected of late by the first detecting means and the centric phase detected of late by the second detecting means, on the basis of a predetermined regulation; and operating means for operating an opening characteristic of the engine valve on the basis of the centric phase selected at the selecting means.",
    "15. A method for controlling an internal combustion engine which has a Variable valve Timing Control mechanism which makes a centric phase of an operating angle of an engine valve variable due to a rotational phase of a camshaft with respect to a crankshaft being varied, comprising the steps of: detecting a centric phase of an operating angle of the engine valve at every reference rotational position on the basis of an interval between a reference rotational position of the crankshaft and a reference rotational position of the camshaft; detecting a centric phase of an operating angle of the engine valve at a period shorter than a period between the reference rotational positions; selecting one of a most up-to-date value of the centric phase detected at every reference rotational position and a most up-to-date value of the centric phase detected at a period shorter than the period between the reference rotational positions on the basis of a predetermined regulation; and operating an opening characteristic of the engine valve on the basis of the selected centric phase.",
    "16. A method for controlling an internal combustion engine according to claim 15, wherein the step of selecting one of the two centric phases comprises a step of selecting one by which an opening characteristic of the engine valve is operated so as to be at a safer side, between a most up-to-date value of the centric phase detected at every reference rotational position and a most up-to-date value of the centric phase detected at a period shorter than the period between the reference rotational positions.",
    "17. A method for controlling an internal combustion engine according to claim 15, wherein the step of operating the opening characteristic of the engine valve comprises a step of outputting a operate signal to the Variable valve Timing Control mechanism on the basis of the selected centric phase and a target value for the centric phase.",
    "18. A method for controlling an internal combustion engine according to claim 17, wherein the Variable valve Timing Control mechanism makes a centric phase of an operating angle of an intake valve variable, and the step of selecting one of the two centric phases comprises a step of selecting one which is further at retard side, between a most up-to-date value of the centric phase detected at every reference rotational position and a most up-to-date value of the centric phase detected at a period shorter than the period between the reference rotational positions.",
    "19. A method for controlling an internal combustion engine according to claim 15, wherein the internal combustion engine further has a Variable valve Event and Lift mechanism which makes an operating angle and a lift of the engine valve variable, and the step of operating the opening characteristic of the engine valve comprises the steps of; setting a limit value of a operated amount of the Variable valve Event and Lift mechanism on the basis of the selected centric phase, and operating the Variable valve Event and Lift mechanism within the limit value.",
    "20. A method for controlling an internal combustion engine according to claim 19, wherein the step of selecting one of the two centric phases comprises a step of selecting one by which a distance between the engine valve and a piston at a piston top dead center is made shorter, between a most up-to-date value of the centric phase detected at every reference rotational position and a most up-to-date value of the centric phase detected at a period shorter than the period between the reference rotational positions."
  ],
  "description_excerpt": "1. Field of the Invention\n\nThe present invention relates to a variable valve operating control apparatus of an internal combustion engine having a variable valve timing mechanism and a control method thereof.\n\n2. Description of the Related Art\n\nIn Japanese Unexamined Patent Publication 2000-087769, there is disclosed an variable valve operating control apparatus which has a variable valve timing mechanism which varies a rotational phase of a camshaft with respect to a crankshaft of an internal combustion engine, and a variable valve lift mechanism which varies a lift of an engine valve.\n\nIn a conventional art, a rotational phase adjusted by a variable valve timing mechanism is detected on the basis of a interval between a detection signal at a reference rotational position of a crankshaft and a detection signal at a reference rotational position of a camshaft.\n\nThen, the aforementioned variable valve timing mechanism is feedback-controlled on the basis of a detected rotational phase on the basis of the interval.\n\nTherefore, there has been the problem that the feedback control of a rotational phase cannot be carried out when a sensor detecting the reference rotational positions breaks down.\n\nFurther, in the structure in which a rotational phase is detected on the basis of the detection signals of the reference rotational positions, a rotational phase is detected at every constant crank angle.",
  "cpc": [
    "F01L 13/0026",
    "B65D 61/00",
    "B65G 7/12",
    "F01L 2013/0073",
    "F01L 2820/041"
  ],
  "ipc": [
    "F01L 1/34",
    "F01L 1/46",
    "F01L 13/00"
  ],
  "assignees": [
    "Hitachi Ltd"
  ],
  "inventors": [
    "Kenichi Machida",
    "Masahiko Watanabe",
    "Yoshiyuki Kobayashi"
  ],
  "filing_date": "2005-02-25",
  "publication_date": "2006-03-14",
  "grant_date": "2006-03-14",
  "priority_date": "2004-02-26",
  "application_number": "US-6552105-A",
  "family_id": "34752162",
  "cited_by_count": 1,
  "citations": [
    "US5937805A",
    "JP2000087769A",
    "EP1306528A2",
    "EP1310635A2",
    "US20030145815A1",
    "US20040015287A1",
    "US6920852B2"
  ]
}