Abstract: A first swing arm of each cylinder is swung by a fixed cam of an intake camshaft, so as to operate a first intake valve according to a profile thereof. A second swing arm is swung by a second cam and its swing range is changed by a variable mechanism. Hereby, a lift amount of a second intake valve changes continuously. The second cam is selected from a plurality of cams on a cam piece provided around the intake camshaft.

Abstract: When a lock demand of a camshaft phase occurs, a control mode of a hydraulic control valve is switched to a locking mode after the camshaft phase is controlled to a lock phase, and a lock pin is moved to a lock position. The camshaft phase is locked at the lock phase, and timing advance and timing retard chambers communicate with each other through a back space. In this state, a locking time filling control is executed. In the locking time filling control, the control mode of a hydraulic control valve is switched to a filling mode, the hydraulic oil is supplied to a timing advance chamber, both of the timing advance chamber and the timing retard chamber are filled with the hydraulic oil, the back space is filled with the hydraulic oil, and thereafter the control mode of the hydraulic control valve is returned to the locking mode.

Abstract: A first swing arm of each cylinder is swung by a fixed cam of an intake camshaft, so as to operate a first intake valve according to a profile thereof. A second swing arm is swung by a second cam and its swing range is changed by a variable mechanism. Hereby, a lift amount of a second intake valve changes continuously. The second cam is selected from a plurality of cams on a cam piece provided around the intake camshaft.

Abstract: An oil control valve has a housing and a spool valve that is arranged in the housing and is movable in the axial direction. The movement range of the spool valve includes a first area and a second area. In the first area, a port that is connected to a lock mechanism opens to prevent the movement of a variable valve timing mechanism through drainage of oil from the lock mechanism. In the second area, oil is supplied and drained to and from the variable valve timing mechanism through a passage inside the spool valve. The first area exists at a position separated from the second area in the movement range.

Abstract: A variable valve timing apparatus includes: a variable valve timing mechanism; an intermediate locking mechanism that locks the valve timing at an intermediate timing; and a hydraulic pressure supply device that hydraulically actuates these mechanisms. The hydraulic pressure supply device uses a single oil control valve to control a state where lubricating oil is supplied to or drained from each of an advance chamber, a retard chamber and an intermediate chamber of an intermediate locking mechanism. The oil control valve has first to fourth modes. The oil control valve advances the valve timing and actuates the intermediate locking mechanism in a projecting direction in the third mode, and, under a situation that the amount of lubricating oil supplied to the variable valve timing mechanism is smaller than that in the third mode, advances the valve timing and actuates the intermediate locking mechanism in a release direction in the fourth mode.

Abstract: At least a first movable coil part of a plurality of movable coil parts that is in the innermost place in the radial direction does not come into contact with both the fixed coil part, which is radially adjacent inwardly, and a second movable coil part, which is radially adjacent outwardly, at the same place in the circumferential direction while coming into contact with only one of the fixed coil part and the second movable coil part in a plurality of places that are circumferentially displaced, when the spiral spring is in an elasticity retaining state reached from a free length state by elastic deformation in the diameter-reducing direction.

Abstract: When a lock demand of a camshaft phase occurs, a control mode of a hydraulic control valve s switched to a locking mode after an actual camshaft phase is controlled to a lock phase, and a lock pin (an inner pin and an outer pin) is moved to a lock position. Thus, the camshaft phase is locked at the lock phase, and a timing advance chamber and a timing retard chamber are made a state of communicating with each other through a back space. In this state, a locking time filling control is executed. In the locking time filling control, the control mode of a hydraulic control valve is switched to a filling mode, the hydraulic oil is supplied to a timing advance chamber, both of the timing advance chamber and the timing retard chamber are filled with the hydraulic oil, the back space is filled with the hydraulic oil, and thereafter the control mode of the hydraulic control valve is returned to the locking mode.

Abstract: A variable valve timing device that allows a valve timing of an engine valve to be varied by relatively rotating a vane rotor and a housing. The variable valve timing includes a lock mechanism that releases the locking in accordance with the application of a lock releasing oil pressure. A crank angle CCA at which the application of the lock releasing oil pressure is instructed can be varied in accordance with an engine speed NE so that the lock releasing oil pressure rises at a crank angle in which cam torque is suitable for lock releasing.

Abstract: In a variable valve timing device, which varies the rotational phase of a camshaft through the relative rotation of a vane rotor and a housing and is provided with a lock mechanism that releases the lock thereof in response to the application of lock-release hydraulic pressure, the crank angle CCA at which the application of lock-release hydraulic pressure is commanded is set variably in accordance with the pressure of the oil supplied for the application so that the lock-release hydraulic pressure rises at a crank angle at which the state of the cam torque becomes suitable for lock-release without relying on changes of time needed for the lock-release hydraulic pressure to raise resulting from oil temperature.

Abstract: When a start-up failure occurs wherein an internal combustion engine equipped with a variable valve device does not transition to complete combustion before a first prescribed period ? elapses from the start of cranking in conjunction with fuel injection, a control unit for the internal combustion engine executes a start-up failure process addressing a state wherein the valve timing is different from a specific timing.

Abstract: At least a first movable coil part of the plurality of movable coil parts that is in the innermost place in the radial direction does not come into contact with both the fixed coil part, which is radially adjacent on the inside, and a second movable coil part, which is radially adjacent on the outside, at the same place in the circumferential direction while coming into contact with only one of the fixed coil part and the second movable coil part in a plurality of places that are circumferentially displaced, when the spiral spring is in an elasticity retaining state reached from a free length state by elastic deformation in the diameter-reducing direction.

Abstract: An oil control valve has a housing and a spool valve that is arranged in the housing and is movable in the axial direction. The movement range of the spool valve includes a first area and a second area. In the first area, a port that is connected to a lock mechanism opens to prevent the movement of a variable valve timing mechanism through drainage of oil from the lock mechanism. In the second area, oil is supplied and drained to and from the variable valve timing mechanism through a passage inside the spool valve. The first area exists at a position separated from the second area in the movement range.

Abstract: In a hydraulic variable valve timing mechanism including a lock pin that locks a vane rotor and a housing against relative rotation in the most retarding phase, a specified angle ? is set so that release of the lock pin is started at a time when positive cam torque acts on the vane rotor. When the crank angle reaches the specified angle ?, supply of hydraulic pressure to the advancing oil chamber is started to release the lock pin from the engagement with the lock hole, thereby enabling a reliable release of the lock pin prior to start of change of valve timing.

Abstract: A variable valve actuation device for an internal combustion engine includes a variable valve timing mechanism and a valve timing restricting mechanism. When the operating state of the variable valve timing mechanism is in the phase restricting state and the operating state of the variable valve timing mechanism is changed to the phase releasing state on the basis of pressing the accelerator pedal, a torque limiting control is then performed to limit an increase in the torque of the internal combustion engine. With this control the rate of increase of the torque is set less than the rate of increase of the torque corresponding to the operation of pressing the accelerator pedal by retarding and correcting the ignition timing. Thus, when the operating state of the variable valve timing mechanism is changed from the phase restricting state to the phase releasing state, thereby reducing discomfort experienced by the driver.

Abstract: If a relative rotational phase between a first rotor drivably connected to a crankshaft and a second rotor drivably connected to a camshaft is not an intermediate lock phase when an engine is started, a fuel injection starting timing is delayed more than that of the time when the relative rotational phase is the intermediate lock phase. The delay time is determined according to the working oil temperature of a valve timing mechanism during the engine start or the same oil temperature at the previous stop time of the engine, for example. As a result, the start of the engine can be completed as soon as possible while retaining the startability of the internal combustion engine.

Abstract: Provided is a variable valve assembly for internal combustion engines which is capable of accurately determining whether an input rotational component and an output rotational component are fixed to each other. The variable valve assembly includes an intake camshaft for driving an intake valve and a crankshaft for driving the camshaft. The variable valve assembly has a function for changing the relative rotational phase of the intake camshaft with respect to the crankshaft and a function for fixing the intake camshaft to the crankshaft. The variable valve assembly determines whether the intake camshaft is fixed to the crankshaft, on the basis of a total amount of phase variation HCC or the amount of variation in the relative rotational phase of the intake camshaft with respect to the crankshaft.

Abstract: A variable valve timing device that allows a valve timing of an engine valve to be varied by relatively rotating a vane rotor and a housing. The variable valve timing includes a lock mechanism that releases the locking in accordance with the application of a lock releasing oil pressure. A crank angle CCA at which the application of the lock releasing oil pressure is instructed can be varied in accordance with an engine speed NE so that the lock releasing oil pressure rises at a crank angle in which cam torque is suitable for lock releasing.

Abstract: In a variable valve timing device, which varies the rotational phase of a camshaft through the relative rotation of a vane rotor and a housing and is provided with a lock mechanism that releases the lock thereof in response to the application of lock-release hydraulic pressure, the crank angle CCA at which the application of lock-release hydraulic pressure is commanded is set variably in accordance with the pressure of the oil supplied for the application so that the lock-release hydraulic pressure rises at a crank angle at which the state of the cam torque becomes suitable for lock-release without relying on changes of time needed for the lock-release hydraulic pressure to raise resulting from oil temperature.

Abstract: A primary resilient member urges a primary limiting member into a recess in an inserting direction in a state where a rotational phase is a limited phase in a limited phase range. A relative slide gap is radially provided between the primary limiting member and a secondary limiting member at a location adjacent to a working chamber. First and second primary slide gaps are radially provided between the primary limiting member and radially opposed wall surface sections of the receiving hole. A secondary slide gap is radially provided between the secondary limiting member and a radially opposed wall surface section of the receiving hole. The relative slide gap is larger than the first and second primary slide gaps and the secondary slide gap.

Abstract: A variable valve actuation device for an internal combustion engine includes a variable valve timing mechanism and a valve timing restricting mechanism. When the operating state of the variable valve timing mechanism is in the phase restricting state and the operating state of the variable valve timing mechanism is changed to the phase releasing state on the basis of pressing the accelerator pedal, a torque limiting control is then performed to limit an increase in the torque of the internal combustion engine. With this control the rate of increase of the torque is set less than the rate of increase of the torque corresponding to the operation of pressing the accelerator pedal by retarding and correcting the ignition timing. Thus, when the operating state of the variable valve timing mechanism is changed from the phase restricting state to the phase releasing state, thereby reducing discomfort experienced by the driver.