Abstract:
A three-dimensional cam of a three-dimensional map state, having uncountable cam profiles continuously ranged along a rotation axis direction, and a valve lifter following a cam surface of the three-dimensional cam are included, and a lift characteristic of a valve is continuously controlled by relative motions of the three-dimensional cam and the valve lifter. The three-dimensional cam has cam top portions formed to have a smoothly ranged edge line substantially along the rotation axis direction thereof, and a part of the edge line includes at least one valley portion to take on a row of peaks. The cam peak portion of the cam top portion which forms the valley portion of the edge line is moderately set to be deviated toward a delayed side with reference to the rotation direction of the cam from the other cam peak portions.
Abstract:
An engine valve actuation system is provided. An intake valve is moveable between a first position where the intake valve prevents a flow of fluid relative to the intake valve and a second position where the intake valve allows a flow of fluid relative to the intake valve. A cam assembly is configured to move the intake valve between the first position and the second position. A fluid actuator having a chamber is adapted to selectively prevent the intake valve from moving to the first position. A fluid supply system is adapted to deliver fluid to the chamber of the fluid actuator. A pressure sensor is operatively engaged with the fluid supply system and is adapted to sense the pressure of the fluid within the fluid supply system. A controller is adapted to receive the sensed pressure of the fluid within the fluid supply system, to determine an expected pressure of the fluid within the fluid supply system, to identify when the sensed pressure deviates from the expected pressure, and to generate a responsive fault signal.
Abstract:
A valve train device for an engine is adapted to pivot a rocker arm supported on a rocker arm support shaft to drive a valve which opens and closes a valve opening formed in a combustion chamber. The device comprises a valve drive device and a swing member pivotally supported on a swing member support shaft and driven to pivot about the swing member support shaft by the valve drive device. An intermediate rocker member is pivotally supported on the rocker arm support shaft. The intermediate rocker member is provided between a swing cam surface formed on the swing member and a rocker face formed on the rocker arm, for transmitting the movement of the swing cam surface generated by the valve drive device to the rocker face. An intermediate rocker moving mechanism is configured to rotate the rocker arm support shaft and thereby move a first contact point between the intermediate rocker member and the swing cam surface and a second contact point between the intermediate rocker member and the rocker face to continuously vary at least one of the valve opening duration and the amount of valve lift.
Abstract:
A learning apparatus for a variable valve control of an internal combustion engine includes a variable valve operating mechanism, an actuator that rotationally drives the control shaft, a control shaft sensor that detects an angular position of the control shaft, a reference position determining section that determines whether or not the control shaft has reached a predetermined reference position under the drive from the actuator, a learning section that learns an output value of the control shaft sensor when it is determined that the control shaft has reached the reference position and stores the learned output value as a sensor output reference value, and a learning preparing section that causes the control shaft to be driven by the actuator toward the reference position when a crankshaft of the engine is rotating and supply of fuel to the engine is stopped. A learning method is also provided.
Abstract:
A method of controlling an engine having a valve actuation system is provided. The engine is started. A first parameter indicative of a first temperature of the engine is sensed. A second parameter indicative of a second temperature of the engine is sensed. The valve actuation system is disabled to prevent the implementation of a variation on conventional engine valve actuation timing in response to each of the first and second temperatures being below a predetermined value.
Abstract:
A forced opening and closing valve operating system for changing the operating characteristics of an engine valve according to low speed running conditions and high speed running conditions of the engine, includes a low-speed free rocker arm that swings by following a low speed valve-opening cam and a low speed valve-closing cam, a high-speed free rocker arm that swings by following a high speed valve-opening cam and a high speed valve-closing cam, and a valve operating rocker arm that is sandwiched between the low-speed and high-speed free rocker arms and is connected to an engine valve for driving the engine valve in both valve-opening and valve-closing directions. The rocker arms are swingably supported on a rocker shaft. Connection switching means switches alternatively connecting the valve operating rocker arm to the low-speed and high-speed free rocker arms. Thus, the valve operating system is compact, and noise generation is prevented.
Abstract:
A system and method of actuating one or more engine valves is disclosed. In one embodiment, the system comprises: a valve train element; a rocker arm pivotally mounted on a shaft and adapted to rotate between a first position and a second position, the rocker arm selectively receiving motion from the valve train element; a valve bridge disposed above the one or more engine valves; and a lost motion system disposed in the valve bridge.
Abstract:
A compound valve assembly for controlling oil flow includes a first and a second valve. The first valve is a pressure relief valve including a spring-biased plunger in a side gallery opening off a primary oil supply gallery leading to a pressure-actuated device. The relief spring allows oil above a predetermined pressure to displace the plunger and to be returned to an oil sump. The side gallery is closable by a secondary valve seat and a solenoid-actuated valve head. A passage through the plunger leads to the second valve seat. When the solenoid is deactivated, oil flows through the passage, through the second valve, and is returned to the sump. When high pressure is desired at the device, the solenoid closes the second valve. Captive oil assumes the same pressure as the supply pressure, and the relief valve function is disabled, causing high pressure oil to flow to the device.
Abstract:
An engine valve actuation system is provided. The system includes an engine valve moveable between a closed position and an open position. A spring is operatively connected to the engine valve to bias the engine valve towards the closed position. An actuator is operatively connected to the engine valve and is operable to selectively engage the engine valve to prevent the engine valve from returning to the closed position and to release the engine valve to allow the engine valve to return to the closed position. A sensor is configured to provide information related to the operation of the actuator. A controller is configured to transmit a signal to the actuator to engage the engine valve to prevent the engine valve from returning to the closed position and to release the engine valve to the allow the engine valve to return to the closed position. The controller is further configured to receive a signal from said sensor and to identify when the actuator fails to engage the engine valve in response to the transmitted signal or when the actuator fails to release the engine valve.
Abstract:
A valve-driving system for an internal combustion engine is provided with: an electric motor for generating a rotational driving force to drive a valve for intake or exhaust mounted on a cylinder in the internal combustion engine so as to open and close the valve in synchronization with a piston motion in the internal combustion engine; a transmitting device capable of changing between (i) a first condition to transmit therethrough the rotational driving force to the valve from said electric motor and (ii) a second condition to stop an opening or closing operation of the valve or to make the valve driven by a low lift amount; a judging device for judging whether or not synchronization between the opening or closing operation of the valve and the piston motion is abnormal; and a fail-safe device for changing said transmitting device to the second condition if it is judged by the judging device that the synchronization is abnormal.