Abstract:
A cylinder head assembly for an internal combustion engine including a cylinder head at least partially defining a flow path through the engine, including an intake port, an exhaust port, and a combustion chamber disposed between the intake port and the exhaust port. A valve is coupled to the cylinder head and movable relative to the cylinder head to selectively open the combustion chamber to one of the intake port and the exhaust port. A valve spring is positioned between the valve and the cylinder head and biases the valve to a closed position. A thermally insulating washer is positioned between the cylinder head and the valve spring.
Abstract:
An intake valve assembly of an internal combustion engine. The intake valve assembly comprises a primary valve, a secondary valve mounted about the primary valve coaxially therewith, a primary valve spring for normally biasing the primary valve toward a closed position, a secondary valve spring for normally biasing the secondary valve toward a closed position, and a secondary valve lifter fixed to the primary valve and axially spaced from the secondary valve when both the primary and secondary valves are in closed positions. The secondary valve is operated mechanically by the secondary valve lifter and fluidly in response to pressure differential between the intake passage and the combustion chamber. The secondary valve is engageable with the primary valve through the secondary valve lifter after opening of the primary valve. The primary and secondary valve springs are normally contracted for continuously biasing the valves toward the closed position thereof.
Abstract:
A valve system is disclosed for an internal combustion engine which allows a secondary valve event, serving for example to provide internal EGR, to be selectively disabled. The system comprises two valve 10 and 22, a first cam 20 acting on the first valve 10 by way of a rocker 12 pivotable about a fixed pivot axis and a second cam 36 having at least two lobes and acting on the second valve 22 by way of a second rocker 24 pivotable about an eccentric 26. The second of the two lobes of the second cam 36 is arranged to open the second valve 22 at a time that the first valve 10 is opened by the first cam 20. A selectively operable latching mechanism 50 latches the eccentric 26 in a fixed position in which each of the cam lobes of the second cam causes the second valve to open. When the latching mechanism 50 is released, a coupling between the eccentric 26 and the first rocker 12 causes or permits the eccentric 26 to move during the opening of the first valve 10 in a sense to oppose the lifting of the second valve 22 by the second lobe of the second cam.
Abstract:
A damper is shown for damping the movements of a valve spring in an engine. The valve spring can be housed within the damper or the damper may be located inside of the valve spring. The damper is made from a suitable polymer and has one or more tabs or slots located radially to a central axis and one or more helical springs, rings or bands housed in the slots or between the tabs. The helical springs, rings or bands are located on the outer surface of the damper where the valve spring is housed within the damper. The cross section, number and location of the tabs, slots, helical springs, rings or bands can be adjusted depending on the particular application of the damper and the amount of damping that is desired for the particular application. The damper can also incorporate a hub or stem seal.
Abstract:
An outwardly-opening gas-exchange valve assembly for an internal combustion engine. The valve assembly includes a port in a firing chamber in an engine head, the port having a valve seat on a side opposite from the firing chamber. A piston-shaped poppet valve head slides in a bore in the engine head for mating with the valve seat to occlude passage of gas across the valve seat. Withdrawal of the poppet valve head from the seat opens the firing chamber to communication with an intake or exhaust manifold runner in the engine head. The poppet valve head may be actuated by an overcenter lever arrangement actuated selectively by hydraulic pressure or mechanical actuation. In a preferred embodiment, OO intake and exhaust valves are radially arranged in a hemispherical fire deck and may include an adjustable pitch helical channel to induce swirl to the incoming gas.
Abstract:
Actuators and corresponding methods and systems for controlling such actuators offer efficient, fast, flexible control with large forces. In an exemplary embodiment, an fluid actuator includes a housing having first and second fluid ports, an actuation cylinder in the housing defining a longitudinal axis and having first and second ends in first and second directions, an actuation piston in the cylinder with first and second surfaces moveable along the longitudinal axis, a spring subsystem biasing the actuation piston to a neutral position, a first fluid space defined by the first end of the actuation cylinder and the first surface of the actuation piston, and a second fluid space defined by the second end of the actuation cylinder and the second surface of the actuation piston. A first flow mechanism controls fluid communication between the first fluid space and the first port, whereas a second flow mechanism controls fluid communication between the second fluid space and the second port. The first and second flow mechanisms are substantially restricted through two integrated snubbing mechanisms when the actuation piston approaches the first and second direction ends of its travel, respectively. In addition to a differential fluid force on the actuation piston, there is a centering or returning spring force available to help open the engine valve against the high cross-over passage pressure, without the need for the fluid actuation system to be bulky and consume too much energy.
Abstract:
A variable valve actuating mechanism includes an output cam pivotally disposed upon an input shaft of an engine. First and second frame members are disposed upon the input shaft on respective sides of the input cam lobe. A first link arm is pivotally coupled at a first end thereof to the first and second frame members. A rocker arm assembly is pivotally coupled at a first end thereof to a second end of the link arm. The rocker arm assembly carries a cam follower that engages an input cam lobe of the input shaft. A biasing means is grounded to the first and second frame members, and biases the cam follower into engagement with the input cam lobe.
Abstract:
A piston air engine comprises an intake system at an outer side of a cylinder and parallel to the cylinder; a piston in the cylinder; a piston inner exhaust valve device in an interior of the piston; and a piston positioning actuating device for actuating an engine and positioning in a power stroke. The lever force apply point of the intake lever is at an upper dead point of the piston to be confined by the movement of the piston; and the lever force accept point of the intake lever is installed at the intake valve door for confining the intake valve.
Abstract:
To lighten the weight of an electromagnetic actuator and a valve-open-close mechanism by forming the stems from a lighter material than conventional. A pair of electromagnets formed of stators and coils are opposed to each other with a gap therebetween. An armature is disposed in the gap so as to be reciprocable between one electromagnet and the other electromagnet by the electromagnets. A first stem for transmitting the movement of the armature from one electromagnet toward the other electromagnet to a valve of the internal combustion engine is inserted in a guide hole formed in the stator of one electromagnet. The first stem is formed of a lighter material than the armature to lighten the weight of the electromagnetic actuator and a valve-open-close mechanism of an internal combustion engine.
Abstract:
An electromagnetic actuator for an automotive internal combustion engine is provided which has a stator, the weight of which is reduced. The electromagnetic actuator has a pair of electromagnets each made up of a stator and a coil, an armature disposed between the pair of electromagnets so as to be reciprocable therebetween, and a first stem provided on one side of the armature for transmitting the movement of the armature to external. The stator is formed by powder molding.