摘要:
Engine valve actuation systems and methods used to decompress an engine cylinder during engine start-up, shut-down, and for bleeder braking are disclosed. An exemplary system may include a rocker arm pivotally mounted on a rocker shaft, and a structure mounted adjacent to the rocker arm in a fixed position relative to the rocker arm. A latch piston may be slidably disposed between the rocker arm and the structure. The latch piston may be selectively extended to engage both the rocker arm and structure to limit the pivotal motion of the rocker arm and maintain the engine valves in an open condition.
摘要:
In an internal combustion engine equipped with a variable compression ratio mechanism, the occurrence of knocking is reduced during deceleration. When it is determined that a target compression ratio of the variable compression ratio mechanism is greater than a threshold PRSL during the deceleration, an air bypass valve interposed in a passage for bypassing a compressor of an exhaust turbo supercharger is opened to return intake air upstream (between the compressor and a throttle valve) of the throttle valve to upstream of the compressor, thereby reducing intake pressure upstream of the throttle valve and reducing in-cylinder compression pressure to reduce the occurrence of knocking.
摘要:
Engine valve actuation systems and methods used to decompress an engine cylinder during engine start-up, shut-down, and for bleeder braking are disclosed. An exemplary system may include a rocker arm pivotally mounted on a rocker shaft, and a structure mounted adjacent to the rocker arm in a fixed position relative to the rocker arm. A latch piston may be slidably disposed between the rocker arm and the structure. The latch piston may be selectively extended to engage both the rocker arm and structure to limit the pivotal motion of the rocker arm and maintain the engine valves in an open condition.
摘要:
A valve actuation mechanism for an internal combustion engine includes rockers moved by a camshaft, each rocker being adapted to exert a valve opening force on at least a portion of a valve opening actuator of each cylinder, via an activation piston, housed in a bore of the rocker and movable with respect to the rocker under action of a fluid pressure raise in a chamber fluidly connected to the bore, from a first position to a second position with respect to the rocker, in which a cam follower of the rocker is adapted to read at least one auxiliary valve lift sector of a cam of the camshaft so as to perform an engine operating function. Each rocker includes a check valve adapted to control the fluid pressure raise in the chamber. The valve actuation mechanism includes, for each rocker, a stopper fast with a housing of the engine and adapted to exert, on a member of the rocker, a force for opening a valve independent from the check valve, adapted to release fluid from the chamber when the piston has to be moved from its second position to its first position.
摘要:
A fixed chain engine braking device includes a brake box, a driving mechanism and a braking mechanism. One upright blind hole and one horizontal blind hole are placed in the brake box, and the upright blind hole intersects the horizontal blind hole orthogonally. The driving mechanism includes a rolling ball and/or a driving piston placed in the horizontal blind hole, the braking mechanism includes a braking plunger placed in the upright blind hole. A fluid passage is placed in the brake box, and the fluid passage is communicated with the entry of the horizontal blind hole.
摘要:
An internal combustion engine includes a hydraulically-driven variable valve timing device for adjusting the opening timing and the closing timing of an intake valve and configured to include a start retard position for decompression that is retarded further from the most retarded position during a normal operating state, and a control system configured to start a cranking operation of the internal combustion engine while the variable valve timing device is positioned in the start retard position for decompression, to determine during the cranking operation whether operating oil has drained from the variable valve timing device, when it has been determined that oil has drained from the variable valve timing device, to set a delay time between the cranking operation start and an advance operation of the variable valve timing device longer than the situation in which operating oil is replete.
摘要:
A rocker arm arranged between a camshaft and a valve which opens/closes an intake port or an exhaust port. A rolling bearing for supporting a support hole formed in a rocker arm is of a type of bearing wherein a plurality of needles are mounted on an inner side of an outer peripheral shell, and the outer peripheral shell is fixed to the support hole, the cam follower includes an outer ring which is supported on a periphery of a cam follower shaft which is held by a pair of left and right arm portions of the rocker arm by way of a plurality of rollers, a position of the outer ring and a position of the rollers in the lateral direction are restricted by the arm portion, and an outer diameter of the outer ring is set equal to or less than an inner diameter of the support hole.
摘要:
A valve operating system for an internal combustion engine, which includes a decompression cam member (47) that is supported on a camshaft (26) and that operates an exhaust valve operating member (29e) in an opening direction of an exhaust valve (17e) in a compression stroke when the engine is started, an exhaust gas recirculation cam member (48) that is supported on the camshaft (26) and that operates the exhaust valve operating member (29e) in the opening direction of the exhaust valve (17e) in an intake stroke when the engine is running at high speed, and a centrifugal mechanism (46) that is mounted on a driven timing rotating member (32) rotating integrally with the valve operating cam (25) and makes the decompression cam member (47) and the exhaust gas recirculation cam member (48) move, wherein the valve operating cam (25) is provided with a recess (39) surrounding the camshaft (26), the recess (39) opening on the face on the other side of the driven timing rotating member (32) and on a base face of the valve operating cam (25), and the decompression cam member (47) and the exhaust gas recirculation cam member (48) are housed in the recess (39). This can provide a valve operating system for an internal combustion engine that can be made compact in spite of a driven timing rotating member and an exhaust cam being installed.
摘要:
A valve opening arrangement includes a first contact surface on a first member, and a second contact surface on a second member discrete from the first member. A first and a second opening are provided, and a first and a second valve movable to open and close the first and second opening, respectively, are provided. A yoke is arranged to move the first valve and not the second valve when contacted by the first contact surface and is arranged to move the first valve and the second valve when contacted by the second contact surface.
摘要:
A method of operating a hybrid powertrain system is provided for a vehicle that includes an internal combustion engine having an engine output to drive the vehicle and a motor having a motor output to drive the vehicle. The motor is operatively connected to the engine and operable to crank the engine. The method includes the steps of reducing compression in at least one engine cylinder and operating the motor to crank the engine. A hybrid powertrain system for a hybrid vehicle is also provided.