Abstract: A valve actuation device for an internal combustion engine having at least one combustion cylinder, a piston positioned within said cylinder for reciprocal motion therein; a pressurized hydraulic fluid gallery in a closed lubrication system; at least one valve in gas exchange communication for either intake or exhaust, said valve equipped with a valve spring and a seat and moveable between an open and closed position as controlled by said valve actuation device, a cam shaft with a cam for actuating said valve synchronously with said piston motion, said valve actuation device comprising: a cam configured for primary and secondary valve motion; a cam follower to transmit cam movement through a hydraulic circuit in fluid communication with said hydraulic fluid gallery into the valve between an open and closed position, and a fixed stroke accumulator selectively hydraulically controlled in said hydraulic circuit for loosing a portion of cam follower motion and to effect valve motion; an electro-hydraulic control

Abstract: In control apparatus and method for an internal combustion engine having variably operated engine valves, a target vacuum pressure is calculated on the basis of an engine driving condition and an opening angle of an electronically controlled throttle valve is disposed in an intake air passage to achieve the target vacuum pressure. A target air quantity to be sucked within an engine cylinder on the basis of the engine driving condition is calculated and a valve closure timing of an intake valve of, e.g., an electromagnetic operation type is controlled to achieve the target air quantity. At this time, in accordance with the target vacuum pressure TBOOST(or in accordance with an actual vacuum pressure BOOST detected by means of a vacuum pressure sensor), the target air quantity to calculate the valve closure timing of the intake valve calculated on the basis of target air quantity is corrected or the intake valve closure timing IVC per se is corrected by a correction value of &Dgr;IVC.

Abstract: Improving compression brake systems (10) require better control of timing an actuation event. Numerous systems use complicated electronic controls to achieve such control. Cam actuated compression brake systems may reduce braking power by allowing a valve 32 on an internal combustion engine (30) to remain open well after an optimum crank angle. Using a by-pass port (42), pressure may be increased in a second actuator volume (22) opposite a first actuator volume (20). Increasing pressures in the second actuator volume (22) promotes closing the valve (26) near the optimum crank angle.

Abstract: The invention relates to a method and an arrangement for engine braking a four-stroke internal combustion engine. The engine has for each cylinder (2) at least one inlet valve (7) and at least one exhaust valve (9) for controlling communication between a combustion chamber (5) in the cylinder (2) and an inlet system (8) and an exhaust system (10) respectively. In accordance with the invention, the arrangement also establishes communication between the combustion chamber (5) and the exhaust system (10) in conjunction with the exhaust stroke and also when the piston (3) is located in the proximity of the its bottom-dead-center position after the inlet stroke and during the latter part of the expansion stroke.

Abstract: Compression brake systems using “back-fill” between combustion cylinders or requiring an exhaust valve to be opened twice during a braking cycle require brake actuation systems able to maintain control over the exhaust valve during different loading conditions. In a first opening event where a piston is at or near bottom dead center, pressures in the combustion cylinder are low. During a second opening event near top dead center pressures are higher. Movement of the exhaust valve may be slowed during the first opening event by controlling fluid leaving a second actuator volume opposite a first actuator volume providing opening force on an exhaust valve.

Abstract: An integral engine fueling and engine compression braking hydraulically actuated, electronically controlled unit injector (HEUI) system comprises a fuel injection piston. A brake rocker arm extends transversely through the fuel injector and axially accommodates the fuel injector plunger and plunger return spring. The brake rocker arm is also operatively connected to the engine exhaust valve rocker arm, and a camming shaft, having a flat or planar surface portion, is operatively connected to an end portion of the brake rocker arm. When the end portion of the brake rocker arm is disposed in contact with the flat or planar surface portion of the camming shaft, normal fuel injection can occur in accordance with an electronic control module (ECM).

Abstract: Compression brake systems using “back-fill” between combustion cylinders or requiring an exhaust valve to be opened twice during a braking cycle require brake actuation systems able to maintain control over the exhaust valve during different loading conditions. In a first opening event where a piston is at or near bottom dead center, pressures in the combustion cylinder are low. During a second opening event near top dead center pressures are higher. Movement of the exhaust valve is controlled by delivery of fluid to a brake actuator piston. Fluid delivery is slowed as the brake actuator piston moves to cover a first cylinder port and uncover a second cylinder port.

Abstract: An apparatus and method for effectuating multi-cycle engine braking is disclosed. The present invention controls the operation of the engine valves to permit more than one compression release event during a single engine operating cycle. The apparatus includes an assembly for operating at least one exhaust valve of an engine cylinder during a positive power operation. The apparatus further includes an assembly for operating at least one intake valve of the engine cylinder. The apparatus further including an assembly for operating the at least one exhaust valve during an engine braking operation. The apparatus further including an assembly for selectively operating the at least one exhaust valve during an engine braking operation.

Abstract: The present invention relates to methods of improving engine braking of a reciprocating piston internal combustion engine by variable valve actuation. One embodiment of the present invention enables independent two-valve actuation for each cylinder, and engine braking horsepower can be optimized using two-valve braking at high engine speeds and one-valve braking at low speeds. Another embodiment of the present invention enables better a sequential valve actuation to reduce engine braking load and compliance. Another embodiment of the present invention enables better engine starting and warming up by controlling timing and lift of each valve.

Abstract: A control method of an internal combustion engine with which braking force while reducing the speed of the motor vehicle can be established by generating pumping loss effectively by using a variable valve mechanism enabling to control arbitrarily the open-close timing and the lift amount of air intake and exhaust valves of the engine. When the break step-on force detection means detects a step-on force on a brake and an operation of the anti-lock brake system is selected, at least one of the intake valve or the exhaust valve is made close, another one not closed of the intake valve or the exhaust valve is made open once in a single revolution of the engine while a piston moves from a top dead center to a bottom dead center, and a lift of the valve is controlled to be a designated value.

Abstract: The present invention is directed to an apparatus for operating at least one intake valve and at least one exhaust valve in an engine cylinder. The apparatus includes an exhaust valve operating assembly for operating the at least one exhaust valve of the engine cylinder, wherein the exhaust valve operating assembly is capable of producing an exhaust gas recirculation event. The apparatus also includes an intake valve operating assembly for operating the at least one intake valve of the engine cylinder. The apparatus further includes an exhaust modifying assembly for modifying the operation of the exhaust valve operating assembly during a predetermined engine operating condition and an intake modifying assembly for modifying the operation of the intake valve operating assembly during a predetermined engine operating condition.

Abstract: A compression release engine brake assembly adapted for use with an internal combustion engine, and an exhaust valve (29) operable to open in a normal exhaust lift event (FIG. 9) and in a brake lift event (FIG. 15). The engine includes an exhaust valve actuating mechanism (23,31,37) for imparting reciprocal movement to said exhaust valve (29) in response to rotation of a cam shaft (11) including a cam profile (13), a normal lift portion (17) and a brake lift portion (19). The assembly includes a lost motion device (75) moveable between a normal lost motion condition (FIG. 4) and an actuated condition (FIG. 14) in response to movement of an input member (91). An energy storage spring (117) is operable, after being compressed to an energy storage condition (FIG. 12) to be able to bias the input member (91) toward a second position, effecting the actuated condition of the lost motion device (75).

Abstract: In an internal combustion engine comprising a gas recirculation passage connecting a first member to an intake manifold, a compression release means, and at least one gas pulse created during a first event, a method for retarding the engine comprising the steps of opening the compression release means, releasing at least one gas pulse into the gas recirculation passage after a first event, redirecting the at least one gas pulse into the intake manifold, and using the at least one gas pulse to increase air charge in a cylinder.

Abstract: An assembly for providing an engine brake system for an internal combustion engine, in particular of an industrial vehicle, which engine comprises a plurality of cylinders, a cylinder head provided, for each such cylinder, with at least one exhaust valve and, for each such exhaust valve, with a relative control cam having a profile comprising at least one section that can be selectively actuated by varying the valve play, the assembly comprising, for each cylinder, a support body adapted to be connected to the cylinder head and bearing at least one rocker arm support spindle, the rocker arm support spindle being coupled, by means of an eccentric bushing, to a rocker arm adapted to be interposed between an exhaust valve and a cam in order to oscillate about an axis, the assembly lastly comprising an actuator adapted to rotate the eccentric bushing with respect to the support body in order to displace the axis of oscillation of the rocker arms and to vary the valve play between these rocker arms and the exhaust

Abstract: An engine brake application system for an internal combustion engine. The engine has at least one cylinder, at least one exhaust valve associated with the cylinder, and a rocker arm for activating the exhaust valve. The rocker arm is arranged on a hollow rocker means responsive to an increase in oil pressured in the hollow rocker arm shaft and incorporated into the rocker arm for taking up clearance between the rocker arm and the exhaust valve. To effect a reduction of engine speed during a gear shift, the system includes means responsive to a signal generated in response to a need to effect a gear shift for rapidly increasing the oil pressure in the hollow rocker arm shaft to thereby effect valve clearance take-up.

Abstract: The present invention is directed to a control value 20 which incorporates the functions of both a shuttle valve and a check valve into a single structure for use in a lost motion engine brake system. In response to a supply of hydraulic fluid from switched low pressure supply circuit 320, control valve body 200 of control value 20 may index within control valve bore 204, such that hydraulic fluid flows through upper annulus 260, first horizontal bore 270, first vertical bore 280, middle annulus 261 and out through lashless fluid supply circuit 340 and accumulator control circuit 350 to acuate engine valve 100. In an embodiment for clipping/rest of the valve actuating piston 130, clipping/reset spool 450 provided in rocker shaft 405. In response to rotational or linear motion, spool annuluses 451 on clipping/reset spool 450 move to open and close clipping reset/passageway 455 and accumulator control circuit 350, thereby providing clipping of piston 130.

Abstract: This invention is an exhaust gas recirculation apparatus such that exhaust gas recirculation master piston (12) is activated and acts to open exhaust valve (4) on the same cylinder (1) by driving a slave piston (14), thus recirculating exhaust gas into combustion chamber (2) from exhaust port (5) as a result of the pressure difference, thereby lowering the combustion temperature within combustion chamber (2) on the next power stroke and working to reduce NOx. Moreover, by selectively maintaining and releasing oil pressure in two types of passages (13) and (31), it can also be used as a compression pressure-release engine brake.

Abstract: A method of compression braking is provided for use in an internal combustion engine having a plurality of combustion chambers that share a common exhaust manifold, such as, for example, a six-cylinder engine. The method comprises the steps of moving each exhaust valve to an open position at a first time corresponding to approximately the beginning of the power portion of the cycle of the combustion chamber associated with the exhaust valve and moving each exhaust valve to the open position at a second time corresponding to approximately the end of the intake portion of the cycle of the combustion chamber associated with the exhaust valve.

Abstract: A lost motion valve actuation system for an internal combustion engine is disclosed. The system includes a motion feedback system (100) for detecting the motion and timing of a valve actuator (130) and an engine valve (140). By providing information on the condition of the engine during operation, the motion feedback system (100) permits adjustment of the valve actuation system that can optimize operation or prevent engine damage. The motion feedback system may be used in a common rail or a lost motion valve actuation system. In alternate embodiments, the valve actuation system includes an accumulator (300) with an accumulator piston (310) whose motion is limited by an accumulator stop (330) or a control valve (200). The limited accumulator (300) controls the amount of lost motion in the valve actuation system to provide fail-safe operation in the event of electrical failure.

Abstract: An internal-combustion engine has an engine braking device which has brake valves by way of which the combustion chamber content of the cylinders can be diverted in the engine braking phase. In the engine braking operation, the brake valves are changed into the opening position. In order to increase the operational reliability of the engine braking device, a blocking device is provided which acts upon the brake valves and which can be adjusted between a holding position and a release position. In the holding position of the blocking device, the brake valves are held in the opening position.

Abstract: An internal combustion engine may include a hydraulic linkage used to transfer motion from a valve train element, such as a cam, to an engine valve. Method and apparatus for selectively limiting the motion transferred by the hydraulic linkage from the valve train element to the engine valve are disclosed. The motion transferred by the hydraulic linkage may be limited by a means for resetting or clipping that is integrated into the rocker arm/shaft assembly provided in the valve train.

Abstract: A rocker arm assembly for an engine is disclosed. The rocker arm assembly comprises a rocker shaft having a first side and a second side and a rocker arm pivotably disposed on the rocker shaft. The rocker arm comprises a first portion disposed on the first side of the rocker shaft for receiving a force in a first direction from a brake actuator. The rocker arm further comprises a second portion disposed on the second side of the rocker shaft for engaging a valve in a second direction opposite the first direction. When the braking mode is desired, the brake actuator forces the first portion of the rocker arm in a first direction causing the rocker arm to transfer motion from the brake actuator to the exhaust valve or valves, thereby allowing exhaust to exit the combustion chamber.

Abstract: A two-cycle compression brake apparatus and braking method is provided according to the invention.

Abstract: A method of operating an internal combustion engine having a hydraulic supply circuit, a hydraulically-powered fuel injector assembly, and a hydraulically-powered compression release brake assembly includes the step of advancing a pressurized hydraulic fluid to the fuel injector assembly from the hydraulic supply circuit so as to cause fuel to be injected into a cylinder associated with the engine when the engine is being operated in a drive mode of operation. The method also includes the step of advancing the pressurized hydraulic fluid to the compression release brake assembly so as to cause a piston to be moved from a retracted position to an extended position when the engine is being operated in a brake mode of operation.

Abstract: An apparatus for limiting the travel of a slave piston (110) in a slave piston cylinder (100) in a compression release engine brake is disclosed. The apparatus provides stroke-limiting means and independent lash adjustment means which may be installed in a common rail, variable valve actuation system. The independent lash adjustment means comprises a sleeve (300) around the slave piston (110), threadably mounted in the brake housing (40). The stroke-limiting means comprises a slave piston (110) in a slave piston cylinder (100), a trigger valve (90) and a hydraulic circuit connected thereto. The slave piston stroke is limited when a lower flow port (130) in the slave piston cylinder (100) is opened to drain (81) slightly before high-pressure flow is cut off through an upper flow port (120) in the slave piston cylinder (100).

Abstract: A valve actuation system for an internal combustion engine is disclosed. The system includes two hydraulic plungers (master pistons) that are selectively hydraulically coupled to a slave piston. The hydraulic motion from one of the hydraulic plungers may provide a valve opening motion to the slave piston and the hydraulic motion from the other hydraulic plunger may provide a valve closing motion. The net hydraulic motion of both hydraulic plungers may be zero, so that when both plungers have hydraulic communication with the slave piston, no slave piston motion occurs. The system may provide full authority over all engine valve actuations, such as main intake, main exhaust, compression release, and exhaust gas recirculation.

Abstract: An exhaust brake is incorporated with an internal combustion engine. The brake comprises an exhaust rocker arm actuated by an exhaust cam for operating an exhaust valve; a brake rocker arm actuated by a brake cam; a first contacting unit held by either one of the exhaust and brake rocker arms; a second contacting unit held by the other of the exhaust and brake rocker arms. The second contacting unit is contactable with the first contacting unit when an exhaust braking is needed. Only when the brake rocker arm is actuated by the brake cam upon need of the exhaust braking, there induces the contact between the second and first contacting units, which provides an integral action of the exhaust and brake rocker arms thereby to actuate the exhaust valve for establishing the exhaust braking.

Abstract: The present invention is directed to an exhaust gas recirculation apparatus in which an exhaust-gas-recirculation master piston (12) is actuated by a suction rocker arm (10) to drive a slave piston (14) which in turn opens an exhaust valve (4) on the same cylinder (1) during a suction stroke. As a result, owing to pressure difference, the exhaust gas is recirculated from an exhaust port (5) into a combustion chamber (2) to lower the combustion temperature in the combustion chamber (2) during a next power stroke and to promote decrease of NOx.

Abstract: An engine compression braking system having an integral rocker lever and reset valve utilizes a single rocker lever to operate an engine in both normal power and braking modes while effectively closing an exhaust valve to define a braking mode exhaust valve opening event prior to a primary opening event. The system includes a reset valve mounted on the rocker arm a spaced distance from an actuator piston to relieve fluid pressure from a high pressure circuit after an initial opening of the exhaust valve. A reset contact element is mounted on a stationary engine component for engagement by the reset valve during movement of the rocker lever to cause opening of the reset valve and relief of the pressure. In one embodiment, a bias chamber and bias chamber supply circuit are provided to permit low pressure braking fluid to be continuously supplied to an actuator supply circuit.

Abstract: A valve actuating assembly for actuating at least one valve is disclosed. The valve actuating assembly includes a housing assembly, an actuating assembly for actuating at least one valve during a first valve operating event and a second valve operating event, and an assembly for modifying valve motion travel of the at least one valve during at least one of the first valve operating event and the second valve operating event. A system for providing exhaust gas recirculation and compression release braking in an engine is also disclosed.

Abstract: An engine exhaust braking method and apparatus is provided according to the invention. The engine exhaust braking method includes the steps of actuating an exhaust valve during an intake stroke of the engine, holding the exhaust valve open during a first portion of a compression stroke of the engine, and closing the exhaust valve when a corresponding piston of the engine is more than one-half way through a compression stroke, wherein a cylinder corresponding to the exhaust valve is precharged by higher pressure air from the exhaust manifold.

Abstract: An engine compression braking system includes an exhaust rocker arm pivotally supported on rocker shaft. One end of the rocker arm carries a roller which engages a camshaft which has a lost motion bump formed thereon. The other end of the rocker arm engages an exhaust valve stem assembly. A part of the rocker shaft engages a pressure operated piston. Extension of the piston moves the rocker shaft transversely to its axis, so that the rocker arm can selectively react to or ignore the lost motion portion bump. A pressure control system includes a solenoid operated valve controlled by an operator controlled switch, so that the piston selectively applies a light force or a very high force to the rocker arm rocker shaft, thus controlling the pivot point of the rocker arm.

Abstract: An engine valve actuation system is disclosed, which is capable providing compression release engine braking in combination with exhaust gas recirculation while maintaining main exhaust and main intake valve events of constant magnitude during both positive power and engine braking. The system is also capable of providing a constant level of desired overlap between main exhaust and main intake valve events during both positive power and engine braking. The system may provide the foregoing functions by using first and second valve actuation subsystems to provide the full spectrum of exhaust valve motions. Both the first and second subsystems may receive an input motion from a valve train element. The first subsystem operates only when the engine braking system is enabled. The second subsystem operates both during positive power and during engine braking.

Abstract: A control method of an internal combustion engine with which braking force while reducing the speed of the motor vehicle can be established by generating pumping loss effectively by using a variable valve mechanism enabling to control arbitrarily the open-close timing and the lift amount of air intake and exhaust valves of the engine. When the break step-on force detection means detects a step-on force on a brake and an operation of the anti-lock brake system is selected, at least one of the intake valve or the exhaust valve is made close, another one not closed of the intake valve or the exhaust valve is made open once in a single revolution of the engine while a piston moves from a top dead center to a bottom dead center, and a lift of the valve is controlled to be a designated value.

Abstract: A variably timed internal combustion engine valve actuation system and method for opening valves in internal combustion engines. The system functions during both positive power and engine braking, to control the amount of "lost motion" between a valve and a means for opening the valve. In particular, the invention relates to a lost motion engine valve actuation system using a dedicated cam for effecting exhaust valve openings for compression release braking and exhaust gas recirculation ("EGR").

Abstract: An internal combustion engine has electrically controlled hydraulic linkages between engine cams and engine cylinder valves. If it is desired to skip a cam lobe or to modify the response of an engine cylinder valve to a cam lobe, hydraulic fluid is selectively released from the associated hydraulic linkage to permit lost motion between the cam and the engine cylinder valve. Electrically controlled hydraulic fluid valves are used to produce the selective release of hydraulic fluid from the hydraulic linkages. The mode of operation of the engine can be changed (e.g., from positive power mode to compression release engine braking mode or vice versa), or more subtle changes can be made to modify the timing and/or extent of engine cylinder valve openings to optimize engine performance for various engine or vehicle operating conditions (e.g., different engine or vehicle speeds). The valves can be controlled to produce an exhaust gas recirculation event during various operating modes of the engine.

Abstract: An apparatus for limiting the travel of a slave piston in a slave piston cylinder in a compression release engine retarder is disclosed. The apparatus is connected to a hydraulic circuit and comprises an internal passageway in the slave piston head. The internal passageway comprises a vertical bore, a horizontal bore, and an annular channel which together provide a path for bleeding off the pressure on the top of the slave piston when the annular channel and an aperture in the slave piston cylinder are aligned. The bleeding of the hydraulic pressure on top of the slave piston clips the motion of the slave piston at a desired stroke. The apparatus includes a locking adjustable foot on the slave piston stem which provides a means to adjust the lash.

Abstract: The present invention is directed to a control system for controlling operation of an engine compression release brake for an engine. The control system includes a valve actuation assembly for actuating at least one valve during a predetermined engine operating condition. The control system also includes an energy supply assembly for supplying energy to operate the valve actuation assembly. The control system includes a control assembly for controlling the operation of valve actuation assembly.

Abstract: A lost motion engine valve actuation system and method of actuating an engine valve are disclosed. The system may comprise a valve train element, pivoting bridge, an adjustable tappet, and a valve stem. The pivoting bridge may include a first end for contacting the adjustable tappet, a second end for contacting the valve stem and a pivot point between the first and second ends for contacting the valve train element. The amount of lost motion provided by the system may be selected by varying the position of the adjustable tappet relative to the pivoting bridge. Variation of the adjustable tappet position may be carried out by placing the adjustable tappet in hydraulic communication with a control trigger valve. Actuation of the trigger valve releases hydraulic fluid allowing for adjustment of the adjustable tappet position.

Abstract: A method and apparatus for carrying out variable timing exhaust gas recirculation is disclosed for use during both positive power and retarding operation of an internal combustion engine. Motion or energy is derived from an engine component and stored as potential energy. The stored energy is selectively applied to a valve actuator to carry out exhaust gas recirculation in an engine cylinder. The energy derived from the engine may be stored and selectively applied to the valve actuator with an electronically controlled trigger valve. The valve actuator may be a slave piston having an inner core and an outer sleeve capable of opening the valve of the cylinder in response to independent exhaust gas recirculation and compression release hydraulic systems.

Abstract: An auxiliary brake system includes a turbocharger, including an exhaust turbine driven by exhaust gas supplied from an internal combustion engine, nozzle vanes disposed therearound at intervals for a vane-opening-degree adjustment, and an actuator for adjusting the vane opening degree; a compression-releasing engine brake unit for generating an engine brake force by discharging suction air compressed in a combustion chamber of the engine at the timing in the vicinity of compression top dead center; and an electronic control unit. This control unit actuates the engine brake unit when the engine is in a fuel-cut region, and rotates the nozzle vanes through an actuator so that the opening degree of each nozzle vane is smaller than that attained when the engine brake unit is disabled and meets an engine rotation speed.

Abstract: The present invention relates to a co-axial master piston for use in providing hydraulic fluid to effectuate a compression release braking function and hydraulic fluid to effectuate an exhaust gas recirculation function. In particular, the coaxial master piston includes an inner master piston driven by an exhaust cam to provide the hydraulic force to cause the compression release braking function. An outer piston, driven by the same exhaust cam, provides the hydraulic force to cause the EGR function during positive power operation of the engine and during compression release braking when required.

Abstract: A decompression engine brake device is incorporated with an internal combustion engine. The device comprises an exhaust valve arranged to open and close an exhaust port of a combustion chamber of the engine. A valve stem extends from the exhaust valve. A valve lifter is slidably disposed in a cylinder head of the engine. The valve lifter has the valve stem contacting thereto. An exhaust cam disposed about an exhaust cam shaft is operatively engageable with the valve lifter to actuate the exhaust valve in accordance with a contour of the exhaust cam. An engine brake cam is defined by the exhaust cam. A hydraulically operating device is employed for inducing an operative engagement between the engine brake cam with the valve lifter thereby to actuate the exhaust valve in accordance with a contour of the engine brake cam.

Abstract: A method and apparatus of carrying out exhaust gas recirculation and compression release retarding is disclosed for use during both positive power and retarding operation of an overhead cam internal combustion engine. Energy is derived from an engine component and stored as potential energy. The stored energy is selectively applied to a valve actuator to carry out exhaust gas recirculation in an engine cylinder. The energy derived from the engine may be stored in the form of a compressed hydraulic fluid and selectively applied to the valve actuator with an electronically controlled trigger valve. The valve actuator may be a slave piston having an inner core and an outer sleeve capable of opening the valve of the cylinder in response to independent exhaust gas recirculation and compression release hydraulic systems.

Abstract: An apparatus and method for effectuating multi-cycle engine braking is disclosed. The present invention controls the operation of the engine valves to permit more than one compression release event during a single engine operating cycle. The apparatus includes an assembly for operating at least one exhaust valve of an engine cylinder during a positive power operation. The apparatus further includes an assembly for operating at least one intake valve of the engine cylinder. The apparatus further including an assembly for operating the at least one exhaust valve during an engine braking operation.

Abstract: In an engine-brake assisting system comprising a hydraulic pressure producing unit, an exhaust valve driving unit and a hydraulic circuit member which are constructed as discrete elements, the hydraulic pressure producing unit produces a desired hydraulic pressure by rotating a camshaft disposed on a cylinder head to drive an engine-brake assisting cam. The generated hydraulic pressure is then supplied to an exhaust cam of the exhaust valve driving unit, which causes exhaust valves to open and close at a timing different from a valve opening and closing timing during a normal operation, thereby giving the engine a large brake force. With this arrangement, the reduction of overall size of the system and consequent reduction of overall height of an engine can be achieved.

Abstract: The present invention is directed to a locking assembly for use in a rocker arm assembly for an engine brake assembly. The rocker arm assembly includes a rocker arm pivotally mounted on a shaft. The rocker arm has a first end and a second end, wherein the first end includes a cam follower and the second end includes an actuator assembly for operating at least one valve during a braking operation. The improved rocker arm includes a locking assembly for releasably securing the rocker arm to the shaft to prevent pivoting of the rocker arm during a positive power operation. The locking assembly includes a releasable latching assembly located on one of the rocker arm and the shaft. The locking assembly also includes a latch receiving recess located on another of the rocker arm and the shaft. The releasable latching assembly engages the latch receiving recess during a positive power operation.

Abstract: An internal combustion engine includes a mechanism for releasing compression from the cylinder during starting. That mechanism has an actuator attached to the engine camshaft for sliding between first and second positions. In first position the actuator is engaged by a lifter to open the engine exhaust valve during the compression phase of the combustion cycle. At the second position, the valve lifter does not engage the actuator and the exhaust valve remains closed during the compression phase. A weight lever is pivotally attached to the camshaft and drives the actuator between the first and second positions in response to engine speed. At slow speeds occurring while before the engine starts, the actuator is held the first position so that the compression is relieved. After the engine starts, centrifugal force causes the weight lever to drive the actuator into the second position at which normal compression occurs.

Abstract: In an internal combustion engine for motor vehicles with an engine shutdown driven capability, wherein the engine has intake and exhaust valves with a variable timing valve actuating system permitting the generation of an engine braking torque depending on the state of vehicle operation, the intake and exhaust valves are controlled during shutdown engine driven operation such that at least on type of valves, that is either all the intake or all the exhaust valves remain closed.

Abstract: Exhaust valve mechanism in an internal combustion engine, comprising a valve play take-up mechanism in the form of a piston (8) disposed in a cylinder chamber (7) at one end of a rocker arm (1) and a hydraulic circuit with valve means (20) for supplying and draining oil to and from the cylinder chamber. Controlled check valve means (22) prevent, at a certain pressure in the hydraulic circuit, drainage of oil from the cylinder chamber. A bypass valve (40) controlled by the rocking movement of the rocker arm opens for draining the cylinder chamber before the exhaust valve reaches the top of its lift curve.