Abstract: A method of engine compression release braking with avoidance of turbine overspeed is disclosed. Initially, an electronic control module determines whether a turbine overspeed condition is present. If an overspeed condition is present, then the blow down timing of an engine compression release braking event is advanced. The present invention is particularly applicable to preventing turbine overspeed for vehicles operating at higher altitudes while compression braking.

Abstract: In many cases, intake and/or exhaust valves and fuel injector plungers are desirably placed in a predetermined condition prior to starting the engine. In hydraulic systems, leakage and thermal contraction can lead to pressure loss during a period of non-operation, thereby allowing the components to move away from the predetermined condition. Similar concerns arise with the use of residual electromagnetic force, which can decay over time. In the case of intake/exhaust valves, for example, such undesired movement can led to a potential collision between the valves and the engine piston during starting. This invention provides a system and method for presetting the engine and/or the components thereof to the predetermined condition just prior to starting the engine.

Abstract: It is known that performance of actual fuel injectors tends to deviate from performance of a nominal injector as a function of rail pressure and on-time, due to such factors as machining tolerances of fuel injector components. In addition, performance characteristics of fuel injectors tend to change after they have been broken in. These changes can lead to unexpected inconsistencies with other engine components. For example, for those engines which utilize smoke limiting maps, when the injectors are not performing as expected, the injection adjustments that result from use of the smoke limiting maps can sometimes become fruitless. Therefore, the present invention includes two in-chassis strategies for evaluating fuel injector performance, including a bare acceleration test and a loaded fuel injector performance test.

Abstract: An enhanced braking mode for a work machine includes activating engine compression release brakes while placing a torque converter in an overspeed condition. By doing so, both the engine and the torque converter contribute to decelerating the work machine. This combined braking horsepower is greater than that available using the engine compression release brakes with the torque converter in a locked condition. In addition, the braking horsepower available in this enhanced braking mode is comparable to that available with the employment of hydraulic retarders, which can be substantially more expensive, and require additional hydraulic cooling system capability. The enhanced braking mode is preferably carried out automatically by the electronic control module when the vehicle is in a retarding mode.

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: A compression release brake system for an internal combustion engine is selectively operable in different modes that provide lower levels of noise emissions at lower levels of vehicle retarding. Lower noise levels are achieved by advancing or otherwise modulating the timing of brake events, thereby reducing cylinder pressure during release and thus reducing noise levels. A system is provided on board the vehicle to determine when the vehicle is operating in a noise restricted region and automatically switch to a braking mode that produces lower, acceptable levels of noise emissions. GPS or other sensors may be used to determine when the vehicle is operating in a restricted region.

Abstract: Traditional engine compression release brake systems include an engine brake that is associated with each cylinder of the engine. However, if the maximum braking horsepower required by the engine is less than that produced using all engine cylinders, the engine includes excess components. In an effort to reduce the number of engine components, and therefore increase engine robustness, the present invention includes an engine compression release brake system that provides a number of engine brakes that is less than the total number of engine cylinders.

Abstract: The present invention finds application in hydraulically actuated valves, such as gas exchange valves, having a valve member that moves within a valve body between an open position and a closed position. In valves such as these, the valve member typically includes a valve surface that contacts a valve seat included on the valve body when moving to its closed position. However, the impact velocity when the valve surface contacts the valve seat can be quite high. This can lead to fatigue of the valve stem and can wear out the valve seat, both of which can shorten the effective life of the valve. Therefore, the present invention includes a hydraulic pulse generator for slowing movement of the valve member which includes the direction of a hydraulic pulse toward the valve member as the valve member moves from its open position to its closed position.

Abstract: An actuator for adjusting a clearance between an end of a valve and an end of the actuator. The actuator has a piston therein having a central bore of which a portion is threaded. The piston has an end and has a flat defined near the end. The actuator has a stem member positioned therein. The stem member has a central portion which is threadedly positioned within the threaded portion of the central bore. The stem member defines a first end and a second end, and a threaded portion is located near the second end. The first end of the stem member and the end of the piston has a predetermined length which is adjustable. The predetermined length is adjusted by threadedly rotating the stem member relative to the piston. A locking device fixes the predetermined length during operation of the engine.

Abstract: A system and method for controlling combustion engine compression braking having the variable timing of the dwell period of at least one exhaust valve by an electronic control module within each one of the engine cylinders during a braking event as well as the variable timing of the commencement or onset of the braking event. The system and method thus facilitate the proper performance of the braking event as a function of engine speed and prevents interference or physical impact with the cam driving elements used for achieving the normal or regular exhaust valve event.

Abstract: An actuator for adjusting a clearance between an end of a valve and an end of the actuator. The actuator has a piston therein having a central bore of which a portion is threaded. The piston has an end and has a flat defined near the end. The actuator has a stem member positioned therein. The stem member has a central portion which is threadedly positioned within the threaded portion of the central bore. The stem member defines a first end and a second end, and a threaded portion is located near the second end. The first end of the stem member and the end of the piston has a predetermined length which is adjustable. The predetermined length is adjusted by threadedly rotating the stem member relative to the piston. A locking device fixes the predetermined length during operation of the engine.

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: A method and an apparatus for controlling combustion engine compression braking has the variable timing of the opening of at least one exhaust valve by an electronic control module within each one of the engine cylinders and within a time range of 15°-150° before the top-dead-center position of each cylinder piston during each compression stroke such that variable compression braking power levels, and attendant noise levels, can be obtained as required or desired dependent upon various road, vehicle, and vehicle location parameters. The system and method facilitate a wide range of braking power levels or values, the braking power is smoothly modulated as a result of all of the designated exhaust valves of the cylinders being activated, and the braking power levels can also be generated as a function of engine speed.

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: A method of engine compression release braking includes an initial step of compressing gas in an engine cylinder. A compression release brake valve is then opened at least in part by fluidly connecting a brake actuator to a source of high pressure actuation fluid. Next, a valve closing timing that results a valve seating velocity that is less than a pre-determined velocity is determined. The compression release brake valve is then closed at the valve closing timing at least in part by fluidly connecting the brake actuator to a low pressure actuation fluid reservoir.

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: The present invention finds application in hydraulically actuated valves, such as gas exchange valves, having a valve member that moves within a valve body between an open position and a closed position. In valves such as these, the valve member typically includes a valve surface that contacts a valve seat included on the valve body when moving to its closed position. However, the impact velocity when the valve surface contacts the valve seat can be quite high. This can lead to fatigue of the valve stem and can wear out the valve seat, both of which can shorten the effective life of the valve. Therefore, the present invention includes a hydraulic pulse generator for slowing movement of the valve member which includes the direction of a hydraulic pulse toward the valve member as the valve member moves from its open position to its closed position.

Abstract: A method of engine compression release braking with avoidance of turbine overspeed is disclosed. Initially, an electronic control module determines whether a turbine overspeed condition is present. If an overspeed condition is present, then the blow down timing of an engine compression release braking event is advanced. The present invention is particularly applicable to preventing turbine overspeed for vehicles operating at higher altitudes while compression braking.

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 enhanced warm-up operation mode operates a first portion of engine cylinders in a power mode and a second portion of engine cylinders in a braking mode. More fuel is injected into the powered cylinders in order to maintain engine speed and overcome the retarding force of the engine compression release brakes on the braking cylinders. The engine cycles through which cylinders are powered and which are braking during the warm-up procedure. The process reduces emissions, such as white smoke, that are common during cold start conditions.