849 results about "Engine braking" patented technology

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.

A bi-directional overrunning clutch is disclosed for controlling torque transmission between a secondary drive shaft and secondary driven shafts. The overrunning clutch includes a pinion input shaft in a differential housing that engages with a clutch housing rotatably disposed within the differential housing. At least one race is located adjacent to the clutch housing and is engaged with an output shaft. A cage is located between the race and the clutch housing. The cage is movable with respect to the clutch housing. A <DEL-S DATE="20030304" ID="DEL-S-00001"/>first<DEL-E ID="DEL-S-00001"/> coil is mounted within the differential housing adjacent to the cage and is adapted to produce an electromagnetic field when energized which causes the cage to drag with respect to the clutch housing. The dragging of the cage with respect to the clutch housing positions <INS-S DATE="20030304" ID="INS-S-00001"/>rolls within <INS-E ID="INS-S-00001"/>the cage to engage the clutch housing with the race when wheels on a primary drive shaft lose traction. <DEL-S DATE="20030304" ID="DEL-S-00002"/>A<DEL-E ID="DEL-S-00002"/> <INS-S DATE="20030304" ID="INS-S-00002"/>If desired a <INS-E ID="INS-S-00002"/>second coil <DEL-S DATE="20030304" ID="DEL-S-00003"/>is<DEL-E ID="DEL-S-00003"/> <INS-S DATE="20030304" ID="INS-S-00003"/>may be <INS-E ID="INS-S-00003"/>mounted within the differential housing adjacent <DEL-S DATE="20030304" ID="DEL-S-00004"/>adjacent<DEL-E ID="DEL-S-00004"/> to the cage. The second coil is adapted to produce an electromagnetic field when energized which advances cage with respect to the clutch housing causing the clutch housing to engage with the races. When the second coil is activated, the output shaft drives the pinion input shaft producing engine braking. An electronic control system is utilized to control the energizing of the coils.

A system for actuating one or more engine valves for positive power operation and engine braking operation is disclosed. In a preferred embodiment, an exhaust valve bridge and intake valve bridge each receive valve actuations from two sets of rocker arms. Each valve bridge includes a sliding pin for actuating a single engine valve and an outer plunger disposed in the center of the valve bridge to actuate two engine valves through the bridge. The outer plunger of each valve bridge may be selectively locked to its valve bridge to provide positive power valve actuation. During engine braking, application of hydraulic pressure to the outer plungers may cause the respective valve bridges and outer plungers to unlock so that all engine braking valve actuations are provided from a rocker arm acting on one engine valve through the sliding pin.

A hybrid power train and method for operating same in which the operation of the engine is modified to effect an improvement in the fuel economy and/or emissions performance of the hybrid power train. In one embodiment, the battery of the power train is employed to provide auxiliary heat to an engine aftertreatment system to thereby improve the effectiveness of the aftertreatment system. In another embodiment, various components of the engine, such as a water pump, are wholly or partly operated by electric motors that receive power from the battery of the power train. In another embodiment, engine braking can be employed in situations where regenerative braking does not provide sufficient braking torque. In a further embodiment, the engine valves may be selectively opened to reduce pumping losses associated with the back-driving of the engine.

Apparatus and method are disclosed for converting an internal combustion engine from a normal engine operation (20) to an engine braking operation (10). The engine includes exhaust valve train components comprising at least one exhaust valve (300) and at least one cam (230) for cyclically opening and closing the at least one exhaust valve (300). The apparatus comprises actuation means (100) having at least one component integrated into at least one of the exhaust valve train components, such as a rocker arm (210) or a valve bridge (400). The actuation means (100) has an inoperative position and an operative position. In the inoperative position, the actuation means (100) is retracted and the small braking cam lobes (232&233) are skipped to generate a main valve lift profile (220m) for the normal engine operation (20). In the operative position, the actuation means (100) is extended to form a mechanical linkage so that the motion from all the cam lobes (220, 232&233) is transmitted to the at least one exhaust valve (300) for the engine braking operation (10). The apparatus further comprises control means (50) for moving the actuation means (100) between the inoperative position and the operative position to achieve the conversion between the normal engine operation (20) and the engine braking operation (10). The apparatus also includes valve lash adjusting mechanism, oil retraining means (350), and engine brake reset means (150).

A hybrid powertrain and method for operating same in which the operation of the engine is modified to effect an improvement in the fuel economy and/or emissions performance of the hybrid powertrain. In one embodiment, the battery of the powertrain is employed to provide auxiliary heat to an engine aftertreatment system to thereby improve the effectiveness of the aftertreatment system. In another embodiment, various components of the engine, such as a water pump, are wholly or partly operated by electric motors that receive power from the battery of the powertrain. In another embodiment, engine braking can be employed in situations where regenerative braking does not provide sufficient braking torque. In a further embodiment, the engine valves may be selectively opened to reduce pumping losses associated with the back-driving of the engine.

Methods are provided for controlling a vehicle speed during a downhill travel. Based on the estimated grade of the downhill travel and further based on an input received from the operator, different combinations of an engine braking torque and a regenerative braking torque are used to maintain the vehicle speed during the downhill travel. A battery rate of charging is also adjusted based on the duration or distance of the downhill travel, as indicated by the operator input.

A method for providing an estimate of brake pad thickness. The method employs fusion of sensors, if used, and driver brake modeling to predict the vehicle brake pad life. An algorithm is employed that uses various inputs, such as brake pad friction material properties, brake pad cooling rate, brake temperature, vehicle mass, road grade, weight distribution, brake pressure, brake energy, braking power, etc. to provide the estimation. The method calculates brake work using total work minus losses, such as aerodynamic drag resistance, engine braking and/or braking power as braking torque times velocity divided by rolling resistance to determine the brake rotor and lining temperature. The method then uses the brake temperature to determine the brake pad wear, where the wear is accumulated for each braking event. A brake pad sensor can be included to provide one or more indications of brake pad thickness from which the estimation can be revised.

Methods and systems are provided for preventing vehicle theft and carjackings. There is provided a method comprising generating an immobilization profile based on the received current vehicle data, and sending the immobilization profile to the vehicle over a wireless communication network. There is also provided a method generally comprising determining current vehicle data regarding vehicle dynamics and driving conditions, obtaining an immobilization profile based on the received current vehicle data, and adjusting vehicle throttle and/or braking (e.g., friction-type braking, engine braking, etc.) so that vehicle speed approximates the immobilization profile. In one embodiment, the above described methods further comprise communicating with the vehicle operator prior to implementing vehicle immobilization profiles.

A variable valve actuation system for providing discrete exhaust and intake valve lift profiles for various operating modes of an internal combustion engine. The variable valve actuation system includes exhaust and intake rocker assemblies, exhaust and intake hydraulic extension devices operatively coupling corresponding rocker assemblies with respective engine valves and exhaust and intake control valves for selectively supplying the pressurized hydraulic fluid to the extension devices so as to independently switch them between a pressurized condition and a depressurized condition. The engine further includes an exhaust brake provided to initiate a small lift of the exhaust valve during the engine braking operation while the exhaust extension device maintains the exhaust valve open during a compression stroke for bleeder-compression release braking. The exhaust and intake valves can be adjusted independently to provide combinations of valve lift modes.

A control method for transitioning from positive power to engine braking (and vice-versa) is disclosed. This transition may be made using variable valve actuation and two-stroke braking. The process may involve three engine operation modes: positive power (i.e., firing or non-braking), engine braking, and transition between engine braking and positive power. The intake and exhaust valve actuations provided for each of the different modes of operation may be different from each other.

A hybrid vehicle mode transition control apparatus includes a hybrid drive system having a first clutch disposed between an engine and a motor generator, and a second clutch disposed between the motor generator and wheels; an engine braking request judging section configured to judge whether a request of an engine braking is present during a motor regenerative braking performed by the motor generator, and a mode transition control section configured to perform a mode transition control of the hybrid drive system in accordance with a transition request. The mode transition control apparatus is configured to decrease a torque capacity of the second clutch being in an engaged state in response to the judgment that the request of the engine braking is present, and to bring the first clutch from a disengaged state to the engaged state to shift to the engine braking.

An automotive automatic transmission control apparatus is provided which works to increase the power of an engine in response to a request to down-shift the gear of an automatic transmission for developing the engine braking. The control apparatus includes a fail-safe circuit working to stop increasing the power of the engine when a defect in operation of a transmission hydraulic control circuit is detected after the hydraulic control circuit starts to control the hydraulic pressures to achieve the downshift of the automatic transmission. This eliminates or alleviates a problem, such as unwanted acceleration of the vehicle during the control of the downshift in the transmission.

Systems and methods of actuating two engine valves associated with a common engine cylinder using one or more lost motion systems and one or more control valves are disclosed. The control valves are capable of selectively trapping hydraulic fluid in the lost motion systems for auxiliary engine valve actuations and selectively releasing the hydraulic fluid to default to cam controlled valve seating of the engine valves. The systems may provide a combination of main exhaust, compression release, exhaust gas recirculation and early exhaust valve opening in preferred embodiments.

A system and method for operating at least an intake and exhaust valve in a cylinder with a piston of an engine in a vehicle are described. In one aspect, the method comprises maintaining at least the exhaust valve in a closed position during a period of net engine torque less than zero. Further, during said period of net engine torque less than zero, operating with at least the intake valve open, then closing the intake valve, and then opening the intake valve.

A compression release engine brake unit includes an oil outlet passage formed in a socket brake, which stores engine brake oil, and a reset member opening or closing the outlet passage. The reset member discharges the engine brake oil by opening the oil outlet passage in response to the rotation of a rocker arm during engine braking and, thereby, the engine brake restores the initial state. Since the compression release engine brake can restore the initial state, the return valve lift is the same as when the compression release engine brake is not actuated. Accordingly, the valve does not butt against an engine piston.