Abstract: A control system for an internal combustion engine having a plurality of cylinders and a switching mechanism for switching between an all-cylinder operation in which all of the plurality of cylinders are operated and a partial-cylinder operation in which at least one of the plurality of cylinders is halted. A condition for performing the partial-cylinder operation is determined, based on the detected operating parameters of the vehicle driven by the engine. A result of the determination is modified so that the partial-cylinder operation may be continued, when the detected operating parameters satisfy a predetermined continuation condition within a predetermined time period from the time a vehicle operating state where the condition for performing the partial-cylinder operation is satisfied, has changed to another vehicle operating state where the condition for performing the partial-cylinder operation is not satisfied.

Abstract: A control system for an internal combustion engine having a plurality of cylinders and a switching mechanism for switching between an all-cylinder operation in which all of the plurality of cylinders are operated and a partial-cylinder operation in which at least one of the plurality of cylinders is halted. A condition for performing the partial-cylinder operation is determined, based on the detected operating parameters of the vehicle driven by the engine. A result of the determination is modified so that the partial-cylinder operation may be continued, when the detected operating parameters satisfy a predetermined continuation condition within a predetermined time period from the time a vehicle operating state where the condition for performing the partial-cylinder operation is satisfied, has changed to another vehicle operating state where the condition for performing the partial-cylinder operation is not satisfied.

Abstract: A control system for an internal combustion engine having a plurality of cylinders and a switching mechanism for switching between an all-cylinder operation in which all of the plurality of cylinders are operated and a partial-cylinder operation in which at least one of the plurality of cylinders is halted. A condition for performing the partial-cylinder operation is determined, based on the detected operating parameters of the vehicle driven by the engine. A result of the determination is modified so that the partial-cylinder operation may be continued, when the detected operating parameters satisfy a predetermined continuation condition within a predetermined time period from the time a vehicle operating state where the condition for performing the partial-cylinder operation is satisfied, has changed to another vehicle operating state where the condition for performing the partial-cylinder operation is not satisfied.

Abstract: A valve train for an internal combustion engine including a plurality of cylinders having different valve mechanism constructions, in which the valve train has a correcting member for correcting a difference in valve lift amount that is produced between the plurality of cylinders due to a difference in construction between valve mechanisms so as to make valve lift amounts of the plurality of cylinders substantially uniform.

Abstract: A knock control system for an internal combustion engine having a plurality of cylinders. Operation of the engine is switchable between a partial-cylinder operation for operating some of the cylinders and an all-cylinder operation for operating all of the cylinders. A determination threshold for determining knocking is set according to an output signal from the knock sensor. A level of the output signal from the knock sensor is compared with the determination threshold, and occurrence of knocking is determined according to a result of the comparison. The determination threshold used during the partial-cylinder operation is set to a value less than a value of the determination threshold used during the all-cylinder operation.

Abstract: A control apparatus for an internal combustion engine having a plurality of cylinders and a cylinder halting mechanism. The cylinder halting mechanism switches between an all-cylinder operation in which all of the plurality of cylinders are operated and a partial-cylinder operation in which at least one of the plurality of cylinders is halted. Operating parameters of the engine and the atmospheric pressure are detected. The cylinder halting mechanism is controlled to perform the all-cylinder operation or the partial-cylinder operation according to the operating parameters of the engine and the detected atmospheric pressure.

Abstract: A valve train for an internal combustion engine including a plurality of cylinders having different valve mechanism constructions, characterized in that the valve train has correcting member for correcting a difference in valve lift amount that is produced between the plurality of cylinders due to a difference in construction between valve mechanisms so as to make valve lift amounts of the plurality of cylinders substantially uniform.

Abstract: A control apparatus for an internal combustion engine having a plurality of cylinders and a cylinder halting mechanism. The cylinder halting mechanism switches between an all-cylinder operation in which all of the plurality of cylinders are operated and a partial-cylinder operation in which at least one of the plurality of cylinders is halted. Operating parameters of the engine and the atmospheric pressure are detected. The cylinder halting mechanism is controlled to perform the all-cylinder operation or the partial-cylinder operation according to the operating parameters of the engine and the detected atmospheric pressure.

Abstract: A control system for an internal combustion engine having a plurality of cylinders and a switching mechanism for switching between an all-cylinder operation in which all of the plurality of cylinders are operated and a partial-cylinder operation in which at least one of the plurality of cylinders is halted. A condition for performing the partial-cylinder operation is determined, based on the detected operating parameters of the vehicle driven by the engine. A result of the determination is modified so that the partial-cylinder operation may be continued, when the detected operating parameters satisfy a predetermined continuation condition within a predetermined time period from the time a vehicle operating state where the condition for performing the partial-cylinder operation is satisfied, has changed to another vehicle operating state where the condition for performing the partial-cylinder operation is not satisfied.

Abstract: A knock control system for an internal combustion engine having a plurality of cylinders. Operation of the engine is switchable between a partial-cylinder operation for operating some of the cylinders and an all-cylinder operation for operating all of the cylinders. A determination threshold for determining knocking is set according to an output signal from the knock sensor. A level of the output signal from the knock sensor is compared with the determination threshold, and occurrence of knocking is determined according to a result of the comparison. The determination threshold used during the partial-cylinder operation is set to a value less than a value of the determination threshold used during the all-cylinder operation.

Abstract: There is provided a failure determination system for a variable-cylinder internal combustion engine which is capable of promptly and accurately carrying out failure determination of the valve-actuating system for cylinders for being made idle during a partial-cylinder operation mode. The failure determination system is capable of switching a cylinder operation mode between an all-cylinder operation mode in which all the cylinders are operated, and a partial-cylinder operation mode in which part of the cylinders are made idle. The failure determination system includes an ECU which executes a failure-determining operation mode for causing a valve-actuating mechanism to resume actuation of intake valves and exhaust valves of the part of the cylinders in a state in which fuel supply to the part of the cylinders is stopped, when the cylinder operation mode is shifted from the partial-cylinder operation mode to the all-cylinder operation mode.

Abstract: A control system for an internal combustion engine having a plurality of cylinders and a cylinder halting mechanism for halting operation of at least one of the plurality of cylinders. The cylinder halting mechanism is controlled to operate all of the plurality of cylinders or to halt the operation of the at least one of the plurality of cylinders. The operating state of the cylinder halting mechanism is detected based on the amount of change in the detected intake pressure of the engine.

Abstract: There is provided a failure determination system for a variable-cylinder internal combustion engine which is capable of promptly and accurately carrying out failure determination of the valve-actuating system for cylinders for being made idle during a partial-cylinder operation mode. The failure determination system is capable of switching a cylinder operation mode between an all-cylinder operation mode in which all the cylinders are operated, and a partial-cylinder operation mode in which part of the cylinders are made idle. The failure determination system includes an ECU which executes a failure-determining operation mode for causing a valve-actuating mechanism to resume actuation of intake valves and exhaust valves of the part of the cylinders in a state in which fuel supply to the part of the cylinders is stopped, when the cylinder operation mode is shifted from the partial-cylinder operation mode to the all-cylinder operation mode.

Abstract: A control system for an internal combustion engine having a plurality of cylinders and a cylinder halting mechanism for halting operation of at least one of the plurality of cylinders. The cylinder halting mechanism is controlled to operate all of the plurality of cylinders or to halt the operation of the at least one of the plurality of cylinders. The operating state of the cylinder halting mechanism is detected based on the amount of change in the detected intake pressure of the engine.

Abstract: In an intake device for a multi-cylinder internal combustion engine, comprising a pair of resonance chambers and a pair of resonance passages, the resonance chambers and the resonance passages are disposed in parallel in a V-space in the internal combustion engine with a dividing wall interposed therebetween, thereby providing a compact intake system. In the intake device, the resonance chambers are defined in one of upper and lower assembly box portions, while the resonance passages are defined in the other assembly box portion, and an on-off valve capable of changing suction characteristics of the internal combustion engine is provided in a plate-like valve unit separating and joined to the opened surfaces of the two box portions. This enables a reasonable layout of the on-off valve. Further, in the intake device, the resonance chambers are capable of communicating with each other through a communication chamber having a predetermined volume.