Methods and systems are provided for reducing torque pulsations during hybrid engine shutdown and restarts. A valve actuating mechanism may be actuated to operate an engine with a selected valve lift profile during engine restart and shutdown events that is distinct from the valve lift profile applied during cylinder combustion. The selected valve lift profile reduces cylinder pressure during engine shutdown and restarts.

A hybrid vehicle includes an electric motor, an internal combustion engine, an exhaust emission control device and a controller. The controller is configured to execute catalyst warm-up control for warming up a catalyst of the exhaust emission control device. The catalyst warm-up control includes first control and second control. The first control is control for operating the internal combustion engine at a first operating point. The second control is control for, after the first control is executed, operating the internal combustion engine at a second operating point irrespective of a driving force that is required to propel the hybrid vehicle. An output of the internal combustion engine at the second operating point is larger than an output of the internal combustion engine at the first operating point. The controller is configured to operate the internal combustion engine while an ignition timing of the internal combustion engine at the time when the first control is executed is set to a retarded side with respect to an ignition timing of the internal combustion engine at the time when the second control is executed. The controller is configured to, when the first control is executed, control the variable valve actuating device such that the operation characteristic becomes the first characteristic. The controller is configured to, when the second control is executed, control the variable valve actuating device such that the operation characteristic is changed to the second characteristic. The controller is configured to, after the second control is executed, operate the internal combustion engine on the basis of the driving force that is required to propel the hybrid vehicle and control the variable valve actuating device on the basis of a rotation speed and torque of the internal combustion engine.

A hybrid vehicle includes an internal combustion engine and a rotary electric machine. The internal combustion engine includes a variable valve actuating device configured to change an operation characteristic of an intake valve. The rotary electric machine is configured to generate driving force for propelling the hybrid vehicle. A controller for the hybrid vehicle includes a traveling control unit and a valve actuation control unit. The traveling control unit executes traveling control for causing the hybrid vehicle to travel by using the driving force of the rotary electric machine while stopping the internal combustion engine. The traveling control unit starts up the internal combustion engine while executing the traveling control. The valve actuation control unit controls the variable valve actuating device. The valve actuation control unit, when the internal combustion engine is started up while the traveling control is executed, sets at least one of a valve lift and valve operating angle of the intake valve such that the at least one of the valve lift and valve operating angle of the intake valve when the hybrid vehicle travels at a first vehicle speed is smaller than the corresponding at least one of the valve lift and valve operating angle of the intake valve when the hybrid vehicle travels at a second vehicle speed. The second vehicle speed is lower than the first vehicle speed.

Methods and systems are provided for using compression heating to heat a cylinder piston before cylinder combustion is resumed. Cylinder heating is achieved using combinations of slow unfueled engine rotation where the engine cylinders are heated via compression stroke heating, and slow compressor rotation where the cylinders are heated via compression heating. One or more intake or exhaust heaters may be concurrently operated to expedite cylinder heating.

A control apparatus of an internal combustion engine is provided. The internal combustion engine includes a port injection valve that injects fuel into an intake-air port, and a cylinder injection valve that injects fuel into a cylinder. The control apparatus includes an electronic control unit that controls the port injection valve and the cylinder injection valve such that when returning from a fuel cut, a value of a port increase amount correction, which is a fuel increase amount correction in which a fuel amount is decreased with a lapse of time during a port injection, differs from a value of a cylinder increase amount correction, which is a fuel increase amount correction in which a fuel amount is decreased with a lapse of time during a cylinder injection.

A camshaft includes, as a cam that opens and closes an exhaust valve and an intake valve, a ball cam whose protrusion amount changes according to rotation of the camshaft, wherein the camshaft has a double structure consisting of an inner shaft and an outer shaft provided in a manner that the inner shaft is helically displaced with respect to the outer shaft around an axis of the camshaft according to a rotation speed of the camshaft, and the ball cam is accommodated movably in a guide groove provided in the inner shaft and protrudes from the outer shaft, and a protrusion amount of the ball cam from the outer shaft changes when the ball cam moves in the guide groove due to the helical displacement of the inner shaft with respect to the outer shaft.

A control apparatus of an internal combustion engine is provided. The internal combustion engine includes a port injection valve that injects fuel into an intake-air port, and a cylinder injection valve that injects fuel into a cylinder. The control apparatus includes an electronic control unit that controls the port injection valve and the cylinder injection valve such that when returning from a fuel cut, a value of a port increase amount correction, which is a fuel increase amount correction in which a fuel amount is decreased with a lapse of time during a port injection, differs from a value of a cylinder increase amount correction, which is a fuel increase amount correction in which a fuel amount is decreased with a lapse of time during a cylinder injection.

In an exemplary embodiment, an internal combustion engine, in which a valve is opened and closed when a piston reciprocates in a cylinder, has a configuration to perform repeatedly the following combined strokes: an intake stroke.fwdarw.a compression stroke.fwdarw.a combustion stroke.fwdarw.an exhaust stroke in a four-cycle internal combustion engine are combined with an intake and compression stroke.fwdarw.a combustion and exhaust stroke in a two-cycle internal combustion engine. The internal combustion engine can reduce pumping loss in a six-cycle internal combustion engine and increase the output.

A camshaft includes, as a cam that opens and closes an exhaust valve and an intake valve, a ball cam whose protrusion amount changes according to rotation of the camshaft, wherein the camshaft has a double structure consisting of an inner shaft and an outer shaft provided in a manner that the inner shaft is helically displaced with respect to the outer shaft around an axis of the camshaft according to a rotation speed of the camshaft, and the ball cam is accommodated movably in a guide groove provided in the inner shaft and protrudes from the outer shaft, and a protrusion amount of the ball cam from the outer shaft changes when the ball cam moves in the guide groove due to the helical displacement of the inner shaft with respect to the outer shaft.

Methods and systems are provided for reducing engine compression torque when an engine having a split exhaust system is spun unfueled. In one example, a method may include maintaining closed a blowdown exhaust valve of a cylinder, the blowdown exhaust valve coupled to a first exhaust manifold that directs gases from the cylinder to a catalyst, and opening a scavenge exhaust valve of the cylinder, the scavenge exhaust valve coupled to a second exhaust manifold that directs gases from the cylinder to an exhaust gas recirculation system. In this way, compression of gases within they cylinder is reduced while gas flow to the catalyst is prevented.