An internal combustion engine having a plurality of cylinders comprises a variable compression ratio mechanism A able to change a mechanical compression ratio. The control device comprises a compression ratio detector for detecting a mechanical compression ratio based on a value of the relative position parameter representing a relative positional relationship between the cylinder block 2 and a piston 4, and a compression ratio controller for feedback controlling the mechanical compression ratio so that the mechanical compression ratio becomes a target mechanical compression ratio. In feedback controlling the variable compression ratio mechanism, the compression ratio controller does not use the mechanical compression ratio detected by the compression ratio detector when a crank angle is in a predetermined crank angle range including a time period where the cylinder pressure is equal to or greater than a preset predetermined pressure at least at one cylinder among the plurality of cylinders.

In the present invention, an internal combustion engine is provided with a variable-compression-ratio mechanism with a variable mechanical compression ratio and the variable-compression-ratio mechanism comprises a drive device for changing the volume of a combustion chamber when a piston reaches top dead center. The drive device comprises a reverse input blocking clutch disposed in a drive power transmission path for transmitting the rotational force of a rotator. A control device estimates the reverse input torque applied to an output shaft of the reverse input blocking clutch and sets a gradient for torque output by the rotator and a continuation duration for continuing the torque increase on the basis of the reverse input torque.

A control device of an internal combustion engine 100 provided with a compression ratio control part controlling a mechanical compression ratio to a target compression ratio. The compression ratio control part is configured provided with an optimum compression ratio calculating part calculating an optimum compression ratio in an engine operating state based on the engine operating state, a permittable changed compression ratio calculating part calculating a permittable changed compression ratio giving an effect of improvement of the fuel efficiency even considering the amount of fuel consumed by driving a motor when the optimum compression ratio is higher than a target compression ratio, and a target compression ratio changing part changing the target compression ratio to the permittable changed compression ratio if the optimum compression ratio is higher than the target compression ratio and the optimum compression ratio becomes the permittable changed compression ratio or more.

According to the present invention an expandable joint is made without removable bearing caps by preassembling eccentric bushings onto the hinge pin. The expandable joint has a hinge type construction, but with the journals for each side of the hinge being spaced apart so that the distance between the two sides of the hinge changes with rotation of the hinge pin. The expandable joint of the present invention is assembled by sliding the hinge pin into the hinged joint with the eccentric bushings attached. Once the hinge pin is in place, the eccentric bushings are locked in place with fasteners so that they do not rotate. After the eccentric bushings are locked in place, the hinge pin can be turned to expand the joint. The expandable joint is intended for use in variable compression ratio engines, where expansion of the joint changes the compression ratio of the engine.

An internal combustion engine provided with a cylinder block able to move relative to a crankcase is provided with a block movement mechanism arranged just at one side of the internal combustion engine, a pair of guide walls provided at the crankcase, a support member supporting a side surface of the cylinder block, and a pushing member pushing against a side surface of the cylinder block. Further, at the guide wall at the side of arrangement of the block movement mechanism, the support member is attached to the top side from the position of attachment of the other end part of the connecting member and the pushing member is attached to the bottom side from the position of attachment of the other end part of the connecting member, while at the guide wall at the opposite side from the side of arrangement of the block movement mechanism, the support member is attached to the bottom side (bottom side of cylinder block) a predetermined space from pushing member.

In the present invention, an internal combustion engine is provided with a variable-compression-ratio mechanism with a variable mechanical compression ratio and the variable-compression-ratio mechanism comprises a drive device for changing the volume of a combustion chamber when a piston reaches top dead center. The drive device comprises a reverse input blocking clutch disposed in a drive power transmission path for transmitting the rotational force of a rotator. A control device estimates the reverse input torque applied to an output shaft of the reverse input blocking clutch and sets a gradient for torque output by the rotator and a continuation duration for continuing the torque increase on the basis of the reverse input torque.

An internal combustion engine can include a piston moving in a cylinder and a junk head disposed opposite the piston head in the cylinder. The junk head can optionally be moveable between a higher compression ratio position closer to a top dead center of the piston and a lower compression ratio position further from the top dead center position of the piston. At least one intake port can deliver a fluid comprising inlet air to a combustion chamber within the cylinder. Combustion gases can be directed out of the combustion volume through at least one exhaust port. One or both of the intake port and the exhaust port can be opened and closed by operation of a sleeve valve that at least partially encircles the piston. Related articles, systems, and methods are described.