A decompression shaft (56) of a decompression device (50) includes an engagement pin (53) that is guided by a guide groove (51a) formed in a decompression weight (51), a decompression cam (54) that is provided on one cam surface of an intake valve cam (25c) and an exhaust valve cam (25b) so as to advance and retreat, and a connection portion (55) that connects the engagement pin (53) and the decompression cam (54). The decompression weight (51) is formed with a rotation restricting groove (51e) that restricts rotation of the decompression shaft (56) when a force acts in a direction in which the decompression cam (54) moves on the decompression shaft (56) from an advanced position to a retracted position when an engine (E) is stopped and that is continuous with the guide groove (51a).

A decompression shaft (56) of a decompression device (50) includes an engagement pin (53) that is guided by a guide groove (51a) formed in a decompression weight (51), a decompression cam (54) that is provided on one cam surface of an intake valve cam (25c) and an exhaust valve cam (25b) so as to advance and retreat, and a connection portion (55) that connects the engagement pin (53) and the decompression cam (54). The decompression weight (51) is formed with a rotation restricting groove (51e) that restricts rotation of the decompression shaft (56) when a force acts in a direction in which the decompression cam (54) moves on the decompression shaft (56) from an advanced position to a retracted position when an engine (E) is stopped and that is continuous with the guide groove (51a).

An engine with rotating assembly is disclosed. The engine includes a block defining a cylinder bore; a crankshaft mounted for rotation in the block; a piston disposed in the cylinder bore; a connecting rod interconnecting the piston to the crankshaft; and a cylinder head coupled to the block having a combustion chamber aligned with the cylinder bore and having an intake opening and an exhaust opening communicating therewith; an intake port; an exhaust port; a rotatable intake valve barrel disposed between the intake opening and the intake port; and a rotatable exhaust valve barrel disposed between the exhaust opening and the exhaust port. A first electric motor is connected to the intake valve barrel and a second electric motor is connected to the exhaust valve barrel, the first electric motor rotates the intake valve barrel and second electric motor rotates the exhaust valve barrel independently of the intake valve barrel.

A rectification structural body includes a pipe line configured such that air flows from an air cleaner to an airflow sensor. The pipe line has a portion bent in an arc shape. In the pipe line, an air guide plate dividing an internal space of the pipe line into an inner portion and an outer portion of the arc is provided substantially parallel with the center line of the pipe line. The air guide plate includes two ribs. The two ribs are each in an arc shape. The two ribs stand, inside the pipe line, facing each other to extend toward each other. End edges of the two ribs are separated from each other in a rib standing direction by 0.5 to 5 mm at least on an airflow sensor side of the pipe line.

In a hybrid vehicle configured such that a sun gear, a carrier and a ring gear of a planetary gear are respectively connected with a rotating shaft of a motor MG1, a crankshaft of an engine and a driveshaft and that a motor MG2 is connected with the driveshaft, when a required braking force that is to be output to the driveshaft is equal to or less than a reference value Tref in an accelerator-off state, the braking force by engine braking is output to the driveshaft by motoring of the engine by the motor MG1. When the required braking force becomes greater than the reference value Tref, on the other hand, the power output from the engine by load operation of the engine in a reverse rotating direction is output as the braking force to the driveshaft.

In a hybrid vehicle configured such that a sun gear, a carrier and a ring gear of a planetary gear are respectively connected with a rotating shaft of a motor MG1, a crankshaft of an engine and a driveshaft and that a motor MG2 is connected with the driveshaft, when a required braking force that is to be output to the driveshaft is equal to or less than a reference value Tref in an accelerator-off state, the braking force by engine braking is output to the driveshaft by motoring of the engine by the motor MG1. When the required braking force becomes greater than the reference value Tref, on the other hand, the power output from the engine by load operation of the engine in a reverse rotating direction is output as the braking force to the driveshaft.

An exhaust heat recovery apparatus includes an exhaust heat passage through which a first heat medium holding exhaust heat flows; a second heat medium passage through which the second heat medium, of which temperature is lower than that of the first heat medium, flows; a Rankine cycle which includes a pump, an evaporator, an expander, and a condenser and causes heat exchange at the evaporator between the first heat medium flowing through the exhaust heat passage and a working fluid, so that the working fluid is evaporated, the evaporated working fluid expands at the expander, and power is generated; and an exhaust heat recovery heat exchanger which causes heat exchange between the first heat medium flowing through the exhaust heat passage and the second heat medium flowing through the second heat medium passage, so that the second heat medium is heated and exhaust heat of the first heat medium is recovered.

In a hybrid vehicle configured such that a sun gear, a carrier and a ring gear of a planetary gear are respectively connected with a rotating shaft of a motor MG1, a crankshaft of an engine and a driveshaft and that a motor MG2 is connected with the driveshaft, when a required braking force that is to be output to the driveshaft is equal to or less than a reference value Tref in an accelerator-off state, the braking force by engine braking is output to the driveshaft by motoring of the engine by the motor MG1. When the required braking force becomes greater than the reference value Tref, on the other hand, the power output from the engine by load operation of the engine in a reverse rotating direction is output as the braking force to the driveshaft.

A method for moving a vehicle in a reverse direction is provided. The method includes: providing an internal combustion engine, a transmission, and an electric machine; adjusting a valve timing of either an intake valve or an exhaust valve during a non-firing mode of the internal combustion engine to reduce a rotational resistance; and, rotating the internal combustion in a backwards or reverse direction so that the vehicle moves in a reverse direction.