An internal combustion engine includes a crankcase that defines a crank chamber, a crankshaft that has a crank housed in the crank chamber and is rotatably supported on the crankcase, a cylinder block that is joined to the crankcase and defines a plurality of cylinders in a horizontally-opposed arrangement, a to-be-detected body that rotates integrally with the crankshaft, and a detection sensor that extends through the crankcase from an upper face of the crankcase, is made to face a trajectory of the to-be-detected body, and generates a pulse signal in response to movement of the to-be-detected body. Thus, in a so-called horizontally-opposed internal combustion engine, a structure for disposing a detection sensor that can detect the angular velocity of a crankshaft with high precision is provided.

An internal combustion engine includes a crankcase that defines a crank chamber, a crankshaft that has a crank housed in the crank chamber and is rotatably supported on the crankcase, a cylinder block that is joined to the crankcase and defines a plurality of cylinders in a horizontally-opposed arrangement, a to-be-detected body that rotates integrally with the crankshaft, and a detection sensor that extends through the crankcase from an upper face of the crankcase, is made to face a trajectory of the to-be-detected body, and generates a pulse signal in response to movement of the to-be-detected body. Thus, in a so-called horizontally-opposed internal combustion engine, a structure for disposing a detection sensor that can detect the angular velocity of a crankshaft with high precision is provided.

A thermal choke, includes (1) a body, comprising a heat conductive material, (2) an electric heater, on or in the body, (3) a temperature sensor, on or in the body, and (4) a fin, in a channel surrounded by the body. The thermal choke is configured to fit between a throttle assembly and a cylinder of a spark ignition engine.

This patent discloses one cylinder axial internal combustion engine having Scotch-Yoke based two phase fuel compression system. Scotch-Yoke actuator employed here is a specially modeled Multi Purpose Multi H-Slot double action Scotch-Yoke Actuator. Each H-slot is quad-laterally operated by a special mechanism. It performs suction and compression in ignition chamber and auxiliary compression chamber via two piston plates one in each chamber and transfers compressed fuel-air mixture from auxiliary compression chamber to ignition chamber through yoke rod. Flywheel is coaxially mounted on the outward side of the auxiliary compression chamber.

This patent discloses one cylinder axial internal combustion engine having Scotch-Yoke based two phase fuel compression system. Scotch-Yoke actuator employed here is a specially modeled Multi Purpose Multi H-Slot double action Scotch-Yoke Actuator. Each H-slot is quad-laterally operated by a special mechanism. It performs suction and compression in ignition chamber and auxiliary compression chamber via two piston plates one in each chamber and transfers compressed fuel-air mixture from auxiliary compression chamber to ignition chamber through yoke rod. Flywheel is coaxially mounted on the outward side of the auxiliary compression chamber.

In vibratory plates (vibratory plate compactor machine), the reciprocating movement of an engine piston is converted into rotation of the crankshaft, and the latter is converted into rotation of an eccentric rotary shaft of vibrator unit, which create a periodic force that leads to reciprocating movement of the plate. Such a vibratory plate is complicated.

It is proposed to use a free-piston engine with one piston as the engine for a vibratory plate. In this free piston engine, the piston moves reciprocally, and the cylinder performs reciprocating movements opposite to the movements of the piston. The cylinder is mounted vertically and fixed to the plate. In each engine cycle the gas pressure acts on the piston and cylinder. After combustion, the piston moves up and the cylinder moves down. Since the cylinder is fixed to the plate, it also moves downward and compacts soil, gravel, etc.

In vibratory plates (vibratory plate compactor machine), the reciprocating movement of an engine piston is converted into rotation of the crankshaft, and the latter is converted into rotation of an eccentric rotary shaft of vibrator unit, which create a periodic force that leads to reciprocating movement of the plate. Such a vibratory plate is complicated.

It is proposed to use a free-piston engine with one piston as the engine for a vibratory plate. In this free piston engine, the piston moves reciprocally, and the cylinder performs reciprocating movements opposite to the movements of the piston. The cylinder is mounted vertically and fixed to the plate. In each engine cycle the gas pressure acts on the piston and cylinder. After combustion, the piston moves up and the cylinder moves down. Since the cylinder is fixed to the plate, it also moves downward and compacts soil, gravel, etc.

Provided is a general purpose engine that has a small external appearance and can be placed in a stable posture even when inverted, and whereby labels attached to the upper surface thereof can be protected. The general purpose engine 1 comprises a shroud 4 covering an engine main body. The shroud 4 includes: a top cover 2 arranged in an upper section of the general purpose engine 1; and a bottom cover 3 arranged in a lower section of the general purpose engine 1. The top cover 2 has a pair of bridges 20, 20 formed so as to protrude from the upper surface of the top cover 2, constituting the apex of the top cover 2 and continually extending from the front surface of the top cover 2 to the rear surface thereof, across the upper surface.

Provided is a general purpose engine that has a small external appearance and can be placed in a stable posture even when inverted, and whereby labels attached to the upper surface thereof can be protected. The general purpose engine 1 comprises a shroud 4 covering an engine main body. The shroud 4 includes: a top cover 2 arranged in an upper section of the general purpose engine 1; and a bottom cover 3 arranged in a lower section of the general purpose engine 1. The top cover 2 has a pair of bridges 20, 20 formed so as to protrude from the upper surface of the top cover 2, constituting the apex of the top cover 2 and continually extending from the front surface of the top cover 2 to the rear surface thereof, across the upper surface.

A thermal choke, includes (1) a body, comprising a heat conductive material, (2) an electric heater, on or in the body, (3) a temperature sensor, on or in the body, and (4) a fin, in a channel surrounded by the body. The thermal choke is configured to fit between a throttle assembly and a cylinder of a spark ignition engine.