Abstract: An internal combustion engine includes: a crankcase that supports a crankshaft rotatably about a rotational axis; a cylinder block connected with the crankcase and including at least one pair of cylinders that sandwich a valve chamber therebetween in an axial direction of the crankshaft, the valve chamber housing therein a valve actuating mechanism that connects a camshaft to the crankshaft; a detected member disposed between crank pins corresponding to the pair of cylinders, the detected member rotating integrally with the crankshaft; and a detection sensor disposed to face a trajectory of the detected member and generating a pulse signal in accordance with movement of the detected member. Accordingly, the internal combustion engine can avoid displacement of a nearby part and enlargement of the crankcase as much as possible, while allowing the detected member to be increased in size.

Abstract: An internal combustion engine includes: a crankcase that supports a crankshaft rotatably about a rotational axis; a cylinder block connected with the crankcase and including at least one pair of cylinders that sandwich a valve chamber therebetween in an axial direction of the crankshaft, the valve chamber housing therein a valve actuating mechanism that connects a camshaft to the crankshaft; a detected member disposed between crank pins corresponding to the pair of cylinders, the detected member rotating integrally with the crankshaft; and a detection sensor disposed to face a trajectory of the detected member and generating a pulse signal in accordance with movement of the detected member. Accordingly, the internal combustion engine can avoid displacement of a nearby part and enlargement of the crankcase as much as possible, while allowing the detected member to be increased in size.