Three-cylinder engine

摘要

A three cylinder engine includes a vibration alleviation unit for alleviating vibrations in a vehicle. The vibration alleviation unit is disposed at least one of upon the crankshaft and upon a part that operates in unison with the crankshaft. The three cylinder is supported by engine mounts that are positioned upon at least both ends of the engine in the direction of the crankshaft axis. Given that KV and KH represent spring constants of one of the engine mounts in the pitch and yaw directions of the crankshaft, MV and MH represent components of a primary couple that occurs in the three cylinder engine in the pitch and yaw directions, and MV0 represents the sum of MV and MH, then spring constants of the engine mounts are set such that KV >KH and the vibration alleviation unit is set so as to satisfy the condition 0

主权项

1. A three cylinder engine comprising:
a crankshaft rotatably mounted; at least two engine mounts supporting the three cylinder engine on a vehicle body through the at least two engine mounts that are arranged at both opposite ends of the three cylinder engine in a direction that corresponds to a direction of the crankshaft axis of the crankshaft; and a vibration alleviation unit disposed on at least one of the crankshaft and a part that operates in unison with the crankshaft, the vibration alleviation unit including at least one of a balance mass and a bore on at least one of the crank shaft and the part that operates in unison with the crankshaft, the at least one of the balance mass and the bore being arranged so as to be displaced 90 degrees with respect to a rotation phase of a middle cylinder of the three cylinder engine, a first of the at least two engine mounts being set with a spring constant Kv in a crankshaft axis pitch direction, and a spring constant KH in a crankshaft axis yaw direction such that an inequality of Kv>KH is established, the vibration alleviation unit being set with respect to the at least one of the crankshaft and the part such that the vibration alleviation unit satisfies an inequality of 0