杨栋，文志永

(潍柴动力股份有限公司，山东 潍坊 261000)

摘要:直列四缸发动机由于其结构特点，在运转时其二阶往复惯性力不能自平衡，发动机产生较大的振动及噪声。通常在此类发动机上采用二级平衡机构以平衡二阶往复惯性力，可以显著降低发动机振动及噪声。本文从直列四缸发动机二级平衡机构设计出发，论述了二级平衡机构对整机振动，整机噪声，整车振动的影响，同时，也分析了机体加强板对振动的影响，通过大量的测试数据证明，二级平衡机构对直列四缸柴油机并不是不可或缺，应当根据不同机型和不同用途合理选用，对于某些机型甚至可以取消二级平衡机构。

关键词:四缸发动机；二阶往复惯性力；二级平衡机构；机体加强板

Abstract：Because of structural features, 4 cylinder engine has a second order reciprocating inertial force that cannot keep self-balance but produce some noise and vibration. To reduce the noise and vibration, a 2nd order balancer is designed. This paper discusses its effects on engine vibration, engine noise, vehicle vibration, and analyzes the effect of reinforced ribs machined in the cylinder block. The result shows that a 2nd order balancer is not indispensable to 4 cylinder engines. The use of the balance system needs to be considered according to the actual engine types and applications. For some engines, a 2nd order is even possibly cancelled.

Key words：4 Cylinder Engine;2nd Order Force;2nd Order Balance System;Ladder Frame