| 摘要 |
PURPOSE:To offset vibration of a hull due to unbalanced force of a Diesel main engine against that due to unbalanced moment by disposing the crank angle of Diesel main engine at unequal angles while adjusting the ignition timing for each cylinder. CONSTITUTION:Crank angles of a Diesel main engine having equal cylinder mass and cylinder interval are disposed at unequal angles, while the firing timing is adjusted for each cylinder to offset the vibration of a hull due to unbalanced force of the Diesel main engine against that due to unbalanced moment. For example, unequal angle firing is carried out by setting the angle up to a sixth cylinder with reference to a first cylinder to 10 deg., the angle up to a third cylinder to 109 deg., the angle up to a fourth cylinder to 136 deg., the angle up to a second cylinder to 240 deg. and the angle up to a fifth cylinder to 250 deg.. Then, vibration composed of the unbalanced force and moment can be set approximately to a small certain value by selecting a proper phase angle.
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