日本国家铁路机车用柴油机的保有量现已达到一万余台。这些柴油机都需尽快加以改造。所剩寿命较短的、改造价值不大的、或者由于结构原因改造比较困难的那些柴油机,都不能作为改造对象。所以选择了内燃机车用的缸径为180毫米的DML61ZB型柴油机列为改造对象。同时计划今后还要按新规格设计和批量生产直喷式柴油机,以增加功率、提高效 Japan’s national railway locomotive diesel engine has now reached more than 10,000 units. These diesel engines need to be rebuilt as soon as possible. The remaining short life, the transformation of small value, or due to structural reasons more difficult to transform those diesel engines, can not be transformed as the object. Therefore, the choice of diesel locomotive with a bore of 180 mm DML61ZB diesel engine as a transformation of the object. In the meantime, it plans to design and mass produce direct injection diesel engine according to the new specifications in the future to increase power and improve efficiency