据有关调查研究显示,现阶段我国的自然资源浪费已经非常严重,能源使用效率仅为美国的26.9%和日本的11.5%。作为内燃机的第二大使用行业,工程机械行业在消耗着巨大的资源和能源的同时,环境污染问题也日益突出。自2010年哥本哈根会议之后,美国及欧洲诸国达成协议,从2014年1月1日起强制实行Tier4标准,这将使 According to relevant investigations and studies, the waste of natural resources in China is very serious at this stage, and the energy use efficiency is only 26.9% in the United States and 11.5% in Japan. As the second largest use of internal combustion engine industry, construction machinery industry consumes huge resources and energy at the same time, the problem of environmental pollution has become increasingly prominent. Since the Copenhagen conference in 2010, the United States and European countries reached an agreement to enforce the Tier4 standard from January 1, 2014, which will enable