内燃机工作过程试验研究与分析

The Test Study and Analysis of Work Process of the Internal- combustion Engine

借助传递函数对农用四轮拖拉机内燃机工作过程产生的噪声进行了比较分析。首先,设定合适的时域,改变内燃机活塞到达上止点时燃烧室净容积大小和点火燃烧膨胀活塞下行过程中缸压脉冲的大小,捕捉做功燃烧噪声和活塞由于受侧压力的影响产生的拍击噪声。之后,改变时域,再检测不同的缸压脉冲的跳动情况和产生噪声的强弱,求取整个做功燃烧过程中噪声函数关系的传递信息,对不同的检测方法求取的传递函数进行比较分析。结果表明,不同的内燃机结构和燃烧压力,其工作过程燃烧噪声传递函数稍有差异,获得了内燃机工作过程噪声的一些有用信息,为进一步研究农用车辆内燃机燃烧噪声的机理和改良燃烧室的内部结构提供了一种有益的方法和试验数据。

With the help of transfer function, the noises of agricultural four-wheel tractor internal-combustion engine work process are analyzed. At first , Setting the right time , changing the combustion chamber net volume size of the in-ternal-combustion engine piston to get to the top dead center and cylinder pressure pulse size of ignition burning expan-sion during piston descending process, work combustion noise and piston panting noise during the influence of the lateral pressure generated are captured. After that, changing the time, to test different cylinder pressure pulse beat and the strength of the producing noise, the transfer information noise function relation during the work combustion is obtained. The transfer functions to be got by different detection method are compared and analyzed. The results show that different internal combustion engine structure and the combustion pressure are slightly different about the transfer function of com-bustion noise of work process. Some useful information of internal combustion engine noises during work process are ob-tained. It provides a useful method and test data to study the combustion noises mechanism principles of the agricultural vehicle and improve the combustion chamber structure of the agricultural vehicle internal engine combustion.