英语翻译内燃机是目前世界上应用最广泛的热动力装置,自1680年法国人设计出第一台煤气内燃机以来,内燃机无论是在结构上还是

英语翻译
内燃机是目前世界上应用最广泛的热动力装置,自1680年法国人设计出第一台煤气内燃机以来,内燃机无论是在结构上还是在性能上都较以前有了很大的进步.在现今社会,几乎所有的交通工具都以内燃机做其核心的动力源[1].科技进步不仅推动了内燃机的发展,也对其性能提出了更高的要求— 燃料燃烧的高效低污染、工作的可靠性和使用的耐久性以及更长的寿命等[2].这都要求内燃机改进设计优化结构以减少工作过程中的各种动态力.曲柄连杆机构的设计是否合理将直接影响内燃机的功率、排放、可靠性和使用寿命等重要性能[3].目前车用内燃机仍然以往复活塞式为主.在往复活塞式内燃机中,曲柄连杆机构是内燃机的传递运动和动力的机构,通过它把活塞的往复直线运动转变为曲轴的旋转运动面输出动力.因此,曲柄连杆机构是内燃机中主要的受力部件,作用在曲柄连杆机构的力主要是由其运动质量产生的惯性力和作用在活塞上的气体作用力,这些力随着曲柄的转角不同而变化,在稳定的工况下,曲柄每转一周或两周为一个变化周期.实际上,内燃机的工况是不断变化的,特别是作为车用动力时,尤其如此.因此,作用在曲柄连杆机构上的力是随着工况的不断变化而变化的[4].连杆在运动的过程中主要承受着气体压力和活塞组往复惯性力所产生的交变载荷,此外,由于连杆在运动过程中的变速摆动而产生惯性力矩,还使连杆承受数值较小的弯矩.如果连杆在交变载荷作用下发生断裂,则将导致恶性破坏是故,甚至整台内燃机报废；如果连杆刚度不足则会对曲柄连杆机构的工作带来不好的影响.例如：连杆在曲柄平面内的弯曲使活塞在气缸内歪斜,造成活塞与气缸、轴瓦与曲柄销的偏磨、活塞组与气缸间漏气、窜油等问题[5].可见,连杆工作的可靠性直接的影响着内燃机工作的可靠性.众所周知,连杆是发动机的重要部件,其作用是将活塞的往复运动转变为曲轴的旋转运动.其好坏与优劣直接关系到发动机的整体性能.在工作过程中,连杆受力较复杂：一方面承受气体的压力和往复运动的惯性力所产生的冲击性拉压交变载荷；同时连杆摆动产生横向惯性力,导致其承受弯曲交变载荷.因其较长,所以要求连杆有足够的强度和刚度[6].在满足要求的前提下,尽量减小自身质量,以减小惯性力,保证发动机运转平稳,降低工作时的噪声和振动,因此材料选择的重要性显而易见.为 了 确 保工作可靠性,连杆需要满足以下要求:(l)结 构 简 单,尺寸紧凑,可靠耐用; (2)在 保 证 足够的刚度和强度的前提下,尽可能减轻质量,以降低惯性力; (3)尽 量 缩 短长度,以降低内燃机的总体尺寸和总重量; (4) 大 小 头轴承工作可靠,耐磨性好; (5)连 杆 螺 栓疲劳强度高,连接可靠:(6) 易于 制 造,成本低.由 于 连 杆既是传力件,又是运动件,因此,不能单靠加大连杆的尺寸来提高强度[7].
对曲柄连杆机构进行可视化运动学和动力学分析,研制集曲柄连杆机构选型、运动学和力学的分析,实现对连杆等主要零部件进行计算机辅助设计、校核和计算的系统,可以更直观清晰的了解曲柄连杆机构在运行过程中的受力状态,便于进行精确计算,并绘制受力分析曲线图,对进一步研究内燃机的平衡与振动、内燃机增压的改造等均有较为实用的应用价值[8].

Internal combustion engine is the world's most extensive application of the thermal power plant, since 1680 the French designed the first gas engine, the internal combustion engine both in structure and in performance than previously made substantial progress. In today's society, almost all modes of transport have to do the core of the internal combustion engine power sources [1]. Scientific and technological progress not only promote the development of the internal combustion engine, its performance has put forward higher requirements - low-pollution fuel combustion efficiency, reliability and the use of the work of the durability and longer life expectancy, etc. [2]. This requires improving the internal combustion engine design and optimize the structure to reduce the working process in the active force. Crank linkage of the design is reasonable will directly affect the internal combustion engine power, emissions, reliability and service life, and other important performance [3]. At present cars are still ever-engine piston-based. In Reciprocating Engine, the internal combustion engine crank linkage is the transfer of power and movement, through which the piston reciprocating linear motion into rotary movement of the crankshaft output power. Therefore, the internal combustion engine crank linkage is the main force components, crank role in the linkage of the main movement is determined by its quality of the inertial force and role in the Pistons force on the gas, along with those of the crank angle Different changes in a stable condition, turn the crank every week or two weeks for a change cycle. In fact, the internal combustion engine condition is constantly changing, especially as a vehicle driving force, in particular. Therefore, the role of the crank linkage on the edge, with the ever-changing conditions and changes in the [4]. Link in the process of movement of the gas main under pressure and the Detroit group reciprocating inertia force generated by alternating load, in addition, the connecting rod in the course of the campaign swing speed and have a moment of inertia, but also to link smaller bear numerical The moment. If the link in alternating load of fracture, it will lead to vicious destruction Therefore, the entire internal combustion engine or even scrapped if the link stiffness will be less than the crank linkage of a negative impact. For example: link in the crank plane bending to skew the Pistons in the cylinder, causing the cylinder and piston, and crank pin bearing the partial grinding, Detroit group and the inter-cylinder gas leakage, channeling oil [5]. Clearly, the reliability of direct linkage of the impact on the work of the internal combustion engine reliability. As everyone knows, the link is an important engine parts, the Pistons will play the role of the reciprocating movement into the rotating crankshaft. And the quality of its merits directly related to the overall engine performance. In the course of their work, the linkage of the more complex: on the one hand to bear the pressure and gas reciprocating movement of the inertia generated by the impact of alternating tension and compression loads, while a horizontal linkage swing inertia force, resulting in bending under alternating Load. Because of their longer, so there is sufficient demand link the strength and stiffness [6]. To meet the requirements of the premise, to minimize their own quality, to reduce the inertia force, and ensure the smooth functioning of the engine, reducing the work the noise and vibration, and therefore the importance of clear material selection. To ensure reliability, link needs to meet the following requirements: (l) structure is simple, compact size, durable and reliable, (2) to ensure adequate strength and stiffness of the premise, as far as possible to reduce quality, to reduce the inertia force; ( 3) minimize the length of the internal combustion engine to reduce the overall size and total weight (4) the size of the first bearing reliable, good wear resistance, (5) connecting rod bolts fatigue, reliable connection: (6) easy to manufacture, cost Low. Chuan is due to linkage of cases, is also moving parts, therefore, can not rely solely on increasing the size of linkage to improve strength [7].
Linkage to the crank visual kinematics and dynamics of the development-crank linkage Selection, kinematics and mechanical analysis, and link major components of a computer-aided design, verification and calculation of the System, a more intuitive understanding of crank clear linkage in the course of the operation of the force, and facilitate accurate calculation, and the mapping of Analysis curve of the internal combustion engine further study the balance and vibration, so the transformation of the internal combustion engine booster A more practical application of [8].