bottom dead center

简明释义

下死点下止点

英英释义

例句

1.During the compression stroke, the piston moves up from bottom dead center to compress the air-fuel mixture.

在压缩行程中，活塞从下死点向上移动以压缩空气-燃料混合物。

2.The crankshaft rotates 180 degrees to reach bottom dead center from top dead center.

曲轴从上死点旋转180度到达下死点。

3.At bottom dead center, the engine requires a precise ignition timing for optimal performance.

在下死点时，发动机需要精确的点火时机以实现最佳性能。

4.To prevent engine knocking, ensure that the timing is set correctly at bottom dead center.

为了防止发动机敲击，确保在下死点时正确设置时机。

5.The piston reaches bottom dead center when it is at its lowest point in the cylinder.

活塞在气缸中到达下死点时，处于最低点。

作文

In the world of mechanical engineering and automotive design, understanding the concept of bottom dead center is crucial for optimizing performance and efficiency. The term refers to the position of a piston in an internal combustion engine when it is at its lowest point in the cylinder. At this position, the piston has completed its downward stroke and is about to begin its upward movement again. This moment is critical because it marks the end of the power stroke and the beginning of the exhaust stroke, which plays a vital role in the overall operation of the engine.The significance of bottom dead center can be understood by examining how an engine operates. During the four-stroke cycle, the engine goes through intake, compression, power, and exhaust strokes. When the piston reaches bottom dead center, it allows for the maximum volume of the air-fuel mixture to enter the cylinder during the intake phase. This is essential for ensuring that the engine has enough fuel and air to generate power efficiently.Moreover, the timing of valve openings and closings is intricately linked to the position of the piston. The intake valve typically opens just before the piston reaches bottom dead center, allowing the engine to draw in the air-fuel mixture more effectively. If the timing is off, it can lead to poor engine performance, increased emissions, and even engine knock, which can cause significant damage over time.Understanding bottom dead center also aids in tuning the engine for better performance. Mechanics and engineers often use this knowledge to adjust ignition timing and fuel delivery systems to optimize the combustion process. By ensuring that the spark plug ignites the air-fuel mixture at the right moment, they can maximize the power output and efficiency of the engine. This is particularly important in high-performance vehicles where every bit of power counts.In addition to performance considerations, knowing the location of bottom dead center is essential for maintenance and diagnostics. When servicing an engine, technicians will often rotate the crankshaft to align the piston at bottom dead center to perform tasks such as adjusting the valve clearance or replacing timing belts. Misalignment can lead to significant issues, including misfires and reduced engine life.The concept of bottom dead center extends beyond just automotive applications. It is also relevant in various machinery and equipment where pistons are used, such as compressors and hydraulic systems. In these systems, understanding the position of the piston at bottom dead center helps in ensuring the efficient operation and longevity of the machinery.In conclusion, the term bottom dead center is not merely a technical jargon but a fundamental concept that underpins the functionality of internal combustion engines and various mechanical systems. Its importance in optimizing performance, ensuring proper maintenance, and facilitating effective diagnostics cannot be overstated. For anyone involved in engineering or automotive fields, mastering the implications of bottom dead center is essential for achieving success in their endeavors.

在机械工程和汽车设计的世界中，理解“底死点”这一概念对于优化性能和效率至关重要。这个术语指的是内燃机中活塞在气缸内最低点的位置。在这个位置，活塞完成了向下的行程，即将开始向上的运动。这个时刻是关键，因为它标志着动力冲程的结束和排气冲程的开始，这在发动机的整体操作中起着重要作用。通过检查发动机的工作原理，可以理解“底死点”的重要性。在四冲程循环中，发动机经历进气、压缩、动力和排气冲程。当活塞达到“底死点”时，它允许空气-燃料混合物在进气阶段进入气缸的最大体积。这对于确保发动机有足够的燃料和空气以高效产生动力至关重要。此外，阀门的开启和关闭时机与活塞的位置密切相关。进气阀通常在活塞到达“底死点”之前打开，从而更有效地让发动机吸入空气-燃料混合物。如果时机不对，可能会导致发动机性能差、排放增加，甚至引发发动机爆震，这可能会随着时间的推移造成重大损害。理解“底死点”还有助于调校发动机以获得更好的性能。机械师和工程师常常利用这一知识来调整点火时机和燃油供给系统，以优化燃烧过程。通过确保火花塞在正确的时刻点燃空气-燃料混合物，他们可以最大化发动机的功率输出和效率。这在高性能车辆中尤为重要，因为每一点功率都至关重要。除了性能考虑之外，知道“底死点”的位置对于维护和诊断也至关重要。在对发动机进行服务时，技术人员通常会旋转曲轴，使活塞对准“底死点”，以执行诸如调整阀间隙或更换定时皮带等任务。对齐不当可能导致重大问题，包括失火和发动机寿命缩短。“底死点”的概念不仅限于汽车应用。它在各种使用活塞的机器和设备中同样相关，如压缩机和液压系统。在这些系统中，了解活塞在“底死点”的位置有助于确保设备的高效运行和长寿命。总之，术语“底死点”不仅仅是技术术语，而是支撑内燃机和各种机械系统功能的基本概念。它在优化性能、确保适当维护和促进有效诊断中的重要性不容小觑。对于任何参与工程或汽车领域的人来说，掌握“底死点”的含义对于在其事业中取得成功至关重要。