upper dead center

简明释义

止止点

英英释义

例句

1.When the piston reaches upper dead center 上止点, the fuel injection occurs.

当活塞达到上止点 upper dead center时，燃油喷射发生。

2.To diagnose the issue, we need to check if the camshaft aligns with upper dead center 上止点.

为了诊断问题，我们需要检查凸轮轴是否与上止点 upper dead center对齐。

3.Adjusting the ignition timing is crucial when the crankshaft is at upper dead center 上止点.

当曲轴处于上止点 upper dead center时，调整点火时机至关重要。

4.The engine must be at upper dead center 上止点 to ensure proper valve timing.

发动机必须处于上止点 upper dead center以确保阀门时机正确。

5.The technician marked the position of upper dead center 上止点 on the timing cover.

技术员在定时盖上标记了上止点 upper dead center的位置。

作文

The term upper dead center refers to a specific position in the cycle of an engine, particularly in internal combustion engines. It is the point at which the piston is at its highest position within the cylinder, and it plays a crucial role in the engine's operation. Understanding this concept is essential for anyone interested in mechanics or automotive engineering. In simple terms, when the piston reaches the upper dead center, it signifies the end of the compression stroke and the beginning of the power stroke. This is a critical moment because it is when the fuel-air mixture is ignited, leading to the explosion that pushes the piston downwards, generating power for the engine. If the timing of this process is off, it can lead to inefficient engine performance or even engine failure.In a typical four-stroke engine, there are four stages: intake, compression, power, and exhaust. The upper dead center occurs at the end of the compression stage. During this stage, the piston moves up the cylinder, compressing the fuel-air mixture. Once it reaches the upper dead center, the spark plug ignites the mixture, resulting in combustion. The force from this combustion then drives the piston downward, completing the power stroke.The importance of the upper dead center cannot be overstated. It is vital for optimizing engine performance. Engineers must ensure that the timing of the ignition occurs precisely when the piston is at the upper dead center. If the ignition happens too early or too late, it can cause knocking, reduced power output, and increased emissions. Therefore, modern engines often use advanced timing systems to control when the ignition occurs, ensuring it is perfectly synchronized with the piston's position.Moreover, understanding the upper dead center can also help in diagnosing engine problems. For instance, if an engine is misfiring or running rough, a mechanic might check the timing of the ignition relative to the piston's position at the upper dead center. This can reveal whether the problem lies in the ignition system or if there are other underlying issues affecting the engine's performance.In addition to its technical implications, the concept of the upper dead center can be metaphorically applied to various life situations. Just as the piston must reach its peak before generating power, individuals often need to reach their own 'upper dead center' in life—whether that means achieving a personal goal, overcoming a challenge, or realizing their potential. It serves as a reminder that sometimes we must push through difficult times (the compression) before we can experience growth and success (the power stroke).In conclusion, the term upper dead center is more than just a mechanical concept; it reflects the importance of timing and precision in both machines and life. Whether you are an engineer, a mechanic, or simply someone striving to achieve your goals, understanding the significance of reaching that peak moment can lead to greater success and efficiency in your endeavors.

“上止点”这个术语指的是发动机周期中的一个特定位置，尤其是在内燃机中。它是活塞在气缸内达到最高位置的点，这在发动机的操作中起着至关重要的作用。理解这个概念对任何对机械或汽车工程感兴趣的人来说都是必不可少的。简单来说，当活塞达到上止点时，意味着压缩行程的结束和动力行程的开始。这是一个关键时刻，因为这是燃料-空气混合物被点燃的时候，导致爆炸推动活塞向下，从而为发动机产生动力。如果这个过程的时机不对，可能会导致发动机性能低效甚至故障。在典型的四冲程发动机中，有四个阶段：进气、压缩、动力和排气。上止点发生在压缩阶段的末尾。在这一阶段，活塞向上移动气缸，压缩燃料-空气混合物。一旦它达到上止点，火花塞就会点燃混合物，导致燃烧。燃烧产生的力量随后推动活塞向下，完成动力行程。上止点的重要性不可低估。它对优化发动机性能至关重要。工程师必须确保点火的时机恰好在活塞处于上止点时发生。如果点火过早或过晚，可能会导致敲击、功率输出减少和排放增加。因此，现代发动机通常使用先进的点火时序系统来控制点火发生的时间，确保与活塞的位置完美同步。此外，理解上止点也有助于诊断发动机问题。例如，如果发动机失火或运行不稳，机械师可能会检查点火的时机与活塞在上止点时的位置的关系。这可以揭示问题是否出在点火系统上，或者是否还有其他潜在问题影响发动机的性能。除了技术意义外，上止点的概念也可以隐喻地应用于各种生活情况。正如活塞必须达到其峰值才能产生动力，个人在生活中也常常需要达到自己的“上止点”——无论这意味着实现个人目标、克服挑战还是实现潜力。它提醒我们，有时我们必须经历困难时期（压缩），才能体验到成长和成功（动力行程）。总之，术语上止点不仅仅是一个机械概念；它反映了在机器和生活中时机和精确度的重要性。无论你是工程师、机械师，还是只是一个努力实现目标的人，理解达到那个顶峰时刻的意义都可以使你的努力更成功、更高效。