bottom dead center

简明释义

下止点

英英释义

例句

1.The mechanic explained that the crankshaft rotates twice for every complete cycle from bottom dead center.

机械师解释说，曲轴在每个完整循环中从下止点旋转两次。

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

活塞在气缸中处于最低位置时到达下止点。

3.During the engine cycle, the valves open just before the piston hits bottom dead center.

在发动机周期中，活塞在击中下止点之前阀门打开。

4.When diagnosing engine problems, checking the position of the piston at bottom dead center is crucial.

在诊断发动机问题时，检查活塞在下止点的位置至关重要。

5.To optimize performance, the timing should be adjusted to account for bottom dead center.

为了优化性能，时机应调整以考虑下止点。

作文

The concept of bottom dead center is crucial in the field of mechanical engineering, particularly in the study of internal combustion engines. To understand this term, we first need to break it down into its components. The term 'dead center' refers to the position of a piston in an engine when it is at its furthest point from the crankshaft. Specifically, the bottom dead center (BDC) is the lowest point the piston can reach during its cycle. This position is significant because it marks the end of the exhaust stroke and the beginning of the intake stroke in a four-stroke engine cycle.In practical terms, when the piston is at bottom dead center, the volume of the cylinder is at its maximum. This is the moment when the engine is prepared to draw in air and fuel for the next combustion cycle. Understanding this position helps engineers design more efficient engines by optimizing the timing of the intake and exhaust valves. For instance, if the intake valve closes too early or too late in relation to the bottom dead center, it can lead to poor engine performance or increased emissions.Moreover, the concept of bottom dead center is not only limited to gasoline engines but is also applicable in diesel engines and even in some rotary engines. In all these cases, the principles remain the same: knowing when the piston reaches this specific point helps in tuning the engine for better performance. Engineers often use various tools and software to ensure that the timing of the piston's movement corresponds perfectly with the opening and closing of the valves relative to the bottom dead center.Furthermore, the bottom dead center also plays a role in diagnosing engine issues. For example, if an engine is misfiring or has a rough idle, mechanics may check the timing related to the bottom dead center. An incorrect timing can cause the engine to run inefficiently, leading to a host of problems such as reduced power output and increased fuel consumption.In addition to its technical implications, the bottom dead center serves as a metaphor in other areas of life. Just as the piston must reach BDC to initiate the next phase of its cycle, individuals often find themselves at a low point before they can rise again. This idea can be applied to personal challenges or career setbacks. Recognizing that reaching your own 'bottom dead center' can be a necessary step towards growth and improvement is essential. It reminds us that sometimes, hitting rock bottom is not the end, but rather a precursor to a new beginning.In conclusion, the term bottom dead center encapsulates both a critical mechanical concept and a broader metaphor for resilience. By understanding its significance in the context of engine performance and personal growth, we can appreciate the importance of knowing when to reset and prepare for the next phase of our journey. Whether in engineering or life, reaching bottom dead center can lead to new opportunities and pathways for success.

“下止点”这一概念在机械工程领域中至关重要，尤其是在内燃机的研究中。要理解这个术语，我们首先需要将其拆分成几个部分。“止点”一词指的是活塞在发动机中达到曲轴最远位置时的状态。具体而言，下止点（BDC）是活塞在其循环中可以达到的最低点。这个位置非常重要，因为它标志着排气行程的结束和进气行程的开始，在四冲程发动机循环中。从实际角度来看，当活塞处于下止点时，气缸的容积达到最大。这是发动机准备吸入空气和燃料以进行下一次燃烧循环的时刻。理解这个位置有助于工程师通过优化进气和排气阀的时机来设计更高效的发动机。例如，如果进气阀在与下止点的关系上关闭得太早或太晚，可能会导致发动机性能不佳或排放增加。此外，下止点的概念不仅限于汽油发动机，还适用于柴油发动机甚至某些旋转发动机。在所有这些情况下，原理保持不变：了解活塞何时达到这个特定点有助于调校发动机以获得更好的性能。工程师们通常使用各种工具和软件来确保活塞运动的时机与阀门的开启和关闭相对应，以便与下止点相协调。此外，下止点在诊断发动机问题时也发挥着作用。例如，如果发动机失火或怠速不稳，机械师可能会检查与下止点相关的时机。不正确的时机可能导致发动机运行效率低下，从而引发一系列问题，如功率输出减少和燃油消耗增加。除了其技术含义外，下止点在生活的其他领域也作为一种隐喻。例如，就像活塞必须达到BDC才能启动其循环的下一个阶段一样，个人常常发现自己在低谷之前才能再次崛起。这个理念可以应用于个人挑战或职业挫折。认识到达到自己的“下止点”可能是成长和改善的必要步骤至关重要。它提醒我们，有时触底并不是终点，而是新开始的前奏。总之，术语下止点既包含了一个关键的机械概念，也为韧性提供了更广泛的隐喻。通过理解其在发动机性能和个人成长背景下的重要性，我们可以欣赏到知道何时重置并为下一个阶段的旅程做准备的重要性。无论是在工程还是生活中，达到下止点都能带来新的机会和成功的途径。