top dead center

简明释义

上死点

英英释义

例句

1.The piston reaches top dead center when it is at its highest point in the cylinder.

当活塞到达气缸的最高点时，它处于上死点。

2.At top dead center, the engine is ready for the next power stroke.

在上死点时，发动机准备好进行下一次动力冲程。

3.To set the ignition timing, you need to find top dead center of the engine's compression stroke.

要设置点火时机，您需要找到发动机压缩行程的上死点。

4.The mechanic marked the flywheel to indicate top dead center for easier alignment.

机械师在飞轮上标记了上死点以便于对齐。

5.Adjusting the valves requires knowing when the engine is at top dead center.

调整气门需要知道发动机何时处于上死点。

作文

Understanding the concept of top dead center is crucial for anyone involved in mechanics, particularly in the automotive industry. The term refers to a specific position in an engine's cycle where the piston is at its highest point in the cylinder. This position is significant because it marks the end of the compression stroke and the beginning of the power stroke in a four-stroke engine. To grasp the importance of top dead center (TDC), one must first understand the basic operation of an internal combustion engine.An internal combustion engine operates on a cycle that includes intake, compression, power, and exhaust strokes. During the intake stroke, the piston moves down, drawing in the air-fuel mixture. As the piston reaches the bottom of its travel, it begins to move back up during the compression stroke. It is at this moment, when the piston reaches its highest position in the cylinder, that we refer to it as top dead center. At TDC, the air-fuel mixture is compressed to its maximum density, which is vital for efficient combustion.Once the piston reaches top dead center, the spark plug ignites the compressed air-fuel mixture, leading to an explosion that forces the piston back down. This is known as the power stroke, and it is what ultimately drives the crankshaft and powers the vehicle. Therefore, understanding TDC is essential for diagnosing engine problems, optimizing performance, and making adjustments to engine timing.In addition to its mechanical implications, the concept of top dead center also plays a role in tuning the engine. Mechanics often adjust the ignition timing to ensure that the spark occurs at the optimal moment, just before the piston reaches TDC. If the spark occurs too early or too late, it can lead to inefficient combustion, reduced power output, and even engine knocking, which can cause serious damage.Moreover, the significance of top dead center extends beyond just the operation of the engine itself. It is also a critical reference point in various engine assembly processes. For instance, when installing timing belts or chains, mechanics must align the engine components to ensure that they are synchronized correctly. Knowing where TDC is located allows them to make these adjustments accurately, ensuring that the engine runs smoothly and efficiently.In conclusion, the term top dead center is much more than just a technical phrase; it embodies the essence of how an internal combustion engine operates. From ensuring proper combustion to facilitating accurate engine assembly, TDC is a fundamental concept that every mechanic should be familiar with. Understanding this term not only enhances one’s mechanical knowledge but also contributes significantly to the overall performance and longevity of the engine. As technology advances and new engine designs emerge, the principles surrounding top dead center will continue to be relevant, underscoring the importance of mastering this concept for both aspiring and seasoned mechanics alike.

理解顶死点的概念对于任何参与机械工作的人来说都是至关重要的，特别是在汽车工业中。这个术语指的是发动机循环中的一个特定位置，即活塞在气缸中的最高点。这个位置非常重要，因为它标志着压缩行程的结束和四冲程发动机动力行程的开始。要掌握顶死点（TDC）的重要性，首先必须了解内燃机的基本操作。内燃机在一个包括进气、压缩、动力和排气行程的循环中工作。在进气行程中，活塞向下移动，吸入空气-燃料混合物。当活塞到达其行程的底部时，它开始在压缩行程中向上移动。此时，当活塞达到气缸的最高位置时，我们称之为顶死点。在TDC时，空气-燃料混合物被压缩到最大密度，这对有效燃烧至关重要。一旦活塞达到顶死点，火花塞就会点燃压缩的空气-燃料混合物，导致爆炸，迫使活塞向下。这被称为动力行程，它最终驱动曲轴并为车辆提供动力。因此，了解TDC对于诊断发动机问题、优化性能和调整发动机时机至关重要。除了机械意义外，顶死点的概念在调节发动机时也发挥着作用。机械师通常会调整点火时机，以确保火花在活塞达到TDC之前的最佳时刻发生。如果火花发生得太早或太晚，可能会导致燃烧效率低下、功率输出减少，甚至发动机敲击，这可能会造成严重损坏。此外，顶死点的重要性不仅限于发动机本身的操作。它在各种发动机组装过程中也是一个关键的参考点。例如，在安装时序皮带或链条时，机械师必须对齐发动机组件，以确保它们正确同步。知道TDC的位置可以让他们准确地进行这些调整，确保发动机平稳高效地运行。总之，术语顶死点不仅仅是一个技术短语；它体现了内燃机运作的本质。从确保适当的燃烧到促进准确的发动机组装，TDC是每个机械师都应该熟悉的基本概念。理解这个术语不仅增强了一个人的机械知识，还显著有助于发动机的整体性能和使用寿命。随着技术的进步和新发动机设计的出现，围绕顶死点的原则将继续保持相关性，强调了掌握这一概念对初学者和经验丰富的机械师的重要性。