top dead center

简明释义

上死点上止点

英英释义

例句

1.The engine's piston reaches top dead center during the compression stroke.

在压缩行程中，发动机的活塞达到上死点。

2.When rebuilding the engine, always check if the piston is at top dead center before installing the head.

在重建发动机时，安装气缸盖之前始终检查活塞是否处于上死点。

3.To adjust the ignition timing, you need to find the top dead center of the crankshaft.

要调整点火时机，您需要找到曲轴的上死点。

4.The mechanic explained that the spark plug fires right after reaching top dead center.

机械师解释说，火花塞在达到上死点后立即点火。

5.Make sure the valve clearance is set when the camshaft is at top dead center.

确保在凸轮轴处于上死点时设置阀门间隙。

作文

Understanding the concept of top dead center is crucial for anyone involved in mechanics, particularly in the field of internal combustion engines. The term refers to a specific position of the piston within the cylinder. When the piston reaches this point, it is at its highest position in the cylinder, which is significant for various reasons. First and foremost, the top dead center (TDC) represents the moment when the piston is about to change direction, moving back down after reaching its peak. This position is vital during the engine's cycle because it marks the end of the compression stroke and the beginning of the power stroke.In an internal combustion engine, the cycle consists of four main strokes: intake, compression, power, and exhaust. During the compression stroke, the piston moves upward toward the top dead center. As it approaches this position, the air-fuel mixture within the cylinder is compressed, increasing its temperature and pressure. When the piston finally reaches the top dead center, the spark plug ignites the compressed mixture, resulting in a powerful explosion that forces the piston downward during the power stroke.The importance of accurately determining the top dead center cannot be overstated. Engine builders and mechanics often use various tools and techniques to find this exact point. For instance, they may employ timing lights or dial gauges to ensure that the piston is precisely at TDC. If the ignition timing is set incorrectly, it can lead to poor engine performance, increased emissions, and even engine damage. Therefore, understanding where the top dead center is located helps in tuning the engine for optimal performance.Moreover, the top dead center also plays a role in other aspects of engine design and function. For example, the valve timing must be coordinated with the position of the piston. The opening and closing of the intake and exhaust valves are timed to occur at specific points in relation to the piston’s movement. If the timing is off, it can lead to back pressure, loss of power, and inefficient fuel consumption.In summary, the concept of top dead center is fundamental in understanding the operation of internal combustion engines. It is the point where the piston is at its highest position in the cylinder, marking critical transitions in the engine cycle. Accurate identification of TDC is essential for proper engine tuning, ensuring efficient performance and longevity. Mechanics and engineers must grasp this concept thoroughly to diagnose issues and optimize engine function effectively. Without a clear understanding of top dead center, one would struggle to appreciate the intricate workings of an engine and how to maintain it properly.

理解上死点的概念对于任何参与机械工作的人，尤其是在内燃机领域，是至关重要的。这个术语指的是活塞在气缸内的特定位置。当活塞达到这一点时，它处于气缸的最高位置，这对各种原因都很重要。首先，上死点（TDC）代表活塞即将改变方向的时刻，在达到其峰值后向下移动。这个位置在发动机的循环中是至关重要的，因为它标志着压缩行程的结束和动力行程的开始。在内燃机中，循环由四个主要行程组成：进气、压缩、动力和排气。在压缩行程期间，活塞向上移动，接近上死点。当它接近这个位置时，气缸内的空气-燃料混合物被压缩，温度和压力增加。当活塞最终到达上死点时，火花塞点燃压缩混合物，导致强大的爆炸，迫使活塞在动力行程中向下移动。准确确定上死点的重要性不容小觑。发动机制造商和机械师通常使用各种工具和技术来找到这个确切的位置。例如，他们可能会使用定时灯或表盘量规，以确保活塞正好位于TDC。如果点火时机设置不正确，可能会导致发动机性能下降、排放增加甚至发动机损坏。因此，了解上死点的位置有助于调节发动机以获得最佳性能。此外，上死点还在发动机设计和功能的其他方面发挥作用。例如，阀门的时机必须与活塞的位置协调。进气和排气阀的开启和关闭必须在活塞运动的特定点进行。如果时机错误，可能会导致背压、功率损失和燃油消耗效率低下。总之，上死点的概念在理解内燃机的操作中是基础。它是活塞在气缸内处于最高位置的点，标志着发动机循环中的关键转变。准确识别TDC对于适当的发动机调校至关重要，确保高效的性能和长寿命。机械师和工程师必须透彻掌握这一概念，以有效诊断问题并优化发动机功能。如果没有对上死点的清晰理解，人们将难以欣赏发动机的复杂工作原理以及如何正确维护它。