upper dead point

简明释义

上死点

英英释义

例句

1.In a four-stroke engine, the intake valve opens just after the upper dead point of the exhaust stroke.

在四冲程发动机中，进气阀在排气行程的上止点后刚打开。

2.Adjusting the timing requires knowing when the crankshaft is at the upper dead point.

调整时机需要知道曲轴何时处于上止点。

3.The engine's piston reaches the upper dead point when it is at its highest position in the cylinder.

当发动机的活塞处于气缸的最高位置时，它达到了上止点。

4.Checking the ignition timing involves setting the engine to the upper dead point.

检查点火时机涉及将发动机设置到上止点。

5.The upper dead point is crucial for understanding the engine's compression cycle.

了解发动机的压缩周期时，上止点至关重要。

作文

In the world of mechanics and engineering, understanding various terms is crucial for the operation and design of machines. One such term is the upper dead point, which refers to a specific position in the cycle of a reciprocating engine or similar machinery. This position is defined as the point at which the piston reaches its highest position in the cylinder before it begins to move back down. The significance of the upper dead point cannot be overstated, as it plays a vital role in the functioning of engines, particularly in relation to timing and efficiency.The upper dead point is essential for several reasons. First, it marks the end of the compression stroke in an internal combustion engine. When the piston reaches this point, the fuel-air mixture is fully compressed, and the ignition occurs shortly after. This timing is critical; if the ignition happens too early or too late, it can lead to inefficient combustion, reduced power output, or even engine knocking. Therefore, understanding the upper dead point allows engineers to optimize engine performance by adjusting ignition timing accordingly.Moreover, the upper dead point is also important for the design of engine components. For instance, the crankshaft and connecting rod must be engineered to accommodate the forces acting on them when the piston is at this position. If the materials or dimensions are not suitable, it could result in mechanical failure. Thus, a thorough comprehension of the upper dead point is necessary for engineers to ensure that their designs can withstand the stresses encountered during operation.In addition to its mechanical implications, the upper dead point also has a direct impact on fuel efficiency. Modern engines are designed to maximize fuel economy while minimizing emissions. By precisely controlling the timing of the ignition and the movement of the piston around the upper dead point, manufacturers can create engines that operate more efficiently. This not only benefits the consumer through better fuel economy but also addresses environmental concerns related to fossil fuel consumption.Furthermore, the concept of the upper dead point is not limited to internal combustion engines alone. It is also applicable in other fields, such as in hydraulic systems and pneumatic devices where similar principles of motion and force apply. Understanding the upper dead point in these contexts allows engineers to design systems that operate smoothly and effectively under varying conditions.In conclusion, the upper dead point is a fundamental concept in mechanics that has far-reaching implications in the design and operation of engines and machinery. Its importance in timing, efficiency, and structural integrity cannot be overlooked. As technology continues to advance, a deeper understanding of such terms will be essential for engineers and designers striving to create more efficient and reliable machines. Therefore, mastering the concept of the upper dead point is not only beneficial but necessary for anyone involved in the field of engineering and mechanics.

在机械和工程的世界中，理解各种术语对于机器的操作和设计至关重要。其中一个术语是上止点，它指的是往复发动机或类似机械循环中的一个特定位置。这个位置被定义为活塞在气缸内达到最高位置后开始向下移动的点。上止点的重要性不容小觑，因为它在发动机功能中扮演着至关重要的角色，特别是在时机和效率方面。上止点之所以重要有几个原因。首先，它标志着内燃机压缩行程的结束。当活塞达到这个点时，燃油空气混合物被完全压缩，点火在此之后不久发生。这个时机至关重要；如果点火发生得太早或太晚，可能会导致燃烧效率低下、功率输出减少，甚至发动机敲击。因此，理解上止点使工程师能够通过相应地调整点火时机来优化发动机性能。此外，上止点对于发动机部件的设计也很重要。例如，曲轴和连杆必须设计成能够承受活塞在这个位置时施加的力量。如果材料或尺寸不合适，可能会导致机械故障。因此，深入理解上止点对工程师确保他们的设计能够承受操作过程中遇到的压力是必要的。除了机械影响外，上止点还直接影响燃油效率。现代发动机旨在最大限度地提高燃油经济性，同时减少排放。通过精确控制点火的时机和活塞在上止点附近的运动，制造商可以制造出更高效的发动机。这不仅通过更好的燃油经济性使消费者受益，还解决了与化石燃料消耗相关的环境问题。此外，上止点的概念并不限于内燃机。在液压系统和气动装置等其他领域也适用类似的运动和力的原理。理解这些上下文中的上止点使工程师能够设计出在不同条件下平稳有效运行的系统。总之，上止点是机械学中的一个基本概念，对发动机和机械的设计与操作具有深远的影响。它在时机、效率和结构完整性方面的重要性不容忽视。随着技术的不断进步，对这些术语的更深理解将对努力创造更高效、更可靠机器的工程师和设计师至关重要。因此，掌握上止点的概念不仅是有益的，而且对于任何从事工程和机械领域的人来说都是必要的。