valve overlap

简明释义

阀重叠

英英释义

例句

1.Understanding valve overlap is crucial for tuning your car's engine.

理解阀门重叠对于调校汽车发动机至关重要。

2.The mechanic explained how valve overlap affects fuel efficiency.

机械师解释了阀门重叠如何影响燃油效率。

3.A greater valve overlap can lead to more power at high RPMs.

更大的阀门重叠可以在高转速下产生更多的动力。

4.The engine's performance improved significantly after adjusting the valve overlap.

在调整了阀门重叠后，发动机的性能显著提高。

5.Reducing valve overlap can help in lowering emissions.

减少阀门重叠有助于降低排放。

作文

Understanding the mechanics of an internal combustion engine can often feel like deciphering a complex puzzle. Among the many components that play a critical role in engine performance, the concept of valve overlap is particularly significant. Valve overlap refers to the period during which both the intake and exhaust valves are open simultaneously at the end of the exhaust stroke and the beginning of the intake stroke. This phenomenon occurs in four-stroke engines and has profound implications for engine efficiency and power output.To grasp the importance of valve overlap, one must first understand the basic operation of a four-stroke engine. The four strokes include intake, compression, power, and exhaust. During the intake stroke, the intake valve opens, allowing the air-fuel mixture to enter the combustion chamber. As the piston moves up during the compression stroke, the intake valve closes, and the mixture is compressed. After the power stroke, where combustion occurs, the exhaust valve opens to expel the burnt gases. It is during this transition between the power stroke and the intake stroke that valve overlap takes place.The timing and duration of valve overlap can significantly affect engine performance. A greater overlap allows for better scavenging of exhaust gases, meaning that more of the spent gases can be expelled from the cylinder before the intake stroke begins. This can lead to improved airflow into the engine, which enhances performance, especially at higher RPMs. However, too much valve overlap can result in a loss of low-end torque, making the engine feel sluggish at lower speeds.Engine designers often manipulate valve overlap through camshaft profiles. By adjusting the lift and duration of the valves, engineers can optimize the timing of when the valves open and close, thereby influencing the degree of overlap. Performance engines typically feature a higher degree of valve overlap to maximize power output at high RPMs, while engines designed for fuel efficiency may have less overlap to enhance low-end torque and improve fuel economy.In summary, valve overlap is a crucial aspect of engine design that affects both performance and efficiency. Understanding how it works allows automotive enthusiasts and engineers alike to appreciate the intricate balance between power and efficiency in internal combustion engines. As technology continues to advance, the role of valve overlap will remain a key factor in the ongoing quest for improved engine performance and reduced emissions. By mastering the principles of valve overlap, one can gain deeper insights into the fascinating world of automotive engineering and the continuous innovations that drive it forward.

理解内燃机的机械原理常常让人感觉像是在解读一个复杂的难题。在众多对发动机性能起关键作用的组件中，阀重叠的概念尤为重要。阀重叠是指在排气冲程结束和进气冲程开始时，进气阀和排气阀同时打开的时间段。这种现象发生在四冲程发动机中，对发动机效率和功率输出有深远的影响。要理解阀重叠的重要性，首先必须了解四冲程发动机的基本运作。四个冲程包括进气、压缩、动力和排气。在进气冲程中，进气阀打开，允许空气-燃料混合物进入燃烧室。随着活塞在压缩冲程中向上移动，进气阀关闭，混合物被压缩。在动力冲程中发生燃烧后，排气阀打开以排出废气。正是在动力冲程和进气冲程之间的过渡期间，发生了阀重叠。阀重叠的时机和持续时间会显著影响发动机性能。更大的重叠允许更好的废气清扫，这意味着在进气冲程开始之前，可以更有效地排出更多的废气。这可以改善空气流入发动机的情况，从而增强性能，特别是在高转速时。然而，过多的阀重叠可能导致低转速扭矩的损失，使得发动机在低速时感觉迟缓。发动机设计师通常通过凸轮轴轮廓来操控阀重叠。通过调整阀门的升程和持续时间，工程师可以优化阀门打开和关闭的时机，从而影响重叠的程度。高性能发动机通常具有更高的阀重叠以最大化高转速下的功率输出，而为了提高燃油效率而设计的发动机则可能具有较少的重叠，以增强低端扭矩并改善燃油经济性。总之，阀重叠是发动机设计中的一个关键方面，影响着性能和效率。理解它的工作原理使汽车爱好者和工程师能够欣赏内燃机中功率与效率之间的微妙平衡。随着技术的不断进步，阀重叠的作用将继续成为提高发动机性能和减少排放的持续追求中的关键因素。通过掌握阀重叠的原理，人们可以深入了解汽车工程的迷人世界，以及推动其前进的持续创新。