overhead valve

简明释义

顶阀上置阀门

英英释义

例句

1.Many modern cars use an overhead valve system for better performance.

许多现代汽车使用顶置气门系统以获得更好的性能。

2.An overhead valve engine tends to produce more power than a pushrod engine.

与推杆发动机相比，顶置气门发动机往往产生更多动力。

3.The overhead valve configuration allows for higher RPMs.

这种顶置气门配置允许更高的转速。

4.Replacing the overhead valve gasket can prevent oil leaks.

更换顶置气门垫圈可以防止油漏。

5.The engine features an overhead valve design, which improves efficiency.

该发动机采用了顶置气门设计，提高了效率。

作文

The engine is a critical component of any vehicle, and its design can significantly impact performance and efficiency. One important feature in many modern engines is the use of an overhead valve (OHV) system. This design places the valves above the combustion chamber, allowing for better airflow and improved engine performance. In this essay, we will explore the advantages of the overhead valve configuration and how it contributes to the overall functionality of an engine.First and foremost, the overhead valve system enhances the engine's breathing capabilities. By positioning the valves directly above the cylinders, the design minimizes the distance that the air-fuel mixture must travel to enter the combustion chamber. This reduced distance allows for a more efficient intake and exhaust process, which can lead to increased power output. The improved airflow also helps in achieving better fuel combustion, resulting in enhanced fuel efficiency.Another significant advantage of the overhead valve design is its ability to accommodate higher engine speeds. As the RPMs increase, the demand for air and fuel rises. The OHV system's configuration allows for quicker valve opening and closing, enabling the engine to maintain optimal performance even at high speeds. This characteristic makes overhead valve engines particularly popular in sports cars and performance vehicles, where speed and responsiveness are paramount.Additionally, the overhead valve system contributes to a reduction in engine weight. Traditional pushrod engines often require additional components such as rocker arms and pushrods, which can add unnecessary weight. In contrast, the OHV design streamlines the engine's architecture, resulting in a lighter overall structure. This weight reduction can lead to improved handling and acceleration, further enhancing the driving experience.Moreover, the durability of overhead valve engines is noteworthy. With fewer moving parts compared to traditional designs, there is less potential for mechanical failure. This reliability is crucial for consumers who seek longevity in their vehicles. Many manufacturers have adopted the OHV design because it not only meets performance expectations but also provides peace of mind to drivers regarding maintenance and repairs.However, it is essential to acknowledge that the overhead valve system is not without its drawbacks. One notable issue is the complexity of the timing mechanism. The timing belts or chains used in OHV engines must be precisely calibrated to ensure that the valves open and close at the correct intervals. Any misalignment can lead to severe engine damage. Therefore, regular maintenance is crucial to prevent such issues from arising.In conclusion, the overhead valve system plays a vital role in modern engine design, offering numerous benefits including improved airflow, higher RPM capabilities, reduced weight, and enhanced durability. While there are challenges associated with maintaining the timing mechanisms, the advantages often outweigh the drawbacks. As automotive technology continues to evolve, the overhead valve design will likely remain a popular choice among engineers and manufacturers striving for optimal engine performance and efficiency.

发动机是任何车辆的关键组成部分，其设计可以显著影响性能和效率。许多现代发动机中的一个重要特征是采用顶置气门（OHV）系统。这种设计将气门放置在燃烧室上方，从而允许更好的气流和改善的发动机性能。在这篇文章中，我们将探讨顶置气门配置的优点，以及它如何促进发动机的整体功能。首先，顶置气门系统增强了发动机的进气能力。通过将气门直接放置在气缸上方，这种设计最小化了空气-燃料混合物进入燃烧室所需的行程。这种距离的减少允许更高效的进气和排气过程，从而可以提高功率输出。改善的气流也有助于实现更好的燃料燃烧，导致燃油效率的提高。顶置气门设计的另一个显著优点是其能够适应更高的发动机转速。当转速增加时，对空气和燃料的需求也随之上升。OHV系统的配置允许气门更快地打开和关闭，使得即使在高转速下，发动机也能保持最佳性能。这一特性使得顶置气门发动机在运动型汽车和性能车中尤其受欢迎，因为速度和响应性至关重要。此外，顶置气门系统有助于减少发动机重量。传统的推杆发动机通常需要额外的组件，如摇臂和推杆，这可能会增加不必要的重量。相比之下，OHV设计简化了发动机的结构，导致整体结构更轻。这种重量减少可以提高操控性和加速性能，进一步增强驾驶体验。此外，顶置气门发动机的耐用性也值得注意。与传统设计相比，活动部件更少，因此机械故障的潜在风险也较小。这种可靠性对于寻求车辆耐用性的消费者至关重要。许多制造商采用OHV设计，因为它不仅满足性能预期，还为驾驶者提供了关于维护和修理的安心。然而，必须承认的是，顶置气门系统并非没有缺点。一个显著的问题是时序机制的复杂性。OHV发动机中使用的时序皮带或链条必须精确校准，以确保气门在正确的时间间隔内打开和关闭。任何对齐不当都可能导致严重的发动机损坏。因此，定期维护对于防止此类问题的发生至关重要。总之，顶置气门系统在现代发动机设计中发挥着至关重要的作用，提供了许多好处，包括改善的气流、更高的转速能力、减轻的重量和增强的耐用性。尽管维护时序机制存在挑战，但优势往往超过缺点。随着汽车技术的不断发展，顶置气门设计可能仍然是工程师和制造商追求最佳发动机性能和效率的热门选择。