挡风玻璃除霜系统测试程序和性能要求 卡车、客车和多用途车辆

[中文适用范围]： 本 SAE 推荐做法为封闭式驾驶室卡车、公共汽车和多用途车辆的除霜系统制定了统一的测试程序和性能要求。它仅限于可在商用实验室设施中使用统一测试设备进行的测试。对于除霜系统的实验室评估，当前的工程实践规定在挡风玻璃和左侧和右侧车窗上涂上已知厚度的冰层，以提供更统一和可重复的测试结果，即使在实际条件下，这种涂层在驾驶前必须刮掉。因此，测试条件比实际条件更为严苛，在实际条件下，除霜系统必须能够保持清晰的视野。由于大多数此类车辆的操作性质特殊（车辆通常停放在车库中或在驾驶前预热），并且由于在稳定状态下的公路操作下除霜是主要关注点，因此采用的测试条件假设发动机在驾驶车辆之前是暖的。本推荐做法中有两种产生热冷却液的方法。在同一辆车上使用这两种方法进行测试不一定会产生相同的结果。许多车型都配有可选发动机，而每种发动机的冷却液温度和流速各不相同。如果进行测试是为了比较一种除霜器设计与另一种除霜器设计的性能，那么外部冷却液源方法（测试 A）将产生最具可比性的结果。如果进行测试是为了验证特定车型和特定发动机上的除霜器安装，那么使用发动机加热冷却液（测试 B）将更为合适。本文件将根据车辆除霜器测试程序的技术进步进行审查和修订。 [外文原描述]： This SAE Recommended Practice establishes uniform test procedures and performance requirements for the defrosting system of enclosed cab trucks, buses, and multipurpose vehicles. It is limited to a test that can be conducted on uniform test equipment in commercially available laboratory facilities. For laboratory evaluation of defroster systems, current engineering practice prescribes that an ice coating of known thickness be applied to the windshield and left- and right-hand side windows to provide more uniform and repeatable test results, even though - under actual conditions - such a coating would necessarily be scraped off before driving. The test condition, therefore, represents a more severe condition than the actual condition, where the defroster system must merely be capable of maintaining a cleared viewing area. Because of the special nature of the operation of most of these vehicles (where vehicles are generally kept in a garage or warmed up before driving), and since defrosting under steady-state over-the-road operations is the main concern, test conditions have been adopted that assume that the engine is warm before the vehicle is driven. There are two options for producing hot coolant in this recommended practice. Testing using these two approaches on the same vehicle will not necessarily provide identical results. Many vehicle models are offered with optional engines, and each engine has varying coolant temperatures and flow rates. If the test is being conducted to compare the performance of one defroster design to another defroster design, then the external coolant source approach (Test A) will yield the most comparable results. If the test is being conducted to validate the defroster installation on a specific vehicle model with a specific engine, then using the engine to heat the coolant (Test B) will be more appropriate. This document will be reviewed and revised as technological progress in vehicle defroster test procedure requires.