大众汽车 VW80000标准详细解读_9
4.11.6-4.11.7是举例说明operating mode,各位可对应自己的产品进行匹配着看。
4.11.8 Service life requirements 使用寿命要求
这节文字比较多,不想费时可直接看最后说明部分。
Table 4 shows the typical parameters for service life requirements.
表4显示了服务寿命要求的典型参数。
这里对零件的使用寿命提出了要求是15年,其中明确了行驶状态是8000小时。其他场景未明确定义,需要参照具体产品的设计规范。
4.11.9 Temperature load spectra 温度载荷谱
In order to describe the temperature load that a component is exposed to at the vehicle point of use, the minimum temperature Tmin and the maximum ambient temperature Tmax must be specified in addition to the distribution that indicates how long the component has been exposed to the various temperatures between Tmin and Tmax.
For vehicles with alternative drives, a distinction must be made between the driving, charging, preconditioning, and parking operating situations, and the respective temperature load spectra must be specified both for the ambient temperature and the coolant circuit temperature.
As a rule, this temperature distribution is a continuous distribution as the ambient temperature of the component can assume any value between Tmin and Tmax.
This continuous distribution can be adequately explained by a few discreet temperature data points Tfield,i to design the component and to simplify the test duration calculation using the accelerated
service life model as per Arrhenius (see appendix D). For each temperature data point, the percentage
share pi of the operating duration during which the component is exposed to the data point temperature must be specified.
为了描述零部件在车辆使用点所受到的温度负荷,除了需要指定最低温度Tmin和最高环境温度Tmax外,还必须指定分布,表明零部件在Tmin和Tmax之间的各种温度下暴露的时间长短。
对于具有可选驱动的车辆,必须区分驾驶、充电、预调节和停车操作情况,并且必须为环境温度和冷却液回路温度分别指定相应的温度负荷谱。通常,这种温度分布是一个连续分布,因为零部件的环境温度可以在Tmin和Tmax之间的任何值之间取值。
可以通过几个离散的温度数据点Tfield,i来充分解释这种连续分布,以设计零部件,并使用阿伦尼乌斯(见附录D)的加速寿命模型简化测试持续时间的计算。对于每个温度数据点,必须指定零部件暴露在该数据点温度下的操作持续时间的百分比Pi。
Therefore, the respective temperature load spectrum has the general shape as per table 5, and is essentially based on field measurements and technical experience.
因此,各自的温度负荷谱具有表5所示的一般形状,并且主要基于现场测量和技术经验。
Typical temperature load spectra for Driving operating situation in terms of different installation areas are indicated in appendix B.
The ability of these typical temperature load spectra to be used for a specific component must be verified, e.g., by vehicle measurement, simulation, or experience. In case of deviations, the temperature load spectrum must be adapted to the particular component.
A component-specific temperature load spectrum must be defined for special points of use or installedconditions (e.g., at a point of use near a heat source).
The applicable temperature load spectrum must be documented. In addition to the typical temperature
load spectra, the typical values for an average temperature rise that a component experiences in the vehicle in driving operating situation are specified in appendix B.
This value must also be determined and documented in a way that is specific to each component for temperature load spectra that have been defined or adapted specifically for each component.
典型的温度负荷谱针对不同安装区域的驾驶工况在附录B中有所指示。
这些典型的温度负荷谱能否用于特定组件必须经过验证,例如通过车辆测量、模拟或经验。在出现偏差的情况下,必须将温度负荷谱调整为特定组件。
必须为特定使用点或安装条件(例如,在靠近热源的使用点)定义特定组件的温度负荷谱。
适用的温度负荷谱必须进行记录。除了典型的温度负荷谱外,附录B中还规定了组件在车辆驾驶工况中经历的平均温升的典型值。
这个值也必须以针对每个组件具体的方式确定和记录,用于已经为每个组件定义或调整的温度负荷谱。
这节说得是零部件在使用周期内所需要经历得温度值和分布比例。首先需要明确零部件的安装位置。Table B.1给出了覆盖全部零件的8个位置,基于位置就能确定零部件在使用周期内的温度载荷谱,共4个选其中一个,注意K值。在根据温度载荷谱里里的温度值和比例,再计算高温耐久或者温度循环耐久时间,后文相应章节会提供示例,请继续关注。