ISO 20574-2019 pdf free.Road vehicles — Durability test method for starter motor for stop andstart system.
At a minimum, the measurement data analysis of entire test (minimum/maximum/average analysis)shall be summarized and predefined in the test planning matrix Table 2,(2/3 reporting items).
Visual observation of starter motor from outside shall be performed and the results should bedocumented by photo.
The performance of the DUT shall be measured again with the same starter motor input as definedin 6.1.4 according to lS0 8856, and the results shall be recorded unless the starter motor was run tofailure.
Tear down analysis shall be performed and the results should be documented by photo.The remaining length of brushes shall be measured according to 7.3 and recorded.Test information and analysis results on Annex D should be summarised.
Additional analysis is specific to engine and/or vehicle manufacturers and starter motor manufactureragreement at planning stage.
One focus of the durability test is the brush wear. Brush temperature influences strongly the brushwear. In the vehicle, brush temperature and yoke temperature are in the same range.However, duringdurability test, the brush temperature becomes much higher than the yoke temperature due tohigh number of starts per hour;, and cooling of the exterior of the starter motor.Using the stabilizedyoke temperature from the vehicle for the durability test will lead to brush temperatures which aresignificantly above the vehicle situation.Therefore, the durability test shall be performed with a brushtemperature comparable to the vehicle situation or below maximum brush temperature defined bystarter motor manufacturer.
Use the following method to measure and calibrate the brush temperature at the pre-check stage.Calibration starter motor shall have thermocouples installed on one or more brushes to measureTbrush. In addition, at least one thermocouple shall be installed at location of control point to measureTcontrol. Location of temperature control point and brush temperature measurement position shall bedocumented (see Table 2,2/3).
Yoke surface can be the control point location. If so, the thermocouple should be installed at theengine side, not receiving cooling effect by air flow (see Figure 1).Thermocouple shall be installed attemperature control point location of both the DUT and the calibration starter motor.
Temperature of brushes should be measured using the calibration starter motor but not the DUT.The reason is that a thermocouple influences the dynamic behaviour of the brush and therefore thebrush wear.ISO 20574 pdf download.