ISO 20574:2019 pdf free.Road vehicles – Durability test method for starter motor for stop and start system.
4 Planning of durability test
4.1 Determination of durability test types
The durability test is performed with an engine simulator or an engine. The following test types can be selected. See Table 1 for comparison of each test type.
1) Engine, using bench controller to control fuel/spark to specifically achieve pre-determined cranking time and overrunning time (see Table3).
2) Engine, using its engine ECU to control the test parameters.
3) Engine simulator, using engine waveform data provided by engine and/or vehicle manufacturers as input to simulator (for cranking time, overrunning time, or torque) (see Table 3).
4) Engine simulator, using synthetic pattern or engine simulation model where starter motor manufacturer or engine and/or vehicle manufacturers define values for torque, cranking and overrunning behaviour (see Table 3).
4.2 Determination of durability test conditions
The starter motor manufacturer and engine and/or vehicle manufacturers should define the test conditions according to the test planning matrix shown in Table 2.
The following items should be specifically considered:
1) In case of engine simulator, multiple starter motors can be tested simultaneously with the same ring gear. In that case, the orientation of the starter motors deviate from those of the target application. Hence, the usage of multiple starter motors shall correspond to the test purpose (e.g. verification of brush durability but not verification of pinion and ring gear durability).
2) The starter motor manufacturer and engine and/or vehicle manufacturers should agree starter motor temperature level during the durability test. Different approaches to define temperature level are established.
For example:
— test at maximum brush temperature defined by starter motor manufacturer;
— test at maximum brush temperature derived from vehicle real drive cycle; and
— test at an average brush temperature derived from brush temperature distributions of vehicle real drive cycle. Each approach covers different testing purposes such as focusing on thermal stress, test duration, mechanical loads or balanced field representation.
3) The starter motor manufacturer and engine and/or vehicle manufacturers should define the test pass criteria and define test stop criteria according to Table 6.
4) Additional test conditions may be defined and shall be documented in test planning matrix.
For example:
— always using “100 % new” battery for every test;
— testing with maximum pinion to ring gear axial gap; and
— number and orientation of starter motors mounted to engine simulator ring gear.
In this stage, the following steps shall be conducted.
1) The engine and gearbox shall be mounted on the appropriate engine mount.
2) The engine fluids (e.g. engine oil, coolant) shall be filled and checked according to vehicle and /or engine manufacturer specifications.
3) A dummy starter motor other than the DLJT shall be mounted to engine or engine simulator. dprg shall be set to appropriate value and verified according to Z4.
4) Before cranking the engine, a fluid leakage check shall be performed. In case a leakage is detected, starter motor shall not be operated.
5) The measurement equipment shall be installed.
6) All electrical connections shall be installed and checked for verifying proper coupling and no damages. NOTE Electrical connections include digital signals, analogue signals, measurement cables and electrical power supplies.
7) To control the starter motor temperature at control point, a cooling system or cooling fan shall be installed.
8) The test bench shall be initialized, Initialization includes switch on electric equipment, boot up software and check measurement values.
9) The target parameters shall be set. Parameters include control timings and rotational frequencies, V-I parameters and temperatures. If parameters are not matching to the agreed test setup, the parameters shall be adjusted.
10) The readiness for operation and runnability of the engine shall be checked.ISO 20574 pdf download.