1、GM DAEWOO Auto & Technology EDS Engineering, GM DAEWOO Auto & Technology Standards TEST METHOD FOR THERMOSTAT ASSEMBLY Do Not Use on New Programs. Being Replaced by GMW14078 EDS-T-4708 ISSUED DATE: 1990. 11. 03 REVISED DATE: 2008. 10. 27 VERSION: 4 (Superceded) EDS-T-4708TEST METHOD FOR THERMOSTAT A
2、SSEMBLY PAGE: 1/3 ISSUED DATE: 1990. 11. 03 REVISED DATE: 2008. 10. 27 VERSION: 4 GM DAEWOO Auto & Technology Note: This standard may be applied only for current project (incl. T250 Program). It is Superceded for all future projects and replaced by GMW14078. 1. PURPOSE This standard aims at specifyi
3、ng requirements and performance and durability test methods and conditions of thermostats for automobiles, thus enhancing test reliability. 2. SCOPE This standard applies to thermostats for automobiles. 3. NUMBER OF THE SAMPLES Unless otherwise specified, 3 samples shall be used at least for approva
4、l and quality control tests. The numbers for quality control and approval tests can be adjusted through discussion between sample manufacturers (or suppliers), design engineer and test engineer. 4. EQUIPMENT 4.1. Water bath (max. 150) : 2 EA 4.2. Thermometer (0.1) 4.3. Stop watch 4.4. Dial gage (50m
5、m) 4.5. Leakage test device 4.6. Durability test equipment 5. TEST PROCEDURE 5.1. Performance test Performance test shall be conducted in the following sequence. Before test, repeat full open and close of the thermostat min. 5 cycles with warm and cool water. Used liquid shall be 1:1 mixture of anti
6、-freezing solution and water. Before each test, the thermostat shall be dipped in water of 235K. 5.1.1. Valve opening temperature test (1) Set the bath temperature to the lower limit of the specified temperature range. (2) Mount the thermostat to the jig and zero the dial gage. EDS-T-4708TEST METHOD
7、 FOR THERMOSTAT ASSEMBLY PAGE: 2/3 ISSUED DATE: 1990. 11. 03 REVISED DATE: 2008. 10. 27 VERSION: 4 GM DAEWOO Auto & Technology (3) Put the jig into the bath and leave it for a time span of 4 times the thermostat time constant. (4) After checking opening of the valve, gradually raise or lower the bat
8、h temperature to measure temperature when the valve opens 0.1mm. 5.1.2. Valve full opening stroke test (1) Set the bath temperature to the specified value. (2) Perform clause 5.1.1 (2) and (3) (3) Measure the valve full opening stroke. 5.1.3. Valve opening speed test (1) Prepare two sets of the bath
9、 and keep them at the specified temperature. 1) Bath 1 : 235K 2) Bath 2 : specified temperature (high temperature) (2) Put the jig with the thermostat into bath 1. (3) Move the jig promptly to bath 2, and with this moment as 0 second, measure the time taken until the valve opens 0.1m. (4) The valve
10、shall open within 70 seconds. 5.1.4. Leakage test * Test pressure : 100 KPa., test temperature : 235K (1) Set the thermostat to the leakage test device. (2) Open the valve to apply water pressure, and measure leakage. 5.1.5. Responsiveness test (1) Take two arbitrary temperature points of t1 and t2
11、in the range where the thermostat valve opening characteristic is virtually of a straight line. (See Fig 1) (2) Prepare two baths and keep water temperature to t1 and t2 respectively. (3) Put the thermostat into t1 bath and keep it until the valve lift is sufficiently stabilized. (4) Move the thermo
12、stat promptly to t2 bath, and with this moment as 0 second, measure and record the time and valve lift simultaneously. This relation is expressed as in Fig 2. The time (T seconds) when valve opening exceeds (L2-L1)0.63 is called the “time constant“ of the thermostat. EDS-T-4708TEST METHOD FOR THERMO
13、STAT ASSEMBLY PAGE: 3/3 ISSUED DATE: 1990. 11. 03 REVISED DATE: 2008. 10. 27 VERSION: 4 GM DAEWOO Auto & Technology 5.2. Durability test Leave the performance-tested thermostat into warm water of 110 until the valve opens fully, and then leave it into cold water of 60 until the valve closes fully. Conduct 30,000 cycles with 3 minutes as one cycle. For every 10,000 cycles of durability test, conduct performance test.
