1、GM DAEWOO Auto & Technology EDS Engineering, GM DAEWOO Auto & Technology Standards DURABILITY TEST PROCEDURE FOR SHOCK ABSORBER ASM Do Not Use on New Programs. Being Replaced by GMW14244 & 14246 EDS-T-2507 ISSUED DATE: 1988. 08. 22 REVISED DATE: 2008. 10. 23 VERSION: 3 (Superceded) EDS-T-2507DURABIL
2、ITY TEST PROCEDURE FOR SHOCK ABSORBER ASM PAGE: 1/5 ISSUED DATE: 1988. 08. 22 REVISED DATE: 2008. 10. 23 VERSION: 3 GM DAEWOO Auto & Technology Note: This standard may be applied only for current project (incl. T255 Program). It is Superceded for all future projects and replaced by GMW14244 and 1424
3、6. 1. PURPOSE The purpose of this standard is to confirm the product characteristics change and determine the durability life through durability test simulating the condition which occurs at the time of vehicle running. 2. EQUIPMENT 2.1. Shock absorber test stand Stand outfitted with eccentric drive
4、 device driven by motor (or servo-hydraulic mechanism) 2.2. Measuring and recording units 2.2.1. Temperature sensor for measuring the shock absorber temperature. 2.2.2. Transducer & indicator for measuring the force applied to sample and sensoring failure(or linear variable differential tranducer(LV
5、DT) 2.3. Cooling equipment 2.3.1. Attach a water cooling jacket to the shock absorber to maintain a constant temperature of the sample. 2.3.2. The water flow through the cooling jacket shall be controlled by water temperature. 3. . TEST CONDITIONS 3.1. Sample mounting The test sample shall be mounte
6、d in the vehicle installation position 3.2. Frequency 3.2.1. Frequency of basic stroke: 1 Hz 3.2.2. Frequency of superimposed stroke: 12.5 Hz 3.3. Stroke(amplitude) The amplitude of basic stroke(H) and superimposed stroke(H) shall not exceed the specified values during the test. 3.4. Temperature 3.4
7、1. During the test, temperature t shall be maintained at the temperature measuring point (Fig. 1) Temperature measuring point EDS-T-2507DURABILITY TEST PROCEDURE FOR SHOCK ABSORBER ASM PAGE: 2/5 ISSUED DATE: 1988. 08. 22 REVISED DATE: 2008. 10. 23 VERSION: 3 GM DAEWOO Auto & Technology (outer tube
8、upper end part) Fig. 1 temperature measuring point 3.4.2. Cool test samples if required 3.4.3. Temperatures outside the temperature measuring area shall not exceed. a) 100 on twin tube shock absorbers b) 120 on single tube shock absorbers(gas pressurized) 3.5. Test time n cycles = number of basic st
9、rokes 3.6. Test data Basic stroke H(mm) Superimposed strokeh(mm) temperature t() Cycles n 100 20 80-5K 1106Temperature measuring point (outer tube upper end part) EDS-T-2507DURABILITY TEST PROCEDURE FOR SHOCK ABSORBER ASM PAGE: 3/5 ISSUED DATE: 1988. 08. 22 REVISED DATE: 2008. 10. 23 VERSION: 3 GM D
10、AEWOO Auto & Technology 4. PERFORMANCE 4.1. Preparation 4.1.1. Remove dust tube(if applicable). 4.1.2. Remove rubber sleeve on shock absorber with additional air spring. 4.1.3. Measure the weight of the sample before testing to know amount of oil leak 4.2. Measurement of initial damping force Measur
11、e the damping force according to basic test(EDS-T-2502) 4.3. Durability test 4.3.1. Install the test sample to the rig(Number of samples: 6EA). 4.3.2. Make the test according to the condition of clause 3. 4.3.3. Observe the presence of oil leak on the sample during the test. 4.4. Measure damping for
12、ce Subsequent to the specified number of cycles, determine damping forces as under clause 4.2. 4.5. Comparision between before and after the test 4.5.1. Compare damping forces of clause 4.2 and 4.5. 4.5.2. Examine the presence of oil leak by observing the change in the weight of the sample after the
13、 test. 4.6. Caution 4.6.1. The center of the basic stroke shall be identical with the center of the entire stroke of the shock absorber. 4.6.2. With single tube shock absorbers(gas pressurized), the piston shall not impact the separator piston at the time of damping force measurement. 5. EVALUATION
14、5.1. Damping force change Deviation between the damping force values measured under clause 4.2 and 4.4 shall be 20% max. 5.2. Damping lag(force drop) Damping lag to EDS-T-2502 under clause 4.5 shall be 25% max. of the test stroke. 5.3. Exit force loss EDS-T-2507DURABILITY TEST PROCEDURE FOR SHOCK AB
15、SORBER ASM PAGE: 4/5 ISSUED DATE: 1988. 08. 22 REVISED DATE: 2008. 10. 23 VERSION: 3 GM DAEWOO Auto & Technology With single tube shock absorber(gas pressurized), the allowed piston rod exit force loss shall not exceed 50% of the initial value. 5.4. Other parts Disassemble test sample, evaluate valv
16、e parts, seal ring and all slide faces. Fig. 2 Installation condition of shock absorber test sample Load cell Water hose Temperature sensor Cooling water jacket EDS-T-2507DURABILITY TEST PROCEDURE FOR SHOCK ABSORBER ASM PAGE: 5/5 ISSUED DATE: 1988. 08. 22 REVISED DATE: 2008. 10. 23 VERSION: 3 GM DAEWOO Auto & Technology Fig. 3 Shock absorber test stand Drive Motor Coolant flow Control valve Control Box
