The oil resistance test and life estimation of automobile control cables are essential to ensure its long-term stable operation under complex conditions.
1. automobile control cables Oil resistance performance test
Oil resistance performance testing is to assess the tolerance of cables when they come into contact with oil substances, mainly through the following methods:
1. Oil immersion test
Immerse the cable samples in a specific type of oil (such as hydraulic oil, lubricating oil, etc.) and conduct tests at a certain temperature and for a certain period of time. During the testing process, the changes in performance indicators such as tensile strength, elongation at break and hardness of the cable are recorded.
For instance, the UL758 standard requires that after PVC material cables are immersed at 100℃ for 96 hours, the retention rates of tensile strength and elongation at break should both be ≥50%, and there should be no cracking.
In the JIS standard, cables are immersed in test oil at 50±2℃ for 20 hours before undergoing winding and withstand voltage tests.
2. Oil pump testing
Simulate the oil pressure during the operation of the engine. The lubricating oil is sprayed onto the cable sample through the oil pump to observe its performance changes under dynamic oil pressure.
This test can more truly reflect the oil resistance of the cable in actual use.
3. Oil dust test
Evaluate whether the cable will generate oil dust when in contact with oily substances, thereby affecting its performance and service life.
By observing whether there are sediments on the surface of the sample, its ability to resist oil dust can be judged.
4. High/low temperature oil resistance test
Oil resistance tests are conducted in high or low temperature environments to evaluate the oil resistance of cables under extreme temperature conditions.
For instance, some cables can still maintain good insulation performance after being heated at 150℃ for 240 hours.
5. Chemical reagent testing
Expose the cables to chemical substances such as acids, alkalis and salts to assess their corrosion resistance.
For instance, after a cable is soaked in gasoline, brake fluid or antifreeze for 24 hours, the mass change rate should be ≤±20%.
2. Estimate of the lifespan of automobile control cables
The estimated lifespan of cables is mainly based on their performance in oil resistance tests and the specific conditions of the usage environment. The following are some key factors:
1. Material properties
The oil resistance of cables is closely related to their materials. For instance, materials such as PVC, polyurethane (PU), and polyethylene (PE) have different oil resistance grades.
After being soaked in PVC material at 100℃ for 96 hours, the retention rate of tensile strength and elongation at break should be ≥50%.
After being soaked at 60℃ for 168 hours, the retention rate of tensile strength and elongation at break of PUR material should be ≥75%.
2. Usage environment
The lifespan of cables is closely related to the environment in which they are located. For instance, in environments with high temperatures, high humidity and high oil contamination, the lifespan of cables will be significantly shortened.
Some studies show that the lifespan of oil-resistant cables is typically 20 years.
In automotive manufacturing, the service life of control cables can reach 16 years or 200,000 kilometers.
3. Test standards
The estimated lifespan of cables is usually based on international or national standards. For example:
UL758: Applicable to PVC material cables, it is required that after being immersed at 100℃ for 96 hours, the retention rate of tensile strength and elongation at break should be ≥50%.
- JIS K 2215: Specifies the composition of lubricating oils No. 1 to No. 3 and is used for oil resistance tests.
- ISO 19642-7:2019: Specifies the durability of cables, including service life and anti-aging performance.
4. Aging test
The performance changes of cables during long-term use are evaluated through methods such as thermal aging tests and thermal elongation tests.
For instance, after being heated at 150℃ for 240 hours, a cable can still withstand a 1000V voltage for one minute after being bent.
Some studies also indicate that the thermal shrinkage rate of cables should be ≤4%.
Iii. Summary
The oil resistance test of automobile control cables is essential to ensure its long-term stable operation under complex conditions. The oil resistance performance of cables can be comprehensively evaluated through methods such as oil immersion tests, oil pump tests, and oil dust tests. Meanwhile, the estimated lifespan of cables mainly depends on their material properties, usage environment and testing standards. In practical applications, oil-resistant cables that meet relevant standards should be selected and regular performance tests should be conducted to ensure their safety and reliability.
