Car oil hose, compared with the traditional automobile engine core parts, engine high-pressure tubing wasn’t special attention for a long time. However, statistics show that in recent years about the high-pressure car oil hose tubing failure cases have increasing trend, the proportion has for years into the number of the top ten automobile engine parts failure, and has increasing trend.
The engine high pressure car oil hose pipe is an important part connecting the fuel injection pump and the fuel injector, which bears the task of conveying high pressure fuel to the engine.
Once the engine high-pressure oil hose pipe cracks, causing oil leakage, not only has a negative impact on the reliability of the engine, but also, after the high-pressure fuel injection leakage, it is very likely to contact with the high-temperature parts of the engine, leading to serious fire accidents.
The inner surface of high pressure tubing goes through a complex drawing deformation process in the manufacturing process, and various inner wall defects are inevitably formed in this process, among which the most important one is inner wall crack.
The inner wall crack will lead to the origin of the fatigue crack of the high pressure tubing, which will seriously reduce the fatigue life of the high pressure tubing. This situation is also the reason for most of the high pressure tubing fatigue failure and oil leakage.
The processing process of high-pressure car oil hose tubing upsetting head is complicated and the deformation is large. The metal on the inner and outer surface of the upsetting head is subjected to strong deformation and flow. If the processing is improper, the metal streamline may be tortuous or even cold folding defects.
All kinds of process defects in upsetting head will become the origin of fatigue cracks in the process of use, leading to oil pipe cracking and oil leakage. Therefore, each enterprise will control the defect form in its internal standard, mainly to control the depth of cold folding crack in upsetting head.
Because the high pressure tubing usually has a galvanized layer on the surface, such defects cannot be detected from the appearance, and the existing national standards cannot be tested and prevented for such defects. In view of this, it is necessary to control the surface quality of rubber car oil hose tubing.