Views:2 Author:Site Editor Publish Time: 2020-01-02 Origin:Site
Inner rubber layer damage
(1) the rubber layer in the hose is hard and cracked. Hose flexibility and plasticity due to plasticizers added to rubber products. Hose works under high temperature and high pressure, hose overheating will overflow plasticizer. In addition, when overheated oil passes through cylinders, valves, or other parts of the system, a larger pressure drop can cause the oil to decompose, causing the hose to oxidize and harden the rubber layer in the hose. In this case, the hydraulic system should first check whether the working temperature is normal, valve throttle, pump suction channel, etc. Replace hose after removing all possible causes of excessive oil temperature and oil decomposition.
(2) the rubber layer in the hose was seriously metamorphosed and obviously bulged. The reason is that the long service time of the hydraulic oil or the oxidized dirt exists in the hydraulic system, the hose is chemically spoiled, and the damaged rubber film is found at the oil return port. If this happens, the physical and chemical indexes of the hydraulic oil should be checked first, and the compatibility and working temperature of the system oil in the hose should be checked whether the compatibility and working temperature of the system oil in the hose meet the standard.
1. Hose one or more ruptures, this phenomenon is due to the system pressure is too high, more than the hose compressive strength. If the system pressure meets the requirements, check that the actual pressure resistance of the hose meets the design requirements.
2. There is torsion at the rupture of the hose, which is caused by the excessive distortion of the hose during installation or use. After the hose is twisted, the structure of the reinforcement layer changes and the gap between the braiding and winding wires increases, which reduces the compressive strength of the hose and makes the hose easy to break under high pressure. Therefore, the hose shall not bear torque during the use or storage of the hose. When installing hoses, the grid lines of both joints should be placed on the same plane as possible to avoid distorting the hose during use.
3. The steel wire is crimped at the ruptured end of the hose, and the neck is obviously reduced. This is caused by overstretching of hoses and separation of layers, which reduces compressive strength. Under high pressure, the hose shrinks or stretches along the length. In general, the shrinkage is 2% / 4% in the normal state. If the hose is too short during installation, it will be subjected to great tension in the working process. In serious cases, there will be failures such as rupture or loosening. If the span of the hose is too large, the weight of the hose and the weight of the oil will also cause the hose to be subjected to a greater tensile force, and this failure will occur in severe cases. Therefore, you should Take the appropriate solution according to the specific situation. If it is too tight during installation, it should be replaced with a new long tube; if the span is too large, the intermediate support clip should be added.