Analysis of the main reasons for the failure of withholding of industrial hose assembly and introduction of the withholding process
Industrial hose assembly is formed by withholding the hose body and the connecting joint. It is used to transport fluid with a certain pressure and flow rate, and connect the separate oil circuit units to make it a complete control function. Control System. Because of its special flexible function, it is easy to install and connect, can absorb shocks and reduce pipeline vibration. It is an important pipeline component in fluid transmission and control systems, and is widely used in food processing equipment, medical engineering, chemical machinery and other fields. However, due to the timeliness of the rubber itself, the strength of the steel wire and the limitation of the crimping structure process, it is prone to damage, aging and oil leakage in actual use. Among them, the oil leakage at the hose joint crimping is the most important form of failure of the hose assembly. In the process of use, there have even been serious safety accidents that caused casualties due to the pulling or breaking of the hose assembly crimping. It can be seen that improving the crimping performance of the hose assembly and improving crimping reliability is very important. The main causes of oil leakage or even pull-out or breakage at the hose joint crimping area are that the crimping size is too large or too small, the crimping structure is unreasonable, the crimping operation is improper, the installation is twisted, the bending radius is too small, being rubbed, and the ambient temperature is too high. The use time is too long, the inner rubber layer is aging, etc. Among them, the main reasons for the failure of the total cost of the hose to be withheld are:
(1) The withholding structure is unreasonable;
(2) The crimping size is too large or too small;
(3) There are defects such as burrs and sharp angles at the crimping part of the joint;
(4) Improper crimping operation;
(5) Problem with crimping equipment. Therefore, how to use a reasonable crimping structure and crimping size, as well as the correct crimping process is the key to reducing crimping failure.
The processing process of industrial hose assembly includes hose cutting, stripping, hose and joint assembly, crimping and cleaning.
(1) Blanking: The hose material should be free from damage, blistering, unevenness and other quality defects within the expiration date. Use blade cutting or grinding wheel cutting, and the perpendicularity of the cutting section to the axis of the hose should not be greater than 6 °, clean the cut part and inner surface of the hose with a nylon brush, remove the residual rubber at both ends, and blow off the dust on the inner surface of the hose with compressed air.
(2) Glue stripping: strip the rubber hose that needs to be stripped. If you need to strip the inner and outer rubber, first peel the inner rubber and then the outer rubber. The thickness of the residual rubber at the peeling point is ≤0.8 mm, and the steel wire cannot be damaged.
(3) Assembling: For non-peeling joints, draw lines on the hose according to the length of the sleeve, and then assemble. With over-tight joints, use a small amount of lubricating oil and use a pipe loader to assemble, peel off the rubber part of the hose Can not be exposed, non-peeling hose according to the line drawing position to confirm whether the assembly is in place.
(4) Crimping: Use special crimping equipment, select crimping mold, set the crimping size of the equipment, and crimp. After crimping different specifications of hoses, the first inspection must be carried out. The minimum crimping size +0.05 mm≤the actual size of the first inspection≤ The maximum crimping size is -0.05 mm, otherwise the crimping size of the device needs to be reset.